Pd-Ag/Al_2O_3催化剂上丁二烯的加氢反应性能

Performance of Pd-Ag/Al_2O_3 catalyst for hydrogenation of butadiene

对Pd-Ag/Al2O3催化剂在裂解混合碳四选择加氢制丁烯反应中的性能进行了研究。实验结果表明,1,3-丁二烯加氢生成1-丁烯的选择性与反应器入口1,3-丁二烯浓度和氢/丁二烯比密切相关,在反应器入口温度40℃、反应压力1.0 MPa、液空速40 h 1的条件下,当入口丁二烯摩尔分数大于2.6%,1-丁烯选择性维持在66%以上;当入口丁二烯摩尔分数降至2.6%以下时,1-丁烯选择性开始下降;当反应器入口1,3-丁二烯摩尔分数小于1.0%时,出口1,3-丁二烯摩尔分数可降至小于1.0×10-5。当反应器入口1,3-丁二烯摩尔分数为0.50%～0.85%时,1-丁烯选择性随着氢/丁二烯摩尔比的增加呈现线性下降趋势,表明过量的氢气是发生丁烯的异构化和加氢反应的重要原因。H2-TPR和XPS表征结果显示,Pd-Ag/Al2O3中的Pd和Ag还原过程中形成了Pd-Ag合金。

Selective hydrogenation of butadiene in C4 mixture to produce 1-butene on Pd-Ag/A1203 catalyst was studied. The test results showed that selectivity of 1-butene produced from 1,3-butadiene hydrogenation was closely related to both inlet 1,3-butadiene concentration and H2/butadiene mole ratio. Under the conditions of inlet temperature 40 ℃, pressure 1.0 MPa, liquid space velocity 40h-~, when inlet butadiene concentration was more than 2.6%, selectivity of 1-butene maintained at more than 66%; when inlet butadiene concentration was less than 2.6%, selectivity of 1-butene began to decline as isomerization reaction was intensified. When inlet butadiene concentration was less than 1.0%, outlet 1,3-butadiene concentration could be reduced to less than 1.0 x 10-5. With the increase of H2/butadiene mole ratio, 1-butene selectivity declined linearly when inlet butadiene concentration was between 0.50% and 0.85%, indicating that excess H2 with respect to butadiene was an important reason for isomerization and hydrogenation reactions of butene. H2-TPR and XPS results showed that Pd-Ag alloy was formed during catalyst reduction.