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Olivine and alkali-feldspar were utilized in separate campaigns in an indirect dual fluidized bed gasification campaign with woody biomass as fuel. After three days, both bed materials were reported to be active towards tar removal and exhibited oxygen-carrying abilities and had formed an ash layer consisting of an outer ash deposition layer and an inner interaction layer. X-ray microtomography analysis concluded that a preferred deposition of ash happens onto convex regions of the bed particles, which results in an increase in thickness of the ash layer over convex regions. This effect is most pronounced for the outer layer which is a product of ash deposition. The inner layer exhibits a homogeneous thickness and is probably formed by interaction of Ca from the outer layer with the particles. Transmission electron microscopy revealed the presence of Fe and Mn on the surface of the particles in a solid solution with Mg. The oxygen-carrying effect which is found for aged particles is therefore attributed to the presence of Fe and Mn on the surface of aged particles. Alkali were found on the surface of both particles which are likely contributing to the catalytic activity of the material towards tar removal. Validerad;2022;Nivå 2;2022-11-02 (sofila);This article has previously appeared as a manuscript in a thesis

Mellan 1960 och idag har världspopulationen dubblerats medan matproduktionen tredubblats. Det har möjliggjorts av kemiskt framställda gödsel som introducerades på mitten av 1900-talet. Sedan 1965 har användandet av kvävegödsel ökat sexdubblet. Kvävegödsel ökar lönsamheten och avkastningen men har stora koldioxdutsläpp och orsaker övergödning. Därför finns det en efterfrågan på andra alternativ. Ett alternativ skulle kunna vara en syntetsik föränding av rhizosfären. För att undersöka om det är möjligt kommer ett modellsystem för insulerat metaboliskt utbyte att skapas. Modellsystemet kommer att ha en kvävefixarande bakterie som fixerar kväve från atmosfären och producerar en kvävekälla till en kolfixerande bakterie, som kommer modellera en växt i system. Den kolfixerande bakterien kommer att fixera koldioxid from atmosfären och producera en kolkälla för den kvävefixerande bakterien att använda. I den här studien har olika produktioner av olika kvävekällor i Escherichia coli och Anabaena sp. undersökts. Fyra olika plasmider har skapats för produktionen av alanin, guanin och allantoin. Alla odlingar med plasmiderna växte bättre än kontrollodlingarna, men de har inte blivit analyserade för produktion av metaboliterna på grund av tidsbrist. Tilläggningsvis, två av tre replikat av Anabaena sp. med en plasmid för allantoin produktion i media med urinsyra verkar ha varit stressade för okända anledningar Between 1960 and today, the world population has doubled while food production has tripled. This has been made through chemical fertilisers being introduced in the middle of the 20th century. From 1965, the usage of nitrogen fertilisers has increased by sixfold. Nitrogen fertilisers improve crop profitability and yield but have large carbon dioxide emissions as well as cause eutrophication. Thus, there is a demand for an alternative. One alternative would be to engineer the rhizosphere. To investigate whether this is possible, a model system for insulated metabolic exchange will be created. The model system will have a nitrogen-fixating bacteria that will fixate atmospheric nitrogen and produce a nitrogen compound to a carbon-fixating bacteria, that will act as a plant in the model system. The carbon-fixating bacteria will fixate carbon dioxide from the atmosphere and produce a carbon source for the nitrogen-fixating bacteria to utilise. In this study, different productions of different nitrogen compounds in Escherichia coli and Anabaena sp. have been investigated. Four different plasmids have been constructed for the production of alanine, guanine and allantoin, respectively. The strains containing the plasmids all grew better than the control cultures, however, they have not been analysed for producing the metabolites due to time constraints.

The role of lignin in enzymatic saccharification of cellulose involving lytic polysaccharide monooxygenase (LPMO) was investigated in experiments with the solid and liquid fractions of pretreated Norway spruce from a biorefinery demonstration plant using hydrothermal pretreatment and impregnation with sulfur dioxide. Pretreated biomass before and after enzymatic saccharification was characterized using HPAEC, HPLC, Py-GC/MS, 2D-HSQC NMR, FTIR, and SEM. Chemical characterization indicated that relatively harsh pretreatment conditions resulted in that the solid phase contained no or very little hemicellulose but considerable amounts of pseudo-lignin, and that the liquid phase contained a relatively high concentration (∼5 g/L) of lignin-derived phenolics. As judged from reactions continuously supplied with either air or nitrogen gas, lignin and lignin fragments from both the solid and the liquid phases efficiently served as reductants in LPMO-supported saccharification. When air was used to promote LPMO activity, the enzymatic conversion of cellulose after 72 h was 25% higher in reactions with pretreated solids and buffer, and 14% higher in reactions with pretreatment liquid and microcrystalline cellulose. Research in this area is useful for designing efficient saccharification steps in biochemical conversion of lignocellulosic biomass.

Biomass char produced from pyrolysis processes is of great interest to be utilized as renewable solid fuels or materials. Forest byproducts and agricultural wastes are low-cost and sustainable biomass feedstocks. These biomasses generally contain high amounts of ash-forming elements, generally leading to high char reactivity. This study elaborates in detail how chemical and physical properties affect CO2 gasification rates of high-Ash biomass char, and it also targets the interactions between these properties. Char produced from pine bark, forest residue, and corncobs (particle size 4-30 mm) were included, and all contained different relative compositions of ash-forming elements. Acid leaching was applied to further investigate the influence of inorganic elements in these biomasses. The char properties relevant to the gasification rate were analyzed, that is, elemental composition, specific surface area, and carbon structure. Gasification rates were measured at an isothermal condition of 800 °C with 20% (vol.) of CO2 in N2. The results showed that the inorganic content, particularly K, had a stronger effect on gasification reactivity than specific surface area and aromatic cluster size of the char. At the gasification condition utilized in this study, K could volatilize and mobilize through the char surface, resulting in high gasification reactivity. Meanwhile, the mobilization of Ca did not occur at the low temperature applied, thus resulting in its low catalytic effect. This implies that the dispersion of these inorganic elements through char particles is an important reason behind their catalytic activity. Upon leaching by diluted acetic acid, the K content of these biomasses substantially decreased, while most of the Ca remained in the biomasses. With a low K content in leached biomass char, char reactivity was determined by the active carbon surface area. publishedVersion

Yeast immobilization with low-cost carrier materials is a suitable strategy to optimize the fermentation of lignocellulosic hydrolysates for the production of second-generation (2G) ethanol. It is defined as the physical confinement of intact cells to a certain region of space (the carrier) with the preservation of their biological activity. This technological approach facilitates promising strategies for second-generation bioethanol production due to the enhancement of the fermentation performance that is expected to be achieved. Using immobilized cells, the resistance to inhibitors contained in the hydrolysates and the co-utilization of sugars are improved, along with facilitating separation operations and the reuse of yeast in new production cycles. Until now, the most common immobilization technology used calcium alginate as a yeast carrier but other supports such as biochar or multispecies biofilm membranes have emerged as interesting alternatives. This review compiles updated information about cell carriers and yeast-cell requirements for immobilization, and the benefits and drawbacks of different immobilization systems for second-generation bioethanol production are investigated and compared. © 2021 The Authors. Biofuels, Bioproducts and Biorefining published by Society of Industrial Chemistry and John Wiley & Sons Ltd.

Penggunaan energi biomassa sebagai sumber energi alternatif terbarukan diupayakan untuk mengurangi emisi CO2. Ampas kopi merupakan limbah biomassa yang dihasilkan dari proses produksi yang digunakan sebagai raw material dalam pembuatan biobriket. Limbah biomassa mempunyai calorific value yang relatif tinggi jika diolah menjadi biobriket dengan perekat. Jenis perekat yang digunakan adalah tepung tapioka dan getah pinus dengan komposisi tepung tapioka yang digunakan 0%, 10% dan 20% sedangkan jumlah perekat getah pinus 0%, 10%, 20%, dan 40%. Dengan mengetahui pengaruh jenis dan jumlah perekat dalam pembuatan biobriket menggunakan metode torefaksi, diharapkan limbah ampas kopi dapat menjadi biomassa sebagai energi alternatif. Penelitian dilakukan pada suhu torefaksi yaitu 200 oC, 250 oC dan 300 oC. Suhu torefaksi yang optimal untuk pembuatan biobriket dari ampas kopi adalah 300 oC dengan perekat getah pinus 40% yang menghasilkan biobriket lebih padat dan tidak mudah hancur dengan nilai kalori sebesar 6124 kal/gr.

The growing, existing demand for low-cost and high-quality hyaluronic acid (HA) needs an outlook of different possible production strategies from renewable resources with the reduced possibility of cross-infections. Recently, the possibility of producing HA from harmless microorganisms appeared, which offers the opportunity to make HA more economical, without raw material limitations, and environmentally friendly. HA production is mainly reported with Lancefield Streptococci A and C, particularly from S. equi and S. zooepidemicus. Various modes of fermentation such as batch, repeated batch, fed-batch, and continuous culture have been investigated to optimize HA production, particularly from S. zooepidemicus, obtaining a HA yield of 2.5 g L-1 - 7.0 g L-1. Among the different utilized DSP approaches of HA production, recovery with cold ethanol (4 degrees C) and cetylpyridinium chloride is the ideal strategy for lab-scale HA production. On the industrial scale, besides using isopropanol, filtration (0.22 um), ultrafiltration (100 kDa), and activated carbon absorption are employed to obtain HA of low molecular weight and additional ultrafiltration to purify HA of higher MW. Even though mature technologies have already been developed for the industrial production of HA, the projections of increased sales volume and the expansion of application possibilities require new processes to obtain HA with higher productivity, purity, and specific molecular weights. In this review, we have put forth the progress of HA technological research by discussing the microbial biosynthetic aspects, fermentation and downstream strategies, industrial-scale scenarios of HA, and the prospects of HA production to meet the current and ongoing market demands.

Biochemical conversion of lignocellulosic feedstocks to advanced biofuels and other bio-based commodities typically includes physical diminution, hydrothermal pretreatment, enzymatic saccharification, and valorization of sugars and hydrolysis lignin. This approach is also known as a sugar-platform process. The goal of the pretreatment is to facilitate the ensuing enzymatic saccharification of cellulose, which is otherwise impractical due to the recalcitrance of lignocellulosic feedstocks. This review focuses on hydrothermal pretreatment in comparison to alternative pretreatment methods, biomass properties and recalcitrance, reaction conditions and chemistry of hydrothermal pretreatment, methodology for characterization of pretreatment processes and pretreated materials, and how pretreatment affects subsequent process steps, such as enzymatic saccharification and microbial fermentation. Biochemical conversion based on hydrothermal pretreatment of lignocellulosic feedstocks has emerged as a technology of high industrial relevance and as an area where advances in modern industrial biotechnology become useful for reducing environmental problems and the dependence on fossil resources.

Det ständigt växande behovet av att minska CO2-utsläpp har lett till en ökad tonvikt på teknik för avskiljning av koldioxid från rökgas. MEA (monoetanolamin) anses vara riktmärket för lösningsmedel för att fånga in koldioxid på grund av dess höga absorptionshastighet. MEA är dock benäget att brytas ner, bilda giftiga biprodukter och dess regenerering har ett högt energibehov. Ett annat lösningsmedel med liknande teknisk mognad är vattenlösning med kaliumkarbonat (K2CO3) som används i den så kallade hot-potash carbonate (HPC)-processen. Emellertid är absorptionshastigheten i K2CO3-lösningen låg i jämförelse med MEA, vilket kräver tillsats av hastighetspromotorer för att öka absorptionshastigheten. Denna avhandling undersöker effekten av olika hastighetspromotorer på absorptionshastigheten av kaliumkarbonat. För detta utfördes absorptionsexperiment i laboratorieskala i en autoklavreaktor av rostfritt stål under kontrollerade förhållanden. Olika promotorer har undersökts, nämligen de organiska promotorerna glycin, piperazin och MEA, och de oorganiska promotorerna borsyra och vanadinpentoxid. Promotorkoncentrationen varierades mellan 3 vikt% till 7 vikt% samtidigt som koncentrationen av K2CO3 hölls konstant vid 25 vikt%. Driftförhållandena såsom det initiala partialtrycket av CO2 och temperaturen var respektiva 5 bar och 50 °C. De oorganiska promotorerna studerades enskilt såväl som i blandningar med K2CO3 för att studera effekten av varje promotor. De organiska promotorerna visade en signifikant förbättring av absorptionshastigheten jämfört med icke promoterad K2CO3. När det gäller de oorganiska promotorerna visade vanadinpentoxid jämförbara resultat med organiska promotorer med endast 3 vikt%. Ökad tillsatts av borsyra minskade absorptionshastigheten av lösningen promoterad av vanadin. Den experimentellt uppmätta absorptionshastigheten är anpassad till en enkel absorptionsmodell från vilken en skenbar absorptionshastighet för de främjade lösningsmedlen härleddes The ever-growing need to reduce CO2 emissions has led to an increased emphasis on carbon capture technologies. MEA (monoethanolamine) is considered the benchmark solvent for CO2 capture due to its high rate of absorption. However, MEA is prone to degradation, forms toxic side products and its regeneration has a high energy demand. Another solvent with similar technological maturity is aqueous potassium carbonate (K2CO3) that is used in the so-called hot-potash carbonate (HPC) process. However, the rate of absorption in aqueous K2CO3 is low in comparison to MEA calling for the addition of rate promoters to enhance the absorption rate. This thesis investigates the effect of different rate promoters on the absorption rate of potassium carbonate. For this, absorption experiments on the laboratory scale were conducted in a stainless-steel autoclave reactor under controlled conditions. Various promoters have been explored, namely the organic promoters glycine, piperazine, and MEA, and the inorganic promoters boric acid and vanadium pentoxide. The promoter concentration was varied between 3 wt% to 7 wt% while keeping the concentration of K2CO3 constant at 25 wt%. The operating conditions, such as the initial partial pressure of CO2 and the temperature were 5 bar and 50°C, respectively. The inorganic promoters were studied alone as well as in blends with K2CO3 to understand the effect of each promoter. The organic promoters demonstrated a significant enhancement of the absorption rate compared to unpromoted K2CO3. Regarding the inorganic promoters, vanadium pentoxide showed comparable results to organic promoters with only 3 wt%. When looking at the results of vanadium and boric acid, increasing concentration of boric acid resulted in a decrease in the absorption rate. The experimentally measured absorption rate are fitted to a simple absorption model from which an apparent absorption rate for the promoted solvents was derived.

