Improvement And Lab-scale Test On The Stability Of Catalyst For The Sweetening Liquefied Petroleum Gas

In order to solve the problems such as low catalytic activity and easy aggregation and deactivation of sulfonated cobalt phthalocyanine catalysts in the process of LPG sweetening,the catalytic performances of three kinds of sulfonated cobalt phthalocyanine catalysts used in industry were studied,which including the effect of reaction temperature,concentration of sodium mercaptides and thiol structure on the conversion of mercaptides.Based on the prior research,the stability of catalyst alkaline solution was studied by using stabilizer.The catalytic activity and the stability of the improved liquid catalysts were evaluated on the laboratory scale test device subsequently.Firstly,the solid content and cobalt content of three kinds of cobalt phthalocyanine cobalt catalysts were determined,and the main chemical components of the three catalysts were analyzed using infrared spectroscopy.The results show that the main component of the catalysts is sulfonated cobalt phthalocyanine,the solid content of the three catalysts above is 15% and the cobalt content between is 7% and 4%.The effect of reaction temperature,concentration of sodium mercaptides and thiol structure on the performance of three kinds of catalyst were investigated.For the same catalyst,with the reaction temperature increased from 10? to 50?,the catalytic conversion of sodium mercaptides were increased;with the increase of the concentration of sodium mercaptides from 100 ?g/g to 400?g/g,the conversion rate was also increased;with the increase of the carbon number and the degree of isomerization of thiols,the catalytic conversion of sodium mercaptides was decreased.Secondly,the stability of the sulfonated cobalt phthalocyanine catalyst in alkali solution was studied.The catalytic activity was decreased and the stability becomes worse after a period of storage of catalyst alkaline solution.Alcohols,amines,quaternary ammonium salts and organic amines were used to improve the stability of selected catalysts,and the results show that the tested stabilizers have stabilizing effect on catalyst alkaline solution.When the mass fraction of the WDA and WDB stabilizers reached 0.006% and 0.02% separately,the performance of the catalyst solution was improved greatly,which catalytic activity and stability were over that of imported catalysts.The researches demonstrated that the improved catalyst has good industrial application possibility.Finally,the process parameters for the catalytic oxidation of sodium mercaptides were studied by the lab-scale.The results show that when the reaction temperature was 50?,and the alkaline concentration of the catalyst was 10m%,the performance of the catalyst was the best with the longest running time of test.The performance of the catalyst with and without the addition of the stabilizer was investigated.The results show that the improved catalyst has batter performance which was proved once again by the lab-scale test.