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Bangladesh has encountered several challenges, including issues like overpopulation, energy shortage, and global warming for the last few decades. Addressing the increasing energy demand has become a crucial concern because of rapid increase in population and lack of growth in the economic. The electricity production of a country heavily relies on fossil fuels, particularly natural gas, which makes up approximately 54% of the current installed capacity. Bangladesh is an agrarian nation and biomass stands out as a source of renewable energy having significant potential to mitigate the demand for heat and electricity. Biomass resources in the country mainly comprise animal dung, agricultural crop residuals, solid waste from municipalities and forest residues. The existing biomass resources contribute to producing a high amount of energy and content of around 1574.16 PJ of energy equivalent to 437.28 TWh of electricity in which agricultural residues, animal manure, municipal solid waste, and forest residues impart around 852.32 PJ, 399.04 PJ, 112.16 PJ, and 210.64 PJ of energy respectively. This paper explores the extent, possibilities, and technologies associated with biomass energy conversion. Additionally, the study delves into the several biomass projects that the government, as well as non-governmental groups, are working on for environmental sustainability along with plans, challenges, and methods that are being utilized to encourage biomass technologies across Bangladesh. [Display omitted] • The biomass potentiality in Bangladesh for heat and electricity generation is emphasized. • The energy scenario and necessity of alternative energy sources in Bangladesh are discussed. • The available energy conversion technologies from biomass in Bangladesh are presented. • The existing biomass resource content of around 1574.16 PJ (437.28 TWh of electricity) of energy. • The economic aspects and challenges of biomass conversion into energy are discussed. [ABSTRACT FROM AUTHOR]

Recirculation of hydrothermal carbonization (HTC) process water (PW) has been revealed as an effective strategy to promote the recovery of lost dissolved organics in the spent solvent. However, the role of operating parameters such as temperature, time and solid load during recirculation needs to be clarified and better investigated in order to achieve a successful PW valorization. In this paper, the effects of different reaction conditions during HTC with PW recirculation were studied by using orange peel waste as feedstock. The results showed that strong synergistic interactions occurred between the biomass and the recycled solvent, leading to a hydrochar mass yield increase between 0.5 and 11 wt% on a dry basis (d.b.), according to the reaction conditions. PW recirculation, especially at low conversion severity and solid load, increased hydrochar carbon content while drastically reduced the oxygen fraction. The reason was probably related to promoted dehydration and decarboxylation. As result, carbon and energy yields were respectively increased by 26.1 % and 27.0 %, on average. The energy balance outcomes showed that the energy recovery rose up to 8 times by recycling PW compared to phases with deionized water as HTC solvent. [Display omitted] • Hydrochar recovery enhancement is obtained by solvent recirculation. • Intense synergistic effects in hydrochar formation occur at low temperatures. • Dehydration and decarboxylation are promoted by solvent recycling. • Hydrochar carbon retention is increased by 6.2 % after recirculation at 180 °C. • Process water recirculation improves the conversion energy efficiency. [ABSTRACT FROM AUTHOR]

Abstract The CarbOn pilot plant is a continuous biomass carbonization system, rated for a capacity of up to 50 kg h−1 and based on open top, downdraft technology, operating in oxidative pyrolysis in the temperature range of 500–650 °C and equivalence ratio (ER) between 0.1 and 0.2. In the reported validation tests, carried out on small size chestnut woodchips, charcoal mass yield in excess of 22.4 ± 0.7 wt% (dry base) has been achieved, with a fixed carbon content higher than 85 wt% (dry base). The fixed carbon yield (FCy) was 18.2 ± 2.2 wt% (dry base), the char carbon yield (CCy) 38.3 ± 1.6 wt% (dry base) and the net energy conversion efficiency to char (ε) equal to 41.2 ± 2.2% (wet base). Volume concentration of permanent gases in the pyrolysis vapors and condensable species were also measured before incineration and critically compared against literature data. The organic condensate from oxidative pyrolysis was obtained as 4.9 wt% of the dry biomass, and around 58 wt% of its constituents have been identified; in order of decreasing abundance, the organic fraction of condensate was composed of organic acids, aromatics, furans, anhydrous sugars, phenols, methanol, PAHs, acetaldehyde, ketones. Measured and calculated performance data shows that the pilot unit can produce high quality charcoal, meeting and exceeding the product specifications set by standard EN 1860-2 for BBQ lump charcoal as well as those set forth by international voluntary standards on biochar quality for soil application. Graphical abstract Image 1 Highlights • Charcoal yield in excess of 22 wt% were obtained in autothermal carbonization. • Yield of condensable organics was 4.91 wt% of the dry biomass. • Attained energy yield in autothermal carbonization exceeding 41%. • Lower stack emission than traditional carbonization process, high T heat as co-product. • Charcoal has FC = 80.8 wt%, VM 17 wt%, Ash 2.2 wt%, BET 135.4 m2 g−1, PAH <2.5 mg kg−1. [ABSTRACT FROM AUTHOR]

The cultivation of energy cane throughout the Southeastern United States may displace grazed pastures on organic soil (Histosols) to meet growing demands for biofuels. We combined results from a field experiment with a biogeochemical model to improve our understanding of how the conversion of pasture to energy cane during early crop establishment affected soil GHG (CO 2 , CH 4 , and N 2 O) exchange with the atmosphere. GHG fluxes were measured under both land uses during wet, hot and cool, dry times of year, and following a fertilization event. We also simulated the impact of changes in precipitation on GHG exchange. Higher fertilization of cane contributed to greater emission of N 2 O than pasture during warmer and wetter times of the year. The model predicted that energy cane emitted more nitrogen than pasture during simulated wetter than drier years. The modeled emission factor for N 2 O was 20 to 30-fold higher than the default value from IPCC (1%), suggesting that the default IPCC value could dramatically underestimate the consequences of this land conversion on the climate system. Predicted soil CH 4 and CO 2 fluxes were higher in pasture than energy cane, and this difference was not affected by increasing precipitation. Model simulations predicted that soils under first year cane emit more GHGs than pasture, particularly during wet years, but this difference disappeared two years after energy cane establishment. Our results suggest that management practices may be important in determining soil GHG emissions from energy cane on organic soils particularly during the first year of cane establishment. [ABSTRACT FROM AUTHOR]

Seaweeds are considered a viable feedstock for producing energy through the anaerobic digestion conversion process. Its exploitation and use as an alternative renewable energy source; however, remains marginal in the EU. This study aims to evaluate BMP in batch tests of the brown algae Fucus vesiculosus from the Baltic Sea and collected from the Latvian coast. The lab scale BMP tests were oriented towards the evaluation of the effects of mechanical and microwave pre-treatment methods, as well as the impact of a different algae-to-inoculum (A/I) ratio using: i) cutting blades together with mortar and pestle (C&PM) in combination with the use of a 700 W capacity microwave, ii) 1:3 and 1:5 A/I ratios. The cumulative CH 4 yields show a value in the range of 68 ± 21 mL CH 4 /g VS – a trial with no microwave treatment and A/I of 1:3) and 144 ± 28 mL CH 4 /g VS – a trial including a microwave treatment for 3 min, and A/I ratio of 1:3. The results show effectiveness in the range of 7.8%–43.7%, when the microwave pre-treatment is applied for 1.5 min, and a range of 37.2%–45.2% when the pre-treatment is applied for 3.0 min. The results of this study suggest promising potential for F. vesiculosus for biogas production, especially in the Baltic region. [ABSTRACT FROM AUTHOR]

