Download or read book Catalytic Conversion of Biomass derived Molecules Into Mono and Dicarboxylic Acids and Esters written by Yuran Wang and published by . This book was released on 2016 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt: Biomass can serve as a renewable alternative to the inevitably depleting fossil fuel resources and provide feedstocks for the production of fuels and chemicals. Mono- and dicarboxylic acids and esters are key intermediates to chemical products, especially for biodegradable polymers. This thesis has addressed the challenges in chemocatalytic synthesis of mono- and dicarboxylic acids and esters, including gluconic acid, succinic acid, itaconic acid and their esters, from biomass-derived molecules. Gold (Au) catalysts have been rarely investigated for the oxidation of glucose in the absence of a base. These conditions are critical, however, to enable the sequential one-pot combination of cellulose hydrolysis and glucose oxidation. The study provides insights into the deactivation of the catalysts caused by leaching and hydrothermal sintering of Au nanoparticles, as well as by adsorption of reaction species. We found that lowering the surface density of Au on metal oxides decreases the sintering rate of the Au nanoparticles and hence enhances the stability and activity of the catalyst. Levulinate derivatives are an attractive platform for the production of renewable chemicals. We report on the oxidation of methyl levulinate into dimethyl succinate with peroxides under mild conditions using Bronsted and Lewis acid catalysts and focuses on the reaction selectivity control. While the molecular structure (i.e., carbon chain length and branching around the C=O group) and the oxidant type affect the product distribution, solvent choice has the strongest impact on changing the location of oxygen insertion into the carbon backbone. In contrast to Brønsted acids, for water-tolerant Lewis acidic triflate salts, the reaction selectivity is affected by the size of the metal cation. We have developed a novel approach to synthesize unsaturated dicarboxylic acid esters via aldol condensation of keto esters catalyzed by Lewis acidic zeolites. Hafnium-containing BEA (Hf- BEA) zeolites are highly active, selective and stable for the condensation of ethyl pyruvate into itaconic acid ester analogues. Analysis of the dynamic behavior of Hf-BEA under flow conditions and studies with Na-exchanged zeolites suggest that Hf(IV) open sites possess dual functionality for Lewis and Bronsted acid catalysis.
Download or read book Advances in the Catalytic Conversion of Biomass Components to Ester Derivatives written by Domenico Licursi and published by Mdpi AG. This book was released on 2022-06 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: Biomass has received significant attention as a sustainable feedstock that can replace diminishing fossil fuels in the production of value-added chemicals and energy. Many new catalytic technologies have been developed for the conversion of biomass feedstocks into valuable biofuels and bioproducts. However, many of these still suffer from several disadvantages, such as weak catalytic performance, harsh reaction conditions, a high processing cost, and questionable sustainability, which limit their further applicability/development in the immediate future. In this context, the esterification of carboxylic acids represents a very valuable solution to these problems, requiring mild reaction conditions and being advantageously integrable with many existing processes of biomass conversion. An emblematic example is the acid-catalyzed hydrothermal route for levulinic acid production, already upgraded to that of higher value alkyl levulinates, obtained by esterification or directly by biomass alcoholysis. Many other chemical processes benefit from esterification, such as the synthesis of biodiesel, which includes monoalkyl esters of long-chain fatty acids prepared from renewable vegetable oils and animal fats, or that of cellulose esters, mainly acetates, for textile uses. Even pyrolysis bio-oil should be stabilized by esterification to neutralize the acidity of carboxylic acids and moderate the reactivity of other typical biomass-derived compounds, such as sugars, furans, aldehydes, and phenolics. This Special Issue reports on the recent main advances in the homogeneous/heterogeneous catalytic conversion of model/real biomass components into ester derivatives that are extremely attractive for both the academic and industrial fields.