To reach the Swedish goal of reaching a completely fossil-free electricity sector by the year 2040, there is a need for an increased rate of installed renewable electricity sources. Companies have the opportunity to work towards this goal by investing in solar power technologies, which results in a lowered electricity bill, and an additional revenue when electricity is sold to the grid. As a result, the investment usually pays back within a reasonable timeframe. GEHAB is a company located that is located in Alvesta, Sweden, and they are interested in investing in rooftop solar power. This thesis investigates the potential and effects of such an investment at the company through energy simulations. This is done through four different scenarios, which aim at finding the largest possible installation, the most cost-optimal installation, according to the Levelized Cost Of Energy (LCOE), the impact of an added battery installation and finding the current issues with becoming a net-zero consumer of electricity. Finally, a sensitivity analysis was made to investigate how different factors impacted the LCOE. The results showed that the most cost-optimal size for the company to invest in was a 215 kWp installation, which is smaller than the maximum possible size of 335 kWp that can be installed on the rooftop. Such an installation would have an LCOE of -366 SEK/MWh when the avoided costs are included. The discounted payback time of that investment was 11.3 years. The involvement of batteries showed that they would lead to a higher LCOE and for the largest possible solar installation size, including a battery, means that it would not pay back within the lifetime of the PVs. Finally, the net-zero electricity consumption scenario found that currently, the largest issue to reach this scenario is that there is a regulation that limits solar installations to 500 kWp to avoid an energy tax.

Användningen av kommunalt avfall för att producera förnybar energi, huvudsaklig biogas, uppfyller 8 av Sveriges 16 miljökvalitetsmål. Två typer av rötningsprocesser som används är kontinuerligt omrörda tankreaktorer (CSTR) och pluggflödesreaktorer (PFR). Rapportens syfte är att direkt jämföra de två reaktorkonfigurationerna, PFR och CSTR, med samma substratblandning. Båda reaktortyperna drevs med samma belastning (5,2 g VS/L dag), hydraulisk retentionstid (30 dagar) och driftstemperatur (520C). Två PFR-reaktorer drevs med återcirkulation av rötrester. Under projektets gång mättes olika parametrar, vilka var: pH, total gasvolym och gassammansättning, FOS/TAC (organiska syror/alkalinitet), flyktiga fettsyror (VFA), ammonium-kvävekoncentration och TS (torrsubstanshalt) och VS (organiska ämnen). Studieresultatet var uppdelat i två sektioner. Avsnitt 1 sammanfattar uppstartsperioden, där alla tre CSTR (D1-R, D2-NR och C1-NR) kördes i icke-återcirkulerande läge. Uppstartsperioden gjordes för att säkerställa reaktorernas stabilitet och det gällde att uppnå en liknande baslinje för detektion. Inom studien accepterades avvikelser för baslinjen inom intervallet 0-5%. För uppstartsperioden varierade den specifika metanproduktionen med 2 % mellan D1-NR och D2-R, D1-R och C1-NR med 6 %, och D2-NR och C1-NR med 8 %. För ammoniak-koncentrationen var skillnaden mellan D1-R och D2-NR 2 % och mellan D1-R och C1-NR 9 %, mellan D2-NR och C1-NR, 7%. Med dessa variationer togs beslutet att utesluta reaktor C1-NR från den experimentella perioden för projektet. Avsnitt 2 jämför PFR och CSTR återcirkulerat/icke återcirkulerat läge. En CSTR drevs med 30 % återcirkulation av rötrest och en CSTR drevs i icke-återcirkulationsläge. Att jämföra PFR och CSTR återcirkulerat/icke återcirkulerat läge visade att PFR:erna övervann båda CSTR:erna när det gäller den specifika metanproduktionen. Där PFR producerade 395±93 NL/KgVS och 372±42 (N)L/KgVS CSTR med återcirkulation 280±10 (N)L/KgVS och den icke-återcirkulerade CSTR producerade 250±7 (N)L/KgVS. NH4+-N-nivåerna mellan PFR och CSTR visade en skillnad på 1 g/L, där PFR var den med högre NH4+-N (2,53±0,39 g/L för PFR-A och 2,73±0,43 g/L för PFR-T). En av skillnaderna mellan de återcirkulerade och de icke-återcirkulerade CSTR:erna var VFA-koncentrationen. VFA-koncentrationen i de återcirkulerade var 1,05±0,90 g/L och 0,43±0,25 g/L i de icke-återcirkulerade. VFA-koncentrationen för PFR var i genomsnitt 0,28±0,12 g/L och 0,40 ±0,16 g/L. Graden av nedbrytning i CSTRs var 90-91%, och 63-65% i PFR. Den är möjligen felberäknad och visar en inkonsekvens mellan reaktorernas prestanda och specifik metanproduktion. The use of municipal waste to produce renewable energy, in the form of biogas, fulfils eight of Sweden's sixteen environmental quality objectives. The most common technology to produce biogas is anaerobic digestion (AD). Two common types of AD processes are continuously stirred reactors (CSTR) and plug flow reactors (PFR). The thesis aims at directly comparing the two reactor configurations using the same substrate mix. For this, two PFRs (PFR-T and PFR-A) and three CSTRs (D1-R, D2-NR and C1-NR) were setup. All reactors were operated at the same organic loading rate (5.2 g VS/L-day), hydraulic retention time (30 days) and operational temperature (52°C). During the project, various parameters were measured to evaluate the reactor performance, such as pH, total gas volume and gas composition, FOS/TAC (organic acids/alkalinity), volatile fatty acids (VFA), ammonium-nitrogen concentration, and solid and volatile solid of digestate. The study result was divided into two sections. Section 1 summarises the start-up period (42 days), where the CSTRs and the PFRs were operated under non-recirculation mode. The start-up period was done to ensure the stability of the reactors and was concerned with achieving a similar baseline for performance. For the start-up period, the specific methane production between D1-R and D2-NR varied by 2% while the variation between C1-NR and D2-NR was 8%. Likewise, for the ammonia concentration, the difference between D1-R and D2-NR was 2%, while C1-NR differed by 9% from D2-NR. Based on these findings, the decision was taken to exclude reactor C1-NR from the experimental period of the project. Section 2 compares the PFR and CSTR. One CSTR was operated with 30% recirculation of digest, while the other CSTR was operated in non-recirculation mode. The two PFRs were operated with recirculation of digestate. The experiments showed that the PFRs outperformed both CSTRs regarding the specific methane production. The PFRs produced 395±93 (N)L/kg-VS and 372±42 (N)L/kg-VS. In contrast, the CSTR with recirculation reached 280±10 (N)L/kg-VS and the non-recirculated CSTR produced 250±7 (N)L/kg-VS. The NH4+-N levels for the PFRs and CSTRs showed a 1 g/L difference, with a higher value for the PFRs (2.53±0.39 g/L for PFR-A, and 2.73±0.43 g/L for PFR-T). One of the significant differences between the recirculated and the non-recirculated CSTRs was the VFA concentration. The VFA concentration in the recirculated and non-recirculated reactor was 1.05±0.90 g/L and 0.43±0.25 g/L, respectively. The VFA concentration for the two PFRs was on average 0.28±0.12 g/L and 0.40 ±0.16 g/L. The degree of degradation in the CSTRs was 90-91% compared to 63-65% in the PFRs. The degree of degradation is possibly miscalculated and shows an inconsistency between the reactor performance in terms of specific methane production.

The urge for more sustainable living motivated the Stockholm Tiny House Expo. The project aims to build a floating, sustainable, man-made island for living and working outside of Stockholm. This paper proposes a waste management method with possible energy recovery for the island. It introduces a comprehensive system that integrates decentralized wastewater treatment with energy generation through anaerobic treatment. A by-product of the wastewater treatment process, the sludge, is combined with food waste to generate energy through biogas. The island’s organic waste (wastewater and food waste) is thereby managed sustainably. The results of this report require further research. The energy supply from the biogas reactor was calculated to be 52.19 MWh. The wastewater treatment process was designed with an objective of 90% reduction of BOD5, to comply with the Swedish regulations for wastewater discharge to natural bodies of water, including the ocean. The system's total volume proposed is 11.25 m3, which is the sum of the volumes of all the reactors, or tanks, needed to complete the treatment.

Contemporary environmental problems require a transition to renewable energy. Biogas is one alternative, which besides being renewable has many other benefits. For further expansion of biogas production, it seems necessary to develop new areas of biogas usage where biogas can replace fossil fuels. This article presents an analysis of the drivers for and barriers to increased biogas usage in three sectors where biogas usage is undeveloped in Sweden: manufacturing, road transport and shipping. Several of the identified drivers and barriers, such as unstable and short-term policies, lack of infrastructure, and contract requirements, have also been found in previous studies even though they may be slightly different depending on the context. A new driver observed in this study is that of intergenerational thinking in family-owned businesses. The study also reiterates the significant influence of policy in the form of subsidies, tax exemptions and regulations on the adoption and use of renewable energy in general and biogas specifically. The results suggest the need for future policymaking to be guided by long-term trajectories, which can be a relevant basis for adopters to make investments into biogas technologies. Funding Agencies|Biogas Research Center (BRC); Environmental Bus Project; Swedish Energy AgencySwedish Energy Agency; Linkoping University; VinnovaVinnova; SLU

Batik merupakan salah satu produk kebanggaan bangsa Indonesia, yang umumnya diproduksi oleh usaha kecil menengah (UKM). Peningkatan permintaan batik mendorong adanya peningkatan jumlah UKM batik serta jumlah limbah cair batik yang dihasilkan. Masih banyak UKM batik yang membuang limbah cairnya langsung ke lingkungan yang berpotensi menimbulkan pencemaran pada tanah dan air. Hal ini disebabkan oleh belum adanya fasilitas pengolahan limbah yang memadai, sesuai dengan kondisi yang dialami oleh UKM Batik Blimbing Malang. Penelitian ini bertujuan untuk mengidentifikasi potensi pengolahan limbah cair batik secara anaerobik untuk memproduksi biogas sebagai sumber energi terbarukan. Pada penelitian ini digunakan teknologi anaerobic digestion yang dioperasikan secara batch dengan kondisi mesofilik (37 °C) tanpa pengadukan, dikenal sebagai uji biochemical methane potential (BMP) dengan waktu pengamatan selama 28 hari. Sampel yang diuji meliputi penambahan 100% limbah cair batik dengan berbagai variasi volume. Hasil penelitian menunjukkan bahwa limbah cair batik memiliki kandungan bahan pencemar organik yang tinggi, yaitu sebesar 8.651 mg/L (BOD) dan 54.700 mg/L (COD). Hasil uji BMP juga menunjukkan rendahnya biogas yang dapat diproduksi dari limbah cair batik. Kondisi ini disebabkan oleh beberapa faktor antara lain tingginya kandungan COD, ammonia, zat pewarna beracun, dan nisbah C/N yang berpengaruh negatif terhadap pertumbuhan mikroorganisme.

Spent mushroom substrates (SMS) from cultivation of shiitake (Lentinula edodes) on three hardwood species were investigated regarding their potential for cellulose saccharification and for ethanolic fermentation of the produced hydrolysates. High glucan digestibility was achieved during enzymatic saccharification of the SMSs, which was related to the low mass fractions of lignin and xylan, and it was neither affected by the relative content of lignin guaiacyl units nor the substrate crystallinity. The high nitrogen content in SMS hydrolysates, which was a consequence of the fungal pretreatment, was positive for the fermentation, and it ensured ethanol yields corresponding to 84–87% of the theoretical value in fermentations without nutrient supplementation. Phenolic compounds and acetic acid were detected in the SMS hydrolysates, but due to their low concentrations, the inhibitory effect was limited. The solid leftovers resulting from SMS hydrolysis and the fermentation residues were quantified and characterized for further valorisation.

Background Slow degradation kinetics of long-chain fatty acids (LCFA) and their accumulation in anaerobic digesters disrupt methanogenic activity and biogas production at high loads of waste lipids. In this study, we evaluated the effect of effluent solids recirculation on microbial LCFA (oleate) degradation capacity in continuous stirred-tank sludge digesters, with the overall aim of providing operating conditions for efficient co-digestion of waste lipids. Furthermore, the impacts of LCFA feeding frequency and sulfide on process performance and microbial community dynamics were investigated, as parameters that were previously shown to be influential on LCFA conversion to biogas. Results Effluent solids recirculation to municipal sludge digesters enabled biogas production of up to 78% of the theoretical potential from 1.0 g oleate l−1 day−1. In digesters without effluent recirculation, comparable conversion efficiency could only be reached at oleate loading rates up to 0.5 g l−1 day−1. Pulse feeding of oleate (supplementation of 2.0 g oleate l−1 every second day instead of 1.0 g oleate l−1 every day) did not have a substantial impact on the degree of oleate conversion to biogas in the digesters that operated with effluent recirculation, while it marginally enhanced oleate conversion to biogas in the digesters without effluent recirculation. Next-generation sequencing of 16S rRNA gene amplicons of bacteria and archaea revealed that pulse feeding resulted in prevalence of fatty acid-degrading Smithella when effluent recirculation was applied, whereas Candidatus Cloacimonas prevailed after pulse feeding of oleate in the digesters without effluent recirculation. Combined oleate pulse feeding and elevated sulfide level contributed to increased relative abundance of LCFA-degrading Syntrophomonas and enhanced conversion efficiency of oleate, but only in the digesters without effluent recirculation. Conclusions Effluent solids recirculation improves microbial LCFA degradation capacity, providing possibilities for co-digestion of larger amounts of waste lipids with municipal sludge.

Due to the increasing climate change concerns, biofuels have attracted more attention in the energy field as potential alternative energy sources. Particularly, microalgal biofuel has stood out because of its higher fuel yield potential and lower water and land demand than terrestrial biomass. Because of its outstanding photosynthetic efficiency, the microalgal technology is also investigated by researchers around the world as a potential biological solution for carbon capturing in the industrial sector. To explore the prospects of microalgal technology in a local context, this research lays it focus on investigating the potentiality of microalgal biofuel in the cement industry on Gotland, which is the largest emitter of greenhouse gases on the island. For this purpose, the thesis implements a series of estimations based on the emission data of Cementa AB, Slite, a picture of the potential production of algal biomass and biofuel was created, followed by comparisons to the energy situation on Gotland. While practical data of the selected microalgae species are presented, the results indicate a high potential of microalgae in the production of algal biofuel and the possibility for algal biofuel to power the industrial sector of Gotland, or even the island entirely. Although the estimations are made based on an assumption where all controlling parameters are assumed to be perfectly manipulated, the results still indicate the significance of microalgal technologies in the near-future bioeconomy and global energy system.

