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Lithium iron phosphate batteries (LFP), widely used as power sources, are forecasted to reach the terawatt-hour scale, inevitably leading to battery waste and expediating the urgency for effective recycling processes for LFP. The modern recycling methodologies based on material recovery face significant economic, environmental, and energy consumption challenges. This research attempts to resolve these challenges by providing direct cathode regeneration based on the principles of an external short-circuit to replenish lithium lost in the spent cathode with lithiated materials (LiC6, Li metal). Given that most active lithium loss in the cathode is caused by the growth of the solid electrolyte interphase rather than structural damage, restoring the lost lithium can revitalize a spent cathode battery’s electrochemical performance to a near-original state. The lithium loss in LFP cathodes ranging from 20% to 80% was renewed by supplementing lithium. Relithiation of 10Ah commercial LFP spent cathode showed revitalized electrochemical performance. Compared to the modern recycling methods, direct cathode regeneration improves the economic benefits of recycling by 33%, decreases energy consumption by 48%, and reduces carbon emissions by 62%. Direct cathode regeneration provides a scaffold for the next generation of recycling methods to improve recycling efficiency while reducing their environmental footprint.

Polymer electrolyte fuel cells occupy a key position in implementing the hydrogen economy on a global scale. However, assessments of cost, availability and sustainability of materials currently used to manufacture state-of-the-art fuel cell stacks have given cause for concern. Platinum and platinum-group metals are prohibitively expensive and of low abundance. The benchmark ion-conductive polymer NafionTM and related perfluorosulfonic acid-based polymers are difficult to synthesize and environmentally persistent to extreme degrees. Graphitic and carbon composite bipolar plates are unsuitable for mass production and have low recycling potential. In the compiled works, alternative materials were evaluated both for the acidic and alkaline variations of polymer electrolyte fuel cells. Electrochemical characterization was carried out in single cell tests with a focus on finding the limitations in terms of ohmic, charge transfer and transport resistances in the cell, through polarization and impedance measurements. Carbon coated stainless steel bipolar plates were tested operando in a proton exchange membrane fuel cell (PEMFC) under realistic conditions based on the New European Drive Cycle. Observed trace metal contamination of the MEA was linked to metal dissolution from coating defects caused by manufacturing (Paper I). A theoretical understanding of observed metal dissolution was confirmed experimentally and a concept for preventing metal dissolution was developed for PEMFC bipolar plates (Paper II). The developed concept was extended to uncoated stainless steel bipolar plates and tested successfully for three stainless steel types in operando PEMFC (Paper III) Anion exchange polymers based on poly(arylene piperidinium) (PAP) were tested as both membranes and ionomers in a comparative study with a commercial reference material, showing higher performance and the significance of ionomer-carbon support interactions (Paper IV). PAP-based ionomers with varying ion exchang, Bränsleceller med polymerelektrolyt har en avgörande roll för implementering av vätgasekonomin globalt. Faktorer som kostnad, tillgänglighet och miljöpåverkan av material som för närvarande används i moderna bränsleceller är dock ett bekymmer. Platina och platinagruppmetaller är dyra och sällsynt förekommande. Den dominerande jonledande polymeren NafionTM och liknande perfluorsulfonsyra-baserade polymerer är krävande att syntetisera och svårnedbrytbara i naturen. Bipolära plattor av grafit och kolkomposit är olämpliga för massproduktion och har låg återvinningspotential. I avhandlingens sammanställda arbeten utvärderades alternativa material både för de sura (PEMFC) och de alkaliska (AEMFC) varianterna av polymerelektrolytbränsleceller. Elektrokemisk karakterisering med polarisations- och impedansmätningar genomfördes i enkelceller för att studera begränsningarna vad gäller laddningsöverföring samt ohmska och transportrelaterade förluster i cellen. Kolbelagda bipolära plattor av rostfritt stål undersöktes in operando i en PEMFC under realistiska förhållanden baserade på en standardiserad europeisk driftcykel. Spår av metalljoner i cellkomponenterna observerades efter test och kopplades till metallupplösning från defekter orsakade vid tillverkningen (Paper I). Upplösningen visade sig bero på potentialgradienter som uppstod vid förändringar i gassammansättningen och kunde undvikas med bättre reglerade flöden (Paper II). Tre typer av rostfritt stål utan kolbeläggning jämfördes i operando PEMFC med belagda bipolära plattor Inte i något av fallen påvisades någon metalljonupplösning(Paper III). Anjonbytarpolymerer baserade på poly(arylenpiperidinium) (PAP) undersöktes både som membran och jonomer. I en jämförande studie med ett kommersiellt Aemion-material visade PAP högre prestanda. Vidare visade studien att interaktionen mellan jonomer och bärarkol hade betydelse för prestandan (Paper IV). PAP-baserade jonomerer med varierande jonbyteskapacitet studerades för att optime, QC 20231218

Defibration of wood chips in high-yield pulping such as CTMP production involves sulfonation of wood chips using (Na2SO3). When aiming to improve product properties, one key issue to investigate is the evenness of the sulfonation, i.e., the distribution of the sulfite (SO32-) ions. The challenge is that the inner parts of the wood chips absorb much less sodium sulfite than the outer parts. As a result, less sulfonated wood fibers have different bonding properties. It is likely that the efficiency and evenness of fiber separation in a chip refiner depend greatly on how evenly the chips have been sulfonated. Uneven sulfonation then results in higher shives (unseparated fibers) content which impairs product properties. We suggest a laboratory-scale miniaturized X-ray fluorescence (XRF) scanner for measuring sulfur distribution in the wood chips on-site. By minimizing the differences in sulphonate content between fibers, we can minimize the requirement for sulfite (SO32-) dosage to a certain degree of fiber separation, thereby reducing the total amount of electricity used in chip refining. There has been a significant improvement in commercial XRF microscopy scanners over the last few years, but the spatial resolutions achieved are insufficient. We have developed an XRF scanner optimized for sulfur fluorescence energies [1], and further continued this development by implementing frontier technology polycapillary X-ray optics. We present spatial resolution measurements and discuss the relevance and usability of the proposed measurement methodology to demonstrate its performance. [1] Rahman, H., et.al, ACS Omega 2022, 7, 51, 48555–48563, DOI: 10.1021/acsomega.2c07086

Defibration of wood chips in high-yield pulping such as CTMP production involves sulfonation of wood chips using (Na2SO3). When aiming to improve product properties, one key issue to investigate is the evenness of the sulfonation, i.e., the distribution of the sulfite (SO32-) ions. The challenge is that the inner parts of the wood chips absorb much less sodium sulfite than the outer parts. As a result, less sulfonated wood fibers have different bonding properties. It is likely that the efficiency and evenness of fiber separation in a chip refiner depend greatly on how evenly the chips have been sulfonated. Uneven sulfonation then results in higher shives (unseparated fibers) content which impairs product properties. We suggest a laboratory-scale miniaturized X-ray fluorescence (XRF) scanner for measuring sulfur distribution in the wood chips on-site. By minimizing the differences in sulphonate content between fibers, we can minimize the requirement for sulfite (SO32-) dosage to a certain degree of fiber separation, thereby reducing the total amount of electricity used in chip refining. There has been a significant improvement in commercial XRF microscopy scanners over the last few years, but the spatial resolutions achieved are insufficient. We have developed an XRF scanner optimized for sulfur fluorescence energies [1], and further continued this development by implementing frontier technology polycapillary X-ray optics. We present spatial resolution measurements and discuss the relevance and usability of the proposed measurement methodology to demonstrate its performance. [1] Rahman, H., et.al, ACS Omega 2022, 7, 51, 48555–48563, DOI: 10.1021/acsomega.2c07086

Återvinning av litiumjonbatterier (LIB) är avgörande på grund av kritiska råmaterialreserver och miljöhänsyn vid kassering. Hydrometallurgisk LIB-återvinning, en framstående industriell teknik, står inför kostnadseffektivitets- och komplexitetsutmaningar. Samtidig kristallisering visar lovande för effektivisering av återvinning genom att extrahera föreningar från förbrukad batterilut med flera komponenter, vilket kräver hög renhet och effektiv kristallseparation. Detta innebär emellertid att man förhindrar oönskade polykristallina partiklar och samkristaller.Kristallisering är vanligt vid LIB-återvinning, men vanligtvis från enkomponentlösningar för att undvika föroreningar. Kärnbildningskontroll, särskilt i flerkomponentlösningar, är fortfarande utmanande, vilket påverkar industriell effektivitet. Sådd, en vanlig kontrollmetod, inducerar ofta oavsiktliga polykristallina partiklar och vätskeinneslutningar, som understuderas på grund av experimentella begränsningar. Microfluidics erbjuder ett värdefullt verktyg för att studera kristallisationskinetik, växla från utrustningsbaserad till prediktiv fysikalisk-kemisk design. Förbättrad blandning och värmeväxling gör den idealisk för kärnbildningsforskning under kristallisation. Denna avhandling fokuserar på avgörande aspekter av samtidig kristallisation. Huvudsyftet är att utveckla en optimerad mikrofluidisk design och simulera mikrofluidikkanalen för att bestämma initiala processparametrar för experiment samt att få det mest förutsägbara området för kristallbildning inom mikrofluidik. Utmaningar i de mikrofluidiska kristallisationssystemen, såsom kanalblockering, som lätt kan uppstå på grund av kristallbildning eller agglomerationer, har tyvärr begränsat de experimentella resultaten. Icke desto mindre kommer denna avhandling att stödja ytterligare experiment med mikrofluidikanordningen under mikroskopi som kommer att hjälpa till att övervinna dessa utmaningar. Arbete med att minska begränsningarna i denna avhandling kan, Recycling lithium-ion batteries (LIB) is essential due to critical raw material reserves and environmental concerns during disposal. Hydrometallurgical LIB recycling, a prominent industrial technology, faces cost-efficiency and complexity challenges. Simultaneous crystallization shows promise for streamlining recycling by extracting compounds from multicomponent spent battery liquor, demanding high purity and effective crystal separation. However, this entails preventing unwanted polycrystalline particles and cocrystals. Crystallization is common in LIB recycling, but usually from single-component solutions to avoid impurities. Nucleation control, especially in multicomponent solutions, remains challenging, affecting industrial efficiency. Seeding, a common control method, often induces unintended polycrystalline particles and fluid inclusions, which are understudied due to experimental limitations. Microfluidics offers a valuable tool for studying crystallization kinetics, shifting from equipment-based to predictive physical-chemical design. Enhanced mixing and heat exchange make it ideal for nucleation research during crystallization. This thesis focuses on crucial aspects of simultaneous crystallization. The main objective is to develop an optimized microfluidic design and simulate the microfluidic channel to determine initial process parameters for experimentation as well as to get the most predictable region of crystal formation within microfluidics. Challenges in the microfluidic crystallization systems, such as channel blockage, which can easily occur due to crystal formation or agglomerations, have unfortunately limited the experimental results. Nonetheless, this thesis will support the further experimentation of the microfluidics device under microscopy which will help to overcome these challenges. Work on reducing the limitations of this thesis can assist in understanding the multicomponent crystallization in real-time and indeed, the necessary setup and i

Kolfiber CF kan användas som positiv elektrod i strukturella batterier om de beläggs med ett aktivt material, såsom litiumjärnfosfat LFP. Fördelen med att använda kolfibrer som elektroder är att de samtidigt kan bära mekanisk belastning och lagra elektrisk energi. Det finns flera tekniker för att belägga kolfibrerna. I denna rapport kommer en jämförelse att göras av fibrer som belagts med elektroforetisk deponering, sprutbeläggning och pulverimpregnering. Elektrokemisk karakterisering kommer att avgöra och utvärdera prestandan hos dessa tre tekniker. Cellerna som monterades med sprutbeläggda och pulverimpregnerade prover visade de högsta kapaciteterna, 141 mAh/g vid C/10 respektive 139 mAh/g vid C/14. Vidare testning utfördes på de pulverimpregnerade proverna för att studera elektriska egenskaper och beteende, såsom elektrokemisk impedansspektroskopi EIS, cyklisk voltammetri CV och långtids-cykling. Svepelektronmikroskop SEM analys genomfördes för att observera ytmorfologin och förstå hur de elektrokemiska testerna kan påverka fibrernas yta., Carbon Fibres (CF) can be used as the positive electrode in structural batteries if they are coated with an active material such as Lithium Iron Phosphate Oxide (LFP). The advantage of using carbon fibres as electrodes is that they simultaneously can carry the mechanical load and store electrical energy. There are several techniques to coat the carbon fibres. In this report, a comparison will be made on fibres coated using electrophoretic deposition, spray coating and powder impregnation. Electrochemical characterisation will determine and evaluate the performance of these three techniques. Cells assembled with spray-coated and powder-impregnated samples delivered the highest capacities, 141 mAh/g at C/10 and 139 mAh/g at C/14, respectively. Further testing was conducted on the powder-impregnated samples to study the electrical properties and behaviour, such as Electrochemical Impedance Spectroscopy (EIS), Cyclic Voltammetry (CV) and long-term cycling. Scanning Electron Microscopy (SEM) analysis was performed to see the surface morphology and understand how electrochemical testing can affect the surface of the fibres.

