The objective of this project is to provide the information needed to develop a coal-based electric power generation process that involves coal conversion in supercritical water (SCW) with CO2 capture and storage. Owing to the solvation properties of SCW, the organic compounds released during coal extraction and devolatilization dissolve in the water and hydrolyze, yielding dissolved H2, CO, CO2, and low molecular weight hydrocarbons. In SCW, sulfur, nitrogen and many of the trace elements in coals are converted to insoluble salts that precipitate from the fluid mixture. When oxygen is added to the SCW to oxidize the dissolved species, any CO2 remains dissolved in the water. The water is injected into a deep saline aquifer, rendering CO2 sequestration. Consequently under SCW conditions, the chemical energy in coal can be extracted and utilized without producing any gaseous emissions.
Research activities are underway to characterize coal extraction, devolatilization and oxidation in SCW conditions and to develop models that accurately predict the coal conversion rates.