A big challenge within pulp and paper mills is the large quantities of waste activated sludge (WAS) that is produced during the wastewater treatment. The WAS is made up of biological cells and extra polymeric substances (EPS) and can bind a large amount of water causing difficulties to dewater the WAS. This study aimed to determine how to improve the dewatering properties of the WAS by using hydrolysis. Hydrolysis will cause the cells to disrupt and the bound water in the cells and the water trapped by the EPS can be released. Specifically, this study investigated what impact hydrolysis with heat, alkalis, and acids had on the WAS dewatering properties. In addition to the impact on the dewatering properties, the release of organic material and nutrients from the cells has also been important for biomethane production. In this study, it was specifically NH4-N, PO43- and COD that have been studied. WAS from paper mills have in general poor methane potential so it was of interest to see how the WAS was affected by hydrolysis and how hydrolysis could improve the methane production. To test the hypothesis of whether hydrolysis could affect the WAS and improve the dewatering properties, several experiments were performed. The experiments included thermal hydrolysis at temperatures of 70-90 °C, acidic hydrolysis with acids such as spent acid and acid water, and alkalis such as green liquor sludge and EOP. All acids and alkalis used in the study were chemicals that exist at the paper mills included in this study. To test the dewatering properties, methods such as TS analysis on the accept, CST-analysis, and a belt press were used. Analyses were also performed on the reject to measure the suspended solids and the nutrients NH4 – N, PO43– and COD in the WAS. This study did also determine what effect hydrolysed WAS had on the biomethane potential. In this study were the paper mills BillerudKorsnäs in Skärblacka and SCA in Östrand included. Hence was sludge from the two mills of interest to analyse. This study has shown better dewatering properties with an increase in the total solids (in the accept) after the thermal hydrolysis, the acidic hydrolysis with spent acid, and the alkali hydrolysis with green liquor sludge. Specifically did the acidic hydrolysis with spent acid improve the dewatering properties in terms of an increase in TS in %. The biggest increase in TS in % could be seen after using 10% spent acid ratio. The TS for the WAS from SCA Östrand increased in this experiment by 107 %. The thermal hydrolysis also showed promising results both in terms of dewatering properties and in the release of organic material. The biochemical methane potential test results showed a better and more rapid stabilized production of biomethane after hydrolysis of WAS compared to untreated WAS. The thermal hydrolysis both increased the rate of production and the total amount of methane produced. The thermally hydrolysed WAS from SCA Östrand improved the methane production from 77 Nml methane/g VS to 95 Nml methane/ g VS. The WAS from BillerudKorsnäs improved the methane production from 40 Nml methane/ g VS to 55 Nml methane/ g VS. These results, both from the methane potential tests and the results of the increased dewatering properties, show that the concept with hydrolysing should be evaluated further for improving the dewatering of the WAS.

Human activities cause many sustainability challenges in the world, which need to be dealt with. One way to decrease the negative impacts related to those challenges is by replacing currently dominating technologies with better, alternative technologies. However, such shifts are not easy to achieve – for example, each new user has to make a decision to start using the technology.The aim of this thesis is to contribute to a greater understanding of what the decisions to use alternative technologies are based on and how the decisions can be supported. In order to achieve this aim, the thesis focuses on the decisions of private companies’ and public organizations in Sweden of whether or not to use biogas in Sweden. The thesis is based upon six appended papers, which are used for addressing three research questions: How do biogas compare to other potential alternatives? Why do decision-makers in Sweden find it interesting to use biogas, and what makes them hesitant? And, how can decision support be used in decision-making to deal with complexities connected to biogas decisions?It is concluded that biogas has environmental and social advantages compared to several other renewable alternatives, but that it can be more expensive. The technical maturity of biogas use depends partly upon the usage area – biomethane buses is a mature area while heavy trucks is less mature. Biogas is perceived by decision-makers as a good environmental option and a better long-term solution than several other renewable alternatives since there are investments done and since the policymakers seem positive towards biogas. Public organizations tend to look at the broader positive aspects of biogas, such as energy security and nutrient recovery, while private companies tend to be more focused on biogas as an environmental action that can benefit the image of the company. However, decision-makers can be hesitant towards biogas due to economic or policy aspects or a lack of technical maturity. The decision-makers can also experience a lack of knowledge that makes them uncertain about biogas. Decision support can help the decision-makers in different ways, with different tools being more suitable for different parts of the complexities connected to biogas decisions. Multi-criteria assessments can help the decision-maker focus on several impacts at once and making the decision process transparent for trade-offs, while socio-technical scenarios can help the decision-maker understand how the wanted changes can be realized. Mänskliga aktiviteter orsakar många hållbarhetsproblem i världen, vilka behöver hanteras för att vi ska få en hållbar värld och ett hållbart samhälle. Ett sätt att hantera dessa problem och minska den negativa påverkan vi människor har är att byta till att använda bättre tekniker istället för de tekniker som används idag. Sådana förändringar är dock inte helt enkelt att vare sig genomföra eller påverka, och för att öka användningen av en bättre teknik måste till exempel varje ny användare ta ett beslut om att använda tekniken.Målet med den här avhandlingen är att hjälpa till att öka kunskapen om beslut kring att använda bättre tekniker – vad sådana beslut är baserade på och hur sådana beslut kan stödjas. Fokuset i avhandlingen är framförallt på ett specifikt fall – företags, kommuner och regioners beslut att använda biogas i Sverige. Avhandlingen innehåller sex vetenskapliga artiklar, som tillsammans hjälper till att svara på tre frågor. Hur skiljer sig biogas från andra potentiella alternativ? Varför är beslutsfattare intresserade av att använda biogas, och vad gör dem tveksamma? Hur kan beslutsstöd användas för att hjälpa beslutsfattarna att hantera komplexa delar i beslut kopplade till biogas?Resultaten visar att biogas har miljö- och samhällsfördelar i jämförelse till flera andra förnybara alternativ, men att biogas kan vara dyrare. Hur bra teknik det finns och hur väl den fungerar beror lite på användningsområde – biogas har använts för bussar ganska länge vilket gör att tekniken är mer välutvecklad där, medan det är ganska nytt att använda biogas i tunga lastbilar som ska köra långa sträckor. Beslutsfattare uppfattar att biogas är ett bra miljöalternativ, och att det är en bättre långsiktig lösning än flera andra förnybara bränslen eftersom investeringar görs i biogas och eftersom de som beslutar om regler och stöd för förnybara bränslen verkar positiva till biogas. Kommuner och regioner tenderar att titta mer på fler positiva saker kring biogas, till exempel att man kan producera energi från lokala råvaror och att biogasproduktionen kan hjälpa till med att återanvända näringsämnen. Företag å andra sidan tenderar att fokusera mer på att biogas kan användas som en miljöåtgärd som kan förbättra bilden av företaget hos allmänheten. Beslutsfattare kan dock tveka kring att använda biogas på grund av ekonomiska anledningar, eller att lagarna och stöden för biogas inte är optimala, eller då tekniken inte är tillräckligt välutvecklad för det företaget vill använda biogas till. Det finns även beslutsfattare som inte har så mycket kunskap om biogas, vilket gör att de är mer osäkra kring att använda det. Beslutsstöd kan hjälpa beslutsfattare på olika sätt, med olika verktyg som passar för olika situationer och olika svårigheter. Multikriterieanalys kan användas för att hjälpa beslutsfattare att fokusera på flera olika typer av påverkan samtidigt och göra beslutsprocessen enkel att förstå så att beslutsfattarna kan besluta vilka typer av påverkan som ska prioriteras. Sociotekniska scenarier kan å andra sidan hjälpa beslutsfattare att förstå hur de ska lyckas med att genomföra de förändringar som de vill införa. Funding agencies: Biogas Research Center, Vinnova, European Regional Development Fund

Biochemical conversion of wheat straw was investigated using hydrothermal pretreatment, enzymatic saccharification, and microbial fermentation. Pretreatment conditions that were compared included autocatalyzed hydrothermal pretreatment at 160, 175, 190, and 205 °C and sulfuric-acid-catalyzed hydrothermal pretreatment at 160 and 190 °C. The effects of using different pretreatment conditions were investigated with regard to (i) chemical composition and enzymatic digestibility of pretreated solids, (ii) carbohydrate composition of pretreatment liquids, (iii) inhibitory byproducts in pretreatment liquids, (iv) furfural in condensates, and (v) fermentability using yeast. The methods used included two-step analytical acid hydrolysis combined with high-performance anion-exchange chromatography (HPAEC), HPLC, ultra-high performance liquid chromatography-electrospray ionization-triple quadrupole-mass spectrometry (UHPLC-ESI-QqQ-MS), and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). Lignin recoveries in the range of 108–119% for autocatalyzed hydrothermal pretreatment at 205 °C and sulfuric-acid-catalyzed hydrothermal pretreatment were attributed to pseudolignin formation. Xylose concentration in the pretreatment liquid increased with temperature up to 190 °C and then decreased. Enzymatic digestibility was correlated with the removal of hemicelluloses, which was almost quantitative for the autocatalyzed hydrothermal pretreatment at 205 °C. Except for the pretreatment liquid from the autocatalyzed hydrothermal pretreatment at 205 °C, the inhibitory effects on Saccharomyces cerevisiae yeast were low. The highest combined yield of glucose and xylose was achieved for autocatalyzed hydrothermal pretreatment at 190 °C and the subsequent enzymatic saccharification that resulted in approximately 480 kg/ton (dry weight) raw wheat straw.

Dimethyl carbonate (DMC) and glycidol are considered industrially important chemical entities and there is a great benefit if these moieties can be synthesized from biomass-derived feedstocks such as glycerol or its derivatives. In this report, both DMC and glycidol were synthesized in an integrated process from glycerol derived 1,3-dichloro-2-propanol and CO2 through a metal-free reaction approach and at mild reaction conditions. Initially, the chlorinated cyclic carbonate, i.e., 3-chloro-1,2-propylenecarbonate was synthesized using the equivalent interaction of organic superbase 1,8-diazabicyclo [5.4.0] undec-7-ene (DBU) and 1,3-dichloro-2-propanol with CO2 at room temperature. Further, DMC and glycidol were synthesized by the base-catalyzed transesterification of 3-chloro-1,2-propylenecarbonate using DBU in methanol. The synthesis of 3-chloro-1,2-propylenecarbonate was performed in different solvents such as dimethyl sulfoxide (DMSO) and 2-methyltetrahydrofuran (2-Me-THF). In this case, 2-Me-THF further facilitated an easy separation of the product where a 97% recovery of the 3-chloro-1,2-propylenecarbonate was obtained compared to 63% with DMSO. The use of DBU as the base in the transformation of 3-chloro-1,2-propylenecarbonate further facilitates the conversion of the 3-chloro-1,2 propandiol that forms in situ during the transesterification process. Hence, in this synthetic approach, DBU not only eased the CO2 capture and served as a base catalyst in the transesterification process, but it also performed as a reservoir for chloride ions, which further facilitates the synthesis of 3-chloro-1,2-propylenecarbonate and glycidol in the overall process. The separation of the reaction components proceeded through the solvent extraction technique where a 93 and 89% recovery of the DMC and glycidol, respectively, were obtained. The DBU superbase was recovered from its chlorinated salt, [DBUH][Cl], via a neutralization technique. The progress of the reactions as well as the purity of the recovered chemical species was confirmed by means of the NMR analysis technique. Hence, a single base, as well as a renewable solvent comprising an integrated process approach was carried out under mild reaction conditions where CO2 sequestration along with industrially important chemicals such as dimethyl carbonate and glycidol were synthesized.

In this study, ash transformation and release of critical ash-forming elements during single-pellet combustion of different types of agricultural opportunity fuels were investigated. The work focused on potassium (K) and phosphorus (P). Single pellets of poplar, wheat straw, grass, and wheat grain residues were combusted in a macro-thermogravimetric analysis reactor at three different furnace temperatures (600, 800, and 950 °C). In order to study the transformation of inorganic matters at different stages of the thermal conversion process, the residues were collected before and after full devolatilization, as well as after complete char conversion. The residual char/ash was characterized by scanning electron microscopy-energy-dispersive X-ray spectroscopy, X-ray diffraction, inductively coupled plasma, and ion chromatography, and the interpretation of results was supported by thermodynamic equilibrium calculations. During combustion of poplar, representing a Ca-K-rich woody energy crop, the main fraction of K remained in the residual ash primarily in the form of K2Ca(CO3)2 at lower temperatures and in a K-Ca-rich carbonate melt at higher temperatures. Almost all P retained in the ash and was mainly present in the form of hydroxyapatite. For the Si-K-rich agricultural biomass fuels with a minor (wheat straw) or moderate (grass) P content, the main fraction of K remained in the residual ash mostly in K-Ca-rich silicates. In general, almost all P was retained in the residual ash both in K-Ca-P-Si-rich amorphous structures, possibly in phosphosilicate-rich melts, and in crystalline forms as hydroxyapatite, CaKPO4, and calcium phosphate silicate. For the wheat grain, representing a K-P-rich fuel, the main fraction of K and P remained in the residual ash in the form of K-Mg-rich phosphates. The results showed that in general for all studied fuels, the main release of P occurred during the devolatilization stage, while the main release of K occurred during char combustion. Furthermore, less than 20% of P and 35% of K was released at the highest furnace temperature for all fuels.

The increasing world population generates huge amounts of wastewater as well as large energy demand. Additionally, fossil fuel’s combustion for energy production causes the emission of greenhouse gases (GHG) and other pollutants. Therefore, there is a strong need to find alternative green approaches for wastewater treatment and energy production. Microalgae biorefineries could represent an effective strategy to mitigate the above problems. Microalgae biorefineries are a sustainable alternative to conventional wastewater treatment processes, as they potentially allow wastewater to be treated at lower costs and with lower energy consumption. Furthermore, they provide an effective means to recover valuable compounds for biofuel production or other applications. This review focuses on the current scenario and future prospects of microalgae biorefineries aimed at combining wastewater treatment with biofuel production. First, the different microalgal cultivation systems are examined, and their main characteristics and limitations are discussed. Then, the technologies available for converting the biomass produced during wastewater treatment into biofuel are critically analyzed. Finally, current challenges and research directions for biofuel production and wastewater treatment through this approach are outlined.