The use of woody biomass in thermochemical conversion is still the most popular method of obtaining bioenergy from this material. Elemental composition has a significant effect on biomass quality and parameters of the combustion process. The aim of this study was to determine the content of selected macroelements (phosphorus, potassium, magnesium, calcium, sodium and sulphur), microelements (boron, copper, iron, manganese and zinc) and trace elements (cadmium, chromium, nickel and lead) in willow biomass of two different varieties and three clones, harvested in annual, biennial and triennial cycles in north-eastern Poland. The study found significant variability between varieties/clones and harvest cycles. Biomass of the UWM 200 clone of Salix alba in triennial harvest rotation had the best parameters as a potential fuel source; it was found to contain the significantly smallest concentrations of P, K, Na, S (1.48, 5.45, 0.08, 0.35 g kg −1 DM, respectively) and Fe, Cr, Pb (208.85, 4.91, 0.83 mg kg −1 , respectively). The content of all of the elements under study decreased significantly with an extended harvest cycle, and the differences, when comparing the triennial to the annual cycle, ranged from −9% to −29% for macroelements, from −7% to −48% for microelements and from −11% to −20% for trace elements. [ABSTRACT FROM AUTHOR]

This paper makes projections of the theoretical and technical potentials of bioenergy supply for 2050. The projections consider changes in available land for bioenergy and food for the global demand and advancements in yield, productivity, expansion of bio-waste recovery, and energy conversion. We present a literature review on projections. We introduced a novel logical and transparent forecasting model. Three future scenarios were established: business as usual (BUS), optimistic trends (OPT), and full adaptation response (FAR). The projection is carried out based on four adjusting factors. An uncertainty analysis was carry-out based on a Monte-Carlo method. Projections of bioenergy production in 2050 were compared with other projections in the literature. The FAR scenario showed that it would be possible to produce twenty-one times the current primary bioenergy supply and to even supply all global primary energy demand in 2050, mostly by energy crops. The assumptions adopted for the BUS and OPT scenarios make their projections more likely. Therefore, the contribution of bioenergy in the global energy matrix is expected to be between 64 and 313 EJ (7.5%–37%) in 2050. There would be a significant change in the composition of the bioenergy supply from today's mostly firewood to energy crops and biowastes. The technical potential for fuel and electric power mostly follow the supply trends for primary bioenergy (theoretical). The potential avoided greenhouse emissions are estimated. The heuristics and the level of transparency of the novel model will allow adjustments and exploration of other scenarios as time passes. • Novel model for projections of the potential of global primary bioenergy supply. • Bioenergy supply potential is shown for 11 different groups of biomass. • Global primary bioenergy supply could increase up to 6 times by 2050 (37% of demand). • Full adaptation response scenario could meet 100% of the global energy demand. • Bioenergy can play a major role in the global energy supply. [Display omitted] [ABSTRACT FROM AUTHOR]

This work concerns the first stage of combustion in a small, air-staged, wood-chip boiler because comprehensive experimental data on the release of wood-volatiles during thermal conversion of solid biomass on grates are necessary to provide reliable data for the validation and optimization of fuel bed models and gas phase combustion models. Despite this importance, data especially from small-scale boilers are rare. This work provides detailed information about the spatial distribution of gaseous species, water and tar above the fuel bed of a commercial boiler with a nominal heat output of 40 kW. Furthermore, the influence of the primary air ratio and the wood-chip moisture on the fuel gas composition and the quantity of fine particulate matter emissions were investigated. Fuel gas volume fractions were: 16.6% CO, 3.6% H 2 , 1.8% CH 4 , 6.3% CO 2 , 0.2% O 2 , 28.3% H 2 O , 43.2% N 2 for wood-chips with a fuel water content of 12% and a primary air ratio of 0.25. The corresponding tar content and the lower calorific value amounted to 78 g m −3 at standard temperature and pressure (STP) and 5.14 MJ kg −1 , respectively. The locally different concentration of species and temperature above the fuel layer resulted from the fuel bed movement. Strong gradients in species fraction were detected in direction of the fuel flow while species fraction gradients perpendicular to fuel bed movement were marginal. Particulate matter emissions of the investigated boiler were 7 mg m −3 (at STP and O 2 volume fraction of 13% in the dry exhaust gas) with aforementioned testing conditions. [ABSTRACT FROM AUTHOR]

The potential of sweet sorghum as an alternative crop for ethanol production was investigated in this study. Initially, the enzymatic hydrolysis of sorghum grains was optimized, and the hydrolysate produced under optimal conditions was used for ethanol production with an industrial strain of Saccharomyces cerevisiae , resulting in an ethanol concentration of 87 g L −1 . From the sugary fraction (sweet sorghum juice), 72 g L −1 ethanol was produced. The sweet sorghum bagasse was submitted to acid pretreatment for hemicellulose removal and hydrolysis, and a flocculant strain of Scheffersomyces stipitis was used to evaluate the fermentability of the hemicellulosic hydrolysate. This process yielded an ethanol concentration of 30 g L −1 at 23 h of fermentation. After acid pretreatment, the remaining solid underwent an alkaline extraction for lignin removal. This partially delignified material, known as partially delignified lignin (PDC), was enriched with nutrients in a solid/liquid ratio of 1 g/3.33 mL and subjected to simultaneous saccharification and fermentation (SSF) process, resulting in an ethanol concentration of 85 g L −1 at 21 h of fermentation. Thus, from the conversion of starchy, sugary and lignocellulosic fractions approximately 160 L ethanol.ton −1 sweet sorghum was obtained. This amount corresponds to 13,600 L ethanol.ha −1 . [ABSTRACT FROM AUTHOR]

The conversion of biomass to hydrocarbon transportation fuels presents unique challenges that generally focus on maintaining high mass and energy yields while removing oxygen from the biomass. Among the many processes proposed and demonstrated, processes that can achieve this efficiently and economically will have a clear advantage. Currently, there is no graphical method to analyze such conversion processes. In this work, we introduce a Funnel Plot to indicate both product quality, in terms of oxygen removal, and energy yield, the energy retained in the product oil from the original biomass. The Funnel Plot is applied to literature data for several processes and compared to an idealized chemical conversion of biomass revealing some of the current challenges associated with biofuel production. [ABSTRACT FROM AUTHOR]

The present study aims to quantify the main biomass resources in South Tyrol (Northern Italy) and estimate the potential contribution for the energy sector. Moreover, four representative feedstocks have been tested in a domestic pellet boiler under standard conditions in order to assess its performance and pollutant emissions. The unexploited biomass potential for energy conversion applications, expressed as dry weight, has been estimated to be 135 000 t y −1 from forest, 14 950 t y −1 for apple pruning residues and 12 000 t y −1 from the industrial sector. The scenario of utilizing the unexploited local biomass resources – in energy systems such as the ones deployed in South Tyrol – would contribute with an annual bioenergy production contribution of 130–270 TJ of electricity and 1700–2100 TJ of heat. Finally, the tested feedstocks can be used in domestic boilers, however, some modifications are required when using agricultural residues. [ABSTRACT FROM AUTHOR]

At pH 4.8 and 50 °C, semi-continuous countercurrent saccharification was performed using α-cellulose. Every second day, solids and liquids were transferred countercurrently and liquid samples were taken to determine sugar concentration in each stage. Train 1 (5 mg protein/g biomass, 8 stages) achieved 87.8% glucose conversion and 102 g/L total sugar. Train 2 (2 mg/g, 8 stages) achieved 56.1% glucose conversion and 65 g/L total sugar. Train 3 (2 mg/g, 16 bottles) achieved 73.6% glucose conversion and 67 g/L total sugar. Compared to 5-day batch saccharification, to achieve the same glucose conversion, enzyme requirements were reduced by factors of 16.8, 8, and 20.5 for Trains 1, 2, and 3, respectively. Further improvements can be realized by changing the enzyme addition point and increasing the number of stages. [ABSTRACT FROM AUTHOR]

