Catalysts Research For Alkylation Of Benzene With Methanol

This paper mainly focused on the catalyst of toluene alkylation with methanol. The contrastive study was finished between benzene alkylation with methanol and toluene alkylation with methanol. The results showed that acid strength of active sites in the two reaction was different. So the results in the study of the catalyst of toluene alkylation with methanol could not used for the study of the catalyst of benzene alkylation with methanol.The performance of the catalyst of benzene alkylation with methanol was studied after modification by different active ingredients on ZSM-5 and MCM-56. The results showed that the catalytic activity significantly increased with P2O5, La2O3 and NiO loaded. The conversion rate of benzene was nearly 46% with 6% P2O5/HZSM-5,6% higher than ZSM-5. It could significantly increase the selective catalytic ability of ZSM-5 with heteropolyacid zeolite loaded. The conversion rate of benzene was more than 50% with the content of toluene and xylene above 90% in the products. Under the reaction conditions of 475℃and the space velocity of 1.33h-1 or 4.67h-1, the catalyst's performance was the best.Benzene alkylation with methanol was studied over the multi-channel ZSM-5. The results showed that the catalytic activity was much higher than the ordinary ZSM-5. And the conversion rate of benzene was 15% higher than the ordinary ZSM-5. The selectivity of main products was nearly 90% with xylene above 30%,while the selectivity of ethyl-benzene decreased significantly. The multi-channel ZSM-5's activity would increase when the MgO was loaded. The results showed that the conversion rate of benzene was 60% and the selectivity of toluene and xylene was nearly 50% under 470℃; In the range of 2.00h-1～6.00h-1 of the space velocity, the catalyst's activity and selectivity increased with the increase of the space velocity. Benzene alkylation with methanol was proved a exothermic reaction by the study results. Meantime, by some exosyndrome methods we could prove that strong acid center would increase the activity of the catalyst of benzene alkylation with methanol.