Characterization and Saccharification of Ionic Liquid Pretreated Lignocellulosic Biomass PDF Download
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Author: Indira Priya Samayam
Publisher:
ISBN:
Category : Biomass conversion
Languages : en
Pages : 208
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Book Description
The goal of this dissertation research is to gain a more fundamental understanding of the impact of ionic liquid (IL) pretreatment of lignocellulosic biomass in production of ethanol and other chemicals through a sugar platform and biochemical conversion of polysaccharides to monomeric sugars. Recalcitrance of cellulose hydrolysis is a primary roadblock for efficient enzymatic conversion of lignocellulosic biomass to monomeric sugars that are fermented to ethanol or other products. The structure of lignocellulosic biomass is rendered amenable to enzymatic saccharification upon IL pretreatment. Changes in the structure of cellulose in relation to the biomass digestibility with varying ionic liquid (IL) pretreatment were examined. Conversion of native cellulose I to amorphous cellulose or cellulose II improved the susceptibility of cellulose to enzymatic hydrolysis. The performance of commercial enzyme mixtures were evaluated through saccharification of IL pretreated biomass substrates (poplar and switchgrass) at low biomass slurry concentrations. Poplar and switchgrass hydrolysis with commercial cellulase, Spezyme CP, and Multifect Xylanase showed synergism between the two enzymes. However, switchgrass hydrolysis was less complete than that of poplar, likely due to differences in hemicellulose structural features. Hydrolysis of polysaccharides in lignocellulose at high biomass slurry concentrations is essential in economical fermentation of hydrolyzates to ethanol and other products. Commercial enzyme mixtures were varied for simultaneous or sequential hydrolysis and fermentation of pentose and hexose sugars with Pichia stipitis for IL treated poplar. In sequential hydrolysis of poplar at modest enzyme loadings of 9 mg/g xylan Multifect Xylanase, 1.8 mg/ g xylan SXA (ß-xylosidase) at 50°C in the first step and 10 FPU/g glucan Spezyme CP, and 40 CBU/g glucan Novozyme 188 at 25°C in the second step, the yields of glucose and xylose at 15% (w/v) solid loadings were 61% and 83%, respectively. The incomplete hydrolysis may be due to the accumulation of cellobiose and low activity of enzymes at 25°C. Further increase in Novozyme 188 loadings or hydrolysis may improve hydrolysis yields. A maximum of 66% theoretical ethanol yield based on initial sugar analysis of poplar was expected from these hydrolyzates if all the released sugars were fermented to ethanol. In sequential hydrolysis and fermentation with P. stipitis, 56% theoretical ethanol yields based on the initial sugar composition of poplar respectively was achieved.
Author: Indira Priya Samayam
Publisher:
ISBN:
Category : Biomass conversion
Languages : en
Pages : 208
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Book Description
The goal of this dissertation research is to gain a more fundamental understanding of the impact of ionic liquid (IL) pretreatment of lignocellulosic biomass in production of ethanol and other chemicals through a sugar platform and biochemical conversion of polysaccharides to monomeric sugars. Recalcitrance of cellulose hydrolysis is a primary roadblock for efficient enzymatic conversion of lignocellulosic biomass to monomeric sugars that are fermented to ethanol or other products. The structure of lignocellulosic biomass is rendered amenable to enzymatic saccharification upon IL pretreatment. Changes in the structure of cellulose in relation to the biomass digestibility with varying ionic liquid (IL) pretreatment were examined. Conversion of native cellulose I to amorphous cellulose or cellulose II improved the susceptibility of cellulose to enzymatic hydrolysis. The performance of commercial enzyme mixtures were evaluated through saccharification of IL pretreated biomass substrates (poplar and switchgrass) at low biomass slurry concentrations. Poplar and switchgrass hydrolysis with commercial cellulase, Spezyme CP, and Multifect Xylanase showed synergism between the two enzymes. However, switchgrass hydrolysis was less complete than that of poplar, likely due to differences in hemicellulose structural features. Hydrolysis of polysaccharides in lignocellulose at high biomass slurry concentrations is essential in economical fermentation of hydrolyzates to ethanol and other products. Commercial enzyme mixtures were varied for simultaneous or sequential hydrolysis and fermentation of pentose and hexose sugars with Pichia stipitis for IL treated poplar. In sequential hydrolysis of poplar at modest enzyme loadings of 9 mg/g xylan Multifect Xylanase, 1.8 mg/ g xylan SXA (ß-xylosidase) at 50°C in the first step and 10 FPU/g glucan Spezyme CP, and 40 CBU/g glucan Novozyme 188 at 25°C in the second step, the yields of glucose and xylose at 15% (w/v) solid loadings were 61% and 83%, respectively. The incomplete hydrolysis may be due to the accumulation of cellobiose and low activity of enzymes at 25°C. Further increase in Novozyme 188 loadings or hydrolysis may improve hydrolysis yields. A maximum of 66% theoretical ethanol yield based on initial sugar analysis of poplar was expected from these hydrolyzates if all the released sugars were fermented to ethanol. In sequential hydrolysis and fermentation with P. stipitis, 56% theoretical ethanol yields based on the initial sugar composition of poplar respectively was achieved.
