Download or read book Kinetics of Catalytic Upgrading Reactions of Biomass derived and Model Oxygenates written by Benginur Demir and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lignocellulosic biomass, as a renewable carbon-neutral resource, can be utilized to sustainably produce versatile chemicals and fuels while eliminating the environmental issues caused by unrestrained use of fossil fuels. Fundamental understanding of reaction mechanisms and kinetics for many catalytic transformations of biomass-derived compounds is required to synthesize a variety of chemical intermediates in the fine chemical, polymer and pharmaceutical industries. This dissertation focuses on the kinetics of catalytic upgrading reactions of biomass-derived and model oxygenates using a combined approach including experimental, characterization and computational methods to design rational solvent systems, novel catalysts and efficient reactors for biorefineries. Chapter 3 and Chapter 4 discuss the fundamentals of catalytic upgrading of biomass-derived carbohydrates, which have high content of oxygenated functional groups. In Chapter 3, we show that the use of polar aprotic solvents in acid-catalyzed biomass conversion reactions such as fructose dehydration to hydroxymethylfurfural leads to improved reaction rates and product selectivities. In Chapter 4, we illustrate that further increases in catalyst performance in polar aprotic solvents can be achieved through the addition of inorganic salts, specifically chlorides, which was explained by the initial and transition state contributions to solvation effects. In Chapter 5 and Chapter 6, we discuss metal-catalyzed hydrogenation of biomass-derived chemicals employing kinetic studies with a model oxygenate. Chapter 5 reports that platinum displays a self-adjusting surface that is active for the hydrogenation of acetone over a wide range of reaction conditions investigated by reaction kinetics measurements under steady-state and transient conditions, electronic structure calculations employing density-functional theory, and microkinetic modeling with Bragg-Williams and Langmuir approximations. Chapter 6 outlines the promotional effects of water addition on the rates of acetone hydrogenation over oxophilic metal catalysts. Chapter 7 and Chapter 8 present the sustainable valorization of lignin streams to propose a depolymerization technique of lignin that can be combined with a current polysaccharide-centric biorefinery process. Chapter 7 focuses on the kinetics and mechanistic studies on lignin hydrogenolysis on Pd/C to continuously manufacture near-theoretical yields of phenolic platform monomers in a flow-through system. Chapter 8 expands upon the process development on continuous lignin hydrogenolysis and provides insights on the reactivity and selectivity of bimetallic catalysts consisting of an easily-reducible metal (i.e., Pt and Pd) and an oxophilic promoter (i.e., Co and Ag) using [beta]-ether lignin model compounds. Finally, this dissertation is concluded with suggestions for future directions.
Download or read book Mechanistic Understanding of Catalytic Upgrading Reactions of Biomass derived C2 Oxygenates written by Tu Nguyet Pham and published by . This book was released on 2014 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Chemical Catalysts for Biomass Upgrading written by Mark Crocker and published by John Wiley & Sons. This book was released on 2020-03-09 with total page 634 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive reference to the use of innovative catalysts and processes to turn biomass into value-added chemicals Chemical Catalysts for Biomass Upgrading offers detailed descriptions of catalysts and catalytic processes employed in the synthesis of chemicals and fuels from the most abundant and important biomass types. The contributors?noted experts on the topic?focus on the application of catalysts to the pyrolysis of whole biomass and to the upgrading of bio-oils. The authors discuss catalytic approaches to the processing of biomass-derived oxygenates, as exemplified by sugars, via reactions such as reforming, hydrogenation, oxidation, and condensation reactions. Additionally, the book provides an overview of catalysts for lignin valorization via oxidative and reductive methods and considers the conversion of fats and oils to fuels and terminal olefins by means of esterification/transesterification, hydrodeoxygenation, and decarboxylation/decarbonylation processes. The authors also provide an overview of conversion processes based on terpenes and chitin, two emerging feedstocks with a rich chemistry, and summarize some of the emerging trends in the field. This important book: -Provides a comprehensive review of innovative catalysts, catalytic processes, and catalyst design -Offers a guide to one of the most promising ways to find useful alternatives for fossil fuel resources -Includes information on the most abundant and important types of biomass feedstocks -Examines fields such as catalytic cracking, pyrolysis, depolymerization, and many more Written for catalytic chemists, process engineers, environmental chemists, bioengineers, organic chemists, and polymer chemists, Chemical Catalysts for Biomass Upgrading presents deep insights on the most important aspects of biomass upgrading and their various types.