Herein, a novel hierarchical porous carbon nanosheet with high N content was successfully prepared by pyrolyzing a spidroin heterologously expressed in engineered Escherichia coli through a pre-carbonization process and a subsequent KOH activation process. The as-obtained carbon materials absolutely inherited the characteristics of natural spidroin at the molecular level and presented a nanosheet structure. At an activation temperature of 800 °C, the material exhibited a large specific surface area (2170 m2 g−1) and a high N content (2.83 wt%). As a result, this material (AS-PC 800) displayed a specific capacitance (C g) of 561 or 384 F g−1 at 0.5 A g−1 in 6 M KOH electrolyte, based on a three- or two-electrode system, respectively. The assembled symmetrical coin-like supercapacitor showed a good rate capability (C g held 353 F g−1 at 20 A g−1) and cycling stability (C g retained over 95.8% after 10000 cycles at 5 A g−1). The symmetrical device delivered a high energy density of 85.84 Wh kg−1 at a power density of 800 W kg−1 with the [BMIm]BF 4 /AN electrolyte. Additionally, AS-PC 800 exhibited the optimal oxygen reduction properties. The onset reduction potential began at 0.98 V vs. RHE which is very close to that of the commercial 20% Pt/C (1.04 V) catalyst. This work provides an innovative method for exploring novel biomass precursors in the development of porous carbon materials for energy conversion and storage applications. [Display omitted] • A new carbon nanosheet derived from a native-sized recombinant spidroin is prepared. • This carbon nanosheet inherits the trait of the spidroin at the molecular level. • The carbon nanosheet exhibits excellent supercapacitance and ORR property. • This work uses the synthetic biology means to explore new carbon materials. [ABSTRACT FROM AUTHOR]

Research is focused on the utilisation of waste or residue biomass for bioenergy conversion. A promising conversion technology for the production of liquid biofuels from residue biomass is a process called Thermo-Catalytic Reforming (TCR ®​ ) which is a combination of prior thermal treatment of the biomass at mild temperatures (intermediate pyrolysis) followed by a second catalytic treatment step at elevated temperatures (reforming). This article focuses on the conversion of TCR ® liquids from digestate as a feedstock for subsequent hydrocarbon production. The generated bio-oil showed a lower heating value of 34.0 MJ kg − 1 with an oxygen content of 7.0% and a water content of 2.2%. The bio-oil was hydrodeoxygenated using an industrial NiMo–Al 2 O 3 catalyst at temperatures of 503 K–643 K and a pressure of 14 MPa. The hydrodeoxygenated bio-oil reached a lower heating value of 42.3 MJ kg −1 with an oxygen content below 0.8 mg kg −1 and water content of 30 ppm. Product yields and catalyst life give confidence that upgrading of the TCR ®​ bio-oil offers a suitable option to meet the high standards of common fuels. [ABSTRACT FROM AUTHOR]

The conversion of lignocellulosic biomass to ethanol involves three major unit operations such as pretreatment, hydrolysis and fermentation. Each unit operation involves processing of biomass with changes in its structure, and release of fermentable and other sugars and lignin degrading compounds. The evaluation of biomass conversion processes through material balance is fundamentally crucial in its commercialization. This gives an idea about the transfer of biomass from one phase to another and hence eventually of the efficiency of the total process. In the present study, material balance has been evaluated in each unit operations for sorghum biomass to ethanol conversion. An account of carbohydrates in the native as well as pretreated sorghum biomass, the release of fermentable sugars and the conversion of sugars to ethanol was maintained and analysed. Ethanol yield of 91.94 g per kg sorghum was achieved without any detoxification and washing of pretreated biomass after mild acid pretreatment followed by enzymatic hydrolysis and fermentation. [ABSTRACT FROM AUTHOR]

Literature values for glucose release from corn stover are highly variable which would likely result in tremendous variability in bio-refinery ethanol yield from corn stover feedstock. A relatively recent change in United States corn genetics is the inclusion of the Bacillus thuringiensis (Bt) trait, which now accounts for three-fourths of all US planted corn acreage. The objective of this study was to evaluate the effect of corn grain yield, inclusion of the Bt trait, and location environment on corn stover quality for subsequent ethanol conversion. Two hybrid pairs (each having a Bt and non-Bt near-isoline) were analyzed giving a total of 4 hybrids. In 2010 and 2011, field plots were located in Michigan at four latitudinal differing locations in four replicated plots at each location. Stover composition and enzymatic digestibility was analyzed and estimated ethanol yield (g g −1 ) was calculated based on hydrolyzable glucan and xylan levels. Analysis showed that there were no significant differences in total glucose or xylose levels nor in enzymatically hydrolyzable glucan and xylan concentrations between Bt corn stover and the non-Bt stover isolines. Regression analyses between corn grain yield (Mg ha −1 ) and corn stover ethanol yield (g g −1 ) showed an inverse relationship indicative of a photosynthate source-sink relationship. Nevertheless, the quantity of stover produced was found to be more critical than the quality of stover produced in maximizing potential stover ethanol yield on a land area basis. [ABSTRACT FROM AUTHOR]

Alkali metals inherent in black liquor (BL) have strong catalytic activity during gasification. A catalytic co-gasification process based on BL with pyrolysis oil (PO) has the potential to be a part of efficient and fuel-flexible biofuel production systems. The objective of the paper is to investigate how adding PO into BL alters fuel conversion under gasification conditions. First, the conversion times of single fuel droplet were observed in a flat flame burner under different conditions. Fuel conversion times of PO/BL mixtures were significantly lower than PO and comparable to BL. Initial droplet size (300–1500 μm) was the main variable affecting devolatilization, indicating control by external heat transfer. Char oxidation was affected by droplet size and the surrounding gas composition. Then, the intrinsic reactivity of char gasification was measured in an isothermal thermogravimetric analyser at T = 993–1133 K under the flow of CO 2 –N 2 mixtures. All the BL-based samples (100% BL, 20% PO/80% BL, and 30% PO/70% BL on mass basis) showed very high char conversion. Conversion rate of char gasification for PO/BL mixtures was comparable to that of pure BL although the fraction of alkali metal in char decreased because of mixing. The reactivities of BL and BL/PO chars were higher than the literature values for solid biomass and coal chars by several orders of magnitude. The combined results suggest that fuel mixtures containing up to 30% of PO on mass basis may be feasible in existing BL gasification technology. [ABSTRACT FROM AUTHOR]

Complete conversion of glycogen to glucose is achieved by using H 3 PW 12 O 40 ·nH 2 O (HPW) and H 4 SiW 12 O 40 ·nH 2 O (HSiW) as catalysts for the hydrolysis under optimized hydrothermal conditions (mass fraction of catalyst 2.4%, 373 K and 2 h reaction time). The reusability of the catalyst (HPW) was demonstrated. In addition to carrying out the glycogen hydrolysis in an autoclave, other novel methods such as microwave irradiation and sonication have also been investigated. At higher mass fraction of the heteropoly acids (10.5%), glycogen could be completely converted to glucose under microwave irradiation. Sonication of an aqueous solution of glycogen in the presence of HPW and HSiW also yielded glucose. Thus, heteropoly acids are efficient, environmentally friendly and reusable catalysts for the conversion of glycogen to glucose. [ABSTRACT FROM AUTHOR]

