Study On Stability Of Copper-based Catalysts For Alkylation Of Aniline

With the increasingly strict environmental regulations,clean gasoline has become a necessity,high octane number is the quality requirement of clean gasoline,it is the most simple and effective way to improve the octane number of gasoline by adding antiknock additive,the alkylation of aniline derivatives is of high efficiency and low pollution type antiknock additive,However,the main factors restricting the industrialization of the product is that copper-based catalysts for aniline alkylation usually deactivate rapidly,with poor stability.In this paper,The deactivation reason of catalyst was analyzed by XRD,BET,H2-TPR and TG-DTG.The effect of composition,precipitation temperature,precipitation pH,calcination temperature,additives,the using conditions on the stability of the catalyst was investigated.The results showed that the conversion rate was reduced from 67.98% to 57.55%,which was decreased by 15.34%% after the operation of 400 h,copper concentration,sintering,carbon deposition and poisoning led to the deactivation of the catalyst,poisoning was the main cause.The stability of copper-based catalysts can be improved by adjusting the preparation conditions,adding additives and optimizing the reaction conditions.When the content of aluminum is 10%(w),the ratio of copper to zinc is 1:1(mol),the precipitation temperature is 75?,the precipitation pH is 8,and the calcination temperature is 400?,the copper was well dispersed and the stability was improved.After the operation of 400 h,the conversion rate is reduced from 69.16% to 60.22%,which is reduced by 12.93%.The addition of Ce can not only improve the dispersion of copper,but also enhance resistance of the sulfur,the stability of the copper-based catalyst was further improved,the stability of the catalyst was improved obviously when the content of Ce was 6%(w),and the conversion rate was reduced from 72.63% to 65.58%,which was reduced by 9.74% after the operation of 400 h.The optimum process conditions were 200?,WHSV 0.6h-1 and the ratio of alcohol to amine of 2:1(mol),conversion rate decreased from 73.74% to 67.36%,which was reduced by 8.65% after the operation of 400 h.Both activity and stability of copper-based catalyst were improved.