Klimatförändringarna medför nya utmaningar för verksamheter som både beror av politiska beslut för att begränsa den globala uppvärmningen och av de fysiska förändringarna i klimatet. Beslut som tas av verksamheter inom det kommande decenniet kan resultera i inlåsningseffekter om klimatförändringsaspekten inte inkluderas. I projektet Passivitet i klimatfrågan: Fjärrvärmesektorns exponering mot en utvecklad bioekonomi och ett förändrat klimat identifieras vilka påverkansfaktorer som fjärrvärmebranschen i Sverige behöver inkludera i framtida investeringsbeslut för att framtidssäkra verksamheten mot klimatförändringarna och undvika inlåsningseffekter. Sammanfattning max 200 ord Den svenska fjärrvärmebranschen står inför stora reinvesteringar detta decennium och tidigare studier visar att majoriteten planerar att investera i liknande teknik som i dag. Inom investeringarnas livslängd kommer förutsättningarna att förändras till följd av klimatförändringarna och ett investeringsbeslut som tas i dag måste inkludera klimatförändringsaspekten för att undvika inlåsningseffekter de kommande 30–40 åren. Projektets mål är att framtidssäkra fjärrvärmens roll i det svenska energisystemet mot förändringar som kan uppstå till följd av klimatförändringarna. Detta genom att identifiera påverkansfaktorer och dess exponering till följd av en utvecklad bioekonomi inom EU och fysiska förändringar i och med ett förändrat klimat. De identifierade påverkansfaktorer grupperas i projektet till tre påverkansbilder. 1) Bränsleberoende: reinvestering i stora produktionsanläggningar centralt belägna i nätet med tungt bränsleberoende och därmed inlåsningseffekter. 2) Det fysiska systemet: störningar på ledningsnät och anläggningar som påverkar leveranssäkerheten. 3) Fjärrvärmeaffären: investeringsbeslut baseras på kunders efterfrågan i dag. Av de tre påverkansbilderna bedöms 3) Fjärrvärmeaffären, vara den mest akuta påverkansbilden att agera på, följt av 1) Bränsleberoendet, och minst akut, 2) Det fysiska systemet. Efter diskussioner med fjärrvärmeföretag bedöms påverkansbild 1) Bränsleberoendet, vara den som medför störst osäkerheter och är svårast att hantera.

I det här examensarbetet har utnyttjande av spillvärme internt för att energieffektiviserapelletstillverkningen vid Bioenergi Luleå projekteras. Arbetet har innefattat attundersöka om det är möjligt att implementera spillvärmen i processen utan att störanuvarande produktion, vilken teknik som efterfrågas och om det blir någon vinst förföretaget. Grundliga litteraturstudier har genomförts för att ta reda på hur spillvärmekan användas och vad det finns för teknik för att göra det möjligt. Att användaspillvärme internt för att effektivisera olika typer av processer är något som används istörre utsträckning idag och verkar vara något som flera företag är beredda att satsa på. Viktiga resultat som tagits fram i det här projektet är att det kommer vara möjligt atteffektivisera pelletstillverkningen utan att störa befintlig produktion. Genom attförvärma kvarnluften från 23 ℃ till 58 ℃ kommer det resultera i att torkeffekten kansänkas till 𝑃𝑇𝑜𝑟𝑘−𝑠𝑝𝑖𝑙𝑙 = 8235 𝑘𝑊, fuktigheten på spånet kommer då öka till 9,35 %och temperaturen på spånet efter torken kommer sjunka till 𝑇2 = 122 ℃. Det kommerinte ske någon stor skillnad i tillsatt ånga innan pelletspressarna med den nyatemperaturen från hur det ser ut idag. Den stora vinsten som Bioenergi Luleå kommerfå av att förvärma kvarnluften är att mängden spån i torken kommer att kunna öka till332,64 𝑡𝑜𝑛/𝑑𝑦𝑔𝑛 vilket resulterar i en ökning på ca 790 𝑡𝑜𝑛 𝑝𝑒𝑙𝑙𝑒𝑡𝑠 𝑝𝑒𝑟 å𝑟. Känslighetsanalysen visar det att oavsett om mätningarna skulle ha en minskning på10 % eller öka med 10 % så skulle vinsten för Bioenergi Luleå fortfarande varamarkant. Ökningen på pelletsproduktionen kommer fortfarande uppgå mot runt700 𝑡𝑜𝑛 𝑝𝑒𝑙𝑙𝑒𝑡𝑠/å𝑟.

Bioenergy with Carbon Capture and Storage represents a crucial technology that enables an energy production with negative carbon emissions, which is needed to achieve global climate goals. Appropriated management of biodegradable waste, including biodegradable lignocellulosic waste, sewage sludge, organic fraction of municipal solid waste, can make this contribution. The implementation of pyrolysis process is able to produce biochar, liquid and gas product from biodegradable waste. Based on the pyrolysis technology, a sustainable management of biodegradable waste for negative carbon emission is proposed in this work. The proposed novel process combines an anaerobic digestion, pyrolysis of the digestate following by catalytic reforming the pyrolytic vapor, then methanation of the reforming gas, separating the stream of CH4 and CO2. The storage of separated CO2 streams and biochar can be considered as negative emissions. Furthermore, the pyrolysis behaviors of the solid residue, which was produced from hydrothermal carbonization pretreatment of biodegradable wastes, are investigated. The pyrolytic liquid was further upgraded to a higher quality product with a less oxygen content, a higher calorific value by using ex-situ and in-situ hydrogen donors. Carbon stability of the pyrolytic biochar, which is one of key parameters to assess the biochar as carbon sink, was evaluated by using the accelerated oxidation method. Finally, energy and mass balance on the proposed process was obtained. The pyrolysis behavior of hydrothermal carbonization-treated sewage sludge digestate, and paper sludges were investigated. Thermogravimetric analysis, Py- Gas chromatography–Mass spectrometry and bench-scale experiments were employed to fulfil this objective. The thermal degradation behavior of these two feedstocks was investigated. Initially, the compounds in the pyrolytic vapor were identified. Thereafter, the pyrolytic product from the bench-scale experiment was characterized. It was found that the pyrolysis reaction of both feedstocks was a two-stage reaction. The organic fraction with a higher heating value around 28.47 to 38.46 MJ/kg was produced from the pyrolysis of hydrothermal carbonization-treated biodegradable waste. More organic fraction can be produced from the pyrolysis of the paper sludge than that from sewage sludge digestate. It was also found that the fixed carbon content in raw materials is difficult to be determined by using the standard method due to the ash oxidation behavior in such materials. Therefore, a method to determine the sample's fixed carbon content without affected by the ash oxidation behavior was developed. Introducing hydrogen donors to upgrade the pyrolytic liquid products for a higher quality product with a lower oxygen content and a higher calorific value is investigated. The H2 was used as an ex-situ hydrogen donor in the lignocellulosic waste pyrolysis in both non-catalytic and catalytic cases. The catalyst used in this study was a commercial HZSM-5, catalyst with a strong selectivity of aromatics. The hydrogen consumption during pyrolysis in the H2 atmosphere was indicated by experiments. The gas and liquid production were promoted while the biochar yield was suppressed in the presence of the H2 atmosphere. However, the presence of an H2 atmosphere was found to increase the acidity of the HZSM-5 and enhance the production of polyaromatics during the pyrolysis process. Further, the study using the sewage sludge digestate as an in-situ hydrogen donor to pyrolysis of lignocellulosic biomass obtained from the salix family was investigated. The sewage sludge digestate was premixed with salix in five blended ratios and pyrolyzed in a bench-scale reactor. The composite of 75% sludge digestate and 25% salix presented the highest mass and energy yields of the organic fraction in the liquid product. The yield of biochar was suppressed in this copyrolysis. The synergistic effect between the sludge digestate and salix was studied with respect to reaction mechanisms, carbon number distribution of the compounds in organic fraction, and biochar stability. The competition reaction between the short-chain carboxylic acid from salix pyrolysis and a long-chain carboxylic acid from digestate pyrolysis was one of the main reasons for the synergistic reaction regarding the composition of the organic fraction. This competition reaction results in a higher amount of long-chain carboxylic acid esters and N-heterocyclic compounds, a lower amount of the long-chain nitriles in the organic fraction produced from copyrolysis compared to it from individual pyrolysis. The stabilities of the biochar products from the copyrolysis of sewage sludge digestate and salix, were determined by using the accelerated oxidation method. It was found that the biochar stabilities are promoted by this copyrolysis. The nitrogen yield in the biochar product was also enhanced by the copyrolysis process. The proposed CO2 negative process was modelled using the process simulation software, and the modelling results were validated by using an experimental data. The pyrolysis temperature and dewatering technology were used for sensitivity analysis. In this process, methane was chosen as the final product. Pyrolytic biochar and compressed CO2 was captured and stored as the negative carbon emission. It was found that for 1000 kg of dry matter digestate, one can obtain 151.4 kg CH4 in a purity of 96 vol%, 304.5kg compressed CO2, and 80.8 kg biochar. The latter two are equal to 355.64 kg negative CO2 emission. Användandet av bioenergi i kombination med avskiljning och lagring av kol representerar en kritisk teknologi som möjliggör en energiproduktion som resulterar i negativa kolutsläpp, vilka är nödvändiga för att uppnå de globala klimatmålen. En lämplig hantering av biologiskt nedbrytbart avfall inkluderande lignocellulosahaltigt avfall, avfallsslam, organiska fraktioner av kommunalt fast avfall, kan bidra till denna utveckling. Genom en process kallad pyrolys kan biokol, flytande och gasprodukter produceras från biologiskt nedbrytbart avfall. Genom pyrolysteknik föreslås i detta arbete en hållbar hantering av biologiskt nedbrytbart avfall för negativa koldioxidutsläpp. Denna avhandling föreslår en unik process som kombinerar anaerob nedbrytning, pyrolys av rötrester (från den anaeroba nedbrytningen) följt av en katalytisk reformering av pyrolysgasen, en metanjäsning av reformeringsgasen och en separering av CH4 och CO2 gaserna. Därefter så kan den separerade CO2 gasen och biokolet räknas som en negative emission. Avhandlingen behandlar också pyrolys av de fasta restprodukterna som är producerade från en hydrotermisk karbonisering av biologiskt nedbrytbart avfall. Den pyrolytiska flytande produkten är förädlad till en högre kvalitet med ett lägre syreinnehåll och ett högre värmevärde, genom användande av ex-situ och in-situ vätegivare. Kolstabiliteten hos biokolet, som är en nyckelparameter för utnyttjandet av biokol som en kolsänka, har utvärderats genom användande av en accelererad oxidationsmetod. Slutligen så har en energi- och massbalans för den föreslagna processen utvecklats. Pyrolysprocessen av hydrotermisk karboniserade rötrester från avfallslam och pappersslam studerades baserat på undersökningar med användande av termogravimetri, Py-GC/MS och experiment i laboratorieskala. Detta inkluderade studier av den termiska nedbrytningen av dessa två råmaterial. Inledningsvis så identifierades föreningarna som ingår i den pyrolytiska gasen. Därefter så karakteriserades pyrolysprodukterna från laboratorieskaleexperimenten. Resultaten visade att pyrolysprocesserna för båda råmaterialen kan beskrivas med en tvåstegsreaktion. Organiska fraktioner med värmevärden inom intervallet 28.47 till 38.46 MJ/kg producerades vid pyrolys av biologiskt nedbrytbart avfall med användande av hydrotermiskt karbonisering. Resultaten visade också att en större andel organisk fraktion produceras med användande av rötslam från papperslam än med användande av rötslam från avfallsslam. Dessutom visade det sig att det är svårt att mäta en bestämd kolhalt i råmaterialen genom att använda standardmetoder, på grund av oxidering av askan som förekommer i råmaterialen. Därför så utvecklades en ny metod för att bestämma ett provs bestämda kolhalt, som inte är beroende av en oxidering av askan. I avhandlingen studeras också möjligheten att använda vätegivare för att förädla den flytande produkten för att erhålla ett lägre syreinnehåll och ett högre värmevärde. En vätgasatmosfär användes för att skapa en ex-situ vätegivning vid pyrolys av lignocellulosahaltigt avfall både med och utan användandet av en katalysator. Den specifika katalysatorn som användes var den kommersiella produkten HZSM-5, som är en katalysator som möjliggör en separation av aromatiska föreningar. Resultaten visar att det är möjligt att bestämma mängden vätgas som förbrukas vid experiment både med och utan användandet av katalysatorn HZSM-5. Användandet av en vätgasatmosfär ledde till en ökad produktion av både gas och vätska, men ett minskat utbyte av biokol. Däremot så ledde detta till en ökad surhet hos HZMS-5 katalysatorn och en ökad andel av polyaromatiska föreningar under pyrolysprocessen. Användandet av rötrester från avfallsslam som in-situ vätegivare vid pyrolys av ligocellulosahaltigt biomassa från salixsläktet undersöktes också. Rötrester från avfallsslam blandades med biomassa från salixsläktet i fem olika proportioner och pyrolysförsök utfördes i laboratorieskala. Försöken visade att en blandning av 75% rötslam från avfallsslam och 25% biomassa från salixsläktet resulterade i de högsta mass- och energiutbytena med avseende på den organiska fraktionen av den flytande produkten, men ett minskat utbyte av biokol. Dessutom så studerades den synergetiska effekten vid användandet av en kombination at rötrester från avfallsslam och biomassa från salixsläktet med avseende på reaktionsmekanismer, kolnummerfördelningen i den organiska fraktionen och stabilitet hos biokol. Resultaten visade att konkurrerande reaktionerna mellan karboxylsyra som har korta kedjor från pyrolys av biomassa från salixsläktet och karboxylsyra med långa kedjor från pyrolys av rötrester var en orsak till uppkomsten av synergetiska reaktioner kopplade till sammansättningen hos den organiska fraktionen. Denna konkurrerande reaktion ger upphov till karboxylsyraestrar och heterocykliska kväveföreningar och en lägre andel nitriler med långa kedjor i den organiska fraktionen som produceras med en kombinerad pyrolysprocessen, i jämförelse med en traditionell enkel pyrolysprocess. En matematisk modell av den föreslagna unika processen har utvecklats med användandet av en kommersiell mjukvara och simuleringsresultaten har verifierats med experimentella data. Fokus var att studera inverkan av pyrolystemperatur och avvattningsteknik på simuleringsresultaten, när metan valdes som den slutligt önskade produkten. Andelen pyrolytiskt biokol och komprimerad CO2 bestämdes och användes sedan för att representera de lagrade negativa koldioxidemissionerna. Simuleringsresultaten visade att 151.4 kg CH4 med en renhet av 96 vol%, 304.5kg komprimerad CO2 och 80.8 kg kol producerades vid pyrolys av 1000 kg torra rötrester. De två senare representerar en 355.64 kg negativ CO2 emission. 生物能源与碳捕获和储存是实现全球气候目标所必需的关键技术。对包含木质纤维素、污泥、固废在内的可降解垃圾的新型处理工艺进行研究，可以有效地对这一技术的发展做出贡献。可降解垃圾的热解工艺可以用于生产热解油、热解碳和热解气。本文结合了可降解垃圾的厌氧消化，残留消化物的热解，热解蒸汽的催化重整和甲烷化等工艺，对热解物的高值化以及碳捕获和储存进行了深入研究。具体来说，本文研究了：可降解垃圾所衍生的水热炭的热解表现；通过应用异位/原位氢供体，对热解油的品质进行改良；通过使用化学加速氧化的方法对热解炭的稳定性进行测试；针对上述工艺进行模拟，分析与评估。 首先，本文研究了市政污泥消化物和造纸厂垃圾所衍生的水热炭的热解表现。热重分析的结果表明，该两种原料的热解反应均是二段反应。通过Py-GC/MS实验，分析表征了水热炭热解蒸气中化合物的成分。两种原料在不同温度热解下得到的热解油均展现出了较高热值（28.47 至 38.46 MJ/kg）。与市政污泥衍生的水热炭相比，通过热解造纸厂污泥衍生的水热炭可以生产更多的热解油。此外，原料中的灰分在高温有氧环境下存在氧化现象，这一现象使得难以使用传统方法来测量固定碳含量。因此，针对这一问题，本文开发了一种不受灰分氧化影响的方法来测量样品固定碳含量。 其次，本文研究了引入原位/异位氢源对热解油质量的影响。在催化和非催化条件下，氢气气氛作为异位氢源被引入了木质纤维素热解工艺。在本研究中使用的催化剂是商用HZSM-5，该催化剂对芳烃具有很强的选择性。实验计算了在氢气气氛中热解过程中的氢消耗量。结果表明，氢气气氛提高了热解气和热解油的收得率，同时降低了热解炭的收得率。与此相对的，氢气气氛的存在也会增加HZSM-5的酸度，并在热解过程中提高多环芳烃的收得率。此外，本文还研究了使用市政污泥消化物作为原位氢源与柳属生物质进行共热解。将污水污泥消化物与柳属生物质以五种混合比例预混合，并在实验室规模（大约50克）的反应器中进行热解。 75% 的市政污泥消化物和 25% 柳属生物质的混合物的热解产出的热解油具有最高的收得率与热值。结果还表明，热解炭的收得率在共热解中受到抑制。本研究还进一步通过研究反应机理、热解油的碳链分布和生物炭稳定性，尝试解释了市政污泥消化物和柳属生物质共热解的协同作用。柳属生物质热解产生的短链羧酸与消化物热解产生的长链羧酸之间的竞争反应可能是形成该协同作用的主要原因之一。这种竞争反应会增加热解油中长链羧酸酯和氮杂环族化合物， 并降低长链腈族化合物的含量。 此外，本文还通过使用化学加速氧化法测定了市政污泥消化物和柳属生物质共热解炭的元素稳定性。该工作表明共热解可以提高热解炭的元素稳定性。共热解条件下，热解炭的氮收得率也得到了提高。 最后，本文还使用了ASPEN Plus对整体工艺的过程进行模拟与仿真，并通过实验数据验证了该模型。本工作采用了不同的热解温度和机械脱水技术作为参数，对该工艺的敏感性进行了分析。本工艺选择甲烷作为最终产品，同时通过储存热解炭和压缩二氧化碳实现负碳排放。 研究结果表明，通过该工艺，每吨干燥消化物可获得151.4千克甲烷（纯度96%），304.5千克压缩二氧化碳和80.8千克生物炭。后两者等同于355.64千克负碳排放。

