Advanced coal liquefaction. Quarterly report, January 1, 1994--March 31, 1994

This project investigated the use of ceramic membranes to improve liquefaction processes to meet both economical and environmental requirements. The separation of model compounds with a series of modified membranes were complete for Yr. I. The experimental system is presently under modification for performing the catalytic membrane reaction. In this quarter, the authors summarized the Yr.I experimental result as quarterly to satisfy the contractual reporting requirement. A series of 1{double_prime} and 10{double_prime} long membranes were modified through the CVD method to reduce the pore size. These tubes were characterized by He and N{sub 2} permeation as well as He/SF{sub 6} separation. The He and N{sub 2} permeances decreased with reducing pore size and porosity. The coronene and compound No. 11 mixture separation were performed in 10-inch long membranes. The model compound chosen for the catalytic membrane reaction was NBBM (naphthyl-bibenzyl-methane). The hydrogenolysis of this compound will generate toluene which can be selectively removed by the modified membrane. The NBBM/toluene separation was performed in 1{double_prime} long modified membranes. The GC calibration of NBBM, coronene, compound No. 11 and toluene were established and gave good accurate analysis. The results were accurate and reproducible using wide board capillary column with appropriate GC conditions. The coal-liquid separation through microporous ceramic membranes could be described by an ultrafiltration model. Two transport phenomenons, molecular diffusion and convection, were the most important mechanisms. The hindrance factors were necessary of these mechanisms to evaluate the separation performance of membrane and to design the catalytic membrane reactor. The hindrance factors can be calculated from that rejection and permeate flux based on the simplified Niemi-Palosaari method