SEPARATION OF GAS MIXTURE

摘要

A gas separation is effected by passing gas from a reservoir (4) into a bed (8) of adsorbent material so as to raise the pressure therein. More readily adsorbable gas is thus adsorbed. Gas flow from the reservoir (4) to the bed (8) continues at substantially constant pressure with gas being displaced from the bed (8) into the reservoir (6). An expansion or pressure reduction in the bed (8) is then performed by withdrawing gas from the bed (8) by means of pump (24) and passing the gas into the reservoir (4). As a result of the pressure reduction more readily adsorbable gas is desorbed. The withdrawal of gas is continued but a substantially constant pressure is maintained in the bed (8) by allowing gas to flow into the bed (8) from the reservoir (6). Product gases may from time-to-time be withdrawn from the reservoirs (4) and (6) and an equal volume of feed gas mixture introduced into the column (2) through the inlet (32). As a result of this cycle there is a net upward flow of the less readily adsorbable component of the gas mixture and a net downward flow of the more readily adsorbable component of the gas mixture. A multiplicity of operating cycles are typically needed to separate each increment of feed gas mixture. The method and apparatus may be employed to separate air into oxygen-rich and nitrogen-rich fractions at relatively high efficiency.