Download or read book Reaction Pathways and Mechanisms in Thermocatalytic Biomass Conversion II written by Marcel Schlaf and published by Springer. This book was released on 2015-10-30 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt: Volume II presents the latest advances in catalytic hydrodeoxygenation and other transformations of some cellulosic platform chemicals to high value-added products. It presents the theoretical evaluation of the energetics and catalytic species involved in potential pathways of catalyzed carbohydrate conversion, pathways leading to the formation of humin-based by-products, and thermal pathways in deriving chemicals from lignin pyrolysis and hydrodeoxygenation. Catalytic gasification of biomass under extreme thermal conditions as an extension of pyrolysis is also discussed. Marcel Schlaf, PhD, is a Professor at the Department of Chemistry, University of Guelph, Canada. Z. Conrad Zhang, PhD, is a Professor at the Dalian Institute of Chemical Physics, Chinese Academy of Sciences, China.
Download or read book Bifunctional Catalysts for Upgrading of Biomass derived Oxygenates written by and published by . This book was released on 2016 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: Deoxygenation is an important reaction in the conversion of biomass-derived oxygenates to fuels and chemicals. A key route for biomass refining involves the production of pyrolysis oil through rapid heating of the raw biomass feedstock. Pyrolysis oil as produced is highly oxygenated, so the feasibility of this approach depends in large part on the ability to selectively deoxygenate pyrolysis oil components to create a stream of high-value finished products. Identification of catalytic materials that are active and selective for deoxygenation of pyrolysis oil components has therefore represented a major research area. One catalyst is rarely capable of performing the different types of elementary reaction steps required to deoxygenate biomass-derived compounds. For this reason, considerable attention has been placed on bifunctional catalysts, where two different active materials are used to provide catalytic sites for diverse reaction steps. Here, we review recent trends in the development of catalysts, with a focus on catalysts for which a bifunctional effect has been proposed. We summarize recent studies of hydrodeoxygenation (HDO) of pyrolysis oil and model compounds for a range of materials, including supported metal and bimetallic catalysts as well as transition-metal oxides, sulfides, carbides, nitrides, and phosphides. Particular emphasis is placed on how catalyst structure can be related to performance via molecular-level mechanisms. Finally, these studies demonstrate the importance of catalyst bifunctionality, with each class of materials requiring hydrogenation and C-O scission sites to perform HDO at reasonable rates.
Download or read book Sustainable Catalysis for Biorefineries written by Francesco Frusteri and published by Royal Society of Chemistry. This book was released on 2018-07-04 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt: Biorefineries are becoming increasingly important in providing sustainable routes for chemical industry processes. The establishment of bio-economic models, based on biorefineries for the creation of innovative products with high added value, such as biochemicals and bioplastics, allows the development of “green chemistry” methods in synergy with traditional chemistry. This reduces the heavy dependence on imports and assists the development of economically and environmentally sustainable production processes, that accommodate the huge investments, research and innovation efforts. This book explores the most effective or promising catalytic processes for the conversion of biobased components into high added value products, as platform chemicals and intermediates. With a focus on heterogeneous catalysis, this book is ideal for researchers working in catalysis and in green chemistry.
