Developments in geothermal energy in Mexico—part six. Evaluation of a process to remove non-condensable gases from flashed geothermal steam upstream of a power plant

Abstract

A process to remove non-condensable gases from flashed geothermal steam, by condensation and reevaporation of the steam in a heat exchanger, upstream of a power plant, was tested at the Cerro Prieto Geothermal Field in Mexico. The nominal capacity of the equipment was 0.4 tonne h⁻¹ of steam and after more than 200 test runs and 3000 operating hours, a mean value of 94% of gas removal efficiency and an overall heat transfer coefficient average value of 3.820 kW m⁻²K⁻¹ was obtained. Non-condensable gas removal efficiency was found to depend on the fraction of steam vented with non-condensable gases. The heat transfer coefficient was not affected by changes in vent rate, pressure, gas content or any of the other parameters varied during the test.