One of the main interests in commercial methane production is to maximize the gas yield, and it is thus appealing to use material with relative high methane potential. However, such material often results in process instability whereas ammonia inhibition is common. Removal of ammonia through adsorption is a fairly unexplored method in the field of biogas production, and could prove to be cost-effective.The adsorption capacity of pulp fibres from the paper making industry were investigated through batch adsorption experiments. Additionally, the fibres effect on small scale batch digesters in terms of methane production and cellulase activity was explored. Overall, the adsorption capacity of the pulp fibres was low, whereas Kraft hardwood had the highest adsorption capacity in both an aqueous ammonium solution and digester fluid at 11±3 and 60±20 mg g-1, respectively. The initial total ammonium nitrogen concentration had the highest effect on the adsorption capacity with a positive correlation. The pulp fibres seemingly had no effect on the ammonia inhibited anaerobic digestion systems. However, the cellulase activity was higher after day 5 in the anaerobic digestion systems with a high ammonia concentration.In essence, the overall results showed that the adsorption of the fibres was relatively low and most likely not suitable as a material to prevent ammonia inhibition in an AD.

Biochar – the carbon rich residue derived from biomass pyrolysis – is recognised as a potential solution to remove carbon dioxide from the atmosphere, while simultaneously delivering socio-environmental benefits through biochar use as a material. Perceived as a sustainable innovation, biochar has raised interest throughout the world. Sweden has witnessed a rising interest for biochar over the past decade, leading to investments in modern biochar production capacity and the development of various biochar-based products. However, as for any emerging technology, it is necessary to study its environmental performance in a systematic manner to guarantee that environmental expectations meet reality, and to enable science-based policy support. This thesis examined the energy, climate and environmental impacts of biochar production and use, supporting on-going and future projects in Sweden. Four case studies were designed, set respectively in Stockholm, Nyköping, Helsingborg and Uppsala areas. The case studies analysed biochar production at various scales, from different biomass feedstocks, and biochar use in urban and rural applications. The main method applied was life cycle assessment, complemented with material flow analysis and energy systems modelling. In addition, a framework was developed to conceptualise and classify environmental effects of biochar in a life cycle perspective. The results showed that biochar systems can deliver more climate change mitigation than conventional bioenergy when energy systems are already rather decarbonised and if biochar stability is high. Biochar carbon sequestration provided the main climate change benefit, but smaller additional benefits were obtained from some material uses of biochar. When compared with reference systems, biochar solutions lead to shifts of burdens between sectors and environmental impact categories. It is possible to integrate pyrolysis to both large district heating networks and decentralised heating systems, but it will lead to a net increase in biomass consumption and related environmental impacts, relative to direct combustion of biomass. In the second half of the century, the need for management of biochar-containing soil masses will arise from today’s emerging urban applications. The case studies illustrated new uses of biochar and quantified several environmental benefits from biochar use. However, gaps remain between biochar effects present in the public discourse and their quantification in life cycle assessment. These differences were attributed to variability in the biochar effects, lack of knowledge, or inappropriate accounting framework. Overall, the thesis stresses the importance of analysing the potential of innovations to contribute to environmental goals by using parametrized life cycle models, depicting multiple contexts, and striving to identify suitability conditions rather than providing a definitive static answer. Biokol – den kolrika produkten som återstår från pyrolys av biomassa– är en potentiell lösning för att fånga koldioxid från atmosfären, samtidigt som den har socio-miljömässiga fördelar genom användning av biokol som material. Biokol uppfattas som en hållbar innovation och har väckt intresse över hela världen. I Sverige har intresset för biokol ökat under de senaste åren, vilket har lett till investeringar i modern produktion av biokol och utveckling av olika biokolbaserade produkter. Liksom med all ny teknik är det nödvändigt att studera dess miljöprestanda på ett systematiskt sätt för att garantera att miljöförväntningarna är uppfyllda och för att möjliggöra vetenskapligt baserat politiskt stöd. Denna avhandling undersökte energi-, klimat- och miljöeffekterna av biokolproduktion och -användning, till stöd för pågående och framtida projekt i Sverige. Fyra fallstudier har utformats, i Stockholm, Nyköping, Helsingborg och Uppsala. Fallstudierna analyserade biokolproduktion i olika skalor, från olika slags biomassa och användning av biokol i stads- och landsbygdstillämpningar. Den huvudsakliga metoden som användes var livscykelanalys, kompletterad med materialflödesanalys och energisystemmodellering. Dessutom utvecklades ett ramverk för att konceptualisera och klassificera miljöeffekter av biokol i ett livscykelperspektiv. Resultaten visade att biokolsystem kan ha lägre klimatpåverkan än konventionell bioenergi när energisystem redan är i stort sett fossilfria och om biokolstabiliteten är hög. Kolinlagring i biokol gav det största bidraget till klimatprestandan, men mindre ytterligare fördelar erhölls från viss materialanvändning av biokol. Jämfört med referenssystemen leder biokolösningar till att miljöbelastning flyttas mellan sektorer och kategorier av miljöpåverkan. Det är möjligt att integrera pyrolys i både stora fjärrvärmenät och decentraliserade värmesystem, men det kommer att leda till en nettoökning av biomassaförbrukningen och relaterad miljöpåverkan, jämfört med direkt förbränning av biomassa. Under andra halvan av seklet kommer det att uppstå ett behov av hantering av biokolhaltiga jordmassor från dagens växande urbana biokolanvändning. Fallstudierna illustrerade nya användningsområden för biokol och kvantifierade flera miljöfördelar. Det kvarstår dock ett glapp mellan de biokoleffekter som diskuteras i samhället och deras kvantifiering i livscykelanalys. Dessa skillnader berodde på variationer i biokols effekter, bristande kunskap eller olämpliga systemgränser. Generellt så betonar avhandlingen vikten av att analysera potentialen för innovationer att bidra till miljömål genom att använda parametriserade livscykelmodeller, analysera flera sammanhang och sträva efter att identifiera lämpliga förhållanden snarare än att ge ett entydigt svar. Le biochar –résidu solide riche en carbone issue de la pyrolyse de biomasse – est envisagé comme une potentielle façon de retirer du dioxyde de carbone de l’atmosphère, tout en apportant des bénéfices socio-environnementaux via son utilisation comme matériau. Perçu comme une innovation contribuant au développement durable, le biochar a connu un fort engouement à travers la planète. En Suède, cet intérêt pour le biochar s’est traduit au cours de la dernière décennie par des investissements dans des capacités modernes de production de biochar et par le développement de nouveaux produits à base de biochar. Cependant, comme pour toute technologie émergente, il est nécessaire d’étudier ses implications environnementales de manière systématique afin de pouvoir garantir que les performances environnementales sont à la hauteur des attentes, et pour guider la définition de politiques basées sur la science. Cette thèse s’est intéressée aux impacts énergétiques, climatiques et environnementaux de la production et de l’utilisation de biochar, supportant le développement de projets en cours et futurs, en Suède. Quatre études de cas ont été réalisées, situées à Stockholm, Nyköping, Helsingborg et Uppsala. Les études de cas ont analysé la production de biochar à différentes échelles et à partir de différents substrats, ainsi que l’utilisation de biochar en agriculture et en milieu urbain. La principale méthodologie appliquée fut l’analyse de cycle de vie, couplée à l’analyse de flux de matière et la modélisation énergétique. De plus, un cadre théorique a été conçu pour décrire et classifier les potentiels effets environnementaux du biochar dans une perspective de cycle de vie. Les résultats ont montré que les systèmes à base de biochar peuvent apporter davantage de bénéfices climatiques que la bioénergie conventionnelle si le système énergétique est déjà relativement décarbonné et si la stabilité du biochar produit est élevée. La séquestration de carbone dans le biochar représente la principale contribution au bénéfice climatique des systèmes étudiés. Des bénéfices climatiques additionnels, mais en général d’importance moindre, sont obtenus par certaines utilisations du biochar. En comparaison avec une situation de référence, les systèmes à base de biochar induisent une modification des conséquences environnementales, à la fois entre secteurs économiques et entre catégories d’impact environnemental. Il est possible d’intégrer la pyrolyse de biomasse à de grands réseaux de chaleur comme à des systèmes décentralisés de chauffage, mais cela induit une augmentation nette de la consommation de biomasse et de ses impacts, en comparaison avec la combustion directe. Par ailleurs, les utilisations du biochar en milieu urbain qui émergent aujourd’hui vont mener à un besoin futur de gestion appropriée de flux secondaires contenant du biochar. Les études de cas ont illustré de nouvelles applications du biochar et quantifié certains de leurs impacts et bénéfices environnementaux. Cela dit, des différences subsistent entre les bénéfices potentiels du biochar présentés dans la sphère publique et leur quantification en analyse de cycle de vie. Ces différences furent attribuées à la grande variabilité des effets du biochar, des manques de connaissances, ou un cadre de modélisation non adaptés à l’inclusion desdits effets. Dans l’ensemble, cette thèse souligne l’importance d’analyser le potentiel d’une innovation à contribuer aux objectifs environnementaux en utilisant des modèles paramétrés d’analyse de cycle de vie, capable de représenter différents contextes, et de s’efforcer d’identifier les conditions de réussite plutôt que de se limiter à une quantification statique des conséquences environnementales. Pflanzenkohle – der kohlenstoffreiche Rückstand, der aus der Pyrolyse von Biomasse gewonnen wird – wird als mögliche Technik in Betracht gezogen, um Kohlendioxid aus der Atmosphäre zu entziehen. Gleichzeitig verspricht die Verwendung von Pflanzenkohle als Material auch sozio-ökologische Vorteile. Als nachhaltige Innovation wahrgenommen, hat Pflanzenkohle weltweit Interesse geweckt. Schweden hat im letzten Jahrzehnt ein wachsendes Interesse für Pflanzenkohle erlebt, sodass die Investitionen in moderne Produktionskapazitäten von Pflanzenkohle und die Entwicklung verschiedener Produkte auf Pflanzenkohlebasis gestiegen sind. Wie bei jeder neuen Technologie ist es jedoch erforderlich, ihre Umweltleistung systematisch zu untersuchen, um sicherzustellen, dass die ökologischen Erwartungen der Realität entsprechen, und eine wissenschaftlich fundierte politische Unterstützung gegeben ist. Diese Arbeit untersuchte die Energie-, Klima- und Umweltauswirkungen der Pflanzenkohleproduktion und -nutzung und unterstützte laufende und zukünftige Projekte in Schweden. Vier Fallstudien sind in Stockholm, Nyköping, Helsingborg und Uppsala durchgeführt worden. Diese Fallstudien haben die Produktion von Pflanzenkohle in verschiedenen Größenordnungen und aus verschiedenen Biomasse-Rohstoffen, sowie die Nutzung von Pflanzenkohle im landwirtschaftlichen und im städtischen Bereich analysiert. Die Hauptmethodik war die Lebenszyklusanalyse, welche mit Stoffstromanalysen und Energiesystemmodellierungen ergänzt worden ist. Darüber hinaus wurde ein Konzept entwickelt, um Umweltwirkungen von Pflanzenkohle aus einer Lebenszyklusperspektive heraus zu erfassen und zu klassifizieren. Die Ergebnisse zeigten, dass pflanzenkohlebasierte Systeme mehr Klimaschutz leisten können als konventionelle Bioenergie, wenn die Energiesysteme bereits weitgehend dekarbonisiert sind und die Stabilität der Pflanzenkohle hoch ist. Die Kohlenstoffspeicherung durch Pflanzenkohle erbrachte hierbei den größten Nutzen für den Klimaschutz, aber auch kleinere zusätzliche Vorteile wurden durch einige Verwendungen von Pflanzenkohle als Werkstoff erzielt. Im Vergleich mit Referenzsystemen führen Pflanzenkohlelösungen zu einer Verschiebung der Belastung sowohl zwischen Wirtschaftssektoren als auch zwischen ökologischen Wirkungskategorien. Pyrolyse lässt sich sowohl in große Fernwärmenetze als auch in dezentrale Wärmesysteme integrieren. Dies aber führt im Vergleich zur direkten Verbrennung von Biomasse zu einem Nettoanstieg des Biomasseverbrauchs und der damit verbundenen Umweltauswirkungen. Außerdem wird die heutige Nutzung von Pflanzenkohle im städtischen Bereich in der zweiten Hälfte dieses Jahrhunderts zum Bedarf einer angemessenen Verwaltung von pflanzenkohlehaltigen Bodenmassen führen. Die Fallstudien veranschaulichten neue Verwendungen von Pflanzenkohle und quantifizierten mehrere ökologische Vorteile dieser Verwendung. Allerdings bleiben Lücken zwischen den im öffentlichen Diskurs präsenten Pflanzenkohle-Effekten und deren Quantifizierung durch die Lebenszyklusanalyse bestehen. Diese Unterschiede wurden auf die große Veränderlichkeit der Auswirkungen von Pflanzenkohle, fehlendes Wissen oder einen unangemessenen Berechnungsrahmen zurückgeführt. Insgesamt betont diese Dissertation, wie wichtig es ist, den möglichen Beitrag einer Innovation zu den Umweltzielen zu analysieren, indem parametrisierte Lebenszyklusmodelle verwendet und mehrere Kontexte abgebildet werden sowie versucht wird, Eignungsbedingungen zu identifizieren, anstatt eine endgültige statische Antwort zu geben. QC 20211124