Download or read book Catalytic Conversion of Biomass derived Compounds to Fuels and Chemicals written by Ron Christopher Runnebaum and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Among the potential routes for production of fuels and chemicals from lignocellulosic biomass, fast pyrolysis accompanied by or followed by catalytic upgrading offers excellent potential because the number of conversion steps is small and the processing may be cost effective. Lignin-derived bio-oils can be converted into fuels and aromatic chemicals, with a key processing challenge being the removal of oxygen. The literature of bio-oils conversion is largely lacking in fundamental chemistry, which limits the usefulness of the available data for predicting catalyst performance. To determine a quantitative reaction network, we designed and constructed four identical tubular flow reactor systems with flexibility to produce data at high and at low conversions and with ability to identify and quantify even trace products by GC-MS and GC-FID. Higher conversion data are necessary to determine trace products formed in the conversions of the individual reactants and enable reaction networks that are more detailed than any previously published to be elucidated. Low conversion data are required to determine quantitative kinetics of reactions that lead to the most abundant products. These reactor systems also enabled mass balance closures of greater than 95%. Reaction networks were elucidated to account for the reactions of a group of compounds prototypical of lignin and compounds derived from it, incorporating the representative functional groups, such as aromatic rings and ether linkages--the compounds are anisole, 4-methylanisole, and furan. These reactants are converted in the presence of catalysts representative of important catalyst classes, including solid acid (HY zeolite), supported metal (platinum on [gamma]-Al2O3, Pt/[gamma]-Al2O3), and bifunctional (platinum of SiO2-Al2O3, Pt/SiO2-Al2O3) catalysts. The results show that one of the dominant classes of reactions observed with anisole and 4-methylanisole is transalkylation. When the catalyst was HY zeolite, transalkylation was the only kinetically significant reaction class. Hydrogenation, dehydrogenation, hydrogenolysis (C--O bond cleavage reactions that did not remove oxygen from the organic reactant), and hydrodeoxygenation (C--O bond cleavage reactions that removed oxygen from the organic reactant) were also observed in the conversion of each reactant (anisole, 4-methylanisole, and furan) with the supported-platinum catalysts. The data determine quantitative conversions and selectivities of the products that were formed in relatively high yields at conversions
Download or read book Catalysis written by James Spivey and published by Royal Society of Chemistry. This book was released on 2019-03-15 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt: Catalysts are required for a variety of applications and researchers are increasingly challenged to find cost effective and environmentally benign catalysts to use. This volume looks at modern approaches to catalysis and reviews the extensive literature including direct methane conversion, nanocomposite catalysts for transformation of biofuels into syngas and hydrogen, and catalytic wet air oxidation technology for industrial wastewater treatment. Appealing broadly to researchers in academia and industry, it will be of great benefit to any researcher wanting a succinct reference on developments in this area now and looking to the future.
Download or read book Fundamental Reaction Kinetics Studies of Acid catalyzed Biomass Conversion Reactions Into Chemicals and Fuels written by Max A. Mellmer and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The transition to a sustainable source of chemicals and energy is being driven by political, economic, and environmental concerns associated with petroleum-derived feedstocks. In this context, the conversion of biomass into platform molecules and fuels has received increasing interest. Acid catalysis is pervasive in biomass conversion processes, and recently, it has been shown that organic solvents are beneficial in the chemical conversion of biomass. This dissertation discusses strategies in utilizing nonaqueous solvents for the efficient upgrading of biomass to platform molecules using both homogeneous and heterogeneous acid catalysts, and based on reaction kinetics studies, we outline fundamental principles in understanding solvation effects in acid-catalyzed reactions. Chapter 3, Chapter 4, and Chapter 5 focus on the upgrading of biomass-derived molecules to yield platform chemicals. In Chapter 3, we show that high yields of hydroxymethylfurfural from glucose can be achieved using biomass-derived solvents and a combination of solid Lewis and Brønsted acids. In Chapter 4, the production of furfural from xylose, arabinose, and ribose was studied using H-Beta zeolite in [gamma]-valerolactone. We show in Chapter 5 that furfuryl alcohol is hydrolyzed to levulinic acid in high yields using H-ZSM-5 zeolite as the catalyst in tetrahydrofuran-water solvent systems. In Chapter 6 and Chapter 7, we use polar aprotic solvents to upgrade constituent fractions of biomass. We show in Chapter 6 that cellulose and corn stover can be converted with high yield to levulinic acid using Amberlyst 70 and [gamma]-valerolactone. Chapter 7 outlines a processing strategy using [gamma]-valerolactone for the simultaneous conversion of hemicellulose and cellulose in a single reactor to produce furfural and levulinic acid. Chapter 8, Chapter 9, and Chapter 10 report reaction kinetics studies providing insights into solvation effects in acid-catalyzed reactions using polar aprotic solvents. In Chapter 8, we studied the reaction kinetics of the dehydration of xylose into furfural using nonaqueous solvents. We show in Chapter 9 that polar aprotic solvents also enhance the kinetics of biomass hydrolysis reactions. Finally, in Chapter 10, we dissect solvation effects into initial and transition state contributions using experimental and computational methodologies. This dissertation is concluded with a discussion of future directions.
