Pressurized water washing
The water scrubbing is a method for purifying biogas from sulfur and carbon dioxide . In the countercurrent process, water and the raw biogas are cleaned under pressure in an absorber , the unwanted gases and a small part of the methane contained in the scrubbing solution dissolve. This process is most widespread in the purification of biogas to produce biomethane for feeding into the public gas network. The cleaned biogas has a methane content of 97-99% and is therefore on a par with natural gas .