A PROCESS FOR ENRICHING BIOGAS FROM SEWERAGE PLANTS OR AGRICULTURAL BASIC INDUSTRIES IN METHANE AND AN APPARATUS FOR CARRYING OUT THE SAME.

摘要

A process for enriching the biogas from sewerage plants or agricultural basic industries in methane, which comprises introducing the biogas to one side of a liquid water membrane which is immobilized in/on a porous hydrophilic support, wherein a stream enriched in methane and depleted in carbon dioxide, sulfane and further undesirable components contained in the biogas is obtained as a retentate, and a stream depleted in methane and enriched in carbon dioxide and further undesirable components contained in the biogas components is obtained as a permeate. As liquid membrane water alone is used, and the losses of water from said membrane, which are caused by driving away said water in said permeate stream, are compensated by saturating said introduced biogas with steam at a temperature which is higher than the temperature at which said membrane separation takes place whereupon said steam is condensed when said biogas is cooled in said membrane. An apparatus for carrying said process which comprises a membrane separator (6), which is divided by a liquid water membrane immobilized in a porous hydrophilic support, into a retentate space (6a) and a permeate space (6b), said retentate space (6a) being connected with supply fittings (1, 3, 5, 11) for said gaseous mixture and discharge fittings (13, 7, 9) for said retentate stream whereas said permeate space is connected with discharge fittings (8, 14) for said permeate stream, wherein a saturator (5) for saturating said biogas with said steam is inserted into the supply tubing (11) for the introduced biogas.