Download or read book Advanced Functional Solid Catalysts for Biomass Valorization written by Chaudhery Mustansar Hussain and published by Elsevier. This book was released on 2020-05-29 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advanced Functional Solid Catalysts for Biomass Valorization presents the basic concepts in catalysis (homogeneous, heterogeneous, and enzymatic) and the properties of various kinds of heterogeneous solid catalysts, including their structure, porosity, particle size, BET surface area, acid-base, and redox properties. Useful information about biorefineries, types of biomass feedstocks, their structures and properties as well as about several potential catalytic routes for biomass upgrading to useful fuels and chemicals is provided in this book. Importantly, this book covers the most recent developments toward functionalization of various solid catalysts, optimization of catalysts’ properties, developing cascade catalytic strategies, exploring reaction kinetics/mechanisms, and evaluating catalysts’ stability/reusability during biomass upgrading. Current challenges and opportunities for the future biorefineries as well as for the design of advanced functional solid catalysts are critically discussed. Describes catalysis as a promising technology for the development of eco-friendly and economically viable strategies for several important energy and environmental applications. Covers heterogeneous solid catalysts because of their versatile benefits in terms of catalysts’ synthesis, production cost, stability, and reusability as compared to homogeneous liquid catalysts. Provides promising strategies for the design of new catalytic materials, such as carbon materials, metal–organic frameworks, zeolites, and mesoporous silicas. Describes functional solid catalysts for developing one-pot cascade processes for efficient biomass valorization and other vital chemical transformations.
Download or read book Biomass Derived Oxygenates Upgrading Over Mixed Oxide Catalysts written by Senthil Subramaniam and published by . This book was released on 2019 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ethanol can be used as a platform molecule for synthesizing valuable chemicals and fuel precursors. Synthesis of C5+ ketones from ethanol in single step was achieved over a stable Pd-promoted ZnO-ZrO2 catalyst. A sequence of reaction steps is involved in the C5+ ketone formation from ethanol and the key reaction step was found to be the in situ generation of acetone intermediate and the cross aldol condensation between the reaction intermediates acetaldehyde and acetone. The formation of Pd-Zn alloy in situ at the reaction condition was identified to be key factor in maintaining high yield to the C5+ ketones and the stability of the catalyst. The yield of >70% to C5+ ketones was achieved over a 0.1%Pd-ZnO-ZrO2 mixed oxide catalyst and the catalyst was demonstrated to be stable beyond 2000 hour time on stream without any catalyst deactivation.Other oxygenates selectivity to higher ketones, olefins had been identified and the mechanisms had been reported.
Download or read book Catalytic Conversion of Lignin derived Compounds to Fuels and Chemicals written by Tarit Nimmanwudipong and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The environmental problems caused by the production and usage of non-renewable fossil fuels has encouraged scientists to conduct research on alternative fuels. Lignocellolusic biomass is considered one of the most promising resources of alternative liquid fuels as well as renewable chemicals. Among several potential routes for biomass conversion, fast pyrolysis and subsequent catalytic upgrading has gained interest widely. Although the combination involves minimum numbers of steps, the cost of resultant fuels and chemicals is not yet low. Therefore, research is needed for better understanding of the process. This study considered the potential use of "bio-oils", product from fast pyrolysis of lignin, the under-utilized part of lignocellulose, as possible aromatic chemical and fuel feedstock source with the key challenge being the removal of excessive oxygen. The literature of catalytic upgrading of lignin-derived bio-oils is still lacking fundamental chemistry. Detailed and quantitative information about the products, the important reaction pathways, and kinetics is limited, but vital as basis for predicting catalyst choices and designing processes. Thus, our goal was to provide such information and to begin unraveling the chemistry of conversion of oxygenate molecules characteristic of lignin-derived bio-oils--and specifically to understand crucial catalytic oxygen-removal reactions. We investigated the conversion of prototypical compounds that represent important components in lignin-derived bio-oils. The reactions were catalyzed by a solid acid (HY zeolite) and supported metals (Pt/[gamma]-Al2O3), which are typical in petroleum and petrochemical industries. This dissertation addresses catalytic reactions of guaiacol, cyclohexanone, and eugenol. For the first time in this field, our data determine quantitative conversion, selectivity of the products, and approximate kinetics of the primary products in the reactions with Pt/[gamma]-Al2O3. The results show that four major reaction classes including transalkylation, hydrogenation, hydrogenolysis, and hydrodeoxygenation were dominant. Without H2 as a reactant and a metal function in the catalyst, transalkylation was the only important reaction class as observed in the conversion catalyzed by acidic HY zeolite. Higher H2 partial pressure led to higher selectivity of oxygen removal products in the conversion catalyzed by Pt/[gamma]-Al2O3. The data identify the role of catalyst functions and imply that a supported-metal catalyst and high pressure H2 will be necessary for oxygen removal of compounds found in lignin-derived bio-oils. Catalyst deactivation was usually observed in the conversion with HY zeolite and Pt/[gamma]-Al2O3. The earlier results indicate that acid sites of the catalysts were associated with the formation of carbonaceous materials on those catalysts. Therefore, the conversion of guaiacol catalyzed by basic supported platinum (Pt/MgO) was investigated. The data show that Pt/MgO deactivated less rapidly compared to other catalysts. The corresponding selectivity to oxygen removal products was nearly doubled the value observed from the reactions catalyzed by Pt/[gamma]-Al2O3, demonstrating potential value of basic support for selective HDO process. In summary, results obtained from this research lead to better understanding of catalytic conversion of lignin-derived compounds. Extrapolation of these understanding will help predicting catalyst performance in the upgrading of bio-oils and ultimately designing suitable catalysts and optimizing operating conditions for the conversion of lignin to fuels and chemicals.
