Hydrothermal And Supercritical Water Processes

Hydrothermal and Supercritical Water Processes presents an overview on the properties and applications of water at elevated temperatures and pressures. It combines fundamentals with production process aspects. Water is an extraordinary substance. At elevated temperatures (and pressures) its properties change dramatically due to the modifications of the molecular structure of bulk water that varies from a stable three-dimensional network, formed by hydrogen bonds at low and moderate temperatures, to an assembly of separated polar water molecules at high and supercritical temperatures. With varying pressure and temperature, water is turned from a solvent for ionic species to a solvent for polar and non-polar substances. This variability and an enhanced reactivity of water have led to many practical applications and to even more research activities, related to such areas as energy transfer, extraction of functional molecules, unique chemical reactions, biomass conversion and fuel materials processing, destruction of dangerous compounds and recycling of useful ones, growth of monolithic crystals, and preparation of metallic nanoparticles. This book provides an introduction into the wide range of activities that are possible in aqueous mixtures. It is organized to facilitate understanding of the main features, outlines the main applications, and gives access to further information - Summarizes fundamental properties of water for engineering applications - Compares process and reactor designs - Evaluates processes from thermodynamic, economic, and social impact viewpoints

The book provides fundamental chemistry and properties of near-critical water (NCW) and supercritical water (SCW), criteria and challenges/solutions in reactor design for NCW and SCW processes, and up-to-date reviews and practice of a wide range of their applications in bio refineries including: production of hydrochars from biomass, SCW oxidation (SCWO) for waste treatment, SCW gasification (SCWG) of biomass and waste for hydrogen and methane production, hydrothermal liquefaction of biomass, production of chemicals and SCWO of biofuels for energy. It also presents techno-economic analysis of hydrogen production via SCWG of biomass. The book will be highly essential for both academic researchers and industrial practitioners for developing novel bio refinery technologies and processes employing NCW or SCW for treatment of various organic waste streams and production of bio-energy and bio-based chemicals from bio-renewable resources. Prof. Dr. Zhen Fang is leader and founder of biomass group, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, China. Dr. Chunbao (Charles) Xu is currently an Associate Professor of Chemical Engineering and NSERC/FP Innovations Industrial Research Chair in Forest Bio refinery at Western University, Canada.

Hydrothermal techniques have been widely used in the synthesis of advanced materials, the treatment of wastes, and the preparation and extraction of special chemicals. They have also been studied for the mimicking of geothermal processes. Nowadays, hydrothermal techniques and sciences play a very important role both in industry and in academia. This book includes contributions from chemists and chemical engineering scientists worldwide who are active in the field of hydrothermal reactions and techniques. The topics covered range from fundamentals of hydrothermal reactions, modeling of hydrothermal processes, new techniques for hydrothermal treatment, and new materials from hydrothermal systems to supercritical fluid reaction systems.

Sub- and Supercritical Hydrothermal Technology: Industrial Applications offers a practical view of a variety of industrial applications and their challenges, offering a deep understanding of the application of sub- and supercritical fluids and their techno-economic viability. This book covers a wide range of applications of hydrothermal processing that result in almost zero waste, high energy efficiency, sustainable chemical processes, and minimal impact over the life cycle. These applications include processing of hazardous waste, bioproducts, coal, lipids, heavy oil and bitumen, and carbon materials. The use of hot-compressed water instead of different organic solvents, such as methanol, acetone, and hexane, is an environmentally benign, green, and sustainable option which can help to design chemical processes that support green chemistry and engineering. This book is pertinent for researchers and professionals in the fields of chemical engineering, industrial chemistry, environmental engineering, materials engineering, and manufacturing.

Hydrothermal techniques have been widely used in the synthesis of advanced materials, the treatment of wastes, and the preparation and extraction of special chemicals. They have also been studied for the mimicking of geothermal processes. Nowadays, hydrothermal techniques and sciences play a very important role both in industry and in academia. This book includes contributions from chemists and chemical engineering scientists worldwide who are active in the field of hydrothermal reactions and techniques. The topics covered range from fundamentals of hydrothermal reactions, modeling of hydrothermal processes, new techniques for hydrothermal treatment, and new materials from hydrothermal systems to supercritical fluid reaction systems.

Discover the many new and emerging applications of supercritical water as a green solvent Drawing from thousands of original research articles, this book reviews and summarizes what is currently known about the properties and uses of supercritical water. In particular, it focuses on new and emerging applications of supercritical water as a green solvent, including the catalytic conversion of biomass into fuels and the oxidation of hazardous materials. Supercritical Water begins with an introduction that defines supercritical fluids in general. It then defines supercritical water in particular, using the saturation curve to illustrate its relationship to regular water. Following this introduction, the book: Describes the bulk macroscopic properties of supercritical water, using equations of state to explain temperature-pressure-density relationships Examines supercritical water's molecular properties, setting forth the latest experimental data as well as computer simulations that shed new light on structure and dynamics Explores the solubilities of gases, organic substances, salts, and ions in supercritical water in terms of the relevant phase equilibria Sets forth the practical uses of supercritical water at both small scales and full industrial scales Throughout the book, the author uses tables for at-a-glance reviews of key information. Summaries at the end of each chapter reinforce core principles, and references to original research and reviews serve as a gateway and guide to the extensive literature in the field. Supercritical Water is written for students and professionals in physical chemistry, chemistry of water, chemical engineering, and organic chemistry, interested in exploring the applications and properties of supercritical water.

Supercritical Fluid Technology for Energy and Environmental Applications covers the fundamental principles involved in the preparation and characterization of supercritical fluids (SCFs) used in the energy production and other environmental applications. Energy production from diversified resources — including renewable materials — using clean processes can be accomplished using technologies like SCFs. This book is focused on critical issues scientists and engineers face in applying SCFs to energy production and environmental protection, the innovative solutions they have found, and the challenges they need to overcome. The book also covers the basics of sub- and supercritical fluids, like the thermodynamics of phase and chemical equilibria, mathematical modeling, and process calculations.A supercritical fluid is any substance at a temperature and pressure above its critical point where distinct liquid and gas phases do not exist. At this state the compound demonstrates unique properties, which can be "fine-tuned," making them suitable as organic solvents in a range of industrial and laboratory processes.This volume enables readers to select the most appropriate medium for a specific situation. It helps instructors prepare course material for graduate and postgraduate courses in the area of chemistry, chemical engineering, and environmental engineering. And it helps professional engineers learn supercritical fluid-based technologies and use them in solving the increasingly challenging environmental issues. - Relates theory, chemical characteristics, and properties of the particular supercritical fluid to its various applications - Covers the fundamentals of supercritical fluids, like thermodynamics of phase and chemical equilibria, mathematical modeling, and process calculations - Includes the most recent applications of supercritical fluids, including energy generation, materials synthesis, and environmental protection