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Upgrading Of Biomass Derived Molecules For Fuels Via Hydrodeoxygenation On Supported Metals
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Book Synopsis Upgrading of Biomass-derived Molecules for Fuels Via Hydrodeoxygenation on Supported Metals by : Trung Tran Quang Pham
Download or read book Upgrading of Biomass-derived Molecules for Fuels Via Hydrodeoxygenation on Supported Metals written by Trung Tran Quang Pham and published by . This book was released on 2010 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Chemical Catalysts for Biomass Upgrading by : Mark Crocker
Download or read book Chemical Catalysts for Biomass Upgrading written by Mark Crocker and published by John Wiley & Sons. This book was released on 2019-11-27 with total page 679 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.
Book Synopsis Fuels and Chemicals from Biomass by : Badal C. Saha
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.
Book Synopsis Bifunctional Catalysts for Upgrading of Biomass-derived Oxygenates by :
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.
Book Synopsis Production of Biofuels and Chemicals with Bifunctional Catalysts by : Zhen Fang
Download or read book Production of Biofuels and Chemicals with Bifunctional Catalysts written by Zhen Fang and published by Springer. This book was released on 2017-12-27 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides state-of-the-art reviews, current research, prospects and challenges of the production of biofuels and chemicals such as furanic biofuels, biodiesel, carboxylic acids, polyols and others from lignocellulosic biomass, furfurals, syngas and γ-valerolactone with bifunctional catalysts, including catalytic, and combined biological and chemical catalysis processes. The bifunctionality of catalytic materials is a concept of not only using multifunctional solid materials as activators, but also design of materials in such a way that the catalytic materials have synergistic characteristics that promote a cascade of transformations with performance beyond that of mixed mono-functional catalysts. This book is a reference designed for researchers, academicians and industrialists in the area of catalysis, energy, chemical engineering and biomass conversion. Readers will find the wealth of information contained in chapters both useful and essential, for assessing the production and application of various biofuels and chemicals by chemical catalysis and biological techniques.
Book Synopsis Biomass Processing over Gold Catalysts by : Olga A. Simakova
Download or read book Biomass Processing over Gold Catalysts written by Olga A. Simakova and published by Springer Science & Business Media. This book was released on 2013-07-13 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book describes the valorization of biomass-derived compounds over gold catalysts. Since biomass is a rich renewable feedstock for diverse platform molecules, including those currently derived from petroleum, the interest in various transformation routes has become intense. Catalytic conversion of biomass is one of the main approaches to improving the economic viability of biorefineries. In addition, Gold catalysts were found to have outstanding activity and selectivity in many key reactions. This book collects information about transformations of the most promising and important compounds derived from cellulose, hemicelluloses, and woody biomass extractives. Since gold catalysts possess high stability under oxidative conditions, selective oxidation reactions were discussed more thoroughly than other critical reactions such as partial hydrogenation, acetalization, and isomerization. The influence of reaction conditions, the role of the catalyst, and the advantages and disadvantages of using gold are presented for all of the reactions mentioned above. This book provides an overview of the recent research results focusing on application of gold catalysts for synthesis of valuable chemicals using renewable feedstocks.
Book Synopsis Catalytic Upgrading of Biomass Through the Hydrodeoxygenation (HDO) of Bio-oil Derived Model Compounds by : Manish Shetty
Download or read book Catalytic Upgrading of Biomass Through the Hydrodeoxygenation (HDO) of Bio-oil Derived Model Compounds written by Manish Shetty and published by . This book was released on 2017 with total page 285 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lignocellulosic biomass is an attractive renewable source for fuels and chemicals. Of the many conversion alternatives, catalytic fast pyrolysis has emerged as an attractive technology to convert biomass into fuel additives and value-added chemicals. Current pyrolysis oils or bio-oils are incompatible with refinery streams due to their high acid, water, and water content. The key roadblock in its commercial exploitation is development of catalytic platforms for selective deoxygenation along with minimum hydrogen consumption and carbon loss. Current catalytic solutions including zeolites, and conventional hydrotreating catalysts employ high hydrogen pressures, leading to aromatic ring hydrogenation, and hydrogen consumption. This thesis focusses on developing fundamental catalytic understanding on cheaper and earth-abundant reducible transition metal oxide catalysts for selective hydrodeoxygenation (HDO) of bio-oil derived model compounds using reactivity, computation and characterization studies. The first section focuses on developing structure-reactivity relationships on bulk and supported MoO3 catalysts for the HDO of lignin-derived model compounds. Characterization reveals that MoO3 undergoes reduction to catalytically inactive MoO2 at a temperature of 673 K, and stabilization of partially reduced MoO3 surface through its partial carburization to oxycarbide phase (MoOxCyHz) at temperatures
