Study On Selective Hydrogenation Of Acetylene By Bimetallic Catalyst

Ethylene is an important chemical raw material. Ethylene is heavily dependent on imports in China, as a large coal production country, a large number of acetylene which is cheap was produced in China every year, using acetylene selective hydrogenation to prepare ethylene is an effective way to get rid of the dependence on foreign ethylene, which has a very good industrial prospects.The single metal palladium catalyst and single metal nickel catalyst have higher acetylene conversion rate, but the selectivity of ethylene is poor, the single metal copper catalyst has high ethylene selectivity, but the acetylene conversion rate is very low. As an acetylene hydrogenation catalyst, the single metal has a great disadvantage.In this paper, we investigate the performance of the bimetallic Pd-Cu catalyst in selective hydrogenation of acetylene. Copper, as a kind of active component, has the activity of acetylene selective hydrogenation, as the catalyst promoter has the effect of enhancing the selectivity of ethylene. Palladium catalyst was introduced into the second components of copper, the catalytic performance is good, the effect of different copper and palladium content on the catalytic performance of the catalyst was studied, and the reasons for the high activity of the bimetallic Pd-Cu catalyst were investigated. Studies have shown that palladium-copper bimetallic catalyst maintained acetylene conversion rate at the higher level, greatly increasing the selectivity of ethylene, which is excellent acetylene hydrogenation catalyst, acetylene conversion rate reached 100%, ethylene selectivity reached more than 90%.In industrial a large number of palladium catalysts were used, whose cost is very high. Cu-Ni bimetallic catalyst was found to be the most likely alternative to palladium based catalysts in the catalyst system, in this paper, we prepared different Cu-Ni Bimetallic Catalyst with silochrom and aluminum oxide as the carrier by many kinds of preparation methods. With the comparison of of various catalysts properties, the copper-nickel catalyst prepared by hydrothermal method or sol-gel method whose catalytic activity is very low, impregnation method whose catalytic activity is very low, the CuNi/SiO2 (cp) catalyst prepared by co-precipitation method, the CuNi/Al2O3 (im) catalyst prepared impregnation method and the CuNi/Al2O3 (cp)catalyst prepared by co-precipitation method has high catalytic performance. The copper-nickel catalyst with silochrom as the carrier by co-precipitation method whose activity is higher than the activity of the catalyst prepared impregnation method, as the temperature is 200 ?, acetylenic hydrogen ratio is 4, space velocity is 24000 cm3 gcat"1 h-1, the acetylene conversion rate rose from 30% to 93%, greatly enhanced the catalyst activity, the selectivity of ethylene is 80%, whose catalytic performance is comparable to the noble metal palladium based catalyst, having a broad industrial prospects.