【摘要】 采用连续固定床反应器,考察了几种具有不同酸性和孔道尺寸的分子筛催化剂上丁烯-2齐聚反应的性能,并与固体磷酸(SPA)催化剂进行了对比.结果表明,分子筛催化剂的酸性和孔道尺寸是影响丁烯-2齐聚反应活性和选择性的重要因素.具有八元环孔道的分子筛的扩散阻力大,反应活性很低;十二元环分子筛的孔道降低了扩散阻力,有利于提高催化剂的低温活性和C9=+选择性;十元环分子筛的孔道尺寸和强酸中心可以提高催化剂的活性,促进C9=+生成.SPA催化剂上C9=+选择性低于30%,而具有强酸中心的十元环ZSM-5和ZSM-22分子筛,以及十二元环β分子筛催化剂上可高达50%以上,这说明分子筛催化剂具有更好的齐聚催化性能.更多还原

【Abstract】 Butene-2 oligomerization was performed in a continuous flow fixed-bed reactor.Several zeolite catalysts with different acidity and textural properties were investigated in order to show the effects of acidity and pore size on the catalyst activity and selectivity for butene-2 oligomerization.A solid phosphorous acid catalyst was included as comparison.The acidity and pore size of various zeolites are important factors that influence the catalyst activity and selectivity for higher olefins in oligomerization.The zeolite with an 8-membered ring system shows low activity because of the strong diffusion resistance to butene-2.The zeolite with an 12-membered ring system lessens the diffusion limitation and results in a higher activity at lower temperature.As for the zeolites with a 10-membered ring system,the pore size and strong acidity improve the catalyst activity and selectivity for higher olefins further.Compared with the solid phosphorous acid catalyst with C=9+ selectivity of less than 30%,the zeolite catalysts,such as ZSM-5,ZSM-22,and β with 10-and 12-membered ring systems and with strong acid sites,show C=9+ selectivity of more than 50%,which indicates the better catalytic performance of the zeolite catalysts.更多还原