Book Synopsis Biomass, Biofuels, Biochemicals by : S. Saravanamurugan
Download or read book Biomass, Biofuels, Biochemicals written by S. Saravanamurugan and published by Elsevier. This book was released on 2019-10-23 with total page 508 pages. Available in PDF, EPUB and Kindle. Book excerpt: Biomass, Biofuels, Biochemicals: Recent Advances in Development of Platform Chemicals provides a detailed overview on the experimentally developed methods that facilitate platform chemicals derivation from biomass-based substrates with robust catalyst systems. In addition, the book highlights the green chemistry approach towards platform chemical production. Chapters discuss platform chemicals and global market volumes, the optimization of process schemes and reaction parameters with respect to achieving a high yield of targeted platform chemicals, such as sugars and furonic compounds by modifying the respective catalytic system, the influence of solvents on reaction selectivity and product distribution, and the long-term stability of employed catalysts. Overall, the objectives of the book are to provide the reader with an understanding of the societal importance of platform chemicals, an assessment of the techno-economic viability of biomass valorization processes, catalyst design for a specific reaction, and the design of a catalytic system. Covers recent developments on platform chemicals Provides comprehensive technological developments on specific platform chemicals Covers organic transformations, catalytic synthesis, thermal stability, reaction parameters and solvent effect Includes case studies on the production of a number of chemicals, such as Levulinic acid, glycerol, phenol derivatives, and more
Book Synopsis Interactions of Biomass Derived Oxygenates with Heterogeneous Catalysts in Aqueous and Vacuum Environments by : John Robert Copeland
Download or read book Interactions of Biomass Derived Oxygenates with Heterogeneous Catalysts in Aqueous and Vacuum Environments written by John Robert Copeland and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Biomass is one of the most promising replacements for fossil fuels as a feedstock for chemical and transportation fuel production. The combination of low vapor pressure and high polarity of most biomass derived molecules makes water the ideal solvent for biomass upgrading reaction schemes. Metal oxide and metal oxide supported catalysts are heavily used in oil refining and petrochemical production, and are capable of upgrading biomass molecules as well. However, the surface chemistries that dictate the behavior of aqueous phase biomass upgrading reactions over metal oxide catalysts are not nearly as well understood as in the case of gas phase hydrocarbon refining systems. This dissertation aims to investigate the surface chemistries of biomass derived oxygenate molecules on metal oxide and metal oxide supported metal catalysts. There are three main objectives in this dissertation: to understand how two and three carbon polyols interact with metal oxide surfaces, to elucidate the role of various surface sites on polyol-metal oxide interactions, and to discover the surface species of kinetic importance in aqueous phase reforming reactions of biomass molecules. Transmission infrared spectroscopy and density functional theory modeling were the major techniques used to demonstrate that polyols with alcohol groups on the first and third carbons, 1,3-propanediol and glycerol, form a multidentate surface species with a bridging alkoxide bond and an acid/base interaction through their two primary alcohol groups with Lewis acid sites of g-Al2O3. These interactions occur in the presence of bulk water. Polyols with alcohol groups only on the first and second carbons, ethylene glycol and 1,2-propanediol, only formed alkoxy bonds with the g-Al2O3 surface when bulk water was not coadsorbed, and these bonds were removed by re-adsorbing water. Glycerol also forms the same surface species on other metal oxides with strong Lewis acidic character: TiO2 anatase, ZrO2, and CeO2. Glycerol only forms hydrogen bonds with MgO, which lacks strongly Lewis acidic sites. Basic surface hydroxyls and surface oxygen atoms of the metal oxides only played a minor role in interacting with the adsorbed glycerol. In-situ attenuated total reflectance infrared spectroscopy demonstrated that the aqueous phase reforming of glycerol over a 5 wt% Pt on g-Al2O3 catalyst is hindered by residual platinum bound hydrogen or oxygen atoms from commonly utilized catalyst reduction or cleaning procedures, respectively. A pretreatment consisting of multiple iterations of dissolved oxygen, dissolved hydrogen, and dissolved helium in water flow periods provides the cleanest Pt surface for monitoring carbon monoxide formation dynamics, and allows for observing the rate limiting step of the aqueous phase reforming reactions water-gas shift removal of Pt bound carbon monoxide. The bridging bound carbon monoxide is preferentially removed over the linearly bound species via water gas shift reactions even at room temperature.
