Two-stage biogas production system for anaerobic digesters

A system for processing biogas from wastewater comprising:

• an anaerobic digester comprising a methanogenic bacterial culture, wherein the anaerobic digester receives wastewater comprising organic material, wherein the methanogenic bacterial culture converts a portion of the organic material to raw biogas comprising methane and waste gases;
• a bioreactor receiving the wastewater from the anaerobic digester, wherein the bioreactor comprises a nitrification zone, an anammox zone, and a denitrification zone, wherein the wastewater is cycled through the zones of the bioreactor, purifying the wastewater by converting ammoniacal nitrogen into dissolved nitrate and nitrogen gas;
• a scrubber comprising a bottom inlet and a top inlet, wherein the scrubber receives the raw biogas from the anaerobic digester pressurized through the bottom inlet, and water from the bioreactor through the top inlet, wherein the scrubber purifies the raw biogas by dissolving a portion of the waste gases into the water;
• a biofilter comprising an anammox bacterial culture in a plastic medium, wherein the biofilter is divided into an upper stage and a lower stage by a perforated barrier, wherein the upper stage receives a flow of water containing dissolved nitrate from the bioreactor, wherein the lower stage receives water comprising dissolved waste gases from the scrubber, wherein the waste gases are decompressed and released into the lower stage of the biofilter, wherein ammonia rises through the perforated barrier and the flow of water from the upper stage, and wherein the ammonia and dissolved nitrate are further converted by the anammox bacterial culture into nitrogen gas.