Author: Christopher James Barr
Publisher:
ISBN:
Category :
Languages : en
Pages : 234
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Book Description
The goal of this dissertation research is to gain a deeper understanding of two major processes in the conversion of lignocellulosic biomass to monomeric sugars. These two core processes are the ionic liquid (IL) pretreatment step as well as biochemical (enzymatic) conversion of polysaccharides to monomeric sugars. Cellulose, one of the three primary components of lignocellulosic biomass, is recalcitrant to enzymatic deconstruction due, in part, to a predominantly crystalline structure. Enzymatic access to cellulose is restricted by hemicellulose and lignin. Pretreatment of lignocellulose by ionic liquids can result in a change in the cellulose structure as well as removal or redistribution of the hemicellulose and lignin. These changes result in a regenerated substrate that is more easily hydrolyzed compared to native substrates. Changes in cellulose structure as well as compositional changes within lignocellulosic biomass were examined as a response to changes in the IL incubation temperature. Maxima in 24 hour hydrolysis of glucan to glucose appears to be substrate dependent with maxima at incubation temperatures: 120°C for poplar, 110°C for switchgrass, and 100°C for corn stover. At these temperatures, native cellulose I was converted to a primarily amorphous substrate where the residual crystalline cellulose exhibits predominantly cellulose II features. This optimal incubation temperature occurred before dramatic xylan losses to the IL wash. In a substrate with minimal lignin and xylan (newspaper), a maximum in enzyme digestibility was seen at a considerably lower (60°C) pretreatment temperature. Differences in polysaccharide structure of IL pretreated poplar and switchgrass can impact hydrolysis of these polysaccharides to monomeric sugars and the formulation of the enzyme mixture needed for complete hydrolysis. These differences predicated studies with mono-component enzymes to determine critical enzyme activities and interactions. Endoglucanase, cellobiohydrolase, ß-glucosidase, endoxylanase, and ß-xylosidase were shown to be critical during hydrolysis for both poplar and switchgrass. Initial studies showed differences between poplar and switchgrass. Beneficial accessory enzymes necessary for hydrolysis of poplar were ferulic acid esterase and exopolygalacturonase while switchgrass required a-L-arabinofuranosidase and ferulic acid esterase. Further studies on switchgrass varying ß-glucosidase activity showed only a-L-arabinofuranosidase was necessary only for hydrolysis of IL pretreated switchgrass. Commercially available enzyme mixtures used for the digestion of lignocellulosic biomass contain many different types of enzymes. The composition of these enzyme mixtures are relatively unknown and are traditionally characterized by the amount of sugar released from the hydrolysis of filter paper in one hour (filter paper unit, FPU). This characterization does not quantitate the xylanolytic component within the mixture, especially accessory hemicellulases whose necessity may vary between substrates. Supplementation of the commercial mixture, Cellic CTec2, with a-L-arabinofuranosidase improved switchgrass xylose yields by 75% and resulted in complete conversion of switchgrass xylan at lower enzyme loadings than previous studies.
Author: Anuj Chandel
Publisher: BoD – Books on Demand
ISBN: 9535111191
Category : Technology & Engineering
Languages : en
Pages : 288
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Book Description
This book provides important aspects of sustainable degradation of lignocellulosic biomass which has a pivotal role for the economic production of several value-added products and biofuels with safe environment. Different pretreatment techniques and enzymatic hydrolysis process along with the characterization of cell wall components have been discussed broadly. The following features of this book attribute its distinctiveness: This book comprehensively covers the improvement in methodologies for the biomass pretreatment, hemicellulose and cellulose breakdown into fermentable sugars, the analytical methods for biomass characterization, and bioconversion of cellulosics into biofuels. In addition, mechanistic analysis of biomass pretreatment and enzymatic hydrolysis have been discussed in details, highlighting key factors influencing these processes at industrial scale.