The presence of contaminants considerably restricts the application of sewage sludge for the fertilisation and reclamation of soils. Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous in the environment and vary widely in sewage sludge depending on the input of industrial effluents. The objective of the study was the investigation whether the pyrolysis affect (reduces or adds) the total quantity of PAHs in sewage sludge-derived biochars and whether the pyrolysis changes the PAHs spectrum in terms of relative contributions of more hazardous components. Additionally, the trace metal content was determined before and after pyrolysis as well as the ecotoxicological parameters test towards plant ( Lepidium sativum ), bacteria ( Vibrio fischeri ) and crustacean ( Daphnia magna ). Sewage sludges conversion to biochar significantly reduced the content of PAHs (from 8- to 25-fold depending on pyrolysis temperature and kind of sludge). The exception was the content of naphthalene. Naphthalene was predominant in sewage sludge-derived biochars. However the concentration of the most hazardous 5- and 6-rings PAHs in sewage sludge-derived biochars was much lower compared to sewage sludge. The pyrolysis of sewage sludges caused also a significant reduction of their toxicity towards the test organisms. Only in the case of crustacean it was observed that the extracts from some biochars, obtained at higher temperatures (600 °C and 700 °C) were more toxic to D. magna than extracts from sewage sludge. In turn, after pyrolysis an increase was noted for trace metals content (Pb, Cd, Zn, Cu, Ni and Cr). [ABSTRACT FROM AUTHOR]

The conversion of glucose into a potential platform chemical for fuels and plastics, 5-hydroxymethylfurfural (HMF), has been studied using B(OH) 3 as a promoter in different solvents, namely molten mixtures made of choline salts and carboxylic acids, with the aim of developing an inexpensive and less harmful alternative to Cr/ionic liquid systems. Choline chloride-based molten mixtures afforded poor yields of HMF, whereas the yields were improved by replacing choline chloride with choline dihydrogen citrate. The combination of choline dihydrogen citrate and glycolic acid was the best choice, providing an HMF yield of ∼60% at 140 °C within 4 h by adding a small volume of water as a co-solvent. [ABSTRACT FROM AUTHOR]

Tar removal in biomass gasification systems is one of the key challenges to overcome for the successful commercialization of this technology. This study focused on tar conversion over the active char particle besides the simultaneous carbon conversion of the char particle. In the presented model, the char particle was assumed a sphere surrounded by a gas film in a bulk gas composition of naphthalene, nitrogen, steam, hydrogen, carbon monoxide, carbon dioxide and methane. The model treated the heterogeneous gasification reaction kinetics, external and internal mass transfer and changing particle properties during gasification. In addition, the effect of different parameters on naphthalene and carbon conversion was investigated. The investigated parameters were particle size, temperature and time on stream. The gas and solid mass balance equations besides the energy balance equation were solved in the radial direction using a set of initial and boundary conditions. The model results show that the naphthalene and carbon conversion reactions were kinetically limited at the reference conditions of 850 °C bulk gas temperature and 600 μm char particle size. Further, the model calculations show that isothermal char particle can be assumed up to a bulk temperature of about 1160 °C. The variation of the physical properties and pore structure of the char particle with carbon conversion affects the active surface area of the particle. Finally, the results of the single particle model will be extended to a fixed bed reactor model and will be validated with experiments. [ABSTRACT FROM AUTHOR]

The methanolysis of jojoba oil has been studied in the presence of tin powder, dibutyltin diacetate (C 4 H 9 ) 2 Sn(OOCCH 3 ) 2 , dioctyltin diacetate (C 8 H 17 ) 2 Sn(OOCCH 3 ) 2 , dibutyltin oxide (C 4 H 9 ) 2 SnO, dioctyltin oxide (C 8 H 17 ) 2 SnO, diphenyltin oxide (C 6 H 5 ) 2 SnO, dibutyltin chloride dihydroxide (C 4 H 9 ) 2 Sn(OH) 2 Cl, butyltinhydroxide hydrate (C 4 H 9 )Sn(=O)OH. x H 2 O, Ni nanoparticles and Pd nanoparticles act as catalysts. Among these, 1 weight % of dibutyltin diacetate shows the maximum conversion. Then, methanolysis of sunflower oil, neem oil, rocket seed oil and linseed oil into methyl esters studied in the presence of 1% dibutyltin diacetate as a catalyst and was compared their percentage conversions. The experimental yield for the conversion of jojoba oil, sunflower oil, neem oil, rocket seed oil and linseed oil into biodiesel was found to be 71%, 51%, 50.78%, 40.90% and 39.66%, respectively. The experimental yield of the conversion of jojoba oil into methyl esters was found to be increased up to 96% by increasing reaction time, without emulsion formation. The synthesis of jojoba seed oil biodiesel (JSOB), soybean oil biodiesel (SOB), neem oil biodiesel (NOB), rocket seed oil biodiesel (RSOB) and linseed oil biodiesel (LSOB) was confirmed by NMR ( 1 H & 13 C) and FT-IR analyses of biodiesel. [ABSTRACT FROM AUTHOR]

Wheat straw has a vast potential as feedstock for biofuel production in China. However, little information is available regarding variation in cell wall composition and enzymatic digestibility of wheat straw. This study investigated cell wall compositions and biomass digestibility of the straw of 115 wheat accessions from central China using a 1% NaOH pretreatment and mixed enzymatic hydrolysis. Significant variation in cell wall composition and sugar release was observed, with a coefficient variation (CV) ranging from 4.7% to 21.2%. Cellulose, hemicelluloses, alkali detergent hemicelluloses (ADH), and acid insoluble lignin (AIL) positively correlated with each other, and they all negatively correlated with acid soluble lignin (ASL). Hexose yields had a negative correlation with ADH and AIL, and positive correlation with ASL. No apparent undesirable correlation was found between sugar release and grain yield, thus yield and biomass convertibility can be potentially improved simultaneously. Furthermore, the features of the cell wall constitutions were compared with other plants and their implication in determining the best possible conversion strategy was discussed. This initial study is essential to understand the cell wall composition of wheat straw and to explore the potential of wheat straw as feedstock for biofuel production. [ABSTRACT FROM AUTHOR]

Due to concerns about the sustainability of the energy sector, conversion of biomass to energy is increasing its hold globally. Life Cycle Impact Assessment (LCIA) is being adopted as an analytical tool to assess the environmental impacts in the entire cycle of biomass production and conversions to different products. This study deals with the LCIA of straw conversion to district heat in a Combined Heat and Power (CHP) plant and in a district heating boiler (producing heat only). Environmental impact categories are Global Warming Potential (GWP), Acidification Potential (AP), aquatic and terrestrial Eutrophication Potential (EP) and Non-Renewable Energy (NRE) use. In the case of CHP, the co-produced electricity is assumed to displace the marginal Danish electricity mix. The current study showed that straw fired in the CHP plant would lead to a GWP of −187 g CO2-eq, AP 0.01 m2 UES (un-protected ecosystem), aquatic EP 0.16 g NO3-eq, terrestrial EP 0.008 m2 UES, and NRE use −0.14 MJ-primary per 1 MJ heat production. Straw conversion to heat in the CHP plant showed better environmental performances compared to the district heating boiler. Furthermore, removing straw from the field is related to the consequence e.g. decline in soil carbon sequestration, limiting soil nutrient availability, and when compared with natural gas the conversion of straw to heat would lead to a higher aquatic and terrestrial EP and AP. The study also outlays spaces for the detail sustainability assessment of straw conversion in a biorefinery and compare with the current study. [ABSTRACT FROM AUTHOR]

Abstract: This paper proposes and tests novel supply chain designs for bioenergy and biobased products that result in logistical costs savings of 2–38%. The proposed supply chain design reduces the costs of: (1) purchasing logistical harvesting equipment; (2) operating logistical harvesting equipment; and (3) holding feedstock inventory, by using a multitude of crop types as feedstock, instead of just one, as is common in research and practice today. In so doing, this research challenges the prevalent assumption that monocultures, despite their known environmental concerns, are preferable from a costs perspective. Simulation/optimization is used to test supply chain designs, and then to find the environmental conditions where these new supply chain designs could be most profitably implemented. [Copyright &y& Elsevier]