Download or read book Catalytic Conversion of Biomass derived Compounds Into Specialty Chemicals and Diesel Fuel Precursor Molecules written by Paolo Andres Cuello Penaloza and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Biomass offers a plethora of opportunities to obtain useful and unique products in a sustainable way, be it chemicals with specialty applications, or molecules that can be blended into our everyday fuels, potentially improving their desired properties. In this work, we study two processes involving the conversion of biomass-derived feedstocks into specialty chemicals and diesel fuel precursors using suitable solid catalysts for each application. In Chapters 2 and 3, we delve into the production of hexane-1,2,5,6-tetrol from levoglucosanol, which is ultimately obtained from a cellulose direct derivate, and a potential application as a polymer precursor. In Chapter 2, we obtain kinetic information for the conversion of levoglucosanol into the polyol using a Pt-WOx/TiO2 catalyst at industrially relevant concentrations (10 - 30wt% reactant in water), showing that with this catalyst we can obtain selectively our product of interests, and also preserve over 90% of the reactant stereocenters. We also demonstrate the relative stability of this catalyst compared to what is known in literature, and its regenerability as well. In Chapter 3, we show a potential application for hexane-1,2,5,6-tetrol in the synthesis of tetrol-boronate copolymers when benzenediboronic acids are used. We prove that a facile synthesis is possible at room temperature with various solvents, and demonstrate that the properties of the polymers are impacted by the choice of a solvent, and the diastereomeric excess of the reactant, managing to obtain a first-known case of a chiral polymer when 98% d.e. (S,R)-hexane-1,2,5,6-tetrol is used. In Chapters 4 and 5, we study the selective conversion of ethanol into larger molecules that can be ultimately converted into compounds that can be blended into diesel by different methods when MgAl mixed metal oxide catalysts that have very low loadings of Cu are used. In Chapter 4, we demonstrate that when Cu loadings less than 0.6wt% are used in MgAl catalysts, very high diesel fuel precursor selectivities may be obtained, with the most significant products being larger alcohols and aldehydes, followed by large esters, and relatively minor amounts of ethyl acetate. We proved that changing the properties of the MgAl support does not greatly impact the performance of the catalyst, instead we found that the loading of Cu is the determinant factor in catalyst performance due to Cu acting more as a promoter of MgAl acid-base chemistry than as an actual catalyst for the Guerbet coupling reaction. The presence of Cu in low amounts also enables the selective production of esters with 6 or more carbons over ethyl acetate. The studied catalysts also promoted high product alcohol linearity, and the alcohol selectivity per carbon number fitted the Schultz-Flory distribution, showing that alcohol growth is dictated by chain growth behavior. In Chapter 5, we studied the performance of a single low Cu loading MgAl catalyst at different contact times, performed tests at varying ethanol-to-hydrogen partial pressure ratios, and performed cofeed studied of ethanol with acetaldehyde and ethyl acetate in order to elucidate the reaction network of ethanol oligomerization to larger oxygenates. We found that selectivity to higher alcohols was greater towards alcohols at all conversions, and alcohols exhibit chain-growth at all contact times. We found that ester and ketone selectivity increase with conversion, with their sizes becoming larger with conversion as well. Esters are series products from alcohols and aldehydes. Finally, we demonstrated that higher linear alcohols will be more selective to esters that ethanol, and that branched alcohols feeds may form esters selectively. Finally, in Chapter 6, we cover the conclusions from all the performed studies, and provide an outlook on future research avenues that enable the effective conversion of biomass-derived feedstocks into products of added value using solid catalysts.
Download or read book Catalytic Processes for The Valorisation of Biomass Derived Molecules written by Francesco Mauriello and published by MDPI. This book was released on 2019-11-22 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the last decades, inedible lignocellulosic biomasses have attracted significant attention for being abundant resources that are not in competition with agricultural land or food production and, therefore, can be used as starting renewable material for the production of a wide variety of platform chemicals. The three main components of lignocellulosic biomasses are cellulose, hemicellulose and lignin, complex biopolymers that can be converted into a pool of platform molecules including sugars, polyols, alchols, ketons, ethers, acids and aromatics. Various technologies have been explored for their one-pot conversion into chemicals, fuels and materials. However, in order to develop new catalytic processes for the selective production of desired products, a complete understanding of the molecular aspects of the basic chemistry and reactivity of biomass derived molecules is still crucial. This Special Issue reports on recent progress and advances in the catalytic valorization of cellulose, hemicellulose and lignin model molecules promoted by novel heterogeneous systems for the production of energy, fuels and chemicals.
Download or read book Advances in the Catalytic Conversion of Biomass Components to Ester Derivatives Challenges and Opportunities written by Domenico Licursi and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Biomass has received significant attention as a sustainable feedstock that can replace diminishing fossil fuels in the production of value-added chemicals and energy. Many new catalytic technologies have been developed for the conversion of biomass feedstocks into valuable biofuels and bioproducts. However, many of these still suffer from several disadvantages, such as weak catalytic performance, harsh reaction conditions, a high processing cost, and questionable sustainability, which limit their further applicability/development in the immediate future. In this context, the esterification of carboxylic acids represents a very valuable solution to these problems, requiring mild reaction conditions and being advantageously integrable with many existing processes of biomass conversion. An emblematic example is the acid-catalyzed hydrothermal route for levulinic acid production, already upgraded to that of higher value alkyl levulinates, obtained by esterification or directly by biomass alcoholysis. Many other chemical processes benefit from esterification, such as the synthesis of biodiesel, which includes monoalkyl esters of long-chain fatty acids prepared from renewable vegetable oils and animal fats, or that of cellulose esters, mainly acetates, for textile uses. Even pyrolysis bio-oil should be stabilized by esterification to neutralize the acidity of carboxylic acids and moderate the reactivity of other typical biomass-derived compounds, such as sugars, furans, aldehydes, and phenolics. This Special Issue reports on the recent main advances in the homogeneous/heterogeneous catalytic conversion of model/real biomass components into ester derivatives that are extremely attractive for both the academic and industrial fields. Dr. Domenico Licursi Guest Editor.
