Study On The Preparation Of Moderate Carbonyl Sulfide Hydrolysis Catalysts And Hydrolysis Of Carbonyl Sulphur

Hydrolysis of carbonyl sulfur?COS?catalysis at moderate temperature is one of the keys to fine desulfurization of gas,but the oxygen and sulfur poisoning of the COS hydrolysis catalysts are an urgent problem for researchers.The influence of the physical and chemical properties of the carrier and modifier TiO₂ on the catalytic hydrolysis activity of COS and the anti-oxygen property will be crucial to the moderate temperature COS hydrolysis catalysts.Therefore,in this paper,the carrier of moderate temperature COS hydrolysis catalyst is?-Al₂O₃ that the precursor of it is the pseudo boehmite,the active component is K₂CO₃ and the modifier is industrial TiO₂ which is prepared by dry mixing method.Meanwhile,the precursor of?-Al₂O₃ carrier is the aluminum hydroxide,or the modifier is nanometer TiO₂ whichis prepared by chemical precipitation method or the carrier of catalyst is MgAl₂O₄were prepared.In the fixed bed,the changes of COS hydrolysis conversion with temperature,space velocity and COS inlet concentration,and the changes in O₂ atmosphere were investigated.Using XRD,BET and CO₂-TPD and other characterization means,the physical and chemical properties of the prepared catalysts were characterized,and the relationship between the properties and the catalytic activity and anti-oxygen property of catalysts was analyzed.The main conclusions are as follows:?1?In the oxygen atmosphere,the COS conversion of moderate temperature COS hydrolysis catalyst which the precursor of?-Al₂O₃ carrier is the pseudo boehmite,the active component is K₂CO₃ and the modifier is industrial TiO₂ that is prepared by dry mixing method decreased to 88%with reaction time and there is still downward trend.?2?In the oxygen atmosphere,the COS conversion of moderate temperature COS hydrolysis catalyst which the precursor of?-Al₂O₃ carrier is the aluminum hydroxide is prepared by dry mixing methodcontinue to decline with the reaction time,there is no steady trend.,but the COS conversion of catalyst which the precursor of?-Al₂O₃carrier is the pseudo boehmite decreased to 88%with reaction time near stability,that is,the latter has better anti-oxygen property.?3?In the oxygen atmosphere,the COS conversion of moderate temperature COS hydrolysis catalyst which modifier is industrial TiO₂ decreased to 88%with reaction time and there is still a downward trend,but the COS conversion of catalyst that is modified by nanometer TiO₂ invariable with the reaction time.This is mainly because the nanometer TiO₂ obtained by chemical precipitation is a complete anatase TiO₂.Tthe catalytic activity of rutile TiO₂ is higher than that of rutile type and the catalytic activity of TiO₂ is improved to some extent after its particle size reaches nanometer level.?4?In the oxygen atmosphere,the COS conversion of moderate temperature COS hydrolysis catalyst which carrier is?-Al₂O₃ decreased to 88%with reaction time and there is still a downward trend,but the COS conversion of catalyst that MgAl₂O₄ is taked as carrier invariable with the reaction time.This is mainly because the complex oxide MgAl₂O₄ structure itself has the catalytic activity,combining the advantages of?-Al₂O₃and MgO.This structure not only helps to improve the hydrolysis activity of the COS hydrolysis catalyst,but also helps to improve the anti-oxygen property.