Pd-Ag/α-Al2O3催化剂在乙烷裂解配套制乙烯工艺中的选择加氢性能研究

在乙烷裂解配套制乙烯选择加氢的工艺条件下,考察载体焙烧温度、助剂Ag含量、溶液pH值、CO含量及空速对等体积浸渍法制备的Pd-Ag/α-Al₂O₃催化剂性能的影响。结果表明,载体焙烧温度的增加,有助于提高催化剂活性;催化剂Ag含量增加,反应温度变化不大,选择性及抗结焦性能增加;不同溶液pH制备催化剂,选择加氢性能差异不大,但溶液的酸性过高会降低催化剂的抗结焦性能;随着CO的升高,乙炔转化率降低,乙烯选择性先增高后降低,为保证催化剂选择性,原料中的CO最好保持在(700~1 600) μL·L^-1;随着空速的升高,乙炔转化率降低,乙烯选择性增加。

Selective hydrogenation performance of Pd-Ag/α-Al2O3 catalyst in the process of ethane cracking to produce ethylene

Under the process conditions for selective hydrogenation of ethylene produced by ethane crac-king,the effects of carrier calcination temperature,Ag content of additives,pH value,CO content and space velocity on the performance of Pd-Ag/α-Al₂O₃ catalyst prepared by equal volume impregnation were investigated.The results show that the increase in the calcination temperature of the carrier helps to improve the activity of the catalyst.The Ag content of the catalyst increases,the reaction temperature does not change much,and the selectivity and anti-coking performance increase.The preparation of catalysts with different solution pH has little difference in hydrogenation performance,but if the acidity of the solution is too high,it will reduce the anti-coking performance of the catalyst.With the increase of CO,the conversion of acetylene decreases,and the ethylene selectivity first increases and then decreases.In order to ensure the catalyst selectivity,the CO in the raw material is best maintained at (700-1 600) μL·L^-1.As the space velocity increases,the conversion of acetylene decreases and the selectivity of ethylene increases.