Download or read book A Study on Catalytic Conversion of Non Food Biomass into Chemicals written by Mizuho Yabushita and published by Springer. This book was released on 2016-01-13 with total page 171 pages. Available in PDF, EPUB and Kindle. Book excerpt: The topic of this thesis is catalytic conversion of non-food, abundant, and renewable biomass such as cellulose and chitin to chemicals. In biorefinery, chemical transformation of polymers to valuable compounds has attracted worldwide interest for building sustainable societies. First, the current situation of this hot research area has been summarized well in the general introduction of the thesis, which helps readers to become familiar with this topic. Next, the author explains high-yielding production of glucose from cellulose by using an alkali-activated carbon as a catalyst, resulting in a yield of glucose as high as 88%, which is one of the highest yields ever reported. The characterization of carbon materials has indicated that weak acid sites on the catalyst promote the reaction, which is markedly different from reported catalytic systems that require strong acids. In addition, the first catalytic transformation of chitin with retention of N-acetyl groups has been developed. The combination of mechanocatalytic hydrolysis and thermal solvolysis enables the production of N-acetylated monomers in good yields of up to 70%. The catalytic systems demonstrated in this thesis are unique in the fields of both chemistry and chemical engineering, and their high efficiencies can contribute to green and sustainable chemistry in the future. Meanwhile, mechanistic studies based on characterization, thermodynamics, kinetics, and model reactions have also been performed to reveal the roles of catalysts during the reactions. The results will be helpful for readers to design and develop new catalysts and reaction systems.
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 Catalytic Conversion of Lignocellulosic Biomass to Carboxylic Acids and Derivatives written by Lisha Yang and published by . This book was released on 2015 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt: The transition from today’s fossil fuel based economy to a sustainable economy that is grounded in renewable biomass is driven by concern of climate change and anticipation of dwindling fossil fuel resources. Biofuel is a central theme of the sustainable transition due to the large market demand in the transportation sector. However, transformation of biomass into high value added chemicals is advantageous to secure optimal use of the biomass resources from economical and ecological perspectives. Therefore, it is important for a modern biorefinery to integrate fuel and chemical production from biomass derived platform chemicals. The aim of this dissertation is to design and develop a novel and environmentally benign process to produce carboxylic acids and their derivatives, which are the building blocks for biofuels and biobased chemicals, from various lignocellulosic biomass types using recyclable heterogeneous catalysts in water and/or alcohol solutions. In this process, wet lignocellulosic biomass is pre-treated by low-temperature partial oxidation that selectively converts lignin to carboxylic acids or phenolics in aqueous-phase solutions. The remaining structured hemicellulose and cellulose are catalytically converted to lactic acid or its esters which can be further upgraded to liquid hydrocarbon fuels or value added chemicals. Although a variety of lignocellulosic biomass can be used as feedstocks in designed conversion processes, the arid-land adapted, highly water-use efficient CAM (crassulacean acid metabolism) species, (e.g., Agave tequilana and Opuntia ficus-indica) which are unique biomass species compared to other C3 and C4 plants, are especially promising. In Chapter 2, Agave and Opuntia were characterized by a series of standard biomass analytical procedures wherein both species were found to contain high water contents which would be potentially useful for aqueous phase processing of biomass, as well as low lignin and high para-crystalline cellulose contents, making them more amenable to deconstruction. In Chapter 3, a lignin model compound, guaiacol, was selectively oxidized with H2O2 as the oxidant and titanium silicate (TS-1) catalyst at low temperatures. The value-added dicarboxylic acid, maleic acid, was obtained in this TS-1/H2O2 catalytic aqueous-phase partial oxidation reaction system. In Chapter 4, hemicellulosic biomass, xylan, and xylose can be converted to lactic acid using ZrO2 catalyst in pH-neutral hydrothermal solutions. The yields of lactic acid, up to 25% and 18%, were produced from xylose and xylan, respectively. The Lewis acid property of ZrO2 was demonstrated to effectively facilitate the retro-aldol condensation of xylose, which is the initial step of the conversion of xylose to lactic acid. In Chapter 5, the mesoporous Zr-SBA-15 materials with increased Lewis acidity compared to ZrO2. were synthesized in order to increase the yields of lactic acid esters. Alkyl lactates were produced from sugars and cellulose with this catalyst in relevant alcohols in a one-pot reaction. The yields of methyl lactate at up to 41% and 44% were produced from pentose and hexose, respectively, with methanol solvent, while the yield of up to 31% ethyl lactate was directly produced from cellulose in ethanol-water solutions with the Zr-SBA-15 catalyst. Lastly, in Chapter 6, the conclusion remarks and future research directions are given.