The article discusses the suitability of several existing empirical models for determining the safe separation distances (SSDs) for waste fuels. Contour plots of SSDs are generated based on isotropic thermal radiation model for safely storing municipal solid waste (MSW) bales under different storage settings and the plots can be employed for routine hazard assessment purposes. Further, experimental design technique was employed, and orthogonal test matrices were generated to conduct the experiments for studying the combustion dynamics of the primary fire under the influence of storage settings of surrounding fuel units. Main and interaction effects of various storage parameters (e.g., height of adjacent fuel sources, clearance between fuel sources and array size) on the response variables (flame height and burn out time) was studied. A list of appropriate measures for minimising the risk of secondary fires at MSW bale storage sites are provided., Prevention and Mitigation of Waste Fires

Novel mixed matrix polymeric membranes were prepared by incorporating self-produced zinc oxide coated by polyaniline (ZnO-PANI) nanoparticles into polyethersulfone (PES) matrix using phase inversion method. Nanoparticles were synthesized, characterized and incorporated in PES matrix with loadings from 0.05 to 0.6 wt%. ZnO-PANI demonstrated effectiveness as a low-cost adsorbent, especially at a loading of 0.2 wt%. ZnO-PANI was used for adsorbing total phenolic compounds (TPC) from olive leaf extract (OLE) at different initial adsorbate concentration (49.92–466.59 mg/L) and pH (2−6). ZnO-PANI proved to be an effective and low-cost adsorbent to remove TPC from OLE. Langmuir model described the adsorption of TPC better than Freundlich model. Effect of incorporated nanoparticles on membranes morphology and hydrophilic properties studied using contact angle measurement, water content, membrane pore size and porosity, SEM, FTIR and pure water flux. Prepared membranes showed a significant increment in porosity, pore size and hydrophilicity by addition of ZnO-PANI in the casting solution up to 0.2 wt%. This led to a considerable improvement in permeability, which decreased with higher additive concentration. During OLE filtration tests (10–30 bar) using bare PES and 0.2 wt% ZnO-PANI/PES membranes, 0.2 wt% ZnO-PANI/PES showed the highest permeate flux and good TPC rejection (83–87%). Bare PES exhibited impressive TPC value rejections (85–92%) and better fouling resistance. Using 0.2 wt% ZnO-PANI achieved a balanced permeate flux and TPC rejection. The research emphasizes the practical applicability of these membranes in various industries due to their enhanced efficacy in removing phenolic compounds from natural extracts, offering a balanced approach between permeate flux and TPC rejection.

Lithium iron phosphate batteries (LFP), widely used as power sources, are forecasted to reach the terawatt-hour scale, inevitably leading to battery waste and expediating the urgency for effective recycling processes for LFP. The modern recycling methodologies based on material recovery face significant economic, environmental, and energy consumption challenges. This research attempts to resolve these challenges by providing direct cathode regeneration based on the principles of an external short-circuit to replenish lithium lost in the spent cathode with lithiated materials (LiC6, Li metal). Given that most active lithium loss in the cathode is caused by the growth of the solid electrolyte interphase rather than structural damage, restoring the lost lithium can revitalize a spent cathode battery’s electrochemical performance to a near-original state. The lithium loss in LFP cathodes ranging from 20% to 80% was renewed by supplementing lithium. Relithiation of 10Ah commercial LFP spent cathode showed revitalized electrochemical performance. Compared to the modern recycling methods, direct cathode regeneration improves the economic benefits of recycling by 33%, decreases energy consumption by 48%, and reduces carbon emissions by 62%. Direct cathode regeneration provides a scaffold for the next generation of recycling methods to improve recycling efficiency while reducing their environmental footprint.

Defibration of wood chips in high-yield pulping such as CTMP production involves sulfonation of wood chips using (Na2SO3). When aiming to improve product properties, one key issue to investigate is the evenness of the sulfonation, i.e., the distribution of the sulfite (SO32-) ions. The challenge is that the inner parts of the wood chips absorb much less sodium sulfite than the outer parts. As a result, less sulfonated wood fibers have different bonding properties. It is likely that the efficiency and evenness of fiber separation in a chip refiner depend greatly on how evenly the chips have been sulfonated. Uneven sulfonation then results in higher shives (unseparated fibers) content which impairs product properties. We suggest a laboratory-scale miniaturized X-ray fluorescence (XRF) scanner for measuring sulfur distribution in the wood chips on-site. By minimizing the differences in sulphonate content between fibers, we can minimize the requirement for sulfite (SO32-) dosage to a certain degree of fiber separation, thereby reducing the total amount of electricity used in chip refining. There has been a significant improvement in commercial XRF microscopy scanners over the last few years, but the spatial resolutions achieved are insufficient. We have developed an XRF scanner optimized for sulfur fluorescence energies [1], and further continued this development by implementing frontier technology polycapillary X-ray optics. We present spatial resolution measurements and discuss the relevance and usability of the proposed measurement methodology to demonstrate its performance. [1] Rahman, H., et.al, ACS Omega 2022, 7, 51, 48555–48563, DOI: 10.1021/acsomega.2c07086

To evaluate the performance of evaporation systems, performance parameters such as overall heat transfer coefficient and evaporation rate need to be evaluated. These parameters are difficult measure and therefore need to be calculated using other measured data. Alfa Laval Technologies AB have evaporation systems connected to the cloud that record measured data for evaluation. In this degree project 3 models for 3 different evaporation systems, a 1- effect system, a 2-effect system, and a 3-effect system, were developed in python. These models should be able to process the measured data and with it calculate and deliver information about system performance. The models were based on simple dynamic mass & energy balances for an evaporation system that were solved using the python function ”scipy.ompimize.minimize” in the python package ”scipy”. In the end the models all models fulfil the requirements however, the 1-effect system cannot collect data from the cloud and can only be run with a specific set of measured data points. All systems were validated by comparing model results to validated results, the 1-effect system using measured data and the 2- and 3-effect systems using an existing program for determining system performance. The validation showed that the 2-effect models results were very accurate. The model results for the 1- and 3-effect systems were less accurate but still okay., Creating a model that continuously gives insight to evaporator performance. Evaporation is method used in the industry to concentrate liquids. It is a energy intensive process and it is therefore important that it is run efficiently. Looking at performance parameters gives a good insight to evaporator efficiency. These parameters are not always easily measured and need to be calculated using other measured data. It is therefore useful to have a model that does this continuously and can handle a lot of data at once. Evaporator systems can have very different designs. Generally, an evaporator consists of a heat exchanger where a liquid stream is evaporated by heat transfer from condensing steam, and a separation chamber where the evaporated vapour is separated from the concentrated liquid. This is called a single-effect evaporator. If the evaporated vapour is used to heat another single-effect evaporator it is called a multi-effect evaporator. Multi-effect evaporators can consist of 2 or more effects in succession. In this degree project 3 models for 3 different evaporator systems were developed, tested, and validated. A model for a 1-effect system, one for a 2-effect system and one for a 3-effect system. The models were meant to calculate the performance parameters of overall heat transfer coefficient (OHTC), how well the heat in the heating media is transferred to the liquid feed stream, and evaporation rate, how much of the feed stream is turned into vapour. In the end two of the models could import over 48 hour’s of measured data from a cloud network, pre-process it by removing ”nan” values, filter that data and divide it into segments based on if the plant is in production or not. For the segments where production is happening the models could calculate the performance parameters and display them. The other model could import, pre-process and filter data from 3 different excel datasets and with these data calculate the performance parameters. When comparing the c

This study aims to scrutinize and compare the environmental impacts of biobased 2,3-butanediol (BDO) and its fossil-based counterpart. BDO is a fundamental chemical in various industries, traditionally derived from petroleum sources. Wood residues, largely available in Nordic countries, are sustainable alternative feedstocks, offering potential environmental benefits. Material flow analysis followed by consequential life cycle assessment (LCA) were employed to quantify the potential environmental burdens associated with various biorefinery stages of wood-based BDO production. The findings indicated that refraining from wood combustion and, instead, utilizing wood in a biorefinery to produce BDO as the main product, with methane and fertilizer as coproducts from the waste residue, resulted in 125%, 52%, and 90% better environmental performance regarding human health, climate change, and resource scarcity, respectively, compared to fossil-based BDO production. The results offer valuable insights for technology developers and policymakers, empowering them to make informed decisions and support sustainable practices.

Deep eutectic solvents (DES) are a new class of environmentally friendly, safe, and inexpensive solvents with a remarkable ability to dissolve metal oxides, proposed as green alternatives to traditional acid leaching in the recycling of lithium-ion battery (LIB) cathode materials. In this work, a closed-loop process is targeted, where LiNi1/3Mn1/3Co1/3O2 (NMC) is leached by a DES (choline chloride and L-(+)-tartaric acid), and the metals are recovered by antisolvent crystallization. Five organic antisolvents have been evaluated, amongst which ethanol provides the highest metal recovery efficiency. The suitability of the solid precipitates as precursors for the sol-gel synthesis of new NMC, and the resulting cycling performance as battery cathodes, have been tested. The effect on the process of impurities Al and Cu from current collectors has been investigated. The impurities partially precipitate with the targeted metals, but the product impurity content can be significantly reduced through the selection of antisolvent, antisolvent-to-leachate ratio, crystallization residence time, and the rate of supersaturation generation in semi-batch mode. The resulting solids can be suitable for direct cathode resynthesis without the addition of a chelating agent, but impurities from current collectors decrease cycling performance. The results highlight the potential of combining DES leaching and antisolvent crystallization as a sustainable and efficient LIB cathode recycling method., QC 20230927