Author: Nour Shafik El-Gendy
Publisher: John Wiley & Sons
ISBN: 1119785359
Category : Technology & Engineering
Languages : en
Pages : 514
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Book Description
SUSTAINABLE SOLUTIONS FOR ENVIRONMENTAL POLLUTION This first volume in a broad, comprehensive two-volume set, Sustainable Solutions for Environmental Pollution, concentrates on the role of waste management in solving pollution problems and the value-added products that can be created out of waste, turning a negative into an environmental and economic positive. Environmental pollution is one of the biggest problems facing our world today, in every country, region, and even down to local landfills. Not just solving these problems, but turning waste into products, even products that can make money, is a huge game-changer in the world of environmental engineering. Finding ways to make fuel and other products from solid waste, setting a course for the production of future biorefineries, and creating a clean process for generating fuel and other products are just a few of the topics covered in the groundbreaking new first volume in the two-volume set, Sustainable Solutions for Environmental Pollution. The valorization of waste, including the creation of biofuels, turning waste cooking oil into green chemicals, providing sustainable solutions for landfills, and many other topics are also covered in this extensive treatment on the state of the art of this area in environmental engineering. This groundbreaking new volume in this forward-thinking set is the most comprehensive coverage of all of these issues, laying out the latest advances and addressing the most serious current concerns in environmental pollution. Whether for the veteran engineer or the student, this is a must-have for any library. AUDIENCE Petroleum, chemical, process, and environmental engineers, other scientists and engineers working in the area of environmental pollution, and students at the university and graduate level studying these areas
Author: Michael Anthony FitzPatrick
Publisher:
ISBN:
Category :
Languages : en
Pages : 320
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Book Description
In the last decade there has been increasing research interest in the value of bio-sourced materials from lignocellulosic biomass. The dissolution of cellulose by ionic liquids (ILs) has led to investigations including the dissolution of cellulose, lignin, and complete biomass samples and the in situ processing of cellulose. Rapid quantitative measurement of cellulose dissolution in ILs is difficult. In this work, Fourier transform infrared spectroscopy (FTIR) spectra of cellulose dissolved in 1-ethyl-3-methylimidazolium acetate ([emim][OAc]) were subjected to partial least squares (PLS) regression to model dissolved cellulose content. PLS regression was used due to the ease in developing predictive models with this technique in addition to linear regression being ineffectual for modeling when applied to potentially thousands of variables. Applying a normalization data treatment, before regression, generated a model that estimated cellulose content within 0.533 wt%. The methods described provided the basis for a rapid methodology to determine dissolved cellulose content. Development of rapid and facile screening techniques to determine the effectiveness of various ILs as solvents for cellulose or lignin will aid in the development of lignocellulosic based bioproducts. In this work, optical microscopy with and without the use of cross-polarized lenses, was used to monitor cellulose and lignin dissolution in two imidazolium-based and two phosphonium-based ILs as well as n, n-dimethylacetamide/lithium chloride (DMAc/LiCl), demonstrating that this technique could be applied more broadly than solely for ILs. The described optical microscopy methodology was more rapid and sensitive than more traditional techniques, such as visual inspection. The viscosity of [emim][OAc] (162 cP) is 100 times that of water at 20°C and could inhibit its use as a solvent for cellulose. There is a need for simple, low-cost and environmentally benign methods to reduce the viscosity of ILs to aid in cellulose dissolution. In this work, 4 wt% cellulose dissolved in [emim][OAc] was subjected to 50 psi CO2 and 20 psi N2, as a control environment, at both 50°C and 75°C. After 24 hours a nearly 2-fold increase in dissolved cellulose over the N2 control was demonstrated through the application of a 50 psi CO2 environment for cellulose dissolution in [emim][OAc] at 50°C.
Author: Shyamal Roy
Publisher: CRC Press
ISBN: 1000481549
Category : Science
Languages : en
Pages : 59
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Book Description
Bioconversion of lignocellulosic biomass to biofuel is materially obstructed by the compositional and chemical complexity of biomaterials, resulting in a challenge in using these as raw materials for the biofuel production process. This book explains various lignocellulosic biomass pre-treatment methods with emphasis on concepts, practicability, mechanisms of action, and advantages and disadvantages and potential for industrial applications. It also highlights the main challenges and suggests possible ways to make these pre-treatment technologies feasible for the biofuel industry. Features Presents different pre-treatment technologies available for lignocellulosic biomass in a concise manner. Covers use of different pre-treatment methods in laboratory to industrial scales. Includes combined pre-treatment and deep eutectic solvents methods. Discusses problems related to industrial adaptation and corresponding economics of different techniques. Explores significant fuels and chemicals derived from lignocellulosic biomass. This book is aimed at graduate students and researchers working on biomass conversion, characterization, cellulose, hemicellulose, lignin, microbial enzymes, fermentation technology, and industrial biotechnology.