Download or read book Catalytic Coupling of Biomass derived Intermediates by Ketonization written by Christian A. Gärtner and published by . This book was released on 2009 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Catalytic Conversion of Biomass derived Molecules written by Hossein Bayahia and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Conversion of Biomass derived Oxygenated Compounds to Hydrocarbon Fuels and Commodity Chemicals Using Solid Acid Catalysts written by and published by . This book was released on 2013 with total page 191 pages. Available in PDF, EPUB and Kindle. Book excerpt: Due to the inevitable depletion of fossil fuel reserves, the development and utilization of renewable resources carry tremendous strategic significance in sustaining society's ever-growing needs for energy and materials in the long run. Amongst all forms of renewable energy resources, biomass assumes the unique position of being the only renewable source of carbon, from which liquid transportation fuels and organic chemicals are produced. The present thesis studies the catalytic conversion of key oxygenated platform molecules derived from the cellulose fraction of lignocellulosic biomass using solid acid catalysts to produce hydrocarbon fuels and commodity chemicals. A catalytic route was first developed to convert an aqueous stream of gamma-valerolactone (GVL) over two solid acid catalysts into liquid alkenes with potential application as jet or diesel fuel precursors. In this process, GVL was nearly quantitatively decarboxylated into a stream of butene, which allowed for the use of well-established olefin oligomerization chemistry to produce C8+ hydrocarbons with overall yields over 60%. Kinetic studies on the inter-conversion between GVL and pentenoic acids and their decarboxylation led to the development of a computerized model that satisfactorily captures experimental trends and thus can serve as a useful tool in reactor design and process optimization. Experimental evidences obtained at short space times revealed that 1-butene was the primary decarboyxlation product. Based on this observation, solid Lewis acid catalysts were used to achieve selective production of 1-butene via GVL decarboxylation by effectively suppressing isomerization of the terminal olefin. Alternatively, GVL was converted into pentanoic acid by consecutive ring opening and hydrogenation over a bifunctional palladium-niobia catalyst. Pentanoic acid was further upgraded via ketonization reaction to form nonanone for use as diesel precursors. Therein, commercial niobia was found to crystallize and lose its surface area under hydrothermal conditions. Two niobia-silica composite materials were synthesized which showed significant improvement in hydrothermal stability. Finally, a highly selective process was developed to convert furanics, including 2,5-dimethylfuran, 2-methylfuran and furan into p-xylene, toluene and benzene, respectively, through Diels-Alder type cycloaddition with ethylene followed by dehydration. Tungstated zirconia was identified as a highly efficient catalyst for this reaction due to its high Brønsted acidity.
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 Sustainable Catalytic Conversion of Biomass for the Production of Biofuels and Bioproducts written by Gabriel Morales and published by MDPI. This book was released on 2020-12-02 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt: Biomass is widely considered as a potential alternative to dwindling fossil fuel reserves. There is a large variety of biomass sources (oleaginous, lignocellulosic, algae, etc.), with many possible conversion routes and products. Currently, biomass is not just viewed as a source of biofuels, but also as an interesting feedstock for the production of bio-based chemicals that could largely replace petrochemicals. In this context, the search for new sustainable and efficient alternatives to fossil sources is gaining increasing relevance within the chemical industry. There, the role of catalysis is often critical for the development of clean and sustainable processes, aiming to produce commodity chemicals or liquid fuels with a high efficiency and atom economy. This book gathers works at the cutting edge of investigation in the application of catalysis, for the sustainable conversion of biomass into biofuels and bio-based chemicals.
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 Catalysis for Renewables written by Gabriele Centi and published by John Wiley & Sons. This book was released on 2008-01-08 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt: With its focus on catalysis and addressing two very hot and timely topics with significant implications for our future lives, this will be a white book in the field. The authority behind this practical work is the IDECAT Network of Excellence, and the authors here outline how the use of catalysis will promote the more extensive use of renewable feedstocks in chemical and energy production. They present the latest applications, their applicability and results, making this a ready reference for researchers and engineers working in catalysis, chemistry, and industrial processes wishing to analyze options, outlooks and opportunities in the field.
Download or read book Catalytic Conversion of Biomass derived Platform Molecules Over Zeolites written by Ivo Freitas Teixeira and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