QC 20230927

Burgeoning concerns on the adverse environmental impacts of fossil-derived products are propelling the pursuit of material production from sustainable resources. Resource recovery from waste is a key component of meeting the environmental sustainability agendas set by the United Nations. Municipal organic wastes present a significant opportunity for resource recovery due to their inherent organic content. Volatile fatty acids (VFAs), the intermediary products of anaerobic digestion of waste streams, can serve as building block chemicals with a wide range of applications. Meanwhile, microbiologically produced biopolymers called polyhydroxyalkanoates (PHAs) hold an enormous potential as an alternative to petrochemical-based plastics, given their comparable physiochemical properties, biodegradability and biocompatibility. In view of this, the focus of this thesis was on bio-based VFA production from food waste (FW) and PHA production from municipal organic waste by exploring process optimization and microbial community dynamics of mono and co-cultures as well as mixed microbial cultures (MMCs). The link between different inocula, retention time and pH on VFA production from FW was elucidated. This part of the study employed three distinct inocula under initial acidic (pH 5) and alkaline (pH 10) conditions for a period of 30 days. Waste-derived VFAs were employed for mono and co-culture PHA biosynthesis with bacteria, Cupriavidus necator, Burkholderia cepacia and Bacillus megaterium. The highest PHA yields of 78 ± 5.7% of cell dried weight (CDW) was obtained with C. necator and a PHA yield of 55 ± 3.7% of CDW was achieved with B. cepacia. In the next part of the study, activated sludge MMC was enriched over short (3 and 5 days) periods in combination with bioaugmentation of C. necator and B. cepacia in both mono and co-culture modes. While bioaugmentation did not increase the total PHA accumulation capacity, the microbial composition of the different bioreactors was m, En växande oro för de negativa miljöeffekterna av fossilbaserade produkter driver strävan efter materialproduktion från hållbara resurser. Resursåtervinning från avfall är en nyckelkomponent för att uppfylla FN:s miljöpolitiska hållbarhetsagendor. Kommunalt organiskt avfall utgör en betydande möjlighet till resursåtervinning på grund av sitt inneboende organiska innehåll. Flyktiga fettsyror (VFA), mellanprodukter från anaerob rötning av avfallsströmmar, kan fungera som byggstenskemikalier med ett brett spektrum av tillämpningar. Samtidigt har mikrobiologiskt framställda biopolymerer som kallas polyhydroxialkanoater (PHA) en enorm potential som ett alternativ till petrokemiskt baserad plast, med tanke på deras jämförbara fysiokemiska egenskaper, biologiska nedbrytbarhet och biokompatibilitet. Mot bakgrund av detta låg fokus för denna avhandling på biobaserad VFA-produktion från matavfall (FW) och PHA-produktion från kommunalt organiskt avfall genom att utforska processoptimering och mikrobiell gemenskapsdynamik hos mono- och samkulturer samt blandade mikrobiella kulturer (MMC).Kopplingen mellan olika inokula, retentionstid och pH på VFA-produktion från FW klargjordes. Denna del av studien använde tre distinkta inokula under initiala sura (pH 5) och alkaliska (pH 10) betingelser under en period av 30 dagar.Avfallshärledda VFAs användes för mono- och samodling av PHA-biosyntes med bakterier, Cupriavidus necator, Burkholderia cepacia och Bacillus megaterium. De högsta PHA-utbytena på 78  5,7 % av celltorkad vikt (CDW) erhölls med C. necator och ett PHA-utbyte på 55  3,7 % av CDW uppnåddes med B. cepacia.I nästa del av studien berikades aktivt slam MMC under korta (3 och 5 dagar) perioder i kombination med bioaugmentation av C. necator och B. cepacia i både mono- och samodling. Även om bioaugmentering inte ökade den totala PHA-ackumuleringskapaciteten, modifierades den mikrobiella sammansättningen av de olika bioreaktorerna.Denna Ph.D. projektet gav insikter om återvin, QC 20230912

The need for multifunctional, robust, reusable, and high-flux filters is a constant challenge for sustainable water treatment. In this work, fully biobased and biodegradable water purification filters were developed and processed by the means of three-dimensional (3D) printing, more specifically by fused deposition modelling (FDM). The polylactic acid (PLA) – based composites reinforced with homogenously dispersed TEMPO-oxidized cellulose nanofibers (TCNF) or chitin nanofibers (ChNF) were prepared within a four-step process; i. melt blending, ii. thermally induced phase separation (TIPS) pelletization method, iii. freeze drying and iv. single-screw extrusion to 3D printing filaments. The monolithic, biocomposite filters were 3D printed in cylindrical as well as hourglass geometries with varying, multiscale pore architectures. The filters were designed to control the contact time between filter's active surfaces and contaminants, tailoring their permeance. All printed filters exhibited high print quality and high water throughput as well as enhanced mechanical properties, compared to pristine PLA filters. The improved toughness values of the biocomposite filters clearly indicate the reinforcing effect of the homogenously dispersed nanofibers (NFs). The homogenous dispersion is attributed to the TIPS method. The NFs effect is also reflected in the adsorption capacity of the filters towards copper ions, which was shown to be as high as 234 and 208 mg/gNF for TCNF and ChNF reinforced filters, respectively, compared to just 4 mg/g for the pure PLA filters. Moreover, the biocomposite-based filters showed higher potential for removal of microplastics from laundry effluent water when compared to pure PLA filters with maximum separation efficiency of 54 % and 35 % for TCNF/PLA and ChNF/PLA filters, respectively compared to 26 % for pure PLA filters, all that while maintaining their high permeance. The combination of environmentally friendly materials with a cost and time-eff, QC 20230626

To provide protection against corrosion in harsh environments, high performance anticorrosive coatings are applied on steel structures at all scales. However, to also limit the use of fossil-based ingredients, there is a growing demand to incorporate renewable raw materials in the coating formulations. In this study, to replace pigments and fillers of an epoxy novolac coating, technical Kraft lignin particles were ground and size fractionated (i.e., sieved), and used for formulation work. The effects of sieved and unsieved Kraft lignin, as structure-reinforcing components, on the anticorrosive and mechanical performance of epoxy coatings were subsequently investigated using the following methods: size exclusion chromatography (SEC), phosphorous nuclear magnetic resonance spectroscopy (31P NMR), scanning electron microscopy (SEM), differential scanning calorimeter (DSC), salt spray exposure, pull-off, König pendulum hardness, and chemical resistance tests. Compared to the unsieved-lignin reference (U-L EN), the coating based on lignin fines (S-L EN) showed about 31 % lower rust creep after 70 days of salt spray exposure. However, no surface defects or chemical degradation were observed for any of the coatings. For the S-L EN coating, excellent adhesion strength (23 MPa) and impact resistance (0.49 N), relative to reference values of 17 and 13 MPa and 0.41 and 0.07 N for commercial and lignin-based diglycidyl ether bisphenol F (L-DGEBF) coatings, respectively, were measured. The addition of lignin particles did not influence the chemical resistance, the hardness, and the glass transition temperature of the epoxy novolac coatings. In summary, chemically unmodified Kraft lignin particles, after grinding and sieving, can be incorporated in epoxy novolac coatings (up to 25 vol%), thereby providing a bio-based alternative to pigments and fillers in heavy duty coatings (primers in particular)., QC 20230719

We discuss the origin of the breakloose (or static) friction force when an ice block is slid on a hard randomly rough substrate surface. If the substrate has roughness with small enough amplitude (of order a 1 nm or less), the breakloose force may be due to interfacial slip and is determined by the elastic energy per unit area, Uel/A0, stored at the interface after the block has been displaced a short distance from its original position. The theory assumes complete contact between the solids at the interface and that there is no elastic deformation energy at the interface in the original state before the application of the tangential force. The breakloose force depends on the surface roughness power spectrum of the substrate and is found to be in good agreement with experimental observations. We show that as the temperature decreases, there is a transition from interfacial sliding (mode II crack propagation, where the crack propagation energy GII = Uel/A0) to opening crack propagation (mode I crack propagation with GI the energy per unit area to break the ice-substrate bonds in the normal direction)., QC 20230707

Various more or less wear-resistant coatings have been developed and used to protect metal substrates. However, the damage caused by wear is still a problem for most coatings. It is of great importance to monitor the wear of coatings in real-time during the applications. Recently reported wear monitoring methods (image processing, luminescent layers and the use of a sensing underlayer) require complex external equipment or additional coating preparation process steps, which limit their applications. As an emerging technology, a triboelectric nanogenerator (TENG) can convert mechanical energy into electricity, and it has been applied as a self-powered sensor. In this study, a new coating wear monitoring method is developed based on a solid-liquid TENG. The developed TENG generates electric signals corresponding to different wear states, which facilitates easy monitoring of the coating's wear conditions. The results show that the surface composition change caused by wear is the main reason affecting the TENG signal output. The coating-liquid contact-separation motion generates realtime output signals that directly reflect the coating wear states without the need of any additional equipment. This study provides a promising new technology for in-situ coating wear monitoring., QC 20230626

Renewable energy sources are indispensable to meet the rising demand of energy usage while reducing the negative environmental impact of utilising fossil fuels. Gasification is an efficient technology to convert biogenic waste into valuable gaseous products. The rate of conversion of char, produced in an intermediate step in the conversion, plays an essential role in the conversion of biogenic materials. The conversion of char is significantly affected by properties such as the structure of the char and its alkali content. This thesis presents findings related to the influence of char pore structure development and alkalis content on char gasification, as well as the alkali release during gasification and co-gasification. Experimental results show that the generation of micropores are directly proportional to the observed reactivity up to 70% of char conversion, after which the catalytic effects of potassium become the dominating factor. Furthermore, investigations of the effect of different intrinsic potassium contents on woody char reactivity demonstrate that no alkali surface saturation point is reached, as is the case for high-ash chars. Application of a modified random pore model enabled a successful capture of the later stages of char conversion in comparison to other kinetic models applied. Alkali release and sample mass changes were monitored simultaneously, using a thermogravimetric analyser together with a surface ionization detector (TGA-SID). The studies revealed a significant release of alkali as woody char conversion approaches completion during CO2 gasification. For straw char the release of alkali decreased continuously throughout the conversion process. Similar results were obtained for biochar gasification under steam conditions in a fixed bed reactor. However, in this case the process is more complex, including transfer of alkali between pa, Förnybara energikällor behövs för att möta den ökande efterfrågan på energianvändning, samtidigt med behoven av att minska den negativa miljöpåverkan som användningen av fossila bränslen medför. Förgasning är en effektiv teknologi för att omvandla biogent avfall till värdefulla gasformiga produkter. I omvandlingsprocessen förkolas biomassan till biokol i ett intermediärt steg. Hastigheten för omvandlingen av biokolet spelar en avgörande roll vid förgasningen av biogena material. Denna omvandling påverkas väsentligt av biokolets egenskaper såsom kolstruktur och dess alkaliinnehåll. I denna avhandling presenteras resultat som relaterar till inverkan av kolstrukturens utveckling och innehåll av alkalier vid förgasningen av biokol samt frigörandet av alkali under förgasning och samförgasning. Experimentella resultat visar på att genereringen av mikroporer är direkt proportionellt mot observerad reaktivitet upp till 70 procents kolomvandling. Därefter är de katalytiska effekterna huvudsakligen relaterade till kaliumhalten. Vidare så observerades ingen effekt av alkalimättnad av kolytan på biokolets reaktivitet vid studier med biokol från trämaterial med olika halter av kalium, något som observerats tidigare för biokol med högre innehåll av aska. Tillämpning av en modifierad randomiserad modell för utvecklingen av porer resulterade i en lämplig beskrivning av de slutliga stadierna i omvandlingen av biokol jämfört med andra kinetiska modeller. Frigörandet av alkalier och förändringar i provernas massa undersöktes med hjälp av termogravimetrisk analys tillsammans med en ytjonisationsdetektor (TGA-SID). Studierna visar att en betydande mängd alkalier frigörs mot slutet av biokolets omvandling under koldioxidförgasning. För biokol från halm observerades däremot ett fortsatt minskat frigörande av alkalier under hela omvandlingsprocessen. Liknande re, QC 2023-04-26

Fuel blends may be used to meet several operational needs in thermal conversion of biomass waste, including optimization of ash properties and fuel conversion efficiency. In this study, online alkali measurements using surface ionization are employed to study synergistic effects produced by inorganic elements during co-pyrolysis/gasification of wood and straw waste. Synergistic effects on the fuel conversion behavior are not observed during co-pyrolysis, while alkali migration from straw to wood is clearly observed above 600 °C by online alkali monitoring. In contrast, synergistic effects on char conversion and alkali release are substantial during co-gasification. Positive effects on char reactivity during most of the gasification process are attributed to alkali migration from the straw to the wood char, and the most pronounced effect occurs at a gasification temperature of 900 °C and a straw content of 25%. Negative effects on char reactivity are observed at the final gasification stage, which is associated with a significantly reduced alkali release from fuel blends compared to pure wood char. The effect is attributed to the migration of silicon, phosphorus, and aluminum to the wood char, as revealed by scanning electron microscopy with energy dispersive spectroscopy, where the elements react with alkali to form catalytically inactive compounds. The mixing of biofuels is concluded to result in substantial effects on the fuel conversion efficiency, which should be taken into consideration in thermochemical conversion of biomass., QC 20230412

