改性Cr_2O_3/Al_2O_3催化剂的丙烷临氢脱氢性能

Catalytic performance of K La modified Cr_2O_3/Al_2O_3 catalysts for catalytic dehydrogenation of propane in presence of hydrogen

研究了K ,La改性Cr2 O3 Al2 O3 催化剂的丙烷脱氢性能 ;在常压 ,6 2 0℃ ,体积空速 75 0h- 1 ,n(H2 )∶n(C3H8)为1∶1的临氢条件下 ,考察了改性催化剂在临氢反应中的活性、选择性 ;结果表明 :w(Cr)在 10 %～ 15 %间丙烯收率有一最佳值 ,随着w(Cr)的增加丙烷转化率下降 ,丙烯选择性提高 ;添加K可以改善催化剂的选择性和稳定性 ,w(K)为 1.0 %时丙烯收率最高 ;在w(Cr)为 15 .7% ,w(K)分别为 1.0 %和 1.5 %的两种催化剂中添加稀土La后 。

The catalytic performances of K and La doped Cr 2O 3/Al 2O 3 catalysts for dehydrogenation of propane to propene in the presence of hydrogen were studied at 620 ℃, atmospheric pressure, C 3H 8/H 2 mole ratio of 1∶1, and GHSV=750 h -1 . The results showed that propane conversion decreases but the selectivity to propene pass through a maximum as the mass fraction of Cr in catalyst increases from 10% to 15%. Both the selectivity and stability are improved by the addition of K, and the highest propene yield was obtained on the catalyst containing of the mass fraction of 1.0% K. The selectivity to propene could be improved when adding rear earth element La to the catalysts containing both of the mass fraction of 1.0% and 1.5% of K.