Supercritical water oxidation (SCWO) is an effective, promising technology for destroying almost all kinds of organic waste with the advantage of high removal efficiency and low residence time, and without producing pollutant byproduct. The chemical energy of organic pollutants can be considered as an emerging renewable energy source. As a high-temperature and pressure process, an immense energy demand is required in the pressurization and preheating sections. On the other side, the reactor effluent has a great potential for energy recovery because of the great amount of heat released during the SCWO reaction combined with the previous energy input. Thus, SCWO is not only an organic waste treatment process but also an energy conversion and utilization system. The application of SCWO has been extended to the clean, efficient utilization of low-quality fuels such as high-sulfur coal, heavy oils, and biomass instead of conventional combustion, hydrothermal spallation drilling in geothermal energy production, and heavy oil recovery. However, energy consumption cost is still rather high in the actual process due to insufficient equipment performance, unreasonable energy system integration, and selection of an anti-corrosion and salt plugging reactor. Thus, a systematic, in-depth analysis on energy conversion and utilization in SCWO is conducted for the first time in the paper. The mechanism of exergy destruction analyses indicates that reducing enthalpy change and energy level difference are critical to reducing energy consumption. Suggestions on improving energy efficiency are proposed in the preheating stage, chemical exergy release, and reactor design. [Display omitted] • Energy conversion and utilization in each stage of an SCWO system are analyzed. • Research methods and evaluation parameters for energy utilization are summarized. • Main factors affecting energy efficiency are summarized and analyzed. • The mechanism of exergy destruction is analyzed to reduce energy consumption. • Suggestions on improving energy efficiency are proposed. [ABSTRACT FROM AUTHOR]

The global increase in agri-food production results in a consequential societal requirement to better manage the unavoidable and copious agri-food waste (AFW) generated throughout the agri-food chain. Currently, attaining a zero AFW status is not feasible due to the inefficiencies in the agri-food chain. However, technologies to recover energy (electricity, heat, biofuel) and value-added biomaterials from AFW exist, and their effective adoption offers significant environmental and economic benefits. However, implementing efficient utilisation and valorisation of AFW at the scale needed is a non-trivial engineering challenge that must accomplish optimised energy yield (and conversion efficiencies) without environmental harm from fugitive emissions and discharge of secondary pollutants. Despite advances in standalone conversion technologies (SCTs), including thermal (incineration), biochemical (fermentation/anaerobic digestion), and thermochemical (pyrolysis, gasification and hydrothermal processes), there are still unresolved challenges (e.g., selectivity, low conversion efficiency, downstream upgrading of energy carriers), exacerbated by the accompanying production of polluting intermediates and by-products that scale with the process; potentially significant sources of GHG emissions and environmental risk if discharged untreated. Integrated conversion technologies (ICTs), that combine SCTs have been proposed as an approach that processes intermediates and by-products for further energy recovery at source. Effective implementation has the potential to enhance conversion efficiencies, energy carriers' diversification and yield. This critical appraisal of SCTs, advances in SCTs exploitation as ICTs, and developmental challenges describes the opportunities for efficient utilisation of AFW. The resultant characterisation of barriers to adopting efficient conversion technologies for AFW exploitation also aligns with growing country-level assessments of AFW bioenergy potentials and the next generation of clean energy policy priorities. • Complete agri-food waste (AFW) valorisation requires innovative approaches. • Standalone conversion technologies by-products have up to 50% residual energy. • Integrated conversion technologies enhance energy yield & conversion efficiencies. • HTC-AD integrations are most favourable for AFW; up to 91% efficiency is feasible. • Optimisation studies are critical to facilitate ICTs scale-up & commercialisation. [ABSTRACT FROM AUTHOR]

Abstract: A partial solution to problems associated with anthropogenic greenhouse gas (GHG) emissions could be the development and deployment of carbon-negative technologies, i.e., producing energy while reducing atmospheric carbon dioxide levels. Biofuels have been considered a possibility but have faced limitations due to competition with food production and GHG emissions through indirect land-use change (ILUC). In this article, we show how emissions from ILUC can potentially be reduced by producing food and bioenergy from biochar amended soils. The possibility of yield improvements from biochar would reduce the land requirement for crop production and thus, lead to a reduction in emissions from ILUC. In our application, biochar and bio-oil are produced via fast pyrolysis of corn stover. Bio-oil is subsequently upgraded into a fuel suitable for use in internal combustion engines. Applying the U.S. regulatory method used to determine biofuel life cycle emissions, our results show that a biochar-induced yield improvement in the U.S. Midwest ranging from 1% to 8% above trend can lead to an ILUC credit between 1.65 and 14.79 t CO2-equivalent ha−1 year−1 when future emissions are assessed over the next 30 years. The model is generalizable to other feedstocks and locations and illustrates the relationship between biochar and crop production. [Copyright &y& Elsevier]

Abstract: Given the energetic, demographic and the climatic challenges faced today, we designed a combined food and energy (CFE) production system integrating food, fodder and mixed belts of Salix, Alnus and Corylus sp. as bioenergy belts. The objective was to assess the shoot dry weight-stem diameter allometric relationship based on stem diameter at 10 (SD10) and 55 cm (SD55) from the shoot base in the mixed bioenergy belts. Allometric relations based on SD10 and SD55 explained 90–96% and 90–98% of the variation in shoot dry weights respectively with no differences between the destructive and the non-destructive methods. The individual stool yields varied widely among the species and within willow species with biomass yield range of 37.60–92.00 oven dry tons (ODT) ha−1 in 4-year growth cycle. The biomass yield of the bioenergy belt, predicted by allometric relations was 48.84 ODT ha−1 in 4-year growth cycle corresponding to 12.21 ODT ha−1 year−1. The relatively high biomass yield is attributed to the border effects and the ‘fertilizing effect’ of alder due to nitrogen fixation, benefitting other SWRC components. On termination of 4-year growth cycle, the bioenergy belts were harvested and the biomass yield recorded was 12.54 ODT ha−1 year−1, in close proximity to the biomass yield predicted by the allometric equations, lending confidence and robustness of the model for biomass yield determination in such integrated agro-ecosystem. [Copyright &y& Elsevier]

Abstract: Empty fruit bunch (EFB) from oil palm is one of the potential biomass to produce biofuels like bio-oil due to its abundant supply and favorable physicochemical characteristics. Confirming the assertion, this paper presents an overview of EFB as a feedstock for bio-oil production. The fundamental characteristics of EFB in terms of proximate analysis, ultimate analysis and chemical composition, as well as the recent advances in EFB conversion processes for bio-oil production like pyrolysis and solvolysis are outlined and discussed. A comparison of properties in terms of proximate analysis, ultimate analysis and fuel properties between the bio-oil from EFB and petroleum fuel oil is included. The major challenges and future prospects towards the utilization of EFB as a useful resource for bio-oil production are also addressed. [Copyright &y& Elsevier]

Abstract: This paper provides a literature review of articles on the primary forest fuel supply chain which have been published in English speaking peer-reviewed journals from 1989 to 2011. The focus is on the key issues of the transportation of primary forest fuel to heat and/or power plants: (i) transportation modes, (ii) terminal types, and (iii) forest fuel supply chain management, and provides basics on the logistically relevant characteristics of wood as feedstock such as on various feedstock assortments. The analysed supply chains include the transshipment, storage, handling (e.g. chipping) and transportation of primary forest fuel from the place of harvest to energy conversion plant. Due to spatial distribution, low mass density, low energy density and low bulk density, the transportation of primary forest fuel is crucial for economic efficiency as well as for reduced CO2 emissions. As a consequence of forests accessibility, road transportation (after hauling the biomass to the forest road) is the first step of the modern primary forest fuel supply chain. For longer transportation distances, rail or waterway is preferred because of lower transportation costs per volume transported and lower CO2 emissions. We highlight that some experience exists in multimodal transport, including truck, train or ship. Intermodal transport, however, has not been studied in the past and, therefore, an outlook for the research requirements is made here. [Copyright &y& Elsevier]