The organic wastes including olive oil mill residues are an inseparable part of food manufacturing processes while implying multi-faceted damages to the environment. A good quantity of research has been conducted to examine the biogas enhancement level in the anaerobic process of olive residues. Seeking the optimum pretreatment method and the co-digesting substrates, the current study has conducted aggregative research on 155 experiments out of 22 studies. The conducted meta-analysis recognized the chemical type of pretreatments as the most effective treating procedures, according to which, application of the combined alkaline and lime, followed by trace metal cobalt supplementations are recognized as the most effective methods. Furthermore, the study found intriguing results on the optimum type of olive main substrate, inoculum, digester type and effective volume as well as the superior country and year, in the anaerobic digestion of the olive mill residues.

The climate on earth keeps getting warmer where heat waves, eutrophication, rising sea levels, extreme weather like flooding, droughts and wildfires are an expanding problem. The focus of this bachelor thesis is to determine the potential of mitigating eutrophication and while contributing to blue growth by harvesting and make use of reeds like Phragmites australis and Arundo donax. Reeds have the ability to quickly absorb nutrients from aquatic environments and there are opportunities to use them as a feedstock for producing biochar to be potentially used in areas such as soil improvement, fodder additive and carbon sequestration. Additionally, optimal biochar properties for the observed applications gets analysed. The thesis is based on a systematic literature review and an interview with Niclas Anvret at the non-profit organisation “Race for the Baltic”. Results show that biochar produced according to parameters such as heating rate, biomass species and especially, different temperatures, results in varied characteristics that change the biochar's adsorption abilities, nutrient retention, alkalinity, stability, surface area and porosity volume. The different applications of biochar are, however, not easily determined. This is because of the fact that certain biochar properties, that are prominent in entirely different pyrolysis conditions, could both be beneficial for the same application. Additionally, the different attributes sometimes influence each other which gives rise to unclear patterns affecting use potential. To overcome these issues, more research is needed to clarify the correlations between attributes of the biochar and to determine which characteristics of biochar are best suited for each application. In terms of how large-scale harvesting of reed could affect the ecosystem is also unclear, there is not enough research regarding the question to be able to draw clear conclusions. The reasoning behind this is that there are knowledge gaps, geographical differences, different unit measuring and methodology. The potential for biochar in the coal market is high and the demand in Sweden has risen over the past couple of years. There is also interest in using biochar as a soil amendment, to make use of nutrient content as well as applying organic matter to soils to potentially achieve long-term carbon sequestration. However, the production cost of biochar out of reed is relatively expensive, and it cannot compete with coal or other fertilisers/soil amendments on the market, with feedstock management usually being the most expensive part of production. Lastly, there is currently no harvesting method that can measure the amount of reed that needs to be harvested to be able to produce biochar on a large scale. Klimatet på jorden blir allt varmare och värmeböljor, övergödning, stigande havsnivåer, extrema väder som översvämningar, torka och bränder är ett stigande problem. Syftet med denna kandidatuppsats är att undersöka potentialen att mildra eutrofiering och samtidigt bidra till blå tillväxt genom att skörda - och använda sig av vass som Phragmites australis och Arundo donax. Vass har en framträdande förmåga att absorbera näringsämnen. Det finns därför möjligheter att använda dem som råvara för att producera biokol som potentiellt kan användas i områden såsom jordförbättring, fodertillsatser och kolbindning. Utöver detta undersöks optimala egenskaper för biokol enligt de observerade applikationerna. Kandidatuppsatsen bygger på en systematisk litteraturstudie och en intervju med Niclas Anvret på den ideella organisationen ”Race for the Baltic”. Resultaten indikerar att biokol, producerad i pyrolys enligt parametrar som uppvärmningshastighet, biomassa och i synnerhet olika temperaturer, resulterar i varierande egenskaper som förändrar biokolets absorptionsförmåga, bibehållande av näring, alkalinitet, stabilitet, ytarea och porositetsvolym. De olika tillämpningarna av biokol är emellertid svåra att avgöra på grund av vissa biokolegenskaper. Dessa egenskaper är framträdande under helt olika pyrolysförhållanden men kan samtidigt vara fördelaktiga för samma typ av applikation. Dessutom påverkar de olika attributen ibland varandra vilket ger upphov till komplexa trender som påverkar användningspotentialen. För att kunna dra tydliga slutsatser behövs mer forskning för att klargöra sambandet mellan biokolens attribut och för att bestämma vilken samling egenskaper hos biokol som passar bäst för varje applikation. Hur storskalig skörd av vass kan påverka ekosystemet är fortfarande oklart. Det finns inte tillräckligt med forskning kring frågan för att kunna dra tydliga slutsatser. Detta beror på att det finns kunskapsluckor, geografiska skillnader, olika måttenheter och metoder för de studier som gjorts inom detta område. Potentialen för biokol på kolmarknaden är hög och efterfrågan i Sverige har ökat de senaste åren. Det finns också intresse för att använda biokol för jordförbättring, dels för att använda näringsinnehållet men också för att applicera biokol i jorden för att potentiellt uppnå långvarig kolbindning. Dock är produktionskostnaden för biokol gjort på vass mycket kostsam och kan därför inte konkurrera med fossilt kol eller andra gödselmedel jordförändringar på marknaden. Detta beror främst på råvaruhanteringen som är den dyraste delen av produktionen. Slutligen finns det för närvarande ingen skördemetod som kan mäta den mängd vass som behöver skördas för att kunna producera biokol i stor skala.

To reach the EU directives and Sweden ́s energy- and climate goals, there is a needto implement new innovative- and technical solutions in each sector. The Swedishgovernment predicts that the buildings sectors energy demand could be reduced byrenovating the existing building stock. The research examines the opportunities to implement indoor design solutionsassociated with an energy renovation measure of an existing single-family house inSweden. The research will cover a broader picture of the concept's feasibility-, addedvalues, and financial cost and benefits. This will be done within the requirements ofthe current building regulations on altering an existing building in Sweden 2021. The research outcome showed that implementing the design solution concept willconstitute a financial benefit on energy renovation measure ́s payback time. Theresult showed that one of the suggested design concepts with the energy renovationmeasures would have a payback time of 8.5 years. Besides, implementing the designsolution concept predicts several beneficial added values, e.g., environment, buildingdesign and society.

För att Sverige ska nå klimatmålet om noll nettoutsläpp av växthusgaser till år 2045 behöver bland annat mer biobränslen fasas in och fossila bränslen fasas ut och därför behövs större produktion och fler alternativ av biobränslen. Pyrolysolja är ett alternativ till biobränsle som har forskats på sedan 1970-talet men som först för några år sedan börjat produceras i större skala för användning till värmeproduktion. Först i år startades även en byggnation för produktion av pyrolysolja som ska uppgraderas till biodrivmedel av Pyrocell. Pyrolysoljan har annorlunda egenskaper och sammansättning mot andra biooljor och fossila oljor. Till exempel har pyrolysolja högt vatteninnehåll, hög viskositet och högt innehåll av syresatta komponenter vilket gör att pyrolysoljan har lågt värmevärde, är svårare att hantera och är ostabil. Karlstad Energi AB har påbörjat ett projekt för att utvärdera en integrerad pyrolysreaktor vid en befintlig kraftvärmepanna med målsättningen att i framtiden producera pyrolysolja. De är intresserade av att använda pyrolysoljan som bränsle i två av deras reservpannor för fjärrvärmeproduktion och för att få produktionen lönsam är de dessutom intresserade av att sälja pyrolysoljan som råvara till drivmedelsindustrin. Syftet med arbetet är att undersöka pyrolysoljans användbarhet i Karlstad Energis system utifrån pyrolysoljans egenskaper, åldring, förbränning och uppgradering till biodrivmedel samt jämföra pyrolysoljans egenskaper och förbränning med biobränslet de använder idag, bio100. Målen är att; (1) kartlägga och jämföra pyrolysoljans egenskaper med bio100 utifrån litteratur, (2) beräkna och bedöma viskositetsförändring samt varmhållnings och förvärmningstemperaturer av färsk och lagrad pyrolysolja utifrån litteratur, (3) beräkna förbränningsegenskaper och förbränningsprestanda vid en uttagen effekt på 30 MW i reservpannan genom simulering i Chemcad tillsammans med en uppbyggd värmeöverföringsmodell i Excel och (4) undersöka möjligheten att uppgradera pyrolysolja till biodrivmedel genom teoretisk beräkning av vätgasbehov och oljeutbyte. Pyrolysoljan undersöks med 25, 15 och 8 vikt % vatten och tillsats av 5 och 10 vikt % metanol och etanol för att stabilisera pyrolysoljan samt förbättra förbränningen. Resultaten visar på att en pyrolysolja med 8 % vatteninnehåll kan ha alltför hög viskositet för att kunna pumpas och förbrännas i rimliga varmhållnings- och förvärmningstemperaturer, medan 26 och 15 % klarar det med rimliga temperaturer, med och utan tillsats av alkohol. Vid förbränning med en uttagen effekt på 30 MW krävs ca 1,9-2,6 gånger så högt oljeflöde och ca 1,05-1,21 gånger så högt rökgasflöde för pyrolysoljorna mot bio100 (3250 kg/h respektive 42900 m3/h). Det innebär att anläggningen skulle kunna vara underdimensionerad för att få ut 30 MW vid förbränning av pyrolysolja där oljeflödet förmodligen är det begränsande flödet. Detta kräver ytterligare utredning av utrustningen. Luft-bränsle förhållandet för att uppnå 4 % syreöverskott är ca dubbelt så stort för bio100 mot pyrolysoljorna (16 mot 6,7-8,6 kg luft/kg olja). Utsläpp av stoft och NOx kan bli väldigt högt på grund av det höga ask- och kväveinnehållet och kommer förmodligen inte klara de framtida utsläppsbegränsningarna varav åtgärder kommer behövas. Verkningsgraden (baserat på det högre värmevärdet) för 8 % vatteninnehåll med 10 % etanol kommer upp i samma verkningsgrad som bio100 (91 %) mot 26 och 15 % vatteninnehåll som kommer upp i ca 84 respektive 88 %. Det teoretiskt beräknade vätgasbehovet och oljeutbytet ligger mellan ca 575-775 liter vätgas/kg pyrolysolja respektive ca 45-62 %. Överlag är tillsats av metanol det bättre alternativet för viskositeten men etanol är bättre vid förbränning och uppgradering till biodrivmedel. For Sweden to reach the goal of zero net emissions of greenhouse gases by the year 2045, more use of biofuels and less use of fossil fuels is needed and for this we need higher production and more options of biofuels. One option is pyrolysis oil which has been in research since the 1970’s but was only recently introduced to large-scale heat production. Also, this year Pyrocell have started the construction of a pyrolysis plant where the pyrolysis oil is going to be upgraded to biofuels. The pyrolysis oil has different properties and composition compared to other biooils and fossil oils. For example, it has high water content, high viscosity and high content of oxygenated compounds which makes the oil more difficult to handle, unstable and gives the oil a low heating value. Karlstads Energi AB has started a project to evaluate an integrated pyrolysis reactor to one of their existing combined heat and power plants with the objective to produce pyrolysis oil in the future. They are interested in using the pyrolysis oil as a fuel in two of their reserve boilers for district heating production and to sell as raw material to the fuel industry. The object of this study is to investigate the possibility of using the pyrolysis oil at Karlstads Energi in the meaning of properties, aging, combustion and upgrading to biofuel and to compare the properties and combustion performance with the fuel they are using today, bio100. The goals are to; (1) map and compare the properties and composition of pyrolysis oil with bio100 from literature, (2) calculate and estimate changes of viscosity and storage- and atomization temperatures of fresh and stored pyrolysis oil using data from literature, (3) calculate combustion properties and combustion performance at 30 MW power outlet from the boiler through simulation in Chemcad and a heat transfer-model in Excel and (4) investigate the possibility to upgrade pyrolysis oil to biofuel through theoretical calculation of hydrogen consumption and biofuel yield. The pyrolysis oil is investigated with 25, 15 and 8 wt% water and addition of 5 and 10 wt% methanol and ethanol to stabilize the oil and to improve the combustion. The results shows that a pyrolysis oil with 8 wt% water could have too high viscosity to be able to be pumped and combusted in reasonable temperatures while 26 and 15 wt% water have lower viscosity and can be used in reasonable temperatures, both with and without addition of alcohol. At combustion with 30 MW power output the flow of pyrolysis oil and flue gases is 1,9-2,6 times and 1,05-1,21 times higher than bio100, respectively (3250 kg/h and 42900 m3/h, respectively for bio100). This means that the facility could be undersized to be able to get 30 MW power output with pyrolysis oil, where the oil flow probably is the limiting factor. This requires further investigation of the equipment. The air-fuel-ratio to receive 4% excess oxygen in the flue gases for the pyrolysis oils is about half of that of bio100 (6,7-8,6 compared to 16 kg air/kg oil, respectively). The emissions of dust and NOx are high for the pyrolysis oils because of high content of ash and nitrogen and will probably exceed the future limitations of which measures will be needed. The efficiency (based on higher heating value) for pyrolysis oil with 8 wt% water and 10 wt% ethanol can reach the same efficiency as bio100 (91%), while 26 and 15 wt% water content reach 84 and 88%, respectively. The theoretical hydrogen consumption and biofuel yield were calculated to 575-775 L hydrogen/kg pyrolysis oil and 45-62%, respectively. Overall, addition of methanol is a better choice for the viscosity, but ethanol performs better in combustion and upgrading to biofuels.

