催化裂化轻汽油中烯烃加氢反应宏观动力学

Hydrogenation macrokinetics of olefin in catalytic cracking light gasoline

基于流化催化裂化(FCC)轻汽油(初馏点—358 K)中所含烯烃组分的性质,将其划分为4个集总,采用管式滴流床反应器,在压力0.5—2 MPa、反应温度353—413 K、液体空速2.5—7.5 h-1的条件下,对烯烃在镍加氢催化剂上的加氢反应进行宏观动力学研究。实验结果显示:n-C4=,n-C5=,i-C5=,n-C6=加氢反应对烯烃的反应级数都为1,对氢压的反应级数分别为2.26,2.16,1.74,1.74,表明氢压对加氢反应的影响程度跟烯烃碳数及其结构有关;加氢活化能依次为19.11,21.11,32.1,21.83 kJ/mol,表明随着烯烃碳数的增加,加氢反应越难,同碳数支链烯烃比直链烯烃更难加氢。对动力学方程的检验表明,计算值与实验值吻合较好,误差基本在10%以内,模型具有较高的可信度,可用于反应过程模拟和反应器的设计。

Based on the nature of olefin components in fluidized catalytic cracking（FCC） light gasoline（HK-358 K）,four lumps were obtained from it,and hydrogenation macrokinetics of four lumps over Ni hydrogenation catalysts were studied in a tubular trickle-bed under the conditions of pressure 0.5-2 MPa,temperature 353-413 K,liquid hourly space velocity（LHSV） 2.5-7.5 h-1.The results show that n-C4=,n-C5=,i-C5=,n-C6= hydrogenation reaction order of olefins is 1,and the reaction order of hydrogen pressure is 2.26,2.16,1.74,1.74,respectively,indicating that the impact of hydrogen pressure on hydrogenation are linked with carbon number and structure.Hydrogenation activation energy is 19.11,21.11,32.1,21.83 kJ/mol respectively,indicating that with the increase of carbon number of olefins,the hydrogenation of olefins is more difficult,and the branched-chain olefins hydrogenation is more difficult than the straight-chain olefins with the same carbon number.The kinetics models are acceptable with a high credibility,and the error of it is less than 10%,which can be used in process simulation and reactor design.