Author: Xin Lu
Publisher: Woodhead Publishing
ISBN: 0128188634
Category : Technology & Engineering
Languages : en
Pages : 268
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Book Description
Advances in 2nd Generation of Bioethanol Production presents a comprehensive overview of technologies and strategies for the conversion of lignocellulosic biomass. This includes issues like sustainable production, environmental and economic benefits, and the main hurdles for upscaling and achieving commercial viability. The book assesses the current biomass conversion technologies, their readiness level for commercial production, and applications of bioethanol in bioenergy and chemical feedstock. The essential conversion process of 2nd generation biofuels, including feedstock composition and pretreatment, is then broken down, with special focus on advantages and pitfalls of each feedstock and process. It also explores the advances and challenges of bioprocessing, hydrolysis technologies and simultaneous fermentation of pentose and hexose. Finally, it presents the current status and bottlenecks for industrial production of bioethanol, as well as its future prospects. Its interdisciplinary approach, drawing upon plant biology, chemistry, biochemistry, microbiology, and genetics, makes Advances in 2nd Generation of Bioethanol Production a must-have reference for researchers in academia and industry R&D. It allows them to compare challenges and opportunities of new technologies and identify the gaps where new technology is needed. Practitioners in the industry also benefit from the information on working principles, design and control of the bioethanol production process, highlighting areas where technology innovation and investment should be placed. Graduate students and researchers newly entered in this field find here a key-resource to thoroughly understand the process as well as the fundamentals of bioethanol and bioproducts production from lignocellulosic biomass. - Presents fundamentals and state-of-the-art of available pathways for bioethanol and bioproducts production from lignocellulosic biomass - Discusses key-challenges for large scale production of bioethanol, such as pretreatment and hydrolysis - Covers the specificities of various feedstocks and processes, the role of microorganisms in fermentation, saccharification limitations and challenges in the C5 and C6 fermentation
Author: Michael E. Himmel
Publisher:
ISBN:
Category : Language Arts & Disciplines
Languages : en
Pages : 522
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Book Description
Discusses the use of enzymatic and microbial biocatalysis for transformation of biomass to liquid or gaseous fuels. Explores metabolic pathway engineering. Discusses characterization of new hydrolytic enzymes. Presents new microorganisms and fermentation techniques. Focuses on lignocellulosic biomass conversion technology.
Author: George T. Tsao
Publisher: Springer Science & Business Media
ISBN: 3540655778
Category : Medical
Languages : en
Pages : 297
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Book Description
This volume reports the latest advances in the science and technology related to the conversion of lignocellulosics. A portion of the volume is devoted to molecular biology of the enzymes and the microbes involved in the conversion. Hydrolysis of cellulose continues to be of prime importance in the overall conversion scheme. Reaction kinetics and mechanisms of cellulases as well as the state-of-the-art methods of cellulase production by submerged fermentation and also by solid state fermentation are included in the volume. The latest advances made in dilute acid hydrolysis of cellulose are described. Finally, some exciting methods and perspectives for bioconverion of lignocellulosics into ethanol, organic acids and other value-added products are described. This volume should be useful to researchers in this area. It should also be helpful to those who want a concise overview of lignocellulosics.
Author: Olga Kuzmina
Publisher: Elsevier
ISBN: 0444633014
Category : Science
Languages : en
Pages : 288
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Book Description
Application, Purification, and Recovery of Ionic Liquids provides a comprehensive overview of the usage of ionic liquids (IL). The book gives a description of the methods used for recovery and purification of ILs, a summary of the economic aspects of using ILs, and a review on the toxicity data of ILs. It is written for researchers, scientists, and engineers working with ILs, their properties, and usages. The book not only describes the chemical aspects, but the economic and environmental aspects as well, making it of particular interest to professionals applying this technology. - Chapters written by scientists in academia and researchers in industry, ensuring coverage of both the scientific fundaments and industrial applications - A single source of information for a broad collection of recovery and purification methods - Provides information on using ionic liquids as green solvents - Includes economic aspects of recovery and reuse of ionic liquids