Zinc, copper and lead are amongst the more abundant trace metals in waste fuels such as municipal solid waste and recovered waste wood. The ashes from waste fuels could contain high contents of these metals, which could be valuable but also toxic in certain environments. Oxygen carrier aided combustion, OCAC, is a novel technology for combustion of biomass and waste. Utilizing oxygen carriers could affect the fate of these metals and have implications for stability and recycling. The aim of this work is to study the fate of zinc, copper and lead during oxygen carrier aided combustion of two waste fuels utilizing ilmenite as an oxygen carrier. In total, four samples have been obtained from two different industrial fluidized bed boilers using ilmenite as bed material. Due to low concentrations, bulk analysis methods are not suitable for speciation, i.e. SEM/EDX and XRD. Hence, this investigation utilizes high resolution x-ray photoelectron spectroscopy (XPS), coupled to detailed thermodynamic modelling, with the aim of understanding trace metal speciation, distribution and phase composition. Characterization of the four samples show that iron at the surface of ilmenite particles interact with both copper and zinc to form ferrites, CuFe2O4 and ZnFe2O4. Lead, on the other hand, is more prone to end up in the fly ash as condensed PbCl2, but the mixed oxide PbTiO3 could be identified at the oxygen carrier surface. Thermodynamic calculations were shown to be in line with the identified compounds.

För att kunna möta framtida energibehov och samtidigt värna om miljön kommer det krävas att energisystemet och transportsektorn, som den ser ut idag, förändras i grunden. För att få till förändring läggs på Europeisk och nationell nivå direktiv respektive mål. Detta har lett till att man på regionala nivåer kollar över sina energibalanser och hur ens klimatpåverkan ser ut och kan minskas. En av dessa regioner är Kronobergs län i Småland som år 2050 vill bli ett Plusenergilän. Plusenergilän innebär att Kronoberg ska vara självförsörjande på sitt energibehov samt vara helt klimatneutrala. Energikontor Sydost har av regionen givits i uppdrag att följa upp de här målen, vilket sätter premisserna för det här projektet.För detta ändamål har en nutida energibalans i länet skapats för år 2019 för att utifrån denna ge en bild av de utmaningar Kronoberg kommer ställas inför, och på så sätt skapa ett framtida scenario med milstolpar för år 2030 och 2050.I rapporten skapas utifrån Energimyndighetens framtidsprognoser, ett elektrifieringsscenario där främst transport och industrisektorn i högre grad förväntas använda elenergi. Utifrån prognoserna och elektrifieringsscenariot fastslogs att Plusenergi inte uppnås år 2050 och därför föreslogs tre ytterligare åtgärder som innefattade mer vindkraft, egenproduktion av flytande biobränslen samt Bioenergy Carbon Capture and Storage. Med dessa åtgärder uppnås Plusenergilän år 2050 men som slutsats dras också att utifrån hur energibalansen såg ut år 2019, är det en lång väg för Kronobergs län att uppnå de fastställda målen till Plusenergi, och att det främst är energi inom transportsektorn och den totala tillförseln av el som är de stora parametrarna som behöver förändras i infrastrukturen. SCB, PHEV, BEV, BECC, Pyrolysolja, HDO, Plusenergilän, Scenario, Elektrifiering, Energibalans, Vindkraft, EnergyPLAN

The effects of the redox environment on acidic hydrothermal pretreatment were investigated in experiments with sugarcane bagasse (190 degrees C, 14 min) and Norway spruce (205 degrees C, 5 min). To modulate the redox environment, pretreatment was performed without gas addition, with N-2 , or with O-2. Analyses covered pretreated solids, pretreatment liquids, condensates, enzymatic digestibility, and inhibitory effects of pretreatment liquids on yeast. Addition of gas, especially O-2 , resulted in increased severity, as reflected by up to 18 percent units lower recoveries of pretreated solids, up to 31 percent units lower glucan recoveries, improved hemicellulose removal, formation of pseudo-lignin, improved overall glucan conversion, and increased concentrations of several microbial inhibitors. Some inhibitors, such as formaldehyde and coniferyl aldehyde, did not, however, follow that pattern. TAC (Total Aromatic Content) values reflected inhibitory effects of pretreatment liquids. This study demonstrates how gas addition can be used to modulate the severity of acidic hydrothermal pretreatment.

Rising environmental concerns and the imminent depletion of fossil resources have sparked a strong interest towards the production of renewable energy such as biomethane. Inclusion of alternative feedstock’s such as lignocellulosic biomass could further expand the production of biomethane. The present study evaluated the potential of a novel hybrid organosolv-steam explosion fractionation for delivering highly digestible pretreated solids from birch and spruce woodchips. The highest methane production yield was 176.5 mLCH4 gVS−1 for spruce and 327.2 mL CH4 gVS−1 for birch. High methane production rates of 1.0–6.3 mL min−1 (spruce) and 6.0–35.5 mL min−1 (birch) were obtained, leading to a rapid digestion, with 92% of total methane from spruce being generated in 80 h and 95% of that from birch in 120 h. These results demonstrate the elevated potential of the novel method to fractionate spruce and birch biomass and deliver cellulose-rich pretreated solids with superior digestibility.

Now that the EU and Sweden have adopted a new climate policy framework to regulate net carbon emission. A new concept, negative CO2 emission, has been considered to neutralize the CO2 generated from necessary consumption of fossil fuel. Biochar, as a pyrolytic product from biomass, can store carbon in a relatively stable way. Therefore, it is one of the most promising and outstanding tools for carbon sink. Biochar stability, defined as the ratio of remaining carbon in biochar after 100 years, is the most crucial factor when using biochar for carbon storage. So far, various approaches have been proposed to measure and predict biochar stability, such as elemental analysis, proximate analysis, accelerating aging methods. Each method has its pros and cons. The reliability of these methods still needs to be verified. In this project, the chemical accelerating aging method has been selected for assessing biochar stability, because this method captures both chemical and physical properties of biochar. Besides, the gas, liquid, and solid products generalized during the chemical treatment are collected and analyzed separately in order to study the oxidation mechanism. Biochar in this project is produced from miscanthus and seaweed at various pyrolysis temperature. It is found that biochar stability can be increased by enhancing pyrolysis temperature, and miscanthus biochar is more sensitive to pyrolysis temperature within the pyrolysis temperature range of 350-600℃. The highest biochar stability (73%) has been achieved with miscanthus-derived biochar produced at 550 ℃, which demonstrates high potential as carbon sequestration tool. Nu när EU och Sverige har antagit en ny klimatpolitisk ram för att reglera nettokoldioxidutsläppen. Ett nytt koncept, negativt koldioxidutsläpp, har ansetts neutralisera den koldioxid som genereras av nödvändig förbrukning av fossila bränslen. Biokol, som en pyrolytisk produkt från biomassa, kan lagra kol på ett relativt stabilt sätt. Därför är det en av de mest lovande och enastående verktyg för kolsänka. Biokolsstabilitet, definierad som förhållandet mellan återstående kol i biokol efter 100 år, är den viktigaste faktorn vid användning av biokol för kollagring. Hittills har olika metoder föreslagits för att mäta och förutsäga biokolsstabilitet, såsom elementär analys, proximate analys, accelererande åldrande metoder. Varje metod har sina för-och nackdelar. Tillförlitligheten hos dessa metoder måste fortfarande kontrolleras. I detta projekt har den kemiska accelererande åldrandemetoden valts ut för att bedöma biokolsstabilitet, eftersom denna metod fångar upp både kemiska och fysikaliska egenskaper hos biokol. Förutom, gasen, flytande, och fasta produkter generaliserade under den kemiska behandlingen samlas in och analyseras separat för att studera oxidation mekanism. Biokol i detta projekt framställs av miscanthus och tång vid olika pyrolystemperatur. Det visar sig att biokolsstabiliteten kan ökas genom att öka pyrolystemperaturen, och miscanthusbiokol är mer känsligt för pyrolystemperatur inom pyrolystemperaturområdet 350-600°C. Den högsta biokolsstabiliteten (73%) har uppnåtts medbiokol som framställts vid 550°C och som visar stor potential som kolbindningsverktyg.

Biofuels and biochemicals play significant roles in the transition towards a fossil-free society. However, large-scale biorefineries are not yet cost-competitive with their fossil-fuel counterparts, and it is important to identify biorefinery concepts with high economic performance. For evaluating early-stage biorefinery concepts, one needs to consider not only the technical performance and process costs but also the economic performance of the full supply chain and the impacts on feedstock and product markets. This article presents and demonstrates a conceptual interdisciplinary framework that can constitute the basis for evaluations of the full supply-chain performance of biorefinery concepts. This framework considers the competition for biomass across sectors, assumes exogenous end-use product demand, and incorporates various geographical and technical constraints. The framework is demonstrated empirically through a case study of a sawmill-integrated biorefinery producing liquefied biomethane from forestry and forest industry residues. The case study results illustrate that acknowledging biomass market effects in the supply chain evaluation implies changes in both biomass prices and the allocation of biomass across sectors. The proposed framework should facilitate the identification of biorefinery concepts with a high economic performance which are robust to feedstock price changes caused by the increase in biomass demand. Validerad;2020;Nivå 2;2020-09-03 (johcin)

Comprehensive knowledge concerning the behavior of phosphorus (P) during combustion is necessary to enable more efficient recovery of P from combustion ashes for agricultural purposes. To this end, parameters that influence the distribution and speciation of P in combustion ashes are important because they may influence which ash fractions are suitable for P recovery. This study aims to determine the fate of P as a result of fuel ash composition and chemical association in the fuel during fluidized bed combustion by a systemic review of previous work. The synthesis was performed by comparing scanning electron microscopy–energy-dispersive X-ray spectroscopy and X-ray diffraction chemical analyses of bed ash, fly ash particles, and deposits from fluidized bed combustion of different blends of P-poor (logging residues or wheat straw) and P-rich (sewage sludge, dried distiller’s grain with solubles, or phosphoric acid) fuels and additives. The blends were produced to have a similar ash composition but with a different P source. The distribution of P among ash fractions indicated that P is mainly found in the coarse ash fractions (bed and cyclone ash), irrespective of fuel ash composition or chemical association in the fuel. The chemical speciation of P in coarse ash fractions differed between biomass blends containing sewage sludge compared to blends with phosphoric acid or dried distiller’s grain with solubles. Phosphates in the ash from the two sewage sludge blends included predominantly Ca with minor inclusion of other cations. In contrast, ashes from the blends with phosphoric acid or dried distiller’s grain with solubles contained phosphates with a significant amount of K, Ca, and Mg. The difference in phosphate speciation could not solely be explained by the combustion conditions and the elemental composition of the ash fractions. These results show that it is necessary to consider the chemical association of P in the fuel to predict the type of phosphates that will form in fluidized bed combustion ashes.

This report presents results from the EU project AGROinLOG (Grant Agreement 727921) and especially focuses on the results from a survey looking at the current practices with straw use in Sweden as well as the farmer’s opinion on supplying straw for the production of second-generation biofuel. The survey was developed as a collaboration between LRF (Federation of Swedish farmers) RISE and Lantmännen.The reader can first read about the context within which the survey was developed and analysed. The questions and the methodology are then presented. The main part of the report presents the questionnaire results before drawing conclusions in line with the project’s objectives.The survey shows that about 60% of the straw from farmers participating in the survey, remains in the field while 40% is harvested mostly for animal production. The county of Skåne, the “ÖSÖ” region (Östergötland, Södermanland, and Örebro counties), the region including Uppsala, Stockholm and Västmanland counties, and the county of Västra Götaland have the largest potential for collection of straw for industrial processes in Sweden. However, farmers from these regions are the most concerned about the decrease of soil quality due to straw removal. The current common practices for straw handling in Sweden, including baling, collection, transport, storage and sale, are highlighted.Some interesting conclusions are drawn concerning the logistics needed for the handling of straw for the biobased industry. Moreover, the answers from the survey give some insights concerning a potential “straw contract” between Lantmännen and the farmers. The report also highlights the aspects to be further researched.More information concerning the Swedish contribution to the AGROinLOG project can be found in the public report AGROinLOG (2020a). EU project AGROinLOG (Grant Agreement 727921)

Research about Hybrid Upflow-Anaerobic Filter (HU-AF) integrated technology for bioenergy generation from vinasse was conducted. Modification of influent flow system, expansion of filter contact area and addition of gas accumulator for biogas collection were used to enhance the degree of vinasse biodegradation biogas generation, and yet to shorten the hydraulic retention time (HRT). Hybrid Upflow-Anaerobic Filter (HU-AF) integrated technology was a double dome reactor with sequential connection, with up-flow inlet distribution inside the reactor. Total volume of HU-AF was 60 m3. A mixing and a feeding chamber, with volume 3 m3, each were installed before HU-AF reactor. A reservoir chamber with volume of 6 m3 was added after HU-AF reactor. OLR was 2.04 kg COD/day. A methanogenic seed sludge derived from anaerobic lagoon. The experiment was carried out initially by seeding, acclimatization and adaptation of microorganisms inside the reactor. A feeding ratio of vinasse: water = 1:4, and initial pH of 6 were adjusted. Result showed that Full-scale HU-AF integrated technology was able to degrade COD with maximum degradation of COD 55.45% at pH 7.1, and shorten the HRT into 32 days. Biogas production was consisted of 57.21 % methane, 13.98% CO2 and various gases 28.1% (H2S, VOC, CO and H2O). This experiment showed that HRT was shorter than conventional reactor.

