The Study Of Carbonyl Sulfide Gas Removal By Catalytic Hydrolysis In Low Temperature

Carbonyl sulfide is a major component of organic sulfur in industrialfeed gas. High concentration of carbonyl sulfide exists in coke-oven gas,petroleum gas, sulfur coal gas and etc. Carbonyl sulfide causes thepoisoning of industrial catalysts, the corrosion of industrial equipment,declines the quality of chemical products. So the removal of carbonylsulfide is very important considering to whether environmental safety oreconomic production. Currently, domestic and overseas carbonyl sulfideremoval technology is mainly for low concentrations of carbonyl sulfidegas, and high temperature is always required. This study is to develop akind of hydrolysis catalyst dealing with high concentration carbonylsulfide in regular or low temperature.This study established a gas chromatographic method for thedetermination of carbonyl sulfide gas concentration. BET specific surfacearea analysis, elemental sulfur analysis, XRD and SEM was used for thecharacterization of the catalyst. The important influences of reaction conditions and experimental methods on the catalyst activity wereinvestigated.Took activated alumina with and without pretreated as the basematerial, loaded them with2%ammonium molybdate,4%potassiumcarbonate and different concentrations of sodium hydroxide as activecomponents by impregnation method. In this way the hydrolysis catalystwas made. By examining the hydrolytic activity and poison tolerance ofdifferent catalysts, we came to the conclusion that the catalysts withpretreated and loaded with2%ammonium molybdate,4%potassiumcarbonate and1%sodium hydroxide performed the highest hydrolyticactivity. In addition, zeolite catalysts were made with the same method ascontrast experiment. The experimental results showed that the activealumina-based hydrolysis catalyst had much higher hydrolytic activitythan the zeolite-based catalyst.The important influences of reaction conditions on the catalystactivity were investigated, including oxygen content, temperature, andhumidity. As to the experimental results, the increase of oxygenconcentration leads to the decrease of the hydrolysis conversion rate ofcarbonyl sulfide, and anaerobic environment is the best for hydrolysis.The increase of temperature helps increase the efficiency of hydrolysis,but exorbitant temperature will lead to the deposition of S, which resultsin the poisoning of catalyst. Considering to this study,80℃is selected to be the optimum reaction temperature. A small amount of water vapor isnecessary to the hydrolysis reaction, but excess vapor will reduce thecatalyst activity. The optimum humidity was25%in this study.In addition, this study also examined the activity of thealumina-based catalyst for carbonyl sulfide in low concentration, and theresult showed that this kind of catalysis performed a good efficiency forcarbonyl sulfide in low concentration too.