Download or read book Reaction Pathways and Mechanisms in Thermocatalytic Biomass Conversion I written by Marcel Schlaf and published by Springer. This book was released on 2015-09-25 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt: Volume I mainly focuses on the current understanding of the reaction pathways and mechanisms involved in several important catalytic conversions of cellulose and carbohydrates. It starts with nanoscale illustrations of biomass structures and describes various reactions including cellulose depolymerization to sugars, catalytic aldose-ketose isomerization and dehydration, selective oxidation, hydrogenolysis of cellulose and sugars, and the conversion of short carbohydrates. The specificity and function of different catalysts and reaction media in relation to the catalytic performances for these reactions are discussed with significant mechanistic details. Marcel Schlaf, PhD, is a Professor at the Department of Chemistry, University of Guelph, Canada. Z. Conrad Zhang, PhD, is a Professor at the Dalian Institute of Chemical Physics, Chinese Academy of Sciences, China.
Download or read book Engineering Mixed Solvent Environments for Acid catalyzed Biomass Conversion Reactions written by Theodore W. Walker and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: It has been shown that mixtures of water with polar aprotic cosolvents (mixed solvent environments) can be used to control the rates and selectivities of acid-catalyzed biomass conversion reactions. A quantitative understanding of these solvent effects would therefore enable a powerful measure of control over biomass conversion processes, but this framework is currently lacking. This dissertation combines reaction kinetics studies, spectroscopic methods and molecular dynamics investigations to explore the fundamental aspects underlying the reactivity of biomass-derived oxygenates in mixed solvent environments, and the solvent-mediated decomposition of real biomasses over acid catalysts. Chapters 3 and 4 focus on the production of levoglucosenone (LGO) from cellulose in mixed solvent environments containing dilute sulfuric acid. In Chapter 3, we show that water mediates the interconversion of LGO and its isomer, 5-hydroxymethylfurfural (HMF). Following this insight, we demonstrate in Chapter 4 how the composition water/tetrahydrofuran mixtures can be modulated to control the selectivity of LGO and HMF as coproducts from cellulose conversion. Chapters 5, 6 and 7 combine reaction kinetics studies and molecular dynamics (MD) investigations to probe the fundamental bases whereby mixed solvent environments control the rates and selectivities of acid-catalyzed biomass conversion reactions. In Chapter 5, we show that the rates of acid-catalyzed reactions of biomass-derived oxygenates generalize with the MD-observable properties of water-enriched local solvent domains that nucleate in the immediate vicinity of solvated reactant molecules. In Chapter 6, we demonstrate how the selectivity of acid-catalyzed biomass conversion reactions can be partially understood in terms of the thermodynamic relationships between solvated reactant and product molecules in mixed solvent environments. In Chapter 7, we distill these insights into a model-predictive framework that allows for the rational design of mixed solvent environments for biomass conversion processes using computationally efficient screening methods and minimal experimentation. In Chapter 8, we use solid-state nuclear magnetic resonance (NMR) spectroscopy to explore how mixed solvents containing acid catalysts alter the properties cellulosic structures in real biomass. We show that these NMR-observable properties predict the extent to which hydrolytic enzymes are able to depolymerize the residual cellulose into glucose. This dissertation is concluded with a discussion of future directions.
