Kinetics of Catalytic Upgrading Reactions of Biomass-derived and Model Oxygenates
Author | : Benginur Demir |
Publisher | : |
Total Pages | : 0 |
Release | : 2020 |
ISBN-10 | : OCLC:1346431369 |
ISBN-13 | : |
Rating | : 4/5 ( Downloads) |
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.