Effects of Hydrogen Sulfide in Geothermal Power Plants of Calenergy International Ltd. Leyte, Operations

Abstract

CalEnergy International Ltd. is currently operating three geothermal plants in the province of Leyte. These are the 733.5 Gross MW CE-Cebu Geothermal Power Company in Upper Mahiao, the 232.5 Gross MW Visayas Geothermal Power Company in Malitbog and the 780 Gross MW CE-Luzon Geothermal Power Company in Mahanagdong. I

n any geothermal plant, emissions of hydrogen sulfide (&S) gas are inevitable. This gas is harmful not only to human beings at a certain level of concentration but also to process equipment and instruments with materials of construction made of iron, copper and silver. At7er two years of commercial operations, the three geothermal power plants have experienced several shutdowns due to malfunctioning of the DCSPLC, false alarm instrument signals and loose electrical contacts. To address this problem, the most probable cause must be determined for immediate solutions. Corrosion attack by hydrogen sulfide was first taken into consideration.

This paper presents the adverse effects of hydrogen sulfide in operations and maintenance as experienced by the three geothermal plants of CalEnergy International Ltd. Leyfe Operations and the solutions taken to correct the problem.