Download or read book Catalytic Conversion of Biomass derived Platform Molecules to Distillate range Fuels written by Nathaniel Eagan and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Current trends in resource consumption and environmental degradation inspire research into the benign transformation of renewable feedstocks to transportation fuels with lower net greenhouse gas emissions. Growing demands in heavier middle-distillate fuels such as diesel and jet fuel particularly motivate the use of carbon-containing feedstocks such as biomass in order to produce liquid fuels substantially similar to those already essential to our economy. Such fuels still require carbon chains larger than those of the monomeric sugars comprising cellulose and hemicellulose, however, thus carbon-carbon bond forming technologies have an important place in the overall biomass-to-distillate landscape. These technologies can be utilized to upgrade platform molecules easily obtainable from biomass. The research discussed here focuses on the use of sorbitol and ethanol platforms, providing promising new directions for their utilization. Sorbitol conversion to distillate fuels first requires a challenging hydrodeoxygenation step focused on producing mono-functional oxygenates. Here this chemistry was promoted by a Co/TiO2 catalyst at yields (56%) competitive with more costly noble-metal catalysts. FT-ICR-MS provided evidence that oligomeric species produced may also act as intermediates in the process. However, this catalyst suffered from irreversible deactivation via oxygenate-promoted Co leaching and sintering which could not be inhibited by the SMSI-stabilization of the catalyst. Pathways by which ethanol can be converted into middle-distillate fuels were then extensively evaluated by considering the fundamental chemistries which can be exploited and how they can be most effectively combined. These processes involve integrating dehydration, hydrogen transfer, olefin oligomerization, aldol condensation, and ketonization in a variety of ways which can overcome the limitations of any one particular technology. From these analyses, promising research directions are recommended. The subsequent focus here is on the use of Guerbet coupling to directly oligomerize ethanol to distillate-range fuels. Cu-doped AlMgO and AlCaO catalysts were first examined for this purpose, with the importance of operating at elevated pressures to promote selective coupling explained. Selective ethanol oligomerization is still challenging with these catalysts, however, given that alcohol selectivities were limited here to ~55% at 20% conversions, and conversions above 30% were difficult to achieve due to inhibition by products of the reaction (e.g. water). Calcium hydroxyapatite (HAP) was then examined as a more selective catalyst for this transformation, though declining selectivities and reaction rates were observed as conversion increased. However, integration of selective ethanol coupling over HAP with bimolecular dehydration shows promise as a novel method to produce diesel-range ethers from biomass-derived sources. Overall a process was developed which can produce these ethers in addition to jet-range paraffins at theoretical yields above 80%. Lastly kinetic modeling was utilized to better understand the limitations and potential of using Guerbet coupling to oligomerize ethanol to distillate-range alcohols. Inhibition effects by water rationalize the aforementioned declining rates and selectivities observed with increasing conversion. In the absence of these phenomena, however, the production of distillate-range alcohols is limited by the underlying kinetics which resemble step-growth oligomerization with the additional stipulation that branched alcohols cannot couple as nucleophiles. The model discussed here suggests that catalysts which promote the electrophilic action of higher alcohols over that of ethanol are promising for promoting linear alcohol formation that cascades into the distillate-range.
Download or read book Fuels and Chemicals from Biomass written by Badal C. Saha and published by . This book was released on 1997 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written for a wide variety of biotechnologists, this book provides a major review of the state-of-the-art in bioethanol production technologies, enzymatic biomass conversion, and biodiesel. It also provides a detailed explanation of a breakthrough in photosynthetic water splitting which could result in a doubling of the efficiency of solar energy conversion by green plants. The book covers production of lactic acid, succinic acid, 1,3-propanediol, 2,3-butanediol, and polyhydroxybutyrate and xylitol. It also includes a chapter on synthesis-gas fermentation.
Download or read book Zeolites in Catalysis written by Jiří Čejka and published by Royal Society of Chemistry. This book was released on 2017-06-07 with total page 547 pages. Available in PDF, EPUB and Kindle. Book excerpt: Accessible references for researchers and industrialists in this exciting field, covering both developments and applications of catalysis.
