Case History: BioGas Purification System

A biogas scrubber was required as part of a full solution for the fermentation of biodegradable organic material separated from municipal garbage. The metals and plastics are separated and recycled while the non-biodegradable organic biosolids are recycled as compost. The produced biogas from the biodegradable organic biosolids contains H2S with levels ranging between 4000 and 5000 ppmv, and following gas scrubbing and dewatering, is to be fed to two 1.2 MW reciprocating engines.

The system was designed to process the H2S at flows of 1080 Nm3/hour followed by an ammonia scubber, a gas chiller to remove water and siloxanes, and a compressor to feed two 1.2 MW reciprocating engines, all supplied by a contractor to GRD Minproc.

GasTec tube measurements and laser spectroscopy of the exit gas indicated less than 2 ppmv of H2S. The overall solution resulted in over 70% of the municipal garbage being recycled, with the engines operating utilizing the scrubbed gas to produce up to 2.4 MW.