In this study, the drying kinetics of noni (Morinda citrifolia L.) was investigated in a laboratory tunnel dryer at air temperatures of 50, 60, and 70 degrees C and velocities of 1.0, 1.5, and 2.0 m/s. Noni showed only a falling drying rate period. Further, a non-linear regression procedure was used to determine the characteristic drying curve. The experimental drying data of noni were employed to fit thin-layer models. Under the evaluated experimental conditions, the Page model provided the best representation of thin -layer drying characteristics of noni. The effective moisture diffusivity ranged from 1.77 x 10-7 to 3.33 x 10-7 m2/s. The activation energy was found to be 3.34 kJ/mol., QC 20230404

In this work, the drying kinetics of ginger (Zingiber officinale Roscoe) was studied considering the shrinkage effect. The experimental data were obtained using three different temperatures (40, 60, and 80 degrees C). For the determination of shrinkage, two cutting orientations were employed. The volumetric and thickness shrinkage was evaluated by direct measurement. The shrinkage showed two periods during drying and had a considerable effect on the drying rate. An equation that relates the changes in the drying area as a function of the moisture content was determined. During drying, ginger showed only a falling rate period and exhibited a characteristic drying curve., QC 20230404

This study aims to scrutinize and compare the environmental impacts of biobased 2,3-butanediol (BDO) and its fossil-based counterpart. BDO is a fundamental chemical in various industries, traditionally derived from petroleum sources. Wood residues, largely available in Nordic countries, are sustainable alternative feedstocks, offering potential environmental benefits. Material flow analysis followed by consequential life cycle assessment (LCA) were employed to quantify the potential environmental burdens associated with various biorefinery stages of wood-based BDO production. The findings indicated that refraining from wood combustion and, instead, utilizing wood in a biorefinery to produce BDO as the main product, with methane and fertilizer as coproducts from the waste residue, resulted in 125%, 52%, and 90% better environmental performance regarding human health, climate change, and resource scarcity, respectively, compared to fossil-based BDO production. The results offer valuable insights for technology developers and policymakers, empowering them to make informed decisions and support sustainable practices.

Med övergången till elektrifiering inom transport uppstår nya utmaningar när det gäller batterisystem som placeras i elfordon. Det finns för närvarande en möjlighet att minska riskerna med toxiciteten hos partiklar som sprutas ut med de gaser som bildas under termisk rusning i litiumjonbattericeller som är placerade i batterisystem. Syftet med denna avhandling är att identifiera potentiella material för partikelfiltrering från dessa gaser, undersöka de valda materialens prestanda i ett experiment, och föreslå material för framtida studier. Filtermaterialet är avsett att sitta vid ventilen i batteripacket. Totalt valdes 5 filter för experimenten, där 3 av dessa var mikrofiberfilter gjorda av kvarts och 2 var mikrofiberfilter av glas. Filtren klämdes mellan stålplattor med ett hål, och placerades 40 cm ovanför battericellens ventil. Battericellerna utlöstes till termisk rusning och filtren placerades i den direkta vägen för utslungade partiklar för att testa deras termiska motstånd och partikelretentionsförmåga. Filtren karaktäriserades med hjälp av vägning, svepelektronmikroskopi, samt energidispersivt röntgenspektroskopi. Efter ett första test ansågs glasfiberfiltren inte ha tillräckligt hög värmeresistens för att fortsätta testas. Kvartsmikrofiberfiltren varierade i fråga om värmeresistens, där de ibland brann upp och ibland förblev helt intakta. Detta berodde troligtvis till stor del på skillnader i termisk rusning mellan experimenten på grund av varierande uppvärmningsparametrar. Kvalitativt sett lyckades kvartsmikrofiberfiltren fånga upp partiklar, men det kan inte kvantifieras i detta experiment hur effektiva de var när det gäller partikelretention. Filtren visade potential för en enkel tillämpning i batteripacket, men ytterligare forskning bör göras för att undersöka viktiga faktorer, såsom mottryck från filtren. Dessutom finns det vissa material som kan vara intressanta att testa i framtiden, bland annat keramiska material, sintrade metallfiberfiltar och abla, With the shift towards electrification in transportation, new challenges arise with regards to battery systems placed in electric vehicles. There is an opportunity to reduce risks associated with the toxicity of particles ejected from the gases that form during thermal runaway (TR) in lithium-ion battery cells placed in battery systems. The aim of this thesis is to identify potential materials for particle filtration from these gases, investigate the performance of the chosen materials in an experiment, and suggest materials for future studies. The filter material is intended to sit by the vent in the battery pack. In total 5 filters were chosen for the experiments, where 3 of those were quartz microfibre filters and 2 were glass microfibre filters. The filters were sandwiched between steel plates with a hole, placed 40 cm above the battery cell vent. The battery cells were triggered into thermal runaway, and the filters were placed in the direct path of ejected particles in order to test their thermal resistance and particle retention capabilities. The filters were characterized using weighing, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. From an initial test, the glass fibre filters were deemed not sufficient enough in terms of thermal resistance to continue being tested. The quartz microfibre filters varied in terms of thermal resistance, where they at times burned away and other times remained intact. This was largely attributed to differences in TRs between the experiments due to varying heating parameters. Qualitatively, the quartz microfibre filters succeeded in catching particles, but it cannot be quantified in this experiment how efficient they were in terms of particle retention. The filters showed potential in an easy application in battery packs, but further research should be done to investigate important factors, such as back pressure from the filters. Furthermore, there are certain materials that could be interesting to tria

Livscykelanalys är en metod som utformades och utvecklades för att kvantifiera miljöpåverkan från produkter och tjänster för mer än trettio år sedan. Sedan dess har den kontinuerligt förbättrats och blivit mer och mer robust. Som tillverkare av kemiska produkter och monomerer använder Arkema livscykelanalys för att mäta sina produkters miljöpåverkan. Detta görs för att förstå enskilda produkters fotavtryck samt företagets övergripande miljöpåverkan. För att göra detta används ISO-normerna 14040 och 14044. Dessa normer anger generiska ramar för LCA-beräkningar men är inte specifika för den kemiska industrin. Med tanke på att metodologiska svårigheter kan uppstå inom den kemiska sektorn har många riktlinjer och rekommendationer publicerats på senare tid. I denna uppsats studeras och jämförs några av dessa riktlinjer. Tillämpningen av dessa metoder utförs på två produkter inom Arkemas portfölj: akrylsyra och etylakrylat, som är byggstenar för många polymerer. Resultaten av utvärderingen visar på områden där förbättringar kan göras. För de studerade produkterna är råvarorna de största bidragande orsakerna. Därför kan det vara fördelaktigt att övergå från petroleumbaserade material till biobaserade. Att välja den minst miljöpåverkande produktionsvägen är också ett sätt att aktivt minska produkternas koldioxidavtryck., Life Cycle Assessment is a methodology that has been designed and developed to quantify the environmental impacts of products and services more than thirty years ago. Since then, it has been in continuous improvement and becomes more and more robust. As a producer of chemical products and monomers, Arkema uses Life Cycle Assessment to measure the environmental impact of its products. This is done to understand the footprints of individual products as well as the company's overall environmental impact. To do so, the ISO norms 14040 and 14044 are used. These norms set generic frames for LCA calculation but are not specific to the chemical industry. Considering that methodological difficulties can arise in the chemical sector, many guidelines and recommendations are being published recently. In this thesis, some of those guidelines are studied and compared. The application of these methodologies is performed on two products within Arkema’s portfolio: acrylic acid and ethyl acrylate, which are building blocks for many polymers. The results of the assessment reveal areas where improvements can be made. For the products studied, the main contributors are the raw materials. Therefore, transitioning from petroleum-based materials to biobased ones could be beneficial. Additionally, selecting the least impactful production route is also a way to actively reduce the carbon footprint of the products.

Since the transportation sector wants to move away from fossil fuels and become more dependen ton clean and green energy, the use of rechargeable batteries is a good solution. Lithium-based batteries work very well as rechargeable batteries in electric vehicles. To extend the cycle life of lithium-based batteries a reversed Li+-trapping protocol has been implemented to extract lostcapacity. Prior to the start of this project, reversed Li+-trapping has been used on a proof-of-concept level and no specific protocol has been utilised in conjunction with full cells. With a protocol that uses constant voltage discharge steps on every fifth cycle, trapped Li+ can diffuse out from the graphite (anode) and travel back to the NMC811 (cathode). This will result in a lower capacity loss than if it only had cycled with constant current, using a C-rate of 1C. If a cell is operated with a constant voltage discharge step on every cycle, high capacity can be maintained for many cycles. This could potentially be used as a formation cycle protocol. The capacity is higher in the long run if the constant voltage discharge step is applied on every fifth cycle rather than every cycle. With a constant voltage discharge cell voltage of 2.8 V good results are obtained. A constant voltage discharge cell voltage of 0 V will however destroy the cell due to Cucurrent collector dissolution.

Avfallsförbränning har länge varit en av de viktigaste processerna i ett fungerande samhälle. Utöver en volymminskning, erhålls värmeenergi, bottenaska, flygaska och rökgaser vid förbränningsprocessen. I och med att utsläppskraven kontinuerligt skärps, ställs höga krav på de involverade aktörerna när det kommer till hanteringen av restprodukter från förbränningsprocessen. Vanliga hanteringsmetoder för askfraktionerna har länge varit deponering eller att använda askorna som utgångsmaterial för framställningen av byggmaterial som cement. Flygaskorna från förbränningsprocessen innehåller en rad olika grundämnen som har visat sig vara av kommersiellt intresse. Bland annat tenderar flygaskor att innehålla höga halter av lättlösliga kloridsalter, vilket leder till en ökad lakbarhet vid både deponering och användningen som byggmaterial. Fortum Waste Solutions som är ett ledande företag inom hanteringen av farligt avfall, deponerar i dagsläget sina flygaskor efter stabilisering. Då lösningen inte anses hållbar i ett längre perspektiv, är Fortum WS angelägna om att ta fram nya lösningar i syftet att skapa en mer kemiskt stabil askrest för deponeringen. I Finland bedriver Fortum i dagsläget en asktvätt där askorna initialt stabiliseras genom lakning med vatten. Lakningen leder till att lättlösliga kloridsalter ackumuleras i vätskefasen och sedan leds ut i Östersjön. För att processen ska vara tillämpbar på Fortums askor i Kumla, där närliggande saltvattenrecipient saknas, krävs det en avskiljning av salterna innan vätskeströmmen kan ledas ut i närliggande recipient. I samband med detta planerar Fortum WS att kloridsalterna som främst består av kalcium-, kalium- och natriumklorid ska separeras och återvinnas. Syftet är att göra processen mer ekonomiskt gynnsam, samtidigt som den cirkulära ekonomin främjas. Projektets mål har således varit att identifiera och studera två metoder för att separera klori, Waste incineration has long been one of the most important processes in the modern society. In addition to a reduction in volume, heat energy, bottom ash, fly ash and flue gases are obtained during the combustion process. As the emission requirements are continuously tightened, a lot of pressure is put on the involved actors when it comes to handling the residual products from the combustion process. Common handling methods for the ash fractions have long been landfilling or using the ashes as a starting material for the production of building materials as cement. The fly ash from the incineration process contains a number of different elements, which have been shown to be of commercial interest. Among other things, fly ash tends to contain high levels of soluble chloride salts, which leads to increased leachability during both disposal and in the use as a building material. Fortum Waste Solutions, a leading company in the management of hazardous waste, is currently depositing its fly ash after stabilization. As the solution is not considered to be sustainable in the long term, Fortum WS is keen to find new solutions with the aim of creating a more chemically stable ash residue for disposal. In Finland, Fortum currently operates an ash washing plant where the ashes are initially stabilized by water leaching. During the leaching process soluble chloride salts are accumulated in the liquid phase which then is discharged into the Baltic Sea. In order for the process to be applicable to Fortum’s ashes in Kumla, where there is no nearby salt-water recipient, a separation of the chloride salts is necessary before the liquid stream can be discharged. In regard to this, Fortum WS plans to separate and recycle the chloride salts, which mainly consists of calcium, potassium and sodium chloride. The aim is to make the process applicable and more economically beneficial, while the promoting circular economy. The aim of the project has thus been to identify and study two method

