Author:
Publisher:
ISBN:
Category : Biomass conversion
Languages : en
Pages :
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Book Description
Following up on previous work, subcontractor investigated three aspects of using NREL ''pretreatment'' technology for total hydrolysis (cellulose as well as hemicellulose) of biomass. Whereas historic hydrolysis of biomass used either dilute acid or concentrated acid technology for hydrolysis of both hemicellulose and cellulose, NREL has been pursuing very dilute acid hydrolysis of hemicellulose followed by enzymatic hydrolysis of cellulose. NREL's countercurrent shrinking-bed reactor design for hemicellulose hydrolysis (pretreatment) has, however, shown promise for total hydrolysis. For the first task, subcontractor developed a mathematical model of the countercurrent shrinking bed reactor operation and, using yellow poplar sawdust as a feedstock, analyzed the effect of: initial solid feeding rate, temperature, acid concentration, acid flow rate, Peclet number (a measure of backmixing in liquid flow), and bed shrinking. For the second task, subcontractor used laboratory trials, with yellow poplar sawdust and 0.07 wt% sulfuric acid at various temperatures, to verify the hydrolysis of cellulose to glucose (desired) and decomposition of glucose (undesired) and determine appropriate parameters for use in kinetic models. Unlike cellulose and hemicellulose, lignins, the third major component of biomass, are not carbohydrates that can be broken down into component sugars. They are, however, aromatic complex amorphous phenolic polymers that can likely be converted into low-molecular weight compounds suitable for production of fuels and chemicals. Oxidative degradation is one pathway for such conversion and hydrogen peroxide would be an attractive reagent for this, as it would leave no residuals. For the third task, subcontractor reacted lignin with hydrogen peroxide under various conditions and analyzed the resulting product mix.
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 61
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Book Description
Following up on previous work, subcontractor investigated three aspects of using NREL ''pretreatment'' technology for total hydrolysis (cellulose as well as hemicellulose) of biomass. Whereas historic hydrolysis of biomass used either dilute acid or concentrated acid technology for hydrolysis of both hemicellulose and cellulose, NREL has been pursuing very dilute acid hydrolysis of hemicellulose followed by enzymatic hydrolysis of cellulose. NREL's countercurrent shrinking-bed reactor design for hemicellulose hydrolysis (pretreatment) has, however, shown promise for total hydrolysis. For the first task, subcontractor developed a mathematical model of the countercurrent shrinking bed reactor operation and, using yellow poplar sawdust as a feedstock, analyzed the effect of: initial solid feeding rate, temperature, acid concentration, acid flow rate, Peclet number (a measure of backmixing in liquid flow), and bed shrinking. For the second task, subcontractor used laboratory trials, with yellow poplar sawdust and 0.07 wt% sulfuric acid at various temperatures, to verify the hydrolysis of cellulose to glucose (desired) and decomposition of glucose (undesired) and determine appropriate parameters for use in kinetic models. Unlike cellulose and hemicellulose, lignins, the third major component of biomass, are not carbohydrates that can be broken down into component sugars. They are, however, aromatic complex amorphous phenolic polymers that can likely be converted into low-molecular weight compounds suitable for production of fuels and chemicals. Oxidative degradation is one pathway for such conversion and hydrogen peroxide would be an attractive reagent for this, as it would leave no residuals. For the third task, subcontractor reacted lignin with hydrogen peroxide under various conditions and analyzed the resulting product mix.
Author: James J. Lischeske
Publisher:
ISBN:
Category : Enzyme kinetics
Languages : en
Pages : 1
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Author: Chang Geun Yoo
Publisher:
ISBN: 9780841298453
Category : Lignin
Languages : en
Pages : 314
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Book Description
Emerging applications of lignin Lignin has great potential as a sustainable, renewable resource for aromatic molecules that can be used in downstream applications. However, its natural heterogeneity and complexity are substantial barriers to its efficient utilization. Industrial lignin, a byproduct from the pulping and biorefinery industries, is usually burned or directly discharged as waste. This work provides a comprehensive exploration of recent lignin utilization strategies with chapters written by experts from agricultural science and engineering, biotechnology, biology, catalysis, chemical engineering, chemistry, wood science, and other related fields.
