Patent ID: 9073002
Filing Date: 2015-07-07
Classification: B01D,C12M,Y02C,Y02P

Abstract:
1. A method for separating off carbon dioxide in biogas plants comprising: preparing crude biogas for processing by drying and desulfurizing the crude biogas and removing minor components to obtain a processed crude biogas, an adsorption phase in which the carbon dioxide is separated off from the processed crude biogas in an adsorber and a biomethane obtained is fed into a natural gas grid as biogas, and a regeneration phase in which the adsorber is regenerated and the carbon dioxide that has been separated from the processed crude biogas is fed to ambient air or into a CO wherein, at the start of the adsorption phase, a purging process is carried out on the adsorber to avoid introducing impurities into the processed crude biogas, the purging process includes feeding into the adsorber an off gas discharged during a previous regeneration phase treatment of the adsorber, and the purging process is controlled at least with respect to time by using a plurality of valves and at least one sensor, in the adsorption phase, the processed crude biogas is passed at ambient pressure through the adsorber which contains an adsorber resin suitable for the adsorption of carbon dioxide, in the regeneration phase the adsorber is regenerated at temperatures between 20 and 100° C. and at ambient pressure using a preheated purge gas selected from the group consisting of air, an inert gas and a mixture thereof, at an end of the regeneration phase, the adsorber is cooled by purging with ambient air, and during the regeneration phase, an off gas exiting the absorber and containing air, desorbed carbon dioxide and small amounts of methane is fed into a catalytic burner and heat generated within the catalytic burner by the off gas is used for increasing efficiency in the biogas plant.