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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]

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]

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: 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: 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: Sunn hemp (Crotolaria juncea), is a fast growing, high biomass yielding tropical legume that may be a possible southeastern bioenergy crop. When comparing this legume to a commonly grown summer legume – cowpeas (Vigna unguiculata), sunn hemp was superior in biomass yield (kgha−1) and subsequent energy yield (GJha−1). In one year of the study after 12 weeks of growth, sunn hemp had 10.7Mgha−1 of biomass with an energy content of 19.0Mgha−1. This resulted in an energy yield of 204GJha−1. The energy content was 6% greater than that of cowpeas. Eventhough sunn hemp had a greater amount of ash, plant mineral concentrations were lower in some cases of minerals (K, Ca, Mg, S) known to reduce thermochemical conversion process efficiency. Pyrolytic degradation of both legumes revealed that sunn hemp began to degrade at higher temperatures as well as release greater amounts of volatile matter at a faster rate. [Copyright &y& Elsevier]