Advanced coal liquefaction. Final quarterly report, April 1, 1996--June 30, 1996

Molecular level liquid phase separations were explored using modified microporous ceramic membrane with pore size reduced from 40{Angstrom} via chemical vapor deposition. At room temperature, membranes with pore sizes <30{Angstrom} were sufficient to achieve >97% rejection of Naphthyl-bibenzyl-methane (NBBM) from toluene, which was primarily attributed to size exclusion due to hindered diffusion. The rejection diminishes dramatically as the temperature is increased. At 400{degrees}C, very small pore sizes are required to separate NBBM from tetralin. In addition to size based separation, active transport at the surface of the membrane was observed at appropriate pore sizes. Also, it was found that the rejection increases along with the transmembrane pressure, probably attributed to the pore size distribution of the membrane. The smaller pore sizes become accessible to the solvent at the higher pressure. Decomposition of NBBM took place at 400{degrees}C in a modified membrane packed with the catalyst synthesized using the similar protocol as membranes. The separation property of this membrane at 400{degrees}C was analyzed indirectly based upon the reaction product distribution