CO2 Production

LO-CAT® II Process Controls H2S Emissions at Geothermal Power Plants

When water seeps into high temperature, high pressure formations below the earth's surface, geothermal steam is produced. This steam provides a source of electrical energy when brought to the surface through production wells, then expanded through a turbine. Condensed steam exiting the turbine is usually pumped back into the underground formation.

Non-condensible gases also exit the turbine. Typically, this gas stream is mostly CO2, but the stream may contain up to 6% hydrogen sulfide. When the volume of H2S exceeds environmental regulations, or when the volume is sufficient to cause odor problems, H2S emissions must be removed from the NCG stream.

The LO-CAT® II system is ideal for geothermal NCG desulfurization, because the system offers H2S removal efficiencies over 99.9%, excellent performance in turndown conditions for both H2S concentration and NCG flow rate, and easy operation, requiring only limited operator attention.

See Process Diagram.

See Full Case History (pdf).