METHOD OF MANUFACTURING ANISOTROPIC MEMBRANES Russian patent published in 1997 - IPC

FIELD: membrane separation of gases. SUBSTANCE: invention deals with rigid anisotropic membranes with selective carbon bed on outside surface of porous substrate minimally loosing its porosity, porous structure of selective bed being controllable. Gas mixture (carbon-containing working gas and gas carrier) moves along outside surface of substrate with linear velocity 5•10^-4-5•10^-3 m/s. Porous membrane substrate employs ceramic and carbon articles with open porosity 40-50% and pore size 0.2-5.0 mcm. As working gas, rather accessible gaseous and liquid hydrocarbons are used: propane-butane fraction; straight-chain and iso-C₃-C₁₀-alkanes; straight-chain and iso-C₂-C₈-olefins; benzene and its homologues. When varying dwell time of membrane in hydrocarbon gas medium at 1000 C, radius of predominant pores can be varied over the range from substrate pore radius to 0.03 mcm. EFFECT: increased versatility of membranes.