nine chapters in the first part of the book cover topics relating to energy, biofuels and bio-aromatics. Chapter 1 highlights the fundamental concept and basic mechanism of photocatalytic transformation of biomass and biomass-derived chemicals into electricity, hydrogen and fine chemicals. A detailed discussion of aspects of a catalyst, such as structure activity relationship, band gap tuning and visible-light-induced activity, is also presented. Chapter 2 covers Biobased materials as feedstocks for the production of bio-aromatics. Chapter 3 focuses on different types of biomasses, methods of preparation, and sustainability. Chapter 4 discusses the basic principles, mechanisms, and advancements in prominent techniques for glycerol valorization along with the synthesis, characterization, and function of different carbon-based catalysts. Chapter 5 discusses various catalysts involved in the conversion of lignocellulosic biomass into platform chemicals and bio-aromatics. Chapter 6 discusses the pyrolysis of triglycerides for the production of fuels and chemicals. Chapter 7 provides a few guidelines for mathematical modeling of a drying process towards its energy and cost analysis, as well as industrial-scale process optimization. Chapter 8 gives a detailed explanation of many chemical procedures, including fermentation, hydrothermal liquefaction, gasification, pyrolysis, and digestion in the absence of oxygen to form biohydrogen, biomethane, biochar, and other Biobased products from algal biomass. Finally, Chapter 9 focuses on valorization of biomass-derived aldehydes into oxygenated compounds.
The chapters contained in the second part of the book cover topics concerning the food, agricultural and environmental sectors. Chapter 10 gives a brief overview of the generation of waste from food processing industries, and highlights the necessity of valorizing food waste. Chapter 11 details the transformation of photocatalytic biomass into valuable products. Chapter 12 highlights the applications of biomass as biofuel in ecological remediation, phytomedicine and as biocatalysts. Chapter 13 focuses on the valorization of secondary metabolites from plants using various techniques, including tissue culture and mutation breeding. Chapter 14 addresses the use of rice starch for green and sustainable food industry applications. Different physical and chemical modifications of rice starches for targeting various food products and their properties are included to provide new insights into the biomass-derived rice starch. Chapter 15 highlights smart materials derived from agrowastes for use in almost every field ranging from applications for energy storage/conversion devices to those for mitigation and remediation technologies for soil, air and water; and from biomedical applications to those related to precision agriculture. Chapter 16 focuses on the valorization of wastes in value-added applications like fertilizer, wastewater treatment, and biofuel. Chapter 17 highlights the concepts involved in various hydrothermal process pathways such as classification of feedstock, conversion mechanism, influencing parameters, product separation and identification. Chapter 18 critically discusses the industrial applications of cellulose extracted from agricultural and food industry wastes. Chapter 19 highlights techniques for the production of adhesives, hydrogels, nanomaterial, and polymer-based composites. Chapter 20 briefly discusses textile wastewater treatment technologies, with a primary focus on the potential treatment methods for valorization of sludge. Chapter 21 deals with biofertilizers and their role in the sustainable growth of the agriculture sector. Finally, Chapter 22 presents a detailed overview of the effect of adsorption parameters, such as pH, temperature, time, initial concentration of Cr(VI) and bioadsorbent dose, for maximum removal of toxic chromium.
This book will appeal to a broad readership, including scientists, researchers, scholars, engineers and students from diverse backgrounds interested in the field of biomass valorization. It can also be used as a reference book for undergraduate and graduate courses.
In conclusion, I would like to thank all the authors for writing exciting and informative chapters for this book. Last but not least, my special thanks to Mr. Martin Scrivener, President of Scrivener Publishing, USA, for his very friendly and inspiring cooperation.
Shahid-ul-Islam
IUST
November 2021
1
Photocatalytic Biomass Valorization into Valuable Chemicals
Brajesh Kumar1*, Lovjeet Singh2, Pawan Rekha3 and Pradeep Kumar4
1 Department of Chemical Engineering, National Institute of Technology Srinagar, Hazratbal, Srinagar, Jammu and Kashmir, India
2 Department of Chemical Engineering, Malaviya National Institute of Technology, Jaipur, Rajasthan, India
3 Department of Chemistry, Malaviya National Institute of Technology, Jaipur, Rajasthan, India
4 Department of Chemical Engineering, Institute of Engineering & Technology, Lucknow, Uttar Pradesh, India
Abstract
With the increasing demands of green and renewable energy sources due to worldwide environmental concern, the valorization of earth-abundant biomass into valuable fuels and chemicals represents an area of tremendous importance in green chemistry. Biomass has potential to be used as a substitute of non-renewable and rapidly depleting fossil fuels. The integration of biomass utilization and photocatalysis appears as a promising technology to obtain higher grade of sustainability in chemical processes. The photocatalytic process is considered among the top green processes because of its feasibility at room temperature and atmospheric pressure. This chapter thus highlights the fundamental concept and basic mechanism of photocatalytic transformation of biomass and biomass-derived chemicals to electricity, hydrogen and fine chemicals. A detailed discussion on the catalyst aspect such as structure activity relationship, band gap tuning and visible light induced activity will be presented. Furthermore, some possible strategies to avoid various challenges in practical applicability of this process are discussed.
Keywords: Renewable energy, biomass, photocatalysts, solar energy, biohydrogen
1.1 Introduction
A wide range of energy that people use in the human habitation and in other necessary spaces