Ett konsortium bestående av Scania, JOAB, Powercell, KTH och Renova samarbetade för att designa och konstruera en bränslecellsdriven sopbil inom ett FFI-finansierade projekt. Sopbilen har sedan dess varit i drift i Göteborg från 2020 till 2023, med en vätgasinfrastruktur bestående av en tankstation vid tidpunkten för detta arbete. Under den tiden har bränslecellen genomgått kör- och stillastående tester. Verkliga kördata på sopbilens system och bränslecell registrerades. Databaserna var osynkroniserade i tid och därför krävdes datasynkronisering. Detta examensarbete inleddes med huvudsyftet att utveckla ett accelererat åldringstest för bränslecellen baserat på denna applikation. Ett ytterligare syfte var att utvärdera bränslecellens åldrande. På grund av de tillgängliga variablerna baserades bränslecellens åldrande på försämring av elektrisk effekt vid konstanta temperaturer och strömmar. En testcykel (eller effekt-cykel) baserad på testkörningen av sopbilen utvecklades istället. Genom att använda den etablerade metoden "k-means clustering" på bränslecellens effekt-cykler skapades en testcykel som var representativ för sopbils-körning från 2020 till 2023. Testcykeln validerades baserat på ett statistiskt kriterium, verifiering och ytterligare arbete krävs dock. Efter 141,80 timmars bränslecellsdrift kunde ingen åldring identifieras. Mer data från sopbilen behövs och faktumet att ytterligare en vätgastankstation kommer att installeras under 2023 i Göteborg innebär att sopbilens körmönster kan förändras. Resultaten från denna avhandling lägger dock grunden för framtida forskning och erbjuder ett tillvägagångssätt för att studera den bränslecellsdrivna sopbilen., A consortium consisting of Scania, JOAB, Powercell Sweden AB, KTH, and Renova collaborated to design and engineer a fuel cell-powered refuse truck within a FFI-funded project. The refuse truck has been operational in Gothenburg since 2020, with a hydrogen gas infrastructure of one refuelling station at the time of this work. From 2020 to 2023, the fuel cell has gone through driving and standing still tests. Real drive data on the truck's system and fuel cell was recorded. The databases were unsynchronised in time, hence data synchronisation was required. This thesis began with the main aim of developing an accelerated stress test for the fuel cell based on this application. Additionally, the aim was to evaluate the ageing of the fuel cell. Due to the available variables, fuel cell ageing was based on deterioration of fuel cell powers at constant temperatures and currents. A test cycle (or power cycle) based on refuse truck test driving was developed instead. By utilising the established “k-means clustering” method on fuel cell power cycles, a test cycle representative of the truck operation from 2020 to 2023 was made. The test cycle was validated based on a statistical criterion, although verification and further work are required. After 141.80 hours of fuel cell power requests no ageing could be identified. More data from refuse truck operation is needed, also considering that an additional hydrogen refuelling station will be put in place in 2023 in Gothenburg, hence the drive pattern might vary. In this context, however, the results from this thesis lay the foundation for future research and offer an approach to study the fuel cell truck.

Biocider är giftiga ämnen som tillsätts material och produkter i syfte att bevara dem genom att hämma tillväxten av mikroorganismer på dess yta. På så sätt används dessa ämnen för att skydda materialet och förlänga dess livslängd. Trots att biocider har mycket stor nytta i samhället kan de även ha oönskade konsekvenser där de orsakar skada på icke avsedda organismer, såsom växter, djur och människor. Det är därför mycket viktigt att undersöka biocider, samt i vilka material de förekommer, för att kunna göra väl informerade val och främja ett hållbart och giftfritt samhälle. Målet med detta examensarbete var att sammanställa ett antal olika biocider samt bygg- och anläggningsmaterial som bör undersökas vidare. Materialet ska därmed sedan utgöra underlag för forskning gällande urlakning av biocider ur material vid Luleå Tekniska Universitet, som utförs i samarbete med Naturvårdsverket och Miljöförvaltningen. Arbetet genomfördes i form av en djupgående litteraturstudie samt genom informationssökning i miljöbedömningssystemet Byggvarubedömningen. Resultatet från detta arbete redovisas i form av en sammanställning av samtliga relevanta biocider samt deras förekomst i bygg- och anläggningsmaterial, egenskaper och användningsområden. Slutsatserna som framkom från detta arbete är att biocider används frekvent i en mängd olika bygg- och anläggningsmaterial såsom träprodukter, byggnadssten och olika färgprodukter. De vanligast förekommande biociderna i dessa material innefattar ämnesgrupperna isotiazolinoner, fenylureaföreningar, triaziner, triazoler samt karbamater. Vilka biocider som adderas varierar beroende på dess syfte samt användningsområde. De olika biocidernas egenskaper har också visat sig ha en betydande roll när det gäller påverkan på urlakning, där främst vattenlösligheten och hydrofobiciteten är av intresse. Samtliga biocider har även konstaterats som mycket giftiga ämnen, vi, Biocides are toxic substances that are added to materials and products in order to preserve them by inhibiting the growth of microorganisms on their surface. In this way, these substances are used to protect the material and extend its life. Although biocides are very useful in society, they can also have unwanted consequences where they cause damage to non- intended organisms, such as plants, animals and humans. It is therefore of upmost importance to examine biocides, as well as the materials in which they occur, in order to make well-informed choices and promote a sustainable society free from toxins. The purpose of this thesis was to assemble a list of different biocides and construction materials that should be investigated further. This material will then form the basis for research regarding the leaching of biocides from materials by Luleå University of Technology, which is carried out in partnership with the Swedish Environmental Protection Agency and the Swedish Environmental Governance Agency. This thesis was accomplished through an in- depth literature study and by searching for information in the environmental assessment system Byggvarubedömningen. The results of this thesis are presented in the form of a compilation of all relevant biocides, as well as their occurrence in construction materials, properties and areas of application. The conclusions that emerged from this thesis are that biocides are frequently used in a variety of construction materials such as wooden products, masonry and various paint products. The most commonly used biocides in these materials include the substance groups isothiazolinones, phenylureas, triazines, triazoles and carbamates. Which biocides are added varies depending on its purpose and area of application. The properties of the various biocides have also been shown to have a significant role in terms of the impact on leaching, where mainly water solubility and hydrophobicity are of interest. All biocides have also be

Polyester is a synthetic material made from polyethylene terephthalate (PET), which is synthesised from fossil raw materials. Many clothing manufacturers are using polyester in their clothing, which, from an environmental perspective, creates a non-sustainable cycle. However, manufacturing can be made more sustainable by using recycled PET bottles as the raw material for polyester yarn. A clothing company that has taken a stand against materials made from fossil fibres and instead invests in only selling clothes made from sustainable materials is the Swedish children's clothing brand Polarn o. Pyret. Being able to use polyester made from PET bottles is important for Polarn o. Pyret to ensure the use of sustainable fibres in their clothing. In the past, the recycled polyester was used in combination with polyester from virgin fibre, but now the goal is instead to switch completely to the recycled polyester. However, the increased quantity of recycled polyester can involve new risks. The need to map potential contaminants is important because Polarn o. Pyret makes clothes for children, which entails strict requirements on the chemical content of the clothes. The purpose of this work is to get an overview of which contaminants that can accumulate in the polyester fibre and thus pose a risk when using recycled polyester made from PET bottles. The goal is to be able to shed light on these contaminants and write a proposal for a risk assessment guide that can establish a foundation for how Polarn o. Pyret should be able to act when using recycled polyester. The work was carried out through an extensive literature study, where research articles and review articles published on scientific databases were the main source of information. Focus was on the risk of non-intentionally added substances that can be traced from recycled PET bottles. The risk assessment was done in consideration of the regulations that is established within the European Union (EU), using the EU chemica, Polyester är ett syntetiskt material tillverkat av polyetentereftalat (PET), som är syntetiserat från fossila råvaror. Många klädtillverkare använder polyester i sina kläder vilket ur ett miljöperspektiv skapar ett ohållbart kretslopp. Tillverkningen kan dock göras mer hållbar genom att använda återvunna PET-flaskor som råvara för polyestergarn. Ett klädföretag som tagit ställning mot material tillverkade av fossila fibrer och i stället satsar på att endast sälja kläder av hållbara material är det svenska barnklädesmärket Polarn o. Pyret. Att kunna använda polyester tillverkad av PET-flaskor är viktigt för att Polarn o. Pyret ska kunna säkerställa användningen av hållbara fibrer i sina kläder. Tidigare användes den återvunna polyestern i kombination med polyester från jungfruliga råvaror, men nu är målet i stället att helt gå över till den återvunna polyestern. Den ökade mängden återvunnen polyester kan dock medföra nya risker. Behovet av att kartlägga potentiella föroreningar är också viktigt eftersom Polarn o. Pyrets gör kläder för barn, vilket medför hårda krav på klädernas kemikalieinnehåll. Syftet med detta arbete var att få en överblick över vilka kemikalier som kan ansamlas i polyesterfibern och därmed utgöra en risk vid användning av återvunnen polyester tillverkad av PET-flaskor. Målet var att identifiera dessa föroreningar och inkludera dessa ämnen i ett förslag till en riskbedömningsguide. Denna riskbedömningsguide skulle därmed kunna utgöra ett stöd för Polarn o. Pyret vid hantering av återvunnen polyester. Arbetet har utförts genom en omfattande litteraturstudie, där forskningsartiklar och översiktsartiklar publicerade på vetenskapliga databaser var den huvudsakliga informationskällan. Fokus låg på risken för oavsiktligt tillsatta ämnen som kan spåras från återvunna PET-flaskor. Riskbedömningen har gjorts med hänsyn till de regelverk som är etablerade inom Euro

