Geysers Power Plant H2S Abatement Update

Abstract

H2S emissions were a major obstacle during development of The Geysers Geothermal Field. H2S abatement systems have evolved over the years and successful H2S abatement to meet stringent air quality standards has become routine. The primary abatement systems for condenser vent gases are the Stretford Abatement System for surface condenser units and the burnerscrubber system for direct contact condenser units. Abatement of H2S in circulating water is accomplished by a combination of techniques including condensate reroute, direct injection and iron chelate addition. Achieving “ambient air quality attainment status” at The Geysers through reliable operation of H2S abatement systems to meet operating permit limits is an underreported success story. Each of the fifteen power plants has an H2S abatement system and a continuous tail gas process monitor. One power plant operator per unit operates the power plant and abatement system. Strategic water injection into the steam reservoir has become another important tool for reducing gas content in steam and helps reduce abatement system operating costs.