Deashing of coal liquids with ceramic membrane microfiltration and diafiltration. Final quarterly technical progress report, January 1, 1995--March 31, 1995

Removal of mineral matter from liquid hydrocarbons derived from the direct liquefaction of coal is required for product acceptability. Current methods include critical solvent de-ashing and filtration, both of which produce an ash reject stream containing up to 15% of the liquid hydrocarbon product. This program is directed towards development of an improved process for de-ashing and recovery of coal-derived residual oil: the use of ceramic membranes for high-temperature microfiltration and diafiltration. Using laboratory-scale ceramic membrane modules, samples of a coal-derived residual oil containing ash will be processed by crossflow microfiltration, followed by solvent addition and refiltration (diafiltration). Recovery of de-ashed residual oil will be demonstrated. Data from this program will be used to develop a preliminary engineering design and cost estimate for a demonstration pilot plant incorporating full-scale membrane modules. In addition, estimates for production system capital and operating costs will be developed to assess process economic feasibility. The five program tasks include (1) ceramic membrane fabrication, (2) membrane test system assembly, (3) testing of the ceramic membranes, (4) design of a demonstration system using full scale membrane modules, and (5) development of estimates for microfiltration capital and operating costs and assessment of process economic feasibility