The toxicity and foul smell of hydrogen sulfide creates one of the main environmental problems associated with geothermal utilization. Hellisheiði Power Plant annually emits around 13000 tons of H2S into atmosphere. Under certain weather conditions the hydrogen sulfide from the power plant reaches nearby towns and cities, annoying the inhabitants. Reykjavík Energy is preparing injection of the H2S from the power plant back into to hydrothermal system. As a first step towards that goal, experimental injection of around 2-3% of total H2S from Hellisheiði power plant will start in the spring of 2011. H2S will be separated from other geothermal gases at a pilot gas separation plant, dissolved in separated geothermal brine and injected back into the geothermal system. The aim of the project is to use the same governing water-rock reactions that control concentrations of H2S in high temperature geothermal systems to mineralize the H2S in the geothermal reservoir. The concentration of H2S in the injected geothermal brine is considerably higher than the aquifer concentration at the injection site and theoretical calculations indicate sulfide mineralization will have tendency to occur in the aquifer, but the rate and quantity of sulfide mineralization under aquifer conditions is however unknown. In this paper the experimental H2S injection project is introduced, and design of the injection, preparation work and data collection prior to injection are described as well as the scientific outline of the project.

Press the Back button in your browser, or search again.

Copyright 2011, Stanford Geothermal Program: Readers who download papers from this site should honor the copyright of the original authors and may not copy or distribute the work further without the permission of the original publisher.