Book Synopsis Catalytic Conversion of Biomass-derived Platform Molecules to Distillate-range Fuels by : Nathaniel Eagan
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.
Book Synopsis Deoxygenation and Hydrogenation of Biomass-derived Molecules Over Multifunctional Catalysts by : Mshari Alotaibi
Download or read book Deoxygenation and Hydrogenation of Biomass-derived Molecules Over Multifunctional Catalysts written by Mshari Alotaibi and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of this work was to investigate heterogeneous catalysis of the deoxygenation of renewable feedstocks for value-added chemicals and fuels using heteropoly acids. The main focus was on H3PW12O40 (HPW) and its Cs acidic salt Cs2.5H0.5PW12O40 (CsPW), which have sufficiently high thermal stability, with decomposition temperatures of 450 and > 500 °C, respectively. These compounds have very strong Brønsted acidity and are well documented as acid catalysts. They were used for the deoxygenation and hydrogenation of propionic acid, methyl isobutyl ketone (MIBK) and diisobutyl ketone (DIBK) in the gas phase. For comparison, zeolite catalysts doped with Pt were examined for the deoxygenation of MIBK. CsPW was doped with Pd, Pt, Cu and Ru metals using the impregnation method, while Pt was doped on zeolites by ion exchange. The catalysts under study were characterised using various physical and chemical techniques. CsPW and CsPW-supported Pd, Pt and Cu catalysts were found to be stable in the deoxygenation of propionic acid. They retained the Keggin structure of their polyanion (primary structure), as well as the CsPW crystal structure (secondary structure), after reaction at 400 °C in H2, whereas HPW decomposed above 350 °C in N2. The reaction was found to involve several pathways including ketonisation, decarbonylation, decarboxylation and hydrogenation, leading to the partial or total deoxygenation of propionic acid. HPW/SiO2 and CsPW, both in H2 and in N2, exhibited ketonisation activity between 250 and 300 °C to yield 3-pentanone, CsPW being more selective than HPW. At 400 °C, HPW and CsPW were active for the decarbonylation and decarboxylation of propionic acid to yield ethene and ethane respectively. Loading Pd or Pt onto CsPW greatly enhanced decarbonylation in flowing H2, but had little effect in N2. Similar performance was exhibited by Pd and Pt on SiO2, giving almost 100% selectivity to ethene in H2. These results are consistent with the hydrodeoxygenation of propionic acid on Pd and Pt, suggesting that hydrogenolysis of the C-C bond plays an essential role. Cu catalysts were active in the hydrogenation of the C=O bond to yield propanal and 1-propanol. Turnover rates of propionic acid conversion on metal catalysts followed the order Pd > Pt > Cu. Pt/CsPW was found to be a very efficient catalyst for the selective one-step hydrodeoxygenation of biomass-derived aliphatic ketones MIBK and DIBK to yield 2-methylpentane (MP) and 2,6-dimethylheptane (DMH) under mild conditions at 100 °C and 1 bar pressure without isomerisation of the carbon backbone via a metal-acid bifunctional mechanism. For MIBK hydrogenation, the mechanism involves MIBK hydrogenation to MP-ol on metal sites followed by MP-ol dehydration on acid sites to form olefin and finally olefin hydrogenation to 2MP on metal sites. Pt/ZSM-5 matched the catalytic performance of Pt/CsPW at 200 °C, but considerable isomerisation of MP took place at this temperature. This shows that the strong acidity of CsPW is essential for the high efficiency of the Pt/CsPW catalyst.
Book Synopsis Lignin Valorization by : Gregg T. Beckham
Download or read book Lignin Valorization written by Gregg T. Beckham and published by Royal Society of Chemistry. This book was released on 2018-03-29 with total page 544 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Chapters will specifically focus on the production of fuels and chemicals from lignin."--Page [4] of cover.
Download or read book Catalysis written by James J Spivey and published by Royal Society of Chemistry. This book was released on 2021-06-14 with total page 494 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume looks at modern approaches to catalysis and reviews the extensive literature. Chapters highlight application of 2D materials in biomass conversion catalysis, plasmonic photocatalysis, catalytic demonstration of mesoporosity in the hierarchical zeolite and the effect of surface phase oxides on supported metals and catalysis. Looking to the future a chapter on ab initio machine learning for accelerating catalytic materials discovery is included. Appealing broadly to researchers in academia and industry, these illustrative chapters bridge the gap from academic studies in the laboratory to practical applications in industry not only for catalysis field but also for environmental protection. Other chapters with an industrial perspective include heterogeneous and homogeneous catalytic routes for vinyl acetate synthesis, catalysis for production of jet fuel from renewable sources by HDO/HDC and microwave-assisted catalysis for fuel conversion. Chemical reactions in ball mills is also explored. The book will be of great benefit to any researcher wanting a succinct reference on developments in this area now and looking to the future.
