US Patent 7306652 Siloxane removal process

Biogas released from landfills and sewage treatment plants is freed of siloxane contaminants by passing the biogas through a bed containing activated alumina, which absorbs the siloxanes. When the activated alumina becomes saturated with siloxanes, the absorption capability of the activated alumina can be recovered by passing a regeneration gas through the bed of activated alumina. A system containing two or more beds of activated alumina can use one bed to remove siloxanes from biogas while one or more of the other beds are being regenerated.