Kvarteret Silverskopan som ligger i centrala Stockholm har sedan länge haft problem med fukt i fastigheterna. De mätningar som gjorts har visat tydliga resultat på höga fukt- och kaseinhalter. Kasein är ett protein som finns i mjölkprodukter och är ofarligt när det förekommer i torr miljö. Det användes i bjälklagen redan vid 1970-talet då det var revolutionerande för användning i ytspackel. Resultatet blev ett spackel med bra flytegenskaper samtidigt som det underlättade för byggarbetarna ergonomiskt och inte nödvändigt att släta ut betongen hukandes. Dock uppstår problem då flytspackel utsätts för fukt eftersom kasein bryts ned i närvaro av vatten under alkaliska betingelser och bildar bland annat gasen ammoniak, som i sin tur påverkar människans hälsa negativt. Under årens lopp har man vidtagit flera försvarsåtgärder för att de boende ska kunna klara inomhusmiljön, då problemen fortfarande kvarstår har fastighetsägaren beslutat att evakuera boenden och riva fastigheten för att kunna bygga ett nytt, friskt och hälsosamt hus till de boende. På uppdrag av AFA Fastigheter får Toolgate AB leda hela projektet från start till färdig produkt. Man vill på bästa möjliga sätt återvinna kaseininfekterad betong, optimera resursanvändningen och göra det möjligt för cirkulär materialanvändning. Enligt statistiken av allt avfall i Sverige är ca 35% byggavfall. Detta vill man minska på och kunna möjliggöra återvinning och återbruk till 100% av allt byggavfall som uppkommer vid rivning och upprättning av nya bostäder. Resultatet av optimeringen bidrar till positiv inverkan på ekologisk hållbarhet, hälsosam miljö och stor nytta för kommande projekt. Syftet med denna rapport är att föreslå möjliga metoder för återvinning av kaseininfekterad betong på bästa möjliga hållbara sätt. Frågeställningen som kommer att vara i fokus för arbetet är- Kan man återvinna eller återbruka kaseininfekterad betong?, The neighborhood Silverskopan in central Stockholm has long had problems with moisture in the properties. The measurements made earlier have shown clear results of high moisture and casein contents. Casein is a protein found in milk products and is harmless when present in a dry environment. It was used in joists as early in the 1970s when it was used in surface putty. The result was a putty with good flow properties, and it is simpler for construction workers ergonomically which made it easier without the need to smooth the concrete while crouching. However, problems arise when floating putty is exposed to moisture, because casein breaks down in the presence of water under the alkaline conditions in the concrete and forms among other things, the gas ammonia, which affects the human health negatively. Over the years, several defensive measures have been taken so that the residents can cope with the indoor environment, as the problems still persist, the property owner decided to evacuate the residents and demolish the property in order to build a new, healthy house for the residents. On behalf of AFA Fastigheter, Toolgate gets to lead the entire project from start to finished product. They want to recycle casein infected concrete in the best possible way, optimize the use of resources and enable circular material use. According to statistics about 35% of all waste in Sweden is construction waste. They want to reduce this and be able to enable the recycling and reuse 100% of all construction waste that arises when demolishing and erecting new homes. The result of the optimization contributes to a positive impact on ecological sustainability, a healthy environment and great benefit for future projects. The purpose of this report is to suggest possible methods for recycling casein infected concrete in the best possible sustainable way. The question that will be the focus of the work is- Can casein infected concrete be recycled or reused? This project is aimed at A

Food packaging plays a crucial role in protecting and storing food to keep the products fresh and reduce waste. There is a need to increase the number of paper packages in the food industry to meet the growing demand. Therefore, barrier coatings are an essential aspect of the paper industry since they have good resistance to grease and moisture, which protects the food. The development and improvement of these barrier coatings have the potential to contribute to the advancement of environmentally friendly food packaging. This work aims to examine the impact of rheological behavior and properties on the runnability and barrier performance of barrier coating formulations containing two different kaolin clays, Speswhite (K1) and Capim NP (K2), with the addition of nanoclay in varying amounts. Different formulations were tested as multilayer barrier coatings on lab- and pilot-scale in order to determine the effect of various nanoclay concentrations on runnability, water retention, and rheology properties. Various measurement techniques have been used to obtain a wide range of information on the rheological properties, including the viscosity, under varied shear rate ranges. Also studied are runnability, grease and moisture barrier performance, water retention, and high shear testing for rheology to determine flow behavior. The results show that the viscosity was higher on the lab scale than on the pilot scale due to the poor nanoclay dispersion at the pilot scale. As expected for this type of barrier coating, the KIT-test revealed that the grease barrier was highly effective. Measurements of water retention were good for the low amounts of nanoclay content. Lastly, the shear testing gave very similar results between all the different barrier coating formulas. It was determined that a low nanoclay content gave a good barrier coating performance. However, a higher nanoclay content resulted in decreased water resistance compared to a coating with a low nanoclay content., Livsmedelsförpackningar spelar en avgörande roll för att skydda och lagra mat för att hålla produkterna fräscha och minska avfallet. Det finns ett behov av att öka antalet pappersförpackningar inom livsmedelsindustrin för att möta den växande efterfrågan. Därför är barriärbestrykningar en väsentlig del av pappersindustrin eftersom de har god motståndskraft mot fett och fukt, vilket skyddar maten. Utvecklingen och förbättringen av dessa barriärbestrykningar har potential att bidra till utvecklingen av miljövänliga livsmedelsförpackningar. Detta arbete syftar till att undersöka inverkan av reologiskt beteende och egenskaper på körbarheten och barriärprestandan hos barriärbestryknings-formuleringar som innehåller två olika kaolinleror, Speswhite (K1) och Capim NP (K2), med tillsats av nanolera i varierande mängder. Olika formuleringar testades som flerskiktsbarriärbestrykningar i laboratorie- och pilotskala för att bestämma effekten av olika nanolerakoncentrationer på körbarhet, vattenretention och reologiska egenskaper. Olika mättekniker har använts för att erhålla bred information om de reologiska egenskaperna, inklusive viskositeten under varierande skjuvhastighets-intervall. Körbarhet, fett- och fuktbarriärprestanda, vattenretention och högskjuvningstestning för reologi har studeras för att bestämma flödesbeteende. Resultaten visar att viskositeten var högre på laboratorieskalan än på pilotskalan på grund av den dåliga nanolerdispergeringen på pilotskalan. Som förväntat för denna typ av barriärbestrykning visade KIT-testet att fettbarriären var mycket effektiv. Mätningar av vattenretention var bra för de låga värdena på nanolerainnehåll. Slutligen gav skjuvprovningen mycket likartade resultat mellan alla olika barriärbestryknings-formuleringar. Det fastställdes att ett lågt nanolerainnehåll gav en bra barriärbestryknings-prestanda. En högre halt av nanolera resulterade dock i minskad vattenbeständighet jämfört med en beläggning med låg nanolerhalt.

Vacuum dewatering of paper is a heavily energy expensive process, even more so for greaseproof paper, which is one of the main products at Nordic Paper Seffle AB. Due to this being such an energy demanding process, improvements in the vacuum dewatering could save massive amounts of energy. The focus of this thesis is to investigate the effect of a triple vacuum suction box on the dewatering rate of greaseproof paper, using a tried and tested method of simulative triple vacuum suction box at a laboratory scale, with the difference of simulating a quadruple vacuum suction box, and how the grammage of the paper sheet affected this, using unbleached sulphate pulp consisting of soft wood with an addition of 20 % eucalyptus fibers. The results were as expected, showing the expected dryness curve behavior of diminishing returns of the dryness to dwell time ratio, and the method showed valid for improving the energy efficiency compared to a single vacuum suction box, in terms of both expended energy, and yielded dryness. The grammage had a significant effect on the dewatering, with the heavier paper at 100 gsm showing the need of higher dwell times and increased levels of vacuum pressure than the lighter paper at 50 gsm. An addition of a triple vacuum suction box could possibly replace multiple high vacuum suction boxes, leading to even greater savings. Further testing would be required for optimization of the vacuum levels and dwell times for the 100 gsm paper sheet, in order to reach the same dryness as the 50 gsm paper sheet., Vakuumavvattning av papper är en mycket energikrävande process, ännu mer för greaseproofpapper, som är en av huvudprodukterna hos Nordic Paper Seffle AB. Eftersom detta är en så energikrävande process kan förbättringar av vakuumavvattningen spara enorma mängder energi. Fokus för denna avhandling är att undersöka effekten av en trippelvakuumsuglåda på avvattningseffektiviteten av greaseproofpapper, med hjälp av en beprövad metod för simulativ trippelvakuumsuglåda i laboratorieskala, med skillnaden att simulera en fyrdubbelvakuumsuglåda, och hur ytvikten på pappersarket påverkar detta; med oblekt sulfatmassa bestående av långfiber med tillsats av 20 % eukalyptusfibrer. Resultaten var som förväntat och visade den förväntade torrhaltskurvans beteende av avtagande förbättring av torrhalten, och metoden visade sig vara giltig för att förbättra energieffektiviteten jämfört med en enda vakuumsuglåda, både vad gäller förbrukad energi och torrhalt. Ytvikten hade en stor effekt på avvattningen, där det tyngre papperet på 100 gsm visade behov av längre uppehållstider och ökade nivåer av vakuumtryck än det lättare papperet vid 50 gsm. Ett tillägg av en trippelvakuumsuglåda kan troligen ersätta flera högvakuumsugslådor, vilket leder till ännu större besparingar. Ytterligare tester skulle krävas för optimering av vakuumnivåerna och uppehållstiderna för 100 gsm pappersarket, för att nå samma torrhet som 50 gsm pappersarket.

Cardiovascular diseases are currently the leading cause of death globally. Progression of the disease affects the composition and function of the heart and in many cases subsequently results in heart failure over time where a heart transplant is vital. Therefore, there is a need for medical treatments to stop the progression of the disease. Hydrogels as a biomaterial have been investigated for this purpose, but most known research to date has focused on their bioactive properties. Since a part of the disease progression is affected by the mechanical differences between myocardial tissue and the collagen the body replaces the loss of viable myocardium with after myocardial infarction, this thesis conducted a novel approach of comparing a thiol functionalized collagen hydrogel with a healthy left ventricle in terms of viscoelastic properties for tissue-bulking application. Swelling tests showed that the gel did not swell significantly over time during incubation in phosphate buffer and even if self-healing of the gel after subjection to ultrasound radiation could not be proven and previously used methods to obtain mechanical stiffness of a tissue (compression tests) could not be utilized for soft materials such as hydrogels, the material is of great interest as a candidate for tissue bulking purposes. The gel showed viscoelastic properties similar to the healthy left ventricle and was injectable, to be administrated in a minimally invasive manner, indicating that the material could act as a tissue-bulking agent. This project has developed a new approach to evaluating hydrogels as a biomaterial by comparing it to the viscoelastic characterization of the intended application tissue.

Antibiotic resistance is a global health concern. Its increasing development is seemingly due to the irresponsible use of antibiotics and their availability. To ensure the correct treatment of patients and avoid unnecessary strain on the individual and society as a whole, it is vital to ensure access to both new and old antibiotics where there is a distinct need. Temocillin is an antibiotic used in the treatment of febrile UTIs. It is currently unavailable in Sweden, although being well-established and proven effective in other European countries. Hence, this report aims to investigate the introduction of temocillin to the Swedish or Scandinavian market in regards to the economic, technical, medical, and regulatory possibilities and barriers. The research is based on literature, internet, and database reviews and empirical data collection through interviews with people of expertise within the fields of antibiotic resistance and concerned aspects. This study emphasizes the great potential of introducing temocillin to Sweden. The evident conclusion drawn is that a production of the antibiotic is not possible in Sweden in the near future. Despite this, an identified supply chain in Europe can enable a role for Sweden as a distribution country. Through a performed break-even analysis, the calculated break-even point and profit margins indicated a low risk of financial loss for a MAH acting as the supplier of temocillin, such as the company Eumedica S.A.. Only 1 % of the Swedish market would have to be covered to break even, and regardless of the estimated volumes of usage upon introduction being either 50 % or 25 % of the total medical need, a profit is likely. In addition, temocillin holds a great medical and social value. However, the obvious obstacle observed is its out-dated documentation. The dossier is of the wrong format, which complicates the regulatory procedure. Thus, this needs to be taken into consideration for an introduction to be possible.

Hyaluronic acid is an organic polysaccharide with a wide range of uses in medical and cosmetic industries due to its physiological properties. Crosslinked hyaluronic acid is a commonly used filler agent because of its water retention capabilities. N-deacetylation can be performed to enable new derivatives of hyaluronic acid. Both chemical and enzymatical approaches were investigated in this literature study to find methods retaining a high molecular weight product. Chemical N-deacetylation of hyaluronic acid has significant challenges with being treated by acid or base while both preventing degradation and maintaining its molecular weight. The method that seems the most promising is treating hyaluronic acid with hydroxylamine. Another method is enzymatic N-deacetylation. It was found that an enzyme N-deacetylated hyaluronic acid in female breast skin from 69-year-olds and above. The isolated enzyme had molecular weights ranging from 63 kDa to 79 kDa. Another enzyme that was produced recombinantly proved to be efficient since it retained high molecular weight and had a degree of deacetylation of 10.1 %. Today there exists only a few methods for crosslinking deacetylated hyaluronic acid. However, for chitosan, there are multiple methods available for crosslinking. Since it uses similar reactions that could be applicable to that of deacetylated hyaluronic acid. Reacetylation of the free amino groups has proven to be possible after crosslinking with a simple and cheap method resulting in an almost complete reacetylation. NMR proved to be an adequate method for analyzing the degree of deacetylation and higher-order structures. HPLC-UV spectroscopy may be used to increase the credibility of the analysis.

