Method for the adsorptive drying of purified biogas and for regenerating laden adsorbents

摘要

In a method for adsorptively drying purified biogas and regenerating laden absorbents, foreign matter is not allowed to enter the purified biogas, the content of methane in the gas remains virtually unchanged and the effort involved in regenerating the laden adsorbent is reduced. Drying and regeneration are effected in a closed biogas cycle, wherein separate layers based on silica gel and molecular sieves are used as the adsorbent. The biogas to be dried first flows through the silica gel layer. The adsorbent is regenerated with exclusively heated, dried biomethane having a temperature of up to 150° C. which, after contact with adsorbent, is recirculated to the outflow of purified biogas. After regeneration, the bed is cooled by biomethane, which is subsequently recirculated to the outflow of purified biogas. Methane-containing water accumulating during drying and regeneration is recirculated to the biogas generation and/or purification.

主权项

1. A gas drying process, comprising:
providing a purified biogas having a methane content of at least 90% by volume; providing an adsorber with adsorbents in the form of separate layers based on silica gel and molecular sieves; adsorptively drying the purified biogas with the adsorbents and regenerating laden adsorbents in a closed biogas circuit; and conducting the biogas to be dried first through a layer of silica gel, and wherein regenerating further comprises regenerating the adsorbent using exclusively heated dried biomethane having a temperature of up to 150° C. and, after contact with the adsorbent, recycling the biomethane back into a starting stream of the purified biogas; and on completion of regeneration, contacting cooled dried biomethane with the adsorbent and recycling back into the starting stream of the purified biogas, and conducting methane-containing water obtained during the drying and regeneration back to a biogas production and/or purification.