Author: Thomas B. Reed
Publisher: Biomass Energy Foundation
ISBN: 9781890607005
Category :
Languages : en
Pages : 160
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Book Description
Author: Vincenza Faraco
Publisher: Springer Science & Business Media
ISBN: 3642378617
Category : Science
Languages : en
Pages : 207
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Book Description
Bioethanol has been recognized as a potential alternative to petroleum-derived transportation fuels. Even if cellulosic biomass is less expensive than corn and sugarcane, the higher costs for its conversion make the near-term price of cellulosic ethanol higher than that of corn ethanol and even more than that of sugarcane ethanol. Conventional process for bioethanol production from lignocellulose includes a chemical/physical pre-treatment of lignocellulose for lignin removal, mostly based on auto hydrolysis and acid hydrolysis, followed by saccharification of the free accessible cellulose portions of the biomass. The highest yields of fermentable sugars from cellulose portion are achieved by means of enzymatic hydrolysis, currently carried out using a mix of cellulases from the fungus Trichoderma reesei. Reduction of (hemi)cellulases production costs is strongly required to increase competitiveness of second generation bioethanol production. The final step is the fermentation of sugars obtained from saccharification, typically performed by the yeast Saccharomyces cerevisiae. The current process is optimized for 6-carbon sugars fermentation, since most of yeasts cannot ferment 5-carbon sugars. Thus, research is aimed at exploring new engineered yeasts abilities to co-ferment 5- and 6-carbon sugars. Among the main routes to advance cellulosic ethanol, consolidate bio-processing, namely direct conversion of biomass into ethanol by a genetically modified microbes, holds tremendous potential to reduce ethanol production costs. Finally, the use of all the components of lignocellulose to produce a large spectra of biobased products is another challenge for further improving competitiveness of second generation bioethanol production, developing a biorefinery.
Author: Solar Energy Information Data Bank (U.S.)
Publisher:
ISBN:
Category : Agricultural processing
Languages : en
Pages : 180
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Book Description
Decision to produce; Markets and uses; Market assessment; Prodution potential; Equipment selection; Financial requirements; Decision and planning workssheets; Basic ethanol production; Preparation of feedstocks, Fermentation; Distillation; Types of feedstocks; Coproduct yields; Agronomic considerations; Plant design; Overall plant considerations; Process control; Representative ethanol plant; Maintenance checklist; Business plan; Analysis of financial requirements; Organizational form; Financing; Case study; Summary of legislation; Bureau of alcohol, tabacco, and firearms permit information; Enviromental considerations.
Author: W. Wesley Eckenfelder, Jr.
Publisher: McGraw-Hill Companies
ISBN:
Category : Technology & Engineering
Languages : en
Pages : 992
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Book Description
"The Fourth Edition of Industrial Water Quality provides the technical methods, latest information, and current regulations necessary to conceive, design, and operate industrial pollution control facilities - either as an upgrade or as newly developed industrial complex. Advanced technologies are included as well as updated approaches to control, troubleshoot, and solve the complex issues of managing industrial wastewaters and residuals."--BOOK JACKET.
Author: International Energy Agency
Publisher: Simon and Schuster
ISBN: 9264108831
Category : Electronic books
Languages : en
Pages : 208
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Book Description
Hydrogen and fuel cells are vital technologies to ensure a secure and CO2-free energy future. Their development will take decades of extensive public and private effort to achieve technology breakthroughs and commercial maturity. Government research programs are indispensable for catalyzing the development process. This report maps the IEA countries' current efforts to research, develop and deploy the interlocking elements that constitute a "hydrogen economy", including CO2 capture and storage when hydrogen is produced out of fossil fuels. It provides an overview of what is being done, and by whom, covering an extensive complexity of national government R & D programs. The survey highlights the potential for exploiting the benefits of the international cooperation. This book draws primarily upon information contributed by IEA governments. In virtually all the IEA countries, important R & D and policy efforts on hydrogen and fuel cells are in place and expanding. Some are fully-integrated, government-funded programs, some are a key element in an overall strategy spread among multiple public and private efforts. The large amount of information provided in this publication reflects the vast array of technologies and logistics required to build the "hydrogen economy."--Publisher description.
Author: A E. Hokanson
Publisher:
ISBN:
Category : Alcohol as fuel
Languages : en
Pages : 26
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Book Description
