For most of human history biomass has been the principal energy source powering human development. Indeed, biomass can be utilized for the production of heat, steam, motive power and electricity, and can be converted via thermal, biological, or chemical pathways into chemicals and fuels. Although the twentieth century can be regarded as the “petroleum” century, i.e. the time when petroleum came to the fore as the predominant source of fuels and chemicals, in recent years interest in biomass conversion to chemicals and fuels has grown steadily, driven by the issues of sustainability and environmental protection. Increasing concerns surrounding global warming and the contribution of fossil fuel use to atmospheric CO₂ levels mean that humanity is once again looking to biomass resources for the production of essential commodities.

Given the complexity of biomass, as reflected in the wide range of functional groups present, along with its recalcitrance – as exemplified by the lignin component of biomass – catalysis has a major role to play in the conversion of biomass to useful molecules. However, although catalysis is integral to modern life (it has been estimated that catalysis is involved at some stage in the production of ca. 80% of all manufactured goods) the use of catalysis is much less developed for the production of chemicals from biomass compared to petroleum.

Against this backdrop, this book aims to provide the reader with a detailed description of the catalysts and catalytic processes employed in the synthesis of chemicals and fuels from biomass, the information being organized in a way that covers the most abundant and important types of biomass feedstock. The issue of catalyst design is emphasized throughout, bearing in mind that catalysts used for biomass processing must often function in aqueous environments and in the presence of potential poisons such as mineral components.

Two general approaches can be discerned for the conversion of biomass to chemicals and fuels, involving either (i) conversion of the whole biomass into an intermediate product such as pyrolysis oil or syngas that can then be catalytically upgraded to useful products, or (ii) fractionation of the biomass into its main components, followed by the upgrading of these fractions using tailored conversion processes. Following this rationale, Chapters 1–4 of this book focus on the application of catalysts to the pyrolysis of whole biomass and to the upgrading of bio‐oils. Subsequent chapters focus on the valorization of biomass constituents. Chapters 5–7 discuss catalytic approaches to the processing of biomass‐derived oxygenates – as exemplified by sugars – via reactions such as reforming, hydrogenation, oxidation, and condensation reactions. Lignin is considered next, Chapters 8 and 9 providing an overview of catalysts for lignin valorization via oxidative and reductive methods. After that, Chapters 10–12 consider the conversion of fats and oils to fuels and terminal olefins by means of esterification/transesterification, hydrodeoxygenation, and decarboxylation/decarbonylation processes. Chapters 13 and 14 provide an overview of conversion processes based on terpenes and chitin, two emerging feedstocks with a rich chemistry. Finally, Chapter 15 summarizes some of the emerging trends in the field of catalysis for biomass valorization and looks ahead to future developments.

The editors of this book are deeply indebted to the authors of the chapters. Without their time, effort and expertise this book would not have been possible. We would also like to thank Leslie Hughes at the Center for Applied Energy Research for her unflagging help in the preparation of the manuscript.

July 2, 2019
Lexington, Kentucky, U.S.A.