Abstract: The Campine region is diffusely contaminated with heavy metals like cadmium. Since traditional excavation techniques are too expensive, phytoremediation is preferred as a remediation technique. In a previous study, the biomass potential from phytoremediation of contaminated agricultural land in the Campine region in Belgium was assessed. Based on recently upgraded figures of willow potential from phytoremediation on agricultural land in the seven most contaminated municipalities of the Belgian Campine region, the current paper uses GIS-knowledge to investigate which of three previously identified locations is most suitable for a biomass plant, taking into account the spatial distribution of the contaminated willow supply and the total cost of willow transport. Biomass transport distance from the centroid of each contaminated agricultural parcel to each of the three potential biomass plant locations was determined following Euclidian distance calculations and distance calculations over the existing road network. A transport cost model consisting of distance fixed and distance dependent biomass transport costs was developed. Of the locations identified, the Overpelt Fabriek site results in the lowest biomass transport distance and costs. When willow allocation for each parcel occurs based on the nearest potential plant location, transport costs are on average 23% lower than when all biomass is transported to the single Overpelt Fabriek site location. Therefore, when only considering transport costs, installing a smaller plant at each of the three potential plant locations would be less expensive than when installing a single biomass plant at the Overpelt Fabriek site. [Copyright &y& Elsevier]

Abstract: Number of annual harvest days is a critical variable in the scheduling of year-round delivery of grasses to a biorefinery. It defines the number of harvest machines required and the size of satellite storage capacity. An increase in both these parameters increases capital cost and thus the average delivered cost of biomass for year-round operation. The objective of this study was to determine the impact (number of harvest machines required and storage capacity required) of several harvest scenarios for switchgrass (Panicum virgatum). Calculations were done for a database of potential production fields within a 48-km radius of Gretna, Virginia. Four harvest scenarios were chosen ranging from short, October–December to extended, July–March. The extended harvest required only 33 round balers while the short (October–December) harvest required 64; consequently, capital cost for extended-harvest balers was only 51% of the baler capital cost for the short season. Maximum required storage capacity was 75% of the total annual harvest for the short season and 44% for the extended season. Capital cost to build storage was reduced by 41% by selecting the extended harvest season. [Copyright &y& Elsevier]

Abstract: Renewable energy will play a crucial role in the future society of the 21st century. The various renewable energy sources need to be balanced and their use carefully planned since they are characterized by high temporal and spatial variability that will pose challenges to maintaining a well balanced supply and to the stability of the grid. This article examines the ways that future ‘energy landscapes’ can be modelled in time and space. Biomass needs a great deal of space per unit of energy produced but it is an energy carrier that may be strategically useful in circumstances where other renewable energy carriers are likely to deliver less. A critical question considered in this article is whether a massive expansion in the use of biomass will allow us to construct future scenarios while repositioning the ‘energy landscape’ as an object of study. A second important issue is the utilization of heat from biomass energy plants. Biomass energy also has a larger spatial footprint than other carriers such as, for example, solar energy. This article seeks to provide a bridge between energy modelling and spatial planning while integrating research and techniques in energy modelling with Geographic Information Science. This encompasses GIS, remote sensing, spatial disaggregation techniques and geovisualization. Several case studies in Austria and Germany demonstrate a top-down methodology and some results while stepwise calculating potentials from theoretical to technically feasible potentials and setting the scene for the definition of economic potentials based on scenarios and assumptions. [Copyright &y& Elsevier]

Biogas plants, increasing in number, produce a stream of fermentation residue with high organic content, providing an energy source which is by now mostly unused. We tested this biomass as a potential feedstock for catalytic gasification in supercritical water (T ≥374°C, p ≥22MPa) for methane production using a batch reactor system. The coke formation tendency during the heat-up phase was evaluated as well as the cleavage of biomass-bound sulfur with respect to its removal from the process as a salt. We found that sulfur is not sufficiently released from the biomass during heating up to a temperature of 410°C. Addition of alkali salts improved the liquefaction of fermentation residues with a low content of minerals, probably by buffering the pH. We found a deactivation of the carbon-supported ruthenium catalyst at low catalyst-to-biomass loadings, which we attribute to sulfur poisoning and fouling in accordance with the composition of the fermentation residue. A temperature of 400°C was found to maximize the methane yield. A residence time dependent biomass to catalyst ratio of 0.45gg−1 h−1 was found to result in nearly full conversion with the Ru/C catalyst. A Ru/ZrO2 catalyst, tested under similar conditions, was less active. [ABSTRACT FROM AUTHOR]

Abstract: Although biomethanol production has attracted most of the attention in the past years, there is a current trend for the synthesis of higher alcohols (i.e. ethanol, plus C3–C4) from biomass gasification. These compounds could be used directly as fuel or fuel additives for octane or cetane number enhancement. These also serve as important intermediates for the chemical industry. In this paper a comparison is performed between the different process configurations a higher alcohols production plant from biomass gasification can take. These options are modelled in Aspenplus™; all steps and important unit operations are presented with the aim to correctly evaluate the peripheral energy requirements and conclude with the overall thermodynamic limitations of the processes. The differentiation between black liquor and solid biomass gasification, the type of catalyst employed, and the effect of the recycling scheme adopted for the reutilization of unreacted syngas are evaluated. The design has to cope with the limited yields and poor selectivity of catalysts developed so far. The gas cleaning is different depending on the different requirements of the catalysts as far as H2S purity. The process modelling results reveal that the hydrogenation of CO to higher alcohols is favoured by high pressure, temperature around 325 °C and high reactor residence times. A biorefinery using modified Fisher–Tropsch (FT) catalysts (MoS2) prevail over modified MeOH catalyst (Cu–Zn based) for HA production. The efficiency of HA production in HHV terms can reach up to 25%. [Copyright &y& Elsevier]

Abstract: The objective of this study was to explore the magnitude of Zimbabwe's biomass resources available for energy production using thermochemical conversion route. This involved estimation biomass from crops, forestry, livestock and Municipal Solid Residues (MSR). A model for estimating biomass energy potential was developed in Microsoft Excel. The crop and forestry production and livestock data used as a basis of calculations was obtained from FAOSTAT. The biomass residues available for energy production were calculated from residues produced considering economic and environmental concerns associated with the removal of crop residues from land and current residue uses. The energy content was obtained by multiplying the available biomass by specific biomass energy content. The total biomass energy was estimated at an annual average of 413.2 PJ but only 279.5 PJ (23.8% crops, 17.8% crop residues, 45.2% forestry resources, 12.2% livestock residue and 1.0% MSR) is sustainably available. Of this energy 189.3 PJ (26.3% from crop residue, 47.9% from woodfuel, 6.4% from forestry residue, 18.0% from livestock residue and 1.5% from MSR) can be used for energy production without competing for resources with food/feed production and other biomass applications. This can meet approximately 48% of the current energy consumption. [Copyright &y& Elsevier]

