PROCESS FOR THE PRODUCTION OF BIOMETHANE WITH RECYCLING OF THE PERMEAT OF THE MEMBRANE SEPARATION AS INERTING GAS

摘要

The invention relates to a method for producing biomethane wherein at least the harmful components H2S and VOC of the biogas produced are removed therefrom by adsorption. At the end of the purification method, the methane and the carbon dioxide are separated by membrane permeation with production of biomethane and a gaseous permeate rich in carbon dioxide and containing less than 7% methane, and said permeate is used as an inerting/sweep gas during operations for inerting adsorbent tanks. In the methods involving discontinuous dry methanisation, the permeate is also used to inert the digesters during input loading/unloading operations.