Raney镍上松香加氢制备二氢和四氢枞酸的本征动力学

采用FYX-2G型高压搅拌釜,以Raney镍为催化剂,在温度423～453K、压力4.0～7.0MPa下进行松香催化加氢反应动力学的研究。利用改进搅拌器类型、提高搅拌速度、加入200#溶剂油和改变催化剂粒径的方法消除内外扩散,使反应处于化学动力学控制区,然后采集动力学数据,经对17种可能的反应机理模型进行筛选,结果表明,Raney镍催化枞酸加氢生成二氢和四氢枞酸是并行反应,最可几反应机理为:松香中的主要成分枞酸分子与催化剂表面上被吸附的氢原子进行反应,氢原子的吸附为控制步骤,生成二氢枞酸和四氢枞酸的活化能分别为47.18kJ.mol-1和106.35kJ.mol-1。

Intrinsic kinetics of catalytic hydrogenation of rosin to abietenoic-acid and abietanoec-acid on Raney nickel

The kinetics of catalytic hydrogenation of rosin on Raney nickel catalyst was investigated in a FYX-2G high-pressure agitated autoclave at 423—453K and 4.0—7.0 MPa.The external diffusion effect was eliminated by adding 200# solvent oil, increasing rotational speed and improving the type of stirrer so that the reaction was in the region under chemical kinetics control.Then kinetics data were collected.The results showed that hydrogenation of abietic-acid on Raney nickel catalyst to abietenoic-acid and abietanoec-acid is a parallel reaction.A suitable reaction mechanism was selected from 17 probable reaction mechanism models, i.e.the absorption of atomic hydrogen with reaction between atomically absorbed hydrogen on catalyst surface and the main component of rosin abietic-acid could be the controlling step.The activated energy of abietenoic-acid and abietanoec-acid were 47.18 kJ&;#8226;mol-1 and 106.35 kJ·mol^-1, respectively.