Book Synopsis Zeolites in Catalysis by : Jiří Čejka
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.
Book Synopsis Metal-catalysis in Industrial Organic Processes by : Gian Paolo Chiusoli
Download or read book Metal-catalysis in Industrial Organic Processes written by Gian Paolo Chiusoli and published by Royal Society of Chemistry. This book was released on 2008 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt: A definitive reference source, written by practising experts in the field, providing detailed and up-to-date information on key aspects of metal catalysis.
Book Synopsis Design of Supported Metal Catalysts for Aqueous-phase Conversion of Biomass-derived Oxygenates by :
Download or read book Design of Supported Metal Catalysts for Aqueous-phase Conversion of Biomass-derived Oxygenates written by and published by . This book was released on 2015 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt: Increases in the cost of fossil fuels along with growing concerns for greenhouse gas emissions are prompting the search for renewable sources of liquid fuel and chemicals. Biomass has been considered as the only realistic and sustainable source of renewable organic carbon for the foreseeable future. Heterogeneous catalysis has played an important role in the development of efficient chemical processes to convert biomass to fuels and chemicals. In this respect, the design of inexpensive active and stable heterogeneous catalysts is important to develop new and improved processes for the conversion of biomass. This dissertation focuses on aqueous-phase hydrodeoxygenation (APHDO) and aqueous-phase hydrogenation (APH) as model reactions to design improved supported metal catalysts for the conversion of biomass-derived feedstocks. Both APHDO and APH are crucial in converting biomass-derived compounds into liquid fuels and chemicals. In this dissertation, the activity of a number of monometallic and bimetallic catalysts is compared for APH of carbonyl compounds which is an important reaction in APHDO. Bimetallic Pd-Fe is the most active catalyst among the tested catalysts for APH of C=O and C=C bonds. APHDO of sorbitol was performed with the bimetallic Pd-Fe supported on zirconium phosphate (Zr-P). Zr-P was chosen as the support due to its high Brønsted to Lewis acid ratio and stability in the aqueous phase. The Pd1Fe3/Zr-P catalyst is up to 14 times more active than monometallic Pd/Zr-P and Pt/Zr-P catalysts. Moreover, the Pd1Fe3/Zr-P catalyst produces more C4-C6 products by promoting the conversion of sorbitan and isosorbide and more C1-C3 products by promoting C-C bond cleavage (dehydrogenation/retro-aldol condensation) of sorbitol. Another critical issue of designing heterogeneous catalysts for aqueous-phase reactions is stability of the catalysts. A method for stabilizing base-metal particles of a Co/TiO2 catalyst is developed using atomic layer deposition (ALD) of TiO2 film onto the surface of the Co/TiO2 catalyst. The ALD TiO2 coated Co/TiO2 catalyst was tested for APH reactions in a continuous flow reactor and characterized using chemisorption, surface area analysis, electron microscopy, X-ray diffraction, and small-angle X-ray scattering. Through these techniques, it is shown that the ALD TiO2 coating protects the cobalt particles against leaching and sintering under aqueous conditions. High-temperature treatments of a Co/TiO2 catalyst cause migration of partially reduced TiO2 onto cobalt particles caused by strong metal-support interaction (SMSI) between cobalt and TiO2. The SMSI effect in the Co/TiO2 catalyst is elucidated using in situ Raman spectroscopy and electron microscopy. By the SMSI effect, cobalt particles of the Co/TiO2 catalyst are decorated by TiOx (x 2) species. The TiOx decoration stabilizes the cobalt particles in a similar way to ALD TiO2 overcoating. The SMSI effect also creates a bifunctional catalytic site in the Co/TiO2 which facilitates a furanyl ring-opening reaction. The high-temperature treated Co/TiO2 catalyst had 95 % yield for APH of carbonyl compounds to their corresponding alcohols. The two methods for stabilizing cobalt catalysts introduced in this dissertation, ALD and SMSI, may enable the replacement of expensive novel-metal catalysts with inexpensive base-metal catalysts for aqueous-phase conversion of biomass-derived feedstocks.
Book Synopsis Catalytic Conversion of Biomass-derived Compounds Into Specialty Chemicals and Diesel Fuel Precursor Molecules by : Paolo Andres Cuello Penaloza
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.