Abstract: For woody biomass to make a significant contribution to the United States' energy portfolio, harvesting contractors must economically harvest and transport energywood to conversion/processing facilities. We conducted a designed operational study in the Coastal Plain of North Carolina, USA with three replications of three treatments to measure harvesting productivity and costs when utilizing woody biomass. The treatments were: a conventional roundwood only harvest (control), an integrated harvest in which merchantable roundwood was delivered to mills and residuals were chipped for energy, and a chip harvest in which all stems were chipped for energy use. The harvesting contractor in this study typically delivers 2200–2700 t of green roundwood per week and is capable of wet-site harvesting. Results indicate that onboard truck green roundwood costs increased from 9.35 $ t−1 in the conventional treatment to 10.98 $ t−1 in the integrated treatment as a result of reduced felling and skidding productivity. Green energy chips were produced for 19.19 $ t−1 onboard truck in the integrated treatment and 17.93 $ t−1 in the chip treatment. Low skidding productivity contributed to high chip costs in the integrated treatment. Residual green biomass was reduced from 18 t ha−1 in the conventional treatment to 4 and 3 t ha−1 in the integrated and chip treatments, respectively. This study suggests that until energywood prices appreciate substantially, loggers are unlikely to sacrifice roundwood production to increase energywood production. This research provides unique information from a designed experiment documenting how producing energywood affects each function of a harvesting system. [Copyright &y& Elsevier]

Abstract: The most frequently used handling method in Sweden for the extraction of forest fuels is one in which logging residues are piled in harvester heaps to dry within the clear-cutting area before stacking into larger windrows. This handling method, however, requires multiple stages and the amount of handling involved results in a significant loss of biomass that could have been used for energy. This study compares two handling methods for the extraction of logging residues in stands dominated by Norway spruce. The traditional “dried-stacked” method was compared to the “fresh-stacked” method in which logging residues are collected simultaneously during normal logging operations and stacked in windrows at or near the roadside to dry. Determination of fraction composition and moisture content was carried out on the biomass provided to the energy-converting industry shortly after comminuting the logging residues. The results show that the fresh-stacked logging residues contained a higher amount of needles (8%), compared to 4% for the dried-stacked logging residues. However, the amount of needles was considered to be low in both handling methods. Both handling methods were proven to provide adequate drying with moisture content levels at approximately 36% for fresh-stacked and 31% for dried-stacked logging residues. These results indicate that weather and forest conditions have a greater impact on the moisture content than handling method. An acceptance of fresh-stacked logging residues, preferably connected to ash recycling, would afford the energy-converting industries the opportunity to use new technologies, reduce costs and extract a greater biomass total. [Copyright &y& Elsevier]

Abstract: The current study was initiated to evaluate the potential of sugar saps from nipa (Nypa fruticans) palm as sustainable feedstock for ethanol production. Nipa palms managed as plantations on four sites was chosen for this study with palms within 8–100 years of age. All palms studied were found to have the potential to produce sugar saps from 0.4 to 1.2 L d-1 per palm. Further chemical characterization of its saps gave a total composition of 159–214 g kg-1 mainly composed of sucrose, glucose and fructose. In addition, the elemental analysis gave 5 g kg-1 of inorganics with Na, K and Cl being its main inorganic elements. Preliminary batch fermentative assays using Saccharomyces cerevisiae showed that nipa saps can be converted to ethanol within 30–48 h in conditions with and without nutrient supplementation. Furthermore, the fermentation trends were similar to sugarcane sap with high ethanol conversions up to 96.9% and 95.5% achieved for both nutrient conditions. Further analysis on inorganic elements before and after fermentation showed that specific elements of Mg, Ca, P and S were significantly reduced and could have assisted the fermentation. Based on the results obtained from sap collection, chemical characterization and fermentation, the ethanol potential from nipa planted at a density of 1000 ha-1 would range from 4550–9100 L ha-1 y-1. Conclusively, nipa sap showed some interesting characteristics which makes it a potential feedstock for ethanol production. [Copyright &y& Elsevier]

Abstract: The U.S. Energy Independence and Security Act of 2007 mandates the use, if produced, of 6.06 × 1010 L of advanced biofuels by 2022. The objective of this study is to determine the ethanol price necessary for a biorefinery to breakeven when using switchgrass as the single feedstock to produce ethanol. A holistic model that encompasses acquisition of land use services, feedstock production, harvest, harvest machine investment, feedstock logistics (storage, transportation), biorefinery location and size, and biorefinery investment is constructed and used to determine breakeven ethanol price. The model was solved for each of three biomass to ethanol conversion rates (250, 334, and 417 L of ethanol Mg−1 of biomass) and each of three biorefinery investment cost estimates ($2, $4, and $6 × 108 for a biorefinery with annual capacity of 379 × 106 L). Breakeven ethanol prices ranged from $0.44 L−1 with a conversion rate of 417 L of ethanol Mg−1 and an investment cost of $2 × 108, to $0.72 L−1 with a conversion rate of 250 L Mg−1 and an investment cost of $6 × 108. Improving the efficiency of conversion from 250 to 334 L Mg−1 decreases the estimated breakeven cost by $0. 07 L−1. Improved conversion efficiency results in a reduction of the total quantity of feedstock required and in the cost to deliver feedstock. Most of the cost reduction follows from reductions in land required (rent), and biomass harvest, storage, and transportation costs. [Copyright &y& Elsevier]

Abstract: Solid residuals generated from dewatering food processing wastewater contain organic carbon that can potentially be reclaimed for energy through anaerobic digestion. This results in the diversion of waste from a landfill and uses it for a beneficial purpose. Dewatering the waste concentrates the carbon, reducing transportation costs to a farm digester where it can be blended with manure to increase biogas yield. Polymers are often used in the dewatering of the food waste but little is known regarding their impact on biogas production. Four 2 dm3 working volume, semi-continuous reactors, were used at a mesophilic temperature and a solids retention time (SRT) of 15 days. Reactors were fed daily with a blended feedstock containing a food processing sludge waste (FPSW)/manure ratio of 2.2:1 (by weight) as this produced the optimized carbon to nitrogen ratio. Results demonstrated that reconstitution of dewatered FPSW with dairy manure produced approximately 2 times more methane than animal manure alone for the same volume. However, only approximately 30% of volatile solids (VS) were consumed indicating energy potential still remained. Further, the efficiency of the conversion of VS to methane for the blended FPSW/manure was substantially less than for manure only. However, the overall result is an increase in energy production for a given tank volume, which can decrease life cycle costs. Because all FPSW is unique and the determination of dewatering additives is customized based on laboratory testing and field adjustment, generalizations are difficult and specific testing is required. [Copyright &y& Elsevier]

Abstract: Being an agriculture rich state, Punjab has huge potential of biomass resource availability in the form of crop residues. Around 40.142Mty−1 of the total crop residue is generated from various major and minor crops, of which around 71% is consumed in various forms, resulting in 29% as a net surplus available for power generation. Basic surplus and net surplus crop residues for power generation potential were estimated in each district. Sangrur, Ferozpur, Amritsar, Patiala and Ludhiana are the major surplus biomass potential districts, while Rupnagar, Nawashahar, Hoshiarpur, Fatehgarh Sahib, Faridkot and Kapurthalla are least surplus biomass potential districts within the state. It has been estimated that around 1.510 GW and 1.464 GW of power in the state can be generated through basic surplus and net surplus biomass respectively. Besides, the seasonal availability, present usage pattern and costing of important crop residues are also estimated in each district of the state. [Copyright &y& Elsevier]