Det överhängande behovet av att minska utsläppen av växthusgaser för att uppfylla Parisavtalet har väckt ett ökat intresse för elektrifiering som en strategi för att mildra klimatförändringarna. Litiumjonbatterier spelar en central roll vid elektrifiering och har framträtt som det primära alternativet för batteridrivna elfordon. Batteriernas livstidsprestanda är dock en avgörande faktor för att bestämma deras kostnad och miljömässiga hållbarhet. Även om snabbladdning är ett gångbart alternativ för de kunder som vill maximera drifttiden så leder laddning vid höga strömmar till förhöjd åldring genom nedbrytning av elektrodmaterialet och elektrolyten. Nyligen genomförda studier har visat att pulsade laddningscykler kan förlänga livslängden för litiumjonbatterier. Mot bakgrund av detta har denna studie genomförts för att undersöka effekterna av pulsad laddning på bibehållande av kapacitet samt inre motstånd hos litiumjonbatterier. Cylindriska NMC-celler har cyklats med laddningsprofilen PPC-CV (Positive Pulsed Current-Constant Voltage) och deras prestanda har jämförts med motsvarande hos konventionell konstant ström-konstant spänning-laddning (CC-CV). En ny metod utvecklades och implementerades för att utföra en pulsad laddningsprofil inom ett definierat SoC-fönster (State-of-Charge). Testobjekten cyklades kontinuerligt under intervaller om 4 veckor med avbrott för standardiserade referensprestandatester (RPT) för att beräkna standardkapaciteten och det inre motståndet. Därutöver utfördes inkrementell kapacitetsanalys (ICA) och elektrokemisk impedansspektroskopi (EIS) för att utöka analysen. Enligt resultat visar de celler som cyklats med PPC-CV-profilen liknande eller något minskad kapacitetsminskning samt en lägre ökning av internt motstånd efter ungefär 700 ekvivalenta cykler. 0,01-Hz PPC-CV-profilen uppvisade en kapacitetsminskning på 3,65%, 1-Hz PPC-CV-profilen en på 3,75%, 100-Hz PPC-CV- profilen en på 4,06% och CC-CV-profilen en på 4,05%. De interna resistanserna, The urgent need to reduce greenhouse gas emissions in order to comply with the Paris Agreement has sparked an increased interest in electrification as a strategy to mitigate climate change. Li-ion batteries play a crucial role in electrification, and have emerged as the primary option for battery electric vehicles. However, their lifetime performance is a critical factor in determining their cost and environmental sustainability. Although fast charging presents a viable option for customers wishing to maximize operational time, charging at high currents accelerate aging through degradation of the electrode material and the electrolyte. Recent studies have found that pulse charging protocols can extend the cycle life of Li-ion batteries. In light of this, this study has been conducted to investigate the effects of pulse charging on the capacity retention and internal resistance of Li-ion batteries. Prismatic NMC Li-ion battery cells were cycled using the Positive Pulsed Current-Constant Voltage (PPC-CV) charging mode, and their performance has been compared to that of conventional Constant Current-Constant Voltage (CC-CV) charging. A novel method was developed and implemented to execute a pulse charging profile within a defined State-of-Charge (SoC) window. The test objects were continuously cycled over intervals of 4 weeks with interruptions for standardized Reference Performance Tests (RPTs) to calculate the stan- dard capacity and internal resistance. In addition, Incremental Capacity Analysis (ICA) and Electrochemical Impedance Spectroscopy (EIS) were performed to ex- tend the analysis. According to results, cells cycled using the PPC-CV mode show similar or slightly reduced capacity fade and a lower increase in internal resistance after roughly 700 equivalent cycles. The 0.01-Hz PPC-CV mode exhibited a capacity fade of 3.65%, the 1-Hz PPC-CV mode 3.75%, the 100-Hz PPC-CV mode 4.06% and the CC-CV mode 4.05%. Internal resistances remained lower than the beginning

Marginalisering gällande tillgång till elektricitet utgör en betydande utmaning i avlägsna områden i Peru. Elnätets stabilitet är låg och detta utgör ett hot mot viktig infrastruktur såsom sjukhus och vårdcentraler. Enligt Världshälsoorganisationen förloras 50 % av alla vacciner världen över på grund av felaktig hantering där strömavbrott är en viktig del av problemet. Syftet med denna studie var att öka energitåligheten hos ett medicinskt center i Talara i norra Peru. För att uppnå detta mål utfördes teknisk dimensionering av ett avbrottsfritt strömförsörjningssystem (UPS) bestående av solceller och batterier. Två kvalitativa intervjuer med en eldistributör i norra Peru och en tillsynsmyndighet gjordes för att fördjupa kunskapen om vilka utmaningar som finns gällande elnätets tillförlitlighet. Två scenarier utvärderades i dimensioneringen av UPS systemet. Scenario 1 presenterar den ursprungliga planen av EcoSwell som inkluderar all utrustning som var avsedd att strömförsörjas av UPS systemet, medan scenario 2 är en reducerad version av scenario 1 för att minska de totala kostnaderna. För scenario 1 kommer totalt 36 batterier och 48 solceller att krävas för att försörja all utrustning med energi. I scenario 2 kommer 20 batterier och 24 solceller att behövas. OMP Solar blev den utvalda leverantören av solceller och batterier och den totala kostnaden för installation och all extrautrustning är 66 713,98 S/ (184 036 SEK). Det uppskattades att 37 % och 17 % för scenario 1 respektive 2 av den totala energianvändningen vid vårdcentralen kommer att utgöras utav UPS systemet., Marginalization in terms of electricity access presents a significant challenge in remote areas in Peru. The resilience of the electric grid is low, and this presents a threat to important infrastructure such as hospitals and medical centers. According to the World Health Organization, 50% of vaccines worldwide are wasted due to improper handling in which power cuts is a major problem. The aim of this study was to increase the energy resilience of a medical center located in Talara in northern Peru. In pursuit of this aim, technical sizing of an uninterruptable power supply (UPS) system consisting of photovoltaic modules and lead-acid gel batteries was done. Two qualitative interviews with an electricity distributor in northern Peru and a supervisory authority was made to deepen the knowledge of what challenges exist regarding the reliability of the electric grid. Two scenarios were evaluated in the sizing of the UPS. Scenario 1 presents the original plan by EcoSwell including all equipment that was intended to be powered up by the UPS, while scenario 2 is a reduced version of scenario 1 to decrease overall costs. For scenario 1 a total of 36 batteries and 48 solar modules will be required to power up all equipment. In scenario 2, 20 batteries and 24 solar modules will be required. OMP Solar was the chosen provider of solar modules and batteries and the total cost for installation and all auxiliary equipment is 66 713,98 S/ (184 036 SEK). It was estimated that 37% and 17% for scenario 1 and 2 respectively of the total energy usage at the medical center will be from the UPS.

Food sustainability depends significantly on packaging since it helps maintainfood safe and fresh throughout its shelf life, resulting in the least amount ofwaste and the least negative environmental impact. The main objective of thisstudy is to determine the adsorbed and released amount of antimicrobial agents(benzoic acid and thymol) on modified calcium carbonate (MCC) by investigating adsorption isotherm at 25°C and desorption kinetics at both 22°C and5°C of anti-microbial to identify potential solutions to enhance the long-termsustainability of fresh products such as meat. These agents were incorporatedinto specialized food pads to mitigate bacterial growth in food packaging instead of being directly added to the food. Additionally, the study aimed to determine the amount of carbon dioxide generated when MCC, used as an adsorbent in combination with citric acid, comes into contact with the meat liquid,as this has an impact on the growth of aerobic microorganisms.The findings revealed that MCC adsorbed 44% and 55% of the initial quantities of benzoic acid (BA) and thymol, respectively. Furthermore, after 12 seconds from an initial adsorption amount of 19 mg/g, the maximum amount ofthymol released from MCC was measured at 0.120 mg/ml (approximately0.126%). Similarly, for an initial adsorption amount of 15 mg/g, the quantityof BA released was found to be 0.080 mg/ml (approximately 0.106%). TheUV-spectrophotometer was utilized to determine the amounts of adsorbed anddesorbed anti-microbial agents, while Checkmate 3 was used to assess the release of carbon dioxide.Significantly, the utilization of food pads demonstrated a significant enhancement in the release of carbon dioxide. Interestingly, the presence of anti-microbial agents did not have any influence on the generation of carbon dioxide.This research provides valuable insights into the potential application of foodpads and MCC as effective strategies for preserving fresh meat products bycontrolling mic, Sammanfattning Livsmedelshållbarhet beror i hög grad på förpackningar eftersom det hjälpertill att hålla maten säker och fräsch under hela dess hållbarhetstid, vilket resulterar i minskad mängd avfall och mindre negativ miljöpåverkan. Huvudsyftetmed denna studie var att bestämma den adsorberade och frigjorda mängdenantimikrobiella medel (bensoesyra och tymol) på modifierat kalciumkarbonat(MCC) genom att undersöka adsorptionsisoterm vid 25°C och desorptionskinetiken vid både 22°C och 5 °C av antimikrobiellt medel för att identifierapotentiella lösningar för att förbättra den långsiktiga hållbarheten för färskaprodukter som kött. Dessa medel inkorporerades i specialiserade food pad föratt mildra bakterietillväxt i livsmedelsförpackningar istället för att läggas direkt till maten. Dessutom syftade studien till att fastställa mängden koldioxidsom genereras när MCC, som används som adsorbent i kombination med citronsyra, kommer i kontakt med köttvätskan, eftersom detta har en inverkan påtillväxten av aeroba mikroorganismer.Resultaten visade att MCC adsorberade 44 % och 55 % av de initiala mängderna bensoesyra (BA) respektive tymol. Vidare, efter 12 sekunder från eninitial adsorptionsmängd på 19 mg/g, mättes den maximala mängden tymolsom frigjordes från MCC till 0,120 mg/ml (ungefär 0,126%). På liknande sätt,för en initial adsorptionsmängd på 15 mg/g, visade sig mängden frisatt BA vara0,080 mg/ml (ungefär 0,106%). UV-spektrofotometern användes för att bestämma mängderna av adsorberade och desorberade antimikrobiella medel,medan Checkmate 3 användes för att bedöma frisättningen av koldioxid.Betecknande nog visade användningen av food pad betydande förbättring avutsläppet av koldioxid. Intressant nog har närvaron av antimikrobiella medelinte haft någon inverkan på genereringen av koldioxid. Denna forskning gervärdefulla insikter om den potentiella tillämpningen av food pad och MCC someffektiva strategier för att bevara färska köttprodukter genom att kontrolleramikrobiell ak

This study aims to scrutinize and compare the environmental impacts of biobased 2,3-butanediol (BDO) and its fossil-based counterpart. BDO is a fundamental chemical in various industries, traditionally derived from petroleum sources. Wood residues, largely available in Nordic countries, are sustainable alternative feedstocks, offering potential environmental benefits. Material flow analysis followed by consequential life cycle assessment (LCA) were employed to quantify the potential environmental burdens associated with various biorefinery stages of wood-based BDO production. The findings indicated that refraining from wood combustion and, instead, utilizing wood in a biorefinery to produce BDO as the main product, with methane and fertilizer as coproducts from the waste residue, resulted in 125%, 52%, and 90% better environmental performance regarding human health, climate change, and resource scarcity, respectively, compared to fossil-based BDO production. The results offer valuable insights for technology developers and policymakers, empowering them to make informed decisions and support sustainable practices.