Nivåerna av växthusgaser i atmosfären har ökat drastiskt de senaste århundradet, till följd av mänsklig aktivitet. Det krävs en stor omställning för oss människor om klimatförändringarna ska motverkas och för att konsekvenserna för planeten inte ska bli allt för stora. Koldioxid är en av de viktigaste växthusgaserna och skogen är en viktig del i balansen av koldioxid i atmosfären genom att växter och träd binder in koldioxid och lagrar biogent kol i biomassan. Rundvirke kan användas för att producera en mängd olika produkter med olika användningsområden och varierande livslängd och det finns både globala och nationella mål som stödjer ett arbete för en minskad klimatpåverkan med skogens resurser som verktyg. Syftet med examensarbetet var att analysera inbindningen av biogent kol i det årliga tillskottet av träbaserade produkter från svensk skogsindustri, för att sedan undersöka potentialen att öka tiden för inbindning av det biogena kolet. FN:s klimatpanel (IPCC) har tagit fram en generell metod för att beräkna lagringen av kol i skördade träprodukter och beräkningarna bygger på tre produktkategorier, vilka är sågade trävaror, spånskivor och papper och kartong. Detta examensarbete har utvidgat FN:s klimatrapportering genom att studera totalt sexton produktkategorier. Flödet av biogent kol studerades genom en materialflödesanalys, som bygger på massbalans mellan ”inputs” och ”outputs” i ett system. Systemet studerades från det att råvara förbrukas till dess att produkterna går som avfall och förbränns. Statistik över råvaruförbrukning inom sågverksindustrin och massaindustrin, samt produktionsmängd av fibermassa och träbaserade produkter användes i analysen. En stor volym biomassa går dessutom direkt till förbränning och ger bioenergi. Resultatet visade att sågade trävaror från sågverksindustrin har längst medellivslängd och binder även in störst mängd biogent kol. Biobränslen har kortast medellivslängd, och koldioxid frigörs till atmosfären på mycket kortast tid. Enligt detta examensarbete innehåller träbaserade produkter från Sverige 29,0 miljoner ton koldioxid årligen. Tre strategier att förlänga inbindningstiden av biogent kol studerades, vilka är förlängd livslängd för produkter, kaskadanvändning och Bio-Energy with Carbon Capture and Storage (BECCS). Att förlänga livslängden för produkter innebär att återvinning av exempelvis cellulosabaserade textilier införs. Kaskadanvändning innebär att skogsindustrin primärt ska producera långlivade produkter och undvika att biomassa direkt går till förbränning. BECCS bygger på att träden binder in kol i sin biomassa och när en träbaserad produkt förbränns pressas frigjord koldioxid ned i marken och lagras. BECCS bedöms vara den strategi som är mest avancerad. The levels of greenhouse gases have increased drastically over the past hundred years as a result of human activity. Major actions are needed to counter climate change, if the consequences are not to be too great. Carbon dioxide is one of the most important greenhouse gases and the forest is an important part of the balance of carbon dioxide in the atmosphere, by the fact that plants and trees bind carbon dioxide and store biogenic carbon in the biomass. Roundwood can be used to produce a variety of products with different applications and varying life spans and there are both global and national goals that support a work to reduce climate change with forest resources as tools. The aim of the thesis was to analyse the storage of biogenic carbon in the annual addition of wood-based products from the Swedish forest industry, and then to investigate the potential to increase the time of storage. The UN Climate Panel (IPCC) has developed a general method for calculating the storage of carbon in harvested wood products and the calculations is based on three product categories, which are sawn wood, wood-based panels and paper and paperboard. This thesis has expanded the UN climate reporting by studying a total of sixteen product categories. The flow of carbon was studied using a material flow analysis, which is based on the mass balance of inputs and outputs in a system. The system was studied from the raw material being consumed until the products are defined as waste and incinerated. The calculations were based on statistics on raw material consumption in the sawmill industry and the pulp and paper industry, as well as production volume of fibre pulp and wood-based products. A large volume of biomass also goes directly to incineration and provides bioenergy. The binding time of biogenic carbon was analysed to explore the potential of increasing the binding time, using different strategies. Sawn timber products from the sawmill industry have the longest average life span and also bind the highest amount of biogenic carbon. Biofuels have the shortest average life span, which means that carbon dioxide is released into the atmosphere rapidly. A total of 29.0 million tonnes of carbon dioxide are stored in wood-based products annually, according to this study. Three strategies to extend the storage time of biogenic carbon were studied in this study, which were extended life span of the products, cascading wood use and so called BECCS. To extend product life means introducing recycling of, for example, cellulose-based textiles. Cascading wood use means that the forest industry primarily produce long-lived products and avoid biomass going directly to incineration. BECCS is based on the fact that trees bind carbon dioxide in their biomass and when wood-based product is incinerated, the carbon dioxide is stored in the ground. BECCS is considered to be the most advanced strategy, of the three.

In the continual desire to reduce the environmental footprints of human activities, research efforts to provide cleaner energy is increasingly becoming vital. The effect of climate change on present and future existence, sustainable processes, and utilizations of renewable resources have been active topics within international discourse. In order to reduce the greenhouse gases emissions from traditional materials and processes, there has been a shift to more environmental friendly alternatives. The conversion of biomass to bioenergy, including biofuels has been considered to contribute to the future of climate change mitigation, although there are concerns about carbon balance from forest utilization. Bioenergy accounts for more than one-third of all energy used in Sweden and biomass has provided about 60% of the fuel for district heating. Apart from heat and electricity supply, the transport sector, with about 30% of global energy use, has a significant role in a sustainable bioenergy system. This review presents the state of the art in the Swedish bioenergy sector based on literature and Swedish Energy Agency’s current statistics. The review also discusses the overall bioenergy production and utilization in different sectors in Sweden. The current potential, challenges, and environmental considerations of bioenergy production are also discussed Formas project 942-2016-2, 2017-21 Kamprad Family Foundation project 20160052, 2017-19

För att uppnå Sveriges energi- och klimatmål för energieffektivisering och koldioxidutsläpp måste nya tekniker och innovationer undersökas för att bidra till att göra energianvändningen mer effektiv i bostadssektorn. Ett alternativ för att uppnå målen är att använda ett integrerat värmesystem. De integrerade värmesystemen som undersöks i den här rapporten innefattar värmeåtervinning via ventilation som komplement till fjärrvärme, vilket jämförs med uppvärmning av bara fjärrvärme. De valda integrerade värmesystemen från HögforsGST kommer undersökas ur ett livscykelutsläpps- och primärenergiperspektiv. Analysen ska utreda om systemen bidrar till att sänka energianvändningen och hur stora livscykelutsläppen av koldioxidekvivalenter är för värmesystemen i två olika fastigheter. Slutsatsen för rapporten var att de valda integrerade värmesystemen var mer energieffektiva, då de använde mindre primärenergi, oavsett fall för elproduktion. De använde även 36 procent och 32,8 procent mindre producerad energi, för Lärlingen respektive Rundeln. Fjärrvärmesystemet medförde istället lägre totala livscykelutsläpp av koldioxidekvivalenter än det integrerade värmesystemen, för de flesta fallen av elproduktion. För att få ett mer tillförlitligt resultat bör de integrerade värmesystemen granskas under en längre tidsperiod för att vidare analysera använd primärenergi och livscykelutsläpp.

This thesis has investigated the effects of running the two full scale biogas digesters at Slottshagen wastewater treatment plant at 34 °C compared to 37 °C, in terms of process stability, biogas production and energy savings with the aim of saving energy and money by not heating the digesters as much. The main objective was to investigate whether it is at all possible to operate the biogas process at 34 °C or if the process becomes inhibited or otherwise unstable. If the process could be operated at 34 °C it might mean savings of both energy and money, provided that there is still a sufficient production of biogas.The experiment lasted for three months and investigated the short-term effects of the reduction of temperature. The process was monitored closely, and samples from the reactors were collected and analysed twice a week to ensure the stability of the biogas process. Several parameters were monitored online, the biogas production and methane content amongst others. Other parameters were calculated, such as the degree of degradation and specific methane production. This was done to ensure process stability and a sufficient production of biogas. The energy balance was calculated to evaluate if energy was saved by lowering the temperature in the digesters.The results show that the biogas process does remain stable at 34 °C while still producing a satisfactory amount of biogas during the short time of the experiment. Calculations show that both energy and money has been saved during the experiment. However, the system is largely dependent on seasonal variations, therefore further studies over a longer time period would be desirable. During the course of the thesis it has also become evident that the biogas process at Slottshagen is irregular in several aspects, and that it would be beneficial to even the process out, especially with regards to the hydraulic retention time. Making the process more even would enable further improvements to be made and simplify interpretations and comparisons of processstability data.

Over 640 million people in Africa are expected to rely on solid-fuels for cooking by 2040. In Western Kenya, cooking inefficiently persists as a major cause of burden of disease due to household air pollution. Efficient biomass cooking is a local-based renewable energy solution to address this issue. The Life-Cycle Assessment tool Simapro 8.5 is applied for analyzing the environmental impact of four biomass cooking strategies for the Kisumu County, with analysis based on a previous energy modelling study, and literature and background data from the Ecoinvent and Agrifootprint databases applied to the region. A Business-As-Usual scenario (BAU) considers the trends in energy use until 2035. Transition scenarios to Improved Cookstoves (ICS), Pellet-fired Gasifier Stoves (PGS) and Biogas Stoves (BGS) consider the transition to wood-logs, biomass pellets and biogas, respectively. An Integrated (INT) scenario evaluates a mix of the ICS, PGS and BGS. In the BGS, the available biomass waste is sufficient to be upcycled and fulfill cooking demands by 2035. This scenario has the lowest impact on all impact categories analyzed followed by the PGS and INT. Further work should address a detailed socio-economic analysis of the analyzed scenarios.

This thesis is a part of a collaboration between Höganäs AB and Luleå University of Technology, aiming at replacing fossil process coal with bio-coal in their sponge iron process. The difference in gasification reactivity, i.e. reaction rate, between fossil coals and bio-coals is the major challenge in the endeavor to decrease the climate impact of the existing process. The goal of this thesis is to develop a model of reaction rate for bio-coals in relation to particle size distribution. Different particle size distributions were combined and tested to see how that affects the effective reaction rate. Within the scope of this work, gasification reactivities of different materials, including coal, cokes, and bio-coals, were determined. Three bio-coals were selected to study the effect of particle size distribution on reactivity. Kinetic parameters were determined by using thermogravimetric analysis in the temperature range of 770-850 °C while varying CO2 partial pressure between 0.1-0.4 atm. The effect of particle size on the reaction rate was investigated by using particles with diameter between 0.18 and 6.3 mm. The effect of particle size distribution on the reactivity of bio-coal in a packed bed was carried out in a macro thermogravimetric reactor with a constant bed volume of 6.5 cm3 at 980 °C and 40% (vol.) of CO2. The experimental investigation in three different rate-limiting steps was done for one bio-coal sample, i.e. Cortus Bark bio-coal. The activation energy of the bio-coal was 187 kJ mol-1, and the reaction order was 0.365. For the internal diffusion control regime, an increase in particle size resulted in low reaction rate. The effective diffusivity calculated from the Thiele modulus model was 1.41*10-5 m2 s-1. For the external diffusion control regime, an increase in particle size increased the reaction rate up to a certain point where it plateaued at >1 mm. By choosing two discrete particle size distributions, where a smaller average distribution can fit into a larger average distribution the reaction rate was lowered by 30% compared to only using a single narrow particle size distribution. This solution decreased the difference of apparent reaction rate in a packed bed between the bio-coal and anthracite from 6.5 times to 4.5 times. At the moment the model is not generalized for all bio-coals. However, the developed methodology can be routinely applied to assess the different bio-coal samples. One possible error can be that pyrolysis influences the gasification rate for bio-coal that is pyrolyzed below the temperature of the gasification test. There is a clear correlation between particle size distributions, bulk density, and apparent reactivity. By mixing two distributions the reaction rate of Cortus Bark was reduced from 6.5 times the reaction rate of anthracite to 4.5.

Thermal conversion of ash-rich fuels in fluidized bed systems is often associated with extensive operation problems caused by the high amount of reactive inorganics. This paper investigates the behavior of wheat straw lignin—a potential renewable fuel for dual fluidized bed gasification. The formation of coherent ash residues and its impact on the operation performance has been investigated and was supported by thermochemical equilibrium calculations in FactSage 7.3. The formation of those ash residues, and their subsequent accumulation on the surface of the fluidized bed, causes temperature and pressure fluctuations, which negatively influence the steady-state operation of the fluidized bed process. This paper presents a detailed characterization of the coherent ash residues, which consists mostly of silica and partially molten alkali silicates. Furthermore, the paper gives insights into the formation of these ash residues, dependent on the fuel pretreatment (pelletizing) of the wheat straw lignin, which increases their stability compared to the utilization of non-pelletized fuel.

During combustion of biomass, particulate matter is emitted, which has severe health impacts on humans. The company ITK Envifront has developed a scrubber technology that cleans the flue gas while also recovering the flue gas energy, increasing the efficiency of the combustion plant. In this thesis, a simulation model was built in MATLAB according to the Finite Element Method. Validation of the model against 3 different facilities showed reasonable accuracy with a tendency to overestimate the scrubber heat recovery and a mean prediction deviation of approximately 7 %. The model was then used to make suggestions for process optimization. An increase of funnel height, and number of spray nozzles could increase the scrubbers heat recovery with up to 7 % and 8 %, respectively. Addition of moisture to the flue gas through evaporation of water droplets had the potential to increase scrubber efficiency with 10 %, and usage of the highest setting of the adjustable nozzle bank showed the potential to increase the efficiency with up to 5 % compared to the mid-setting. Furthermore, the process parameters of a scrubber with optimized running conditions, was compared to a scrubber with the current running conditions, through running of the developed model. The optimized running conditions showed an increase in scrubber efficiency with up to 14 %, resulting in an increase in scrubber heat recovery of approx. 90 kW at a boiler load of 3 MW. As a final conclusion, the developed model shows great potential to be used to as a toolbox to further investigate and optimize the scrubber design and operation. As a future work, it would be interesting to further model its performance regarding particle removal.

Carbamazepine (CBZ), a widely used pharmaceutical compound, is one of the most detected drugs in surface waters. The purpose of this work was to identify an active and durable catalyst, which, in combination with an ozonation process, could be used to remove CBZ and its degradation products. It was found that the CBZ was completely transformed after ozonation within the first minutes of the treatment. However, the resulting degradation products, 1-(2-benzaldehyde)-4-hydro-(1H,3H)-quinazoline-2-one (BQM) and 1-(2-benzaldehyde)-(1H,3H)-quinazoline-2,4-dione (BQD), were more resistant during the ozonation process. The formation and degradation of these products were studied in more detail and a thorough catalytic screening was conducted to reveal the reaction kinetics of both the CBZ and its degradation products. The work was performed by non-catalytic ozonation and with six different heterogeneous catalysts (Pt-MCM-41-IS, Ru-MCM-41-IS, Pd-H-Y-12-EIM, Pt-H-Y-12-EIM, Pd-H-Beta-300-EIM and Cu-MCM-41-A-EIM) operating at two temperatures 20 &deg, C and 50 &deg, C. The influence of temperature on degradation kinetics of CBZ, BQM and BQD was studied. The results exhibited a notable difference in the catalytic behavior by varying temperature. The higher reactor temperature (50 &deg, C) showed a higher activity of the catalysts but a lower concentration of dissolved ozone. Most of the catalysts exhibited higher removal rate for BQM and BQD compared to non-catalytic experiments in both temperatures. The Pd-H-Y-12-EIM catalyst illustrated a higher degradation rate of by-products at 50 &deg, C compared to other catalysts.