Abstract
Understanding of the reactivity of organic molecules in hot water is developing from studies aimed at explaining how organic matter (kerogen) forms in natural environments and then breaks down into energy source materials. In natural systems where kerogens are depolymerized, hot water is ubiquitous and usually contains salt and minerals. For example, the organic material in oil shale is derived largely from algal material deposited in the mineral sediments of a lacustrine or marine environment. During diagenesis, condensation reactions predominate in the conversion of the initial plant and algal materials into the macromolecular network structures characteristic of kerogen. During catagenesis (the macromolecular depolymerization that generates petroleum) cross-link cleavage and hydrolysis reactions become dominant. Reactions such as ionic condensation, cleavage, and hydrolysis are facilitated by changes in the chemical and physical properties of water as temperature increases. These changes make the solvent properties of water at high temperature similar to those of polar organic solvents at room temperature, thus facilitating reactions with organic compounds. An understanding of aqueous organic chemistry may lead to potential applications areas as diverse as the recycling of plastics, the synthesis of chemicals, and coal liquefaction. Other potential applications for hot water include by-product upgrading, waste-stream cleanup, and recycling of surplus materials. (Author's abstract) 35 081409003