Abstract: Utilizing biomass from urban landscapes could significantly contribute to renewable energy needs. An experiment was begun in 2007 to evaluate the biomass production from a bermudagrass, Cynodon dactylon var. dactylon (L.) Pers., lawn in Woodward, Oklahoma USA and to estimate the potential biomass yield for the City of Woodward. Each year in April, the lawn was dethatched and fertilized. Mowing began in mid-to-late May and biomass dry matter (DM) yield was estimated by harvesting four 1 m × 16 m areas. In addition, the DM yield of fallen leaves and tree limbs from pruning operations were added to the lawn yield estimates for total annual biomass potential. These data suggest that during years of high growing season precipitation it was possible to harvest from 13.5 to 19.0 Mg of DM biomass per planted hectare from an urban landscape and 8.0 to 12.3 Mg of DM biomass per planted hectare in years with near normal precipitation and temperatures. It was estimated that the City of Woodward could generate about 3750 Mg of biomass dry matter in a normal rainfall year and about 6100 Mg in a high rainfall year if every homeowner collected their lawn thatch and clippings, and tree leaves, twigs, and limbs for bioenergy production. On the basis of a 10 Mg ha−1 annual DM yield, an estimated 164 million Mg of dry biomass material could be collected in the USA from planted urban areas. Biomass from urban landscapes is an untapped resource and further research is needed to fully explore its potential. [Copyright &y& Elsevier]

Abstract: Bio-refinery concepts are currently receiving much attention due to the drive toward flexible, highly efficient systems for utilization of biomass for food, feed, fuel and bio-chemicals. One way of achieving this is through appropriate process integration, in this particular case combining enzymatic bio-ethanol production with catalytic liquefaction of the wet distillers grains with soluble, a byproduct from the bio-ethanol process. The catalytic liquefaction process is carried out at sub-critical conditions (280–370 °C and 25 MPa) in the presence of a homogeneous alkaline and a heterogeneous Zirconia catalyst, a process known as the Catliq® process. In the current work, catalytic conversion of WDGS was performed in a continuous pilot plant with a maximum capacity of 30 dm3 h−1 of wet biomass. In the process, WDGS was converted to bio-oil, gases and water-soluble organic compounds. The oil obtained was characterized using several analysis methods, among them elementary analysis and GC–MS. The study shows that WDGS can be converted to bio oil with high yields. The results also indicate that through the combination of bio-ethanol production and catalytic liquefaction, it is possible to significantly increase the liquid product yield and scope, opening up for a wider end use applicability. [Copyright &y& Elsevier]

Abstract: Lignocellulose into fuel ethanol is the most feasible conversion route strategy in terms of sustainability. Oil palm empty fruit bunch (EFB) generated from palm oil production is a huge source of cellulosic material and represents a cheap renewable feedstock which awaits further commercial exploitation. The purpose of this study was to investigate the feasibility of using steam at 0.28 MPa and 140 °C generated from the palm oil mill boiler as a pretreatment to enhance the digestibility of EFB for sugars production. The effects of steam pretreatment or autohydrolysis on chemical composition changes, polysaccharide conversion, sugar production and morphology alterations of four different types of EFB namely fresh EFB (EFB1), sterilized EFB (EFB2), shredded EFB (EFB3) and ground EFB (EFB4) were evaluated. In this study, the effects of steam pretreatment showed major alterations in the morphology of EFB as observed under the scanning electron microscope. Steam pretreated EFB2 was found to have the highest total conversion of 30% to sugars with 209 g kg−1 EFB. This production was 10.5 fold higher than for EFB1 and 1.6 fold and 1.7 fold higher than EFB3 and EFB4, respectively. The results suggested that pretreatment of EFB by autohydrolysis using steam from the mill boiler could be considered as being a suitable pretreatment process for the production of sugars. These sugars can be utilized as potential substrates for the production of various products such as fuel ethanol. [Copyright &y& Elsevier]

Abstract: The black cumin seed cake (BCSC) is a by-product obtained from the black cumin seeds with cold pressing. This by-product can be utilized as a biomass feedstock for conversion to bio-oil with pyrolysis process. The BCSC samples were initially pyrolyzed on a lab-scale pyrolysis system at different values in the ranges of 300–800 °C and 0.050–0.300 L min−1 to determine the effects of operation temperature and N2 flow rate on the yields on products, respectively. Then, the bio-oil in the highest yield (wB = 44.37%) which was obtained at pyrolysis final temperature (450 °C) temperature, heating rate (35 °C min−1), particle size (dp > 850 μm), and sweeping flow rate of 0.200 L min−1 was characterized by Fourier Transform infra-red (FT-IR) spectroscopy, gas chromatography/mass spectrometry (GC-MS) and column chromatography. Consequently, it was shown that the operating temperature and N2 gas flow rate parameters were effective on the product yields. Also, the important some physico-chemical properties of the pyrolytic oil obtained in high yield were determined as the calorific value of 38.48 MJ kg−1, the empirical formula of CH1.651O0.105N0.042S0.001, the rich chemical content containing many different chemical groups, and the density of 970.25 kg m−3, and the viscosity of 63.42 mm2 s−1. Based on the determined properties of the pyrolytic oil, it was decided that the use of pyrolytic oil derived from the BCSC may possible be for the production of the alternative liquid fuels and finely chemicals after the necessary improvements. [Copyright &y& Elsevier]

Abstract: An overview of the research on biomass upgrading by torrefaction for the production of biofuels is presented. Torrefaction is a thermal conversion method of biomass in the low temperature range of 200–300°C. Biomass is pre-treated to produce a high quality solid biofuel that can be used for combustion and gasification. In this review the characteristics of torrefaction are described and a short history of torrefaction is given. Torrefaction is based on the removal of oxygen from biomass which aims to produce a fuel with increased energy density by decomposing the reactive hemicellulose fraction. Different reaction conditions (temperature, inert gas, reaction time) and biomass resources lead to various solid, liquid and gaseous products. A short overview of the different mass and energy balances is presented. Finally, the technology options and the most promising torrefaction applications and their economic potential are described. [Copyright &y& Elsevier]

Abstract: Bioenergy production involves a series of interrelated activities associated with feedstock production and feedstock-to-energy conversion. Thus, decisions on bioenergy production and deployment should be based on the simultaneous consideration of the entire supply chain. Based on cost minimization of both feedstock production and energy conversion, we develop a generic framework for determining the optimal bioenergy conversion plant size, the corresponding feedstock supply radius, and bioenergy production costs. The theoretical framework elucidates the relationships among activities along the bioenergy supply chain, suggesting strategies for enhancing the cost competitiveness of bioenergy. Such relationships as well as applications of our theoretical model are further illustrated using cases of producing electricity and cellulosic ethanol from biomass. [Copyright &y& Elsevier]

Abstract: Knowing the effect of mill operating factors on biomass size reduction would be useful for predicting or adjusting particle size distributions that affect supply chain efficiency and biomass-to-fuel conversion processes. Wheat straw (Triticum aestivum L.) particle size distributions generated by a knife mill were determined for integral classifying screen sizes from 12.7 to 50.8 mm, operating frequencies from 4.17 to 8.33 Hz, and mass input rates from 2 to 9 kg min−1. Particle distributions were obtained with standardized sieves for forage analysis that included horizontal sieving motion with machined-aluminum sieves of thickness proportional to sieve opening dimensions to reduce inadvertent particle spearing through sieve openings. Several analytical descriptors were examined to mathematically represent the range of particle sizes in the distributions. Screen size and feed rate directly influenced particle size, whereas operating frequency had a weak indirect relation with particle size. The Rosin-Rammler equation adequately fit the knife-milled wheat straw particle size distribution data (R 2 > 0.982). Mass relative span was >1, which indicated a wide distribution of particle sizes. Uniformity coefficient was <4.0 for 12.7 and 19.0 mm screens, which indicated particles of relatively uniform size. Knife mill chopping of wheat straw produced fine-skewed mesokurtic particles with 12.7–25.4 mm screens and strongly fine-skewed mesokurtic particles with 50.8 mm screen. Other size related parameters, such as, geometric mean length, Rosin-Rammler size parameter, median length, effective length, and size guide number, were well predicted as a function of knife mill screen size, feed rate, and mill frequency. Results showed the relative effects of knife mill operating factors to produce particular particle sizes of wheat straw. [Copyright &y& Elsevier]