MULTICOMPONENT GAS SEPARATION BY SELECTIVE SURFACE FLOW (SSF) AND POLY-TRIMETHYLSILYLPROPYNE (PTMSP) MEMBRANES

A selective surface flow (SSF) membrane consisting of a thin layer of a nanoporous carbon was produced in a tubular form using a macroporous alumina support. The membrane was tested for hydrogen enrichment appl ications. Simulated waste gases from a petrochemical refinery and a hy drogen pressure swing adsorption unit were used as the feed gas to the membrane. Very high rejections of C-1-C-3 hydrocarbons (saturated and unsaturated) and carbon dioxide over hydrogen were exhibited by the m embrane at low feed gas pressures. The hydrogen enriched stream was pr oduced at the feed gas pressure. The separation characteristics of a p olymeric poly-trimethylsilylpropyne (PTMSP) membrane in a tubular form was also tested for the same applications using identical conditions of operation. This membrane also selectively rejected heavier componen ts of the feed gas mixture over hydrogen and produced the hydrogen enr iched stream at the feed gas pressure. The SSF membrane exhibited much higher hydrogen recovery and hydrocarbon rejections than the PTMSP me mbrane for these applications under identical conditions of operations using identical support materials.