Carbon-Ceramic Composite Membranes for High-Temperature Gas Separation. Phase I Final Report

摘要

The primary thesis of the research was that a highly selective gas separation membrane suitable for continuous use under high temperature reducing atmosphere could be formed from a combination of carbon and a porous ceramic matrix. The objective of the program was to demonstrate the feasibility of preparing such a composite structure using a commercially available microporous ceramic membrane with interstitially formed carbon. Such a membrane will exhibit superior separation capabilities primarily by a molecular sieving effect and secondarily by a combination of Knudsen diffusion and surface diffusion on final pore sizes. In Phase I, twenty carbon/ceramic composite membranes were prepared and tested for gas separation. Experimental results indicated that a highly impermeable carbon/ceramic composite with greater than 99.9% pore closing was produced. It was demonstrated that the gas permeability of this composite membrane could be controlled by further treatment. The final composite membrane with a controlled pore structure exhibited improved separation capability as compared to the state-of-the-art inorganic gas separation membranes. This improved performance may be directly attributed to relatively uniform reduction in the effective pore size.