To provide protection against corrosion in harsh environments, high performance anticorrosive coatings are applied on steel structures at all scales. However, to also limit the use of fossil-based ingredients, there is a growing demand to incorporate renewable raw materials in the coating formulations. In this study, to replace pigments and fillers of an epoxy novolac coating, technical Kraft lignin particles were ground and size fractionated (i.e., sieved), and used for formulation work. The effects of sieved and unsieved Kraft lignin, as structure-reinforcing components, on the anticorrosive and mechanical performance of epoxy coatings were subsequently investigated using the following methods: size exclusion chromatography (SEC), phosphorous nuclear magnetic resonance spectroscopy (31P NMR), scanning electron microscopy (SEM), differential scanning calorimeter (DSC), salt spray exposure, pull-off, König pendulum hardness, and chemical resistance tests. Compared to the unsieved-lignin reference (U-L EN), the coating based on lignin fines (S-L EN) showed about 31 % lower rust creep after 70 days of salt spray exposure. However, no surface defects or chemical degradation were observed for any of the coatings. For the S-L EN coating, excellent adhesion strength (23 MPa) and impact resistance (0.49 N), relative to reference values of 17 and 13 MPa and 0.41 and 0.07 N for commercial and lignin-based diglycidyl ether bisphenol F (L-DGEBF) coatings, respectively, were measured. The addition of lignin particles did not influence the chemical resistance, the hardness, and the glass transition temperature of the epoxy novolac coatings. In summary, chemically unmodified Kraft lignin particles, after grinding and sieving, can be incorporated in epoxy novolac coatings (up to 25 vol%), thereby providing a bio-based alternative to pigments and fillers in heavy duty coatings (primers in particular)., QC 20230719

Sodium sulfite is commonly used for impregnating wood chips prior to refining when producing high-yield pulps such as CTMP. The impregnation process should ideally result in evenly sulfonated lignin, i.e. similar concentrations of sulfite (SO3 ^2-) ions in all parts of each wood chip. Sulfonated lignin is known to swell the fiber wall, which is beneficial for developing higher joint strength between fibers. In reality, even sulfonation is not easy to achieve considering variations in wood chip size, density, quality, etc. Being able to trace where the sulfite ions end up in the wood or fiber structure can therefore be key to both process and product development in the future. Synchrotron measurements can provide an understanding of the sulfur distribution both inside single wood fibers and on a larger scale between wood fibers. There is little knowledge of wood fiber nanostructures in 3 dimensions, although some interesting research has been conducted recently [1]. We have compared these measurements with 2D synchrotron XRF mappings [2]. The 3D material mapping provides insight into a sub-fiber level, but the 2D mapping technique might be preferable when studying sulfur distributions due to the highly uneven sulfur content observed. We can probably learn more about the development of fiber-joint-strength and strength uniformity in products by characterizing the distribution of sulfur on the sub-fiber level. This paper discusses feasible future measurement strategies. [1] Fernando, D., et.al, Sci Rep 13, 2350 (2023). DOI: 101038/s41598-023-29113-x [2] Norlin, B., et.al, JINST 18 C01012. DOI: 10.1088/1748-0221/18/01/C01012

The use of PPE has drastically increased because of the SARS-CoV-2 (COVID-19) pandemic as disposable surgical face masks made from non-biodegradable polypropylene (PP) polymers have generated a significant amount of waste. In this work, a low-power plasma method has been used to degrade surgical masks. Several analytical techniques (gravimetric analysis, scanning electron microscopy (SEM), attenuated total reflection-infra-red spectroscopy (ATR-IR), x-ray photoelectron spectroscopy (XPS), thermogravimetric analysis/differential scanning calorimetry (TGA/DSC) and wide-angle x-ray scattering (WAXS)) were used to evaluate the effects of plasma irradiation on mask samples. After 4 h of irradiation, an overall mass loss of 63 +/- 8%, through oxidation followed by fragmentation, was observed on the non-woven 3-ply surgical mask, which is 20 times faster than degrading a bulk PP sample. Individual components of the mask also showed different degradation rates. Air plasma clearly represents an energy-efficient tool for treating contaminated PPE in an environmentally friendly approach.

Energy use, together with consumption of raw materials, machine clothing, and wet end chemicals, are some of the most critical aspects in successful tissue making today. This work was aimed at developing a laboratory-scale method of estimating dewatering mechanisms, vacuum efficiency, and energy use of Through Air Drying (TAD) of tissue. When compared to pilot data, the results of the new laboratory method for investigating dewatering during TAD were in the same magnitude, around 24 to 26% dryness after vacuum dewatering, and 27 to 29% dryness after TAD molding. Sheet properties, such as caliper and surface profile, were evaluated and compared to commercial tissue sheets. The results indicate that it will be possible to precisely measure accurate dryness development and penetrated air volume for tissue sheet forming and TAD molding at a laboratory scale. This can contribute to the efforts of implementing a circular forest-based bioeconomy by increasing the fundamental understanding of dewatering of tissue paper materials, which is facilitated by improvements in energy use. The new method developed in this work will make it easier to assess ideas that are difficult to bring to pilot scale or full scale before learning more of the dewatering capabilities. The authors are convinced that improved knowledge of tissue dewatering mechanisms, forming, and material transport during and after TAD dewatering can increase the efficiency of the industrial manufacturing processes.

Producing tissue paper is an energy-demanding process; a significant amount of energy is expended when removing water by vacuum, mechanical pressing, and thermal drying. Because the water is most energy-demanding to remove in drying, making the preceding step of vacuum dewatering more efficient would benefit the whole process. This article focuses on developing a laboratory-scale method for verifying the nature of diminishing returns of water removal and investigating efficiency strategies of the vacuum dewatering. The theoretical concept of successive vacuum suction boxes with progressing vacuum levels was tested at the laboratory scale in order to show quantifiable results of the previously solely theoretical concept. The results confirmed that vacuum dewatering can be improved by adding progressively higher vacuum levels and that such a practice can benefit both outgoing dryness levels and expended vacuum pump energy. To truly examine the power of progression of vacuum levels, rewetting can be included in the calculations, by using an approximate value collected from pilot or full-scale measurements. For any new fiber mix, pulp type, vacuum level setup, basis weight, etc. the vacuum levels, rewetting, and dwell times need to be tuned to that specific case., Copyright note from the publisher:Authors retain rights to their material, which, upon acceptance by the journal, is uploaded and made public on the Internet. The journal retains no copyright. Users have the right to read, download, copy, distribute, print, search, or link to the full texts of articles in the journal, and users can use, reuse, and build upon the material in the journal for non-commercial purposes as long as attribution is given when appropriate or necessary.

Livscykelanalys är en metod som utformades och utvecklades för att kvantifiera miljöpåverkan från produkter och tjänster för mer än trettio år sedan. Sedan dess har den kontinuerligt förbättrats och blivit mer och mer robust. Som tillverkare av kemiska produkter och monomerer använder Arkema livscykelanalys för att mäta sina produkters miljöpåverkan. Detta görs för att förstå enskilda produkters fotavtryck samt företagets övergripande miljöpåverkan. För att göra detta används ISO-normerna 14040 och 14044. Dessa normer anger generiska ramar för LCA-beräkningar men är inte specifika för den kemiska industrin. Med tanke på att metodologiska svårigheter kan uppstå inom den kemiska sektorn har många riktlinjer och rekommendationer publicerats på senare tid. I denna uppsats studeras och jämförs några av dessa riktlinjer. Tillämpningen av dessa metoder utförs på två produkter inom Arkemas portfölj: akrylsyra och etylakrylat, som är byggstenar för många polymerer. Resultaten av utvärderingen visar på områden där förbättringar kan göras. För de studerade produkterna är råvarorna de största bidragande orsakerna. Därför kan det vara fördelaktigt att övergå från petroleumbaserade material till biobaserade. Att välja den minst miljöpåverkande produktionsvägen är också ett sätt att aktivt minska produkternas koldioxidavtryck., Life Cycle Assessment is a methodology that has been designed and developed to quantify the environmental impacts of products and services more than thirty years ago. Since then, it has been in continuous improvement and becomes more and more robust. As a producer of chemical products and monomers, Arkema uses Life Cycle Assessment to measure the environmental impact of its products. This is done to understand the footprints of individual products as well as the company's overall environmental impact. To do so, the ISO norms 14040 and 14044 are used. These norms set generic frames for LCA calculation but are not specific to the chemical industry. Considering that methodological difficulties can arise in the chemical sector, many guidelines and recommendations are being published recently. In this thesis, some of those guidelines are studied and compared. The application of these methodologies is performed on two products within Arkema’s portfolio: acrylic acid and ethyl acrylate, which are building blocks for many polymers. The results of the assessment reveal areas where improvements can be made. For the products studied, the main contributors are the raw materials. Therefore, transitioning from petroleum-based materials to biobased ones could be beneficial. Additionally, selecting the least impactful production route is also a way to actively reduce the carbon footprint of the products.

Med övergången till elektrifiering inom transport uppstår nya utmaningar när det gäller batterisystem som placeras i elfordon. Det finns för närvarande en möjlighet att minska riskerna med toxiciteten hos partiklar som sprutas ut med de gaser som bildas under termisk rusning i litiumjonbattericeller som är placerade i batterisystem. Syftet med denna avhandling är att identifiera potentiella material för partikelfiltrering från dessa gaser, undersöka de valda materialens prestanda i ett experiment, och föreslå material för framtida studier. Filtermaterialet är avsett att sitta vid ventilen i batteripacket. Totalt valdes 5 filter för experimenten, där 3 av dessa var mikrofiberfilter gjorda av kvarts och 2 var mikrofiberfilter av glas. Filtren klämdes mellan stålplattor med ett hål, och placerades 40 cm ovanför battericellens ventil. Battericellerna utlöstes till termisk rusning och filtren placerades i den direkta vägen för utslungade partiklar för att testa deras termiska motstånd och partikelretentionsförmåga. Filtren karaktäriserades med hjälp av vägning, svepelektronmikroskopi, samt energidispersivt röntgenspektroskopi. Efter ett första test ansågs glasfiberfiltren inte ha tillräckligt hög värmeresistens för att fortsätta testas. Kvartsmikrofiberfiltren varierade i fråga om värmeresistens, där de ibland brann upp och ibland förblev helt intakta. Detta berodde troligtvis till stor del på skillnader i termisk rusning mellan experimenten på grund av varierande uppvärmningsparametrar. Kvalitativt sett lyckades kvartsmikrofiberfiltren fånga upp partiklar, men det kan inte kvantifieras i detta experiment hur effektiva de var när det gäller partikelretention. Filtren visade potential för en enkel tillämpning i batteripacket, men ytterligare forskning bör göras för att undersöka viktiga faktorer, såsom mottryck från filtren. Dessutom finns det vissa material som kan vara intressanta att testa i framtiden, bland annat keramiska material, sintrade metallfiberfiltar och abla, With the shift towards electrification in transportation, new challenges arise with regards to battery systems placed in electric vehicles. There is an opportunity to reduce risks associated with the toxicity of particles ejected from the gases that form during thermal runaway (TR) in lithium-ion battery cells placed in battery systems. The aim of this thesis is to identify potential materials for particle filtration from these gases, investigate the performance of the chosen materials in an experiment, and suggest materials for future studies. The filter material is intended to sit by the vent in the battery pack. In total 5 filters were chosen for the experiments, where 3 of those were quartz microfibre filters and 2 were glass microfibre filters. The filters were sandwiched between steel plates with a hole, placed 40 cm above the battery cell vent. The battery cells were triggered into thermal runaway, and the filters were placed in the direct path of ejected particles in order to test their thermal resistance and particle retention capabilities. The filters were characterized using weighing, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. From an initial test, the glass fibre filters were deemed not sufficient enough in terms of thermal resistance to continue being tested. The quartz microfibre filters varied in terms of thermal resistance, where they at times burned away and other times remained intact. This was largely attributed to differences in TRs between the experiments due to varying heating parameters. Qualitatively, the quartz microfibre filters succeeded in catching particles, but it cannot be quantified in this experiment how efficient they were in terms of particle retention. The filters showed potential in an easy application in battery packs, but further research should be done to investigate important factors, such as back pressure from the filters. Furthermore, there are certain materials that could be interesting to tria