This book presents a comprehensive and insightful overview of biofuel feedstocks, processing technologies, sustainability dimensions, and policy frameworks shaping the global bioenergy landscape. Designed for students, researchers, industry professionals, and policymakers, the volume brings together diverse perspectives on first-, second-, third-, and emerging fourth-generation biofuel systems.

Beginning with foundational concepts, the book explores the wide array of biofuel feedstocks—from traditional starch- and sugar-rich crops to lignocellulosic biomass, algae, and tree-borne oilseeds. Each crop-specific chapter integrates agronomy, biochemical composition, processing technologies, conversion efficiency, and environmental implications. The text further covers advanced topics such as genetic engineering of biofuel crops, thermochemical innovations, metabolic engineering, and biorefinery approaches that reflect the future of sustainable energy production.

A dedicated section on economics and global policy offers readers a detailed understanding of cost structures, market dynamics, sustainability standards, and evolving regulatory frameworks. Practical insights into the challenges and opportunities of commercial-scale production make this book a valuable reference for professionals working toward cleaner and more resilient energy systems.

Rich in scientific detail and current research, this volume serves as an essential resource for those seeking to advance knowledge or practice in bioenergy, renewable fuels, sustainable agriculture, biotechnology, and climate-smart energy solutions.

Dr. Sree Rangasamy S. R. is a retired professor and prominent expert in cytogenetics, plant breeding, and plant biotechnology. He earned his Ph.D. from Madras University during 1963 and has held key positions as Dean, Basic Sciences (1977-1980), Director, School of genetics (1981-1990) and Founder Director, Centre for Plant Molecular Biology and Biotechnology (1990-1993) at Tamil Nadu Agricultural University (TNAU). A prolific researcher with over 225 publications, Dr. Rangasamy has made significant contributions to crop improvement and seed quality assurance. He is currently the President of the Indian Society for Certification of Organic Products (ISCOP). His achievements include NAAS fellow, many nationally recognized awards, including the TNAU Best Researcher Award and a Lifetime Achievement Award from INSO.

Dr. Sivakumar Subbarayan is a renowned plant breeder and serving as Professor and Head, Department of Millets at Tamil Nadu Agricultural University, Coimbatore. He had 30 years of experience in plant and molecular breeding and, developed and released crop varieties in sorghum, maize, legumes, and cotton including the nationally recognized multicut forage sorghum CSV33MF. After his agriculture graduation, he specialized in genetics and plant breeding and executed doctoral program in biotechnology. He has received prestigious JIRCAS Award (2006), Japan and ICRISAT Research Fellow Award (2008) and held key administrative roles in research management and served as secretary of the Indian Society of Plant Breeders. He has published 45 research papers and authored seven books, and has guided postgraduate and doctoral students.

Preface
Acknowledgement
Section I: Fundamentals of Biofuels
Chapter 1 Introduction to Biofuel Feedstocks and Conversion Technologies
Section II: First-Generation Biofuel Crops
Chapter 2 Maize Grain Starch: Genetics, Processing, and Bioethanol Production
Chapter 3 Sugarcane-Based Bioethanol Technologies
Chapter 4 Sweet Sorghum Juice as a Bioethanol Feedstock
Chapter 5 Castor Bean: Biodiesel Production and Industrial Applications 
Chapter 6 Rapeseed and Sunflower as Biodiesel Sources
Chapter 7 Oil Palm for High-Yield Biodiesel Production 
Chapter 8 Jatropha: Biodiesel and Biogas Potential
Section III: Alternative and Advanced Feedstocks
Chapter 9 Bioethanol from Tuber Crops: Cassava, Sweet Potato, and Others
Chapter 10 Cellulosic Resources (Second-Generation) for Bioethanol Production
Chapter 11 Microalgae as a Source of Biodiesel (Third-Generation)
Chapter 12 Macroalgae for Bioethanol and Bioproducts 
Chapter 13 Tree-Borne Oilseeds and Non-Edible Crops for Biofuels
Section IV: Emerging and Future Biofuel Technologies
Chapter 14 Fourth-Generation Biofuel Crops and Genetic Engineering Approaches
Chapter 15 Advanced Thermochemical and Biochemical Conversion Technologies
Section V: Economics, Policy, and Sustainability
Chapter 16 Economics of Biofuel Crop Cultivation and Processing Global and National Biofuel Policies: Trends, Challenges, and Prospects