Book excerpt: This title includes a number of Open Access chapters. Increasing attention is being paid to the valorization of solid wastes—converting them into energy or other useful products. This book describes recent research into methodologies and technologies for managing various forms of solid waste, while at the same time generating energy and revenue with less impact on the environment. Topics include combustion, gasification, pyrolysis, and hydrothermal carbonization. The transition from a fossil fuel-based economy to a more sustainable economy will require a solid foundation of ongoing scientific research. The editor of this compendium, a well-respected researcher in the field, has selected studies that help to build that foundation.