Process for separating and producing relatively highly adsorbable gases by adsorbents from gas mixtures also containing less adsorbable gases

摘要

1. A method of separating and recovering gases (product gas components) which are relatively highly adsorbable by adsorbents from gas mixtures also containing substantially only weakly adsorbable gases (waste gas components), by adsorption agents by means of pressure-charge adsorption technology, characterized by the combination of the following method steps : a) the adsorption process takes place using four adsorbers which are arranged in parallel and which perform the same adsorption cycle with a time lag in each case ; b) in the adsorption phase the starting gas mixture which is to be separated and which contains methane or carbone dioxide is conveyed in an adsorber at a pressure above atmospheric pressure, during the adsorption of the product gas and the discharge of the waste gas which is used in part for building up pressure in another adsorber driven in parallel, through a layer of a carbon-containing adsorption agent, until the product gas is just on the point of breaking through, c) after the adsorption phase the gas pressure in the adsorbers is reduced by discharging a partial quantity of gas in parallel flow with the direction of flow during adsorption, and this partial quantity of gas is used in another adsorber arranged in parallel for building up pressure or for rinsing ; d) in the rinsing phase the adsorber is rinsed with gas which has approximately product gas quality at least at the end of rinsing and which is removed from another adsorber which is arranged in parallel and is desorbed, the gas which first flows off being conveyed into the waste gas and the gas which subsequently flows off and which is enriched in product gas being conveyed to another adsorber arranged in parallel for building up pressure ; e) in the adsorption phase the product gas component is desorbed by a drop in pressure and, where appropriate, rinsing and a highly enriched product gas in obtained (product gas recovery), of which one part is conveyed for rinsing to another adsorber arranged in parallel and the other part is recovered ; f) in the pressure build-up phase the gas pressure in the adsorber is built up again partly with a gas mixture from another adsorber arranged in parallel and partly with starting gas for a new adsorption phase ; g) the entire cycle of the adsorber then begins again with the adsorption phase.