Development of a pilot-scale acid gas removal system for coal syngas

Abstract

The Korean pilot-scale gasification facility consists of a coal gasifier, hot gas filtering system, and acid gas removal (AGR) system. The syngas stream from the coal gasification at the rate of 100–120 Nm3/hr included pollutants such as fly ash, H2S, COS, etc. The acid gas, such as H2S and COS, is removed in the AGR system before generating electricity by gas engine and producing chemicals like Di-methyl Ether (DME) in the catalytic reactor. A hydrolysis system was installed to hydrolyze COS into H2S. The designed operation temperature and pressure of the COS hydrolysis system are 150 °C and 8 kg/cm2. After the hydrolysis system, COS was reduced below 1 ppm at the normal operating condition. The normal designed operation temperature and pressure of the AGR system are below 40 °C and 8 kg/cm2. Fe-chelate was used as an absorbent. H2S was removed below 0.5 ppm in the AGR system when the maximum concentration of H2S was 900 ppm. A small scale COS adsorber was also installed and tested to remove COS below 0.5 ppm. COS was removed below 0.1 ppm after the COS adsorbents such as the activated carbon and ion exchange resin.