Biofuels, Bioproducts and Biorefining 

About: Biofuels, Bioproducts and Biorefining is an academic journal published by Wiley. The journal publishes majorly in the area(s): Biofuel & Biomass. It has an ISSN identifier of 1932-1031. Over the lifetime, 1204 publications have been published receiving 50430 citations. The journal is also known as: Biofuels, bioproducts & biorefining.

Pretreatment: the key to unlocking low-cost cellulosic ethanol

Abstract: New transportation fuels are badly needed to reduce our heavy dependence on imported oil and to reduce the release of greenhouse gases that cause global climate change; cellulosic biomass is the only inexpensive resource that can be used for sustainable production of the large volumes of liquid fuels that our transportation sector has historically favored. Furthermore, biological conversion of cellulosic biomass can take advantage of the power of biotechnology to take huge strides toward making biofuels cost competitive. Ethanol production is particularly well suited to marrying this combination of need, resource, and technology. In fact, major advances have already been realized to competitively position cellulosic ethanol with corn ethanol. However, although biotechnology presents important opportunities to achieve very low costs, pretreatment of naturally resistant cellulosic materials is essential if we are to achieve high yields from biological operations; this operation is projected to be the single, most expensive processing step, representing about 20% of the total cost. In addition, pretreatment has pervasive impacts on all other major operations in the overall conversion scheme from choice of feedstock through to size reduction, hydrolysis, and fermentation, and on to product recovery, residue processing, and co-product potential. A number of different pretreatments involving biological, chemical, physical, and thermal approaches have been investigated over the years, but only those that employ chemicals currently offer the high yields and low costs vital to economic success. Among the most promising are pretreatments using dilute acid, sulfur dioxide, near-neutral pH control, ammonia expansion, aqueous ammonia, and lime, with significant differences among the sugar-release patterns. Although projected costs for these options are similar when applied to corn stover, a key need now is to dramatically improve our knowledge of these systems with the goal of advancing pretreatment to substantially reduce costs and to accelerate commercial applications. © 2007 Society of Chemical Industry and John Wiley & Sons, Ltd

Hydrothermal carbonization of biomass: A summary and discussion of chemical mechanisms for process engineering

Abstract: Hydrothermal carbonization can be defined as combined dehydration and decarboxy lation of a fuel to raise its carbon content with the aim of achieving a higher calorific value. It is realized by applying elevated temperatures (180–220°C) to biomass in a suspension with water under saturated pressure for several hours. With this conversion process, a lignite-like, easy to handle fuel with well-defined properties can be created from biomass residues, even with high moisture content. Thus it may contribute to a wider application of biomass for energetic purposes. Although hydrothermal carbonization has been known for nearly a century, it has received little attention in current biomass conversion research. This review summarizes knowledge about the chemical nature of this process from a process design point of view. Reaction mechanisms of hydrolysis, dehydration, decarboxylation, aromatization, and condensation polymerization are discussed and evaluated to describe important operational parameters qualitatively. The results are used to derive fundamental process design improvements. Copyright © 2010 Society of Chemical Industry and John Wiley & Sons, Ltd

Enzymatic conversion of lignocellulose into fermentable sugars: challenges and opportunities.

Abstract: The economic dependency on fossil fuels and the resulting effects on climate and environment have put tremendous focus on utilizing fermentable sugars from lignocellulose, the largest known renewable carbohydrate source. The fermentable sugars in lignocellulose are derived from cellulose and hemicelluloses but these are not readily accessible to enzymatic hydrolysis and require a pretreatment, which causes an extensive modification of the lignocellulosic structure. A number of pretreatment technologies are under development and being tested in pilot scale. Hydrolysis of lignocellulose carbohydrates into fermentable sugars requires a number of different cellulases and hemicellulases. The hydrolysis of cellulose is a sequential breakdown of the linear glucose chains, whereas hemicellulases must be capable of hydrolysing branched chains containing different sugars and functional groups. The technology for pretreatment and hydrolysis has been developed to an extent that is close to a commercially viable level. It has become possible to process lignocellulose at high substrate levels and the enzyme performance has been improved. Also the cost of enzymes has been reduced. Still a number of technical and scientific issues within pretreatment and hydrolysis remain to be solved. However, significant improvements in yield and cost reductions are expected, thus making large-scale fermentation of lignocellulosic substrates possible. © 2007 Society of Chemical Industry and John Wiley & Sons, Ltd

Biomass recalcitrance. Part I: the chemical compositions and physical structures affecting the enzymatic hydrolysis of lignocellulose

Abstract: Lignocellulosic biomass is recalcitrant to biodegradation due to the rigid and compact structure of plant cell wall The recalcitrance of biomass is mainly constructed by its chemical compositions that build a spatial network as a protective bulwark Generally, the factors affecting the accessibility of biomass cellulose can be divided into direct and indirect factors The direct factors refer to the accessible surface area, and the indirect factors include biomass structure-relevant factors (pore size and volume, particle size, and specific surface area), chemical compositions (lignin, hemicelluloses, and acetyl group), and cellulose structure-relevant factors (cellulose crystallinity and degree of polymerization) Pre-treatment is actually the process to alter indirect factors and improve direct factors thus enhancing the accessibility of cellulose In this review, we summarize the effects of chemical compositions and physical structures on the enzymatic digestibility of lignocellulosic biomass We suggest that future work should be focused on but not limited to the molecular mechanisms of biomass recalcitrance by investigating the microscale and nanoscale features as well as hydrogen bonds network of lignocellulosic biomass © 2012 Society of Chemical Industry and John Wiley & Sons, Ltd

Review of the pyrolysis platform for coproducing bio-oil and biochar

Abstract: Pyrolysis is a relatively simple, inexpensive, and robust thermochemical technology for transforming biomass into bio-oil, biochar, and syngas. The robust nature of the pyrolysis technology, which allows considerable fl exibility in both the type and quality of the biomass feedstock, combined with a distributed network of small pyrolysis plants, would be compatible with existing agriculture and forestry infrastructure. Bio-oil can be used as a fuel in existing industrial boilers. Biochar can be used with existing infrastructure as a replacement for pulverized coal; however, use of biochar as a soil amendment results in signifi cant environmental and agronomic benefi ts. Soil application of biochar is a means of sequestering large amounts of C and may have other greenhouse gas benefi ts. Preliminary reports of the impact of soil biochar applications on crop yields indicate that biochar quality is very important. Biochar is an effective adsorbent for both nutrients and organic contaminants, hence the presence of biochar in soils has been shown to improve water qual- ity in column leaching and fi eld lysimeters studies and it is anticipated to do the same for agricultural watersheds. The pyrolysis platform for producing bio-oil and biochar from biomass appears to be a practical, effective, and en- vironmentally sustainable means of producing large quantities of renewable bioenergy while simultaneously reducing emissions of greenhouse gases. At the present time, the pyrolysis platform is economically marginal because markets for bio-oil and biochar are highly competitive. However, if the USA adopts a program for controlling greenhouse gases, the pyrolysis platform would be highly competitive. Published in 2009 by John Wiley & Sons, Ltd.