Study On The Alkylation Process Conditions Of Benzene With Ethylene,Propylene And Mixed Oldfins Catalyzed By Ionic Liquids

In this paper,ionic liquids were used as catalysts to systematically investigate the effects of process conditions on the alkylation of benzene with ethylene,propylene and ethylene+propylene,and determine their relatively appropriate application conditions.the catalytic activity of L acid ionic liquid is good,and the catalytic activity of different L acid ionic liquids is not much different.The lower price of triethylamine hydrochloride/aluminum chloride ionic liquid is selected for process conditions optimization.In the alkylation reaction of benzene and ethylene,triethylamine hydrochloride/aluminum chloride ionic liquid showed excellent catalytic activity.The influence of the process conditions on the alkylation of benzene and ethylene was finally determined by the single factor method.The best process conditions are:benzene to olefin ratio 15,reaction temperature 60℃,catalyst dosage 10%,stirring speed 600 r/min,reaction time 90 min.In this case,the ethylene conversion rate can reach 96.1%,and the ethylbenzene selectivity can reach 88.9%.The ionic liquid cycle experiment showed that the catalytic performance of the catalyst remained basically unchanged in the first 4 experiments,and the activity decreased and gradually deactivated in the 5th experiment.Similarly,in the alkylation reaction of propylene,the best process conditions are benzene to olefin ratio of 10,reaction temperature of 40℃,catalyst dosage of 10%,and stirring speed of 600 r/min,In this case,the propylene conversion rate can reach 96.7%,The cumene selectivity can reach 95.3%,ionic liquid circulation experiment results are consistent with ethylene alkylation.In the alkylation reaction of benzene and mixed olefins,The best process conditions are:benzene to olefin ratio 15,reaction temperature 40℃,catalyst dosage 10%,and stirring speed 600 r/min.Under this process condition,the ethylene conversion rate is 92.3%,the propylene conversion rate is up to 96.1%,the selectivity of ethylbenzene is 88.5%,the selectivity of cumene is up to 90.3%,and the total content of the target product is more than 95%;ionic liquid catalyst It has a good service life,and the ionic liquid can be recycled for 4 times without deactivation;the modified ionic liquid can improve the selectivity of the target alkylation product.Among them,the 5%copper chloride modified ionic liquid has the most catalytic activity.