Pd-Ni/δ-Al_2O_3应用于四氢苯酐选择性催化加氢制六氢苯酐

Selective Catalytic Hydrogenation of cis-1,2,3,6-Tetrahydrophthalic Anhydride to Hexahydro Phthalic Anhydride Over Pd-Ni/δ-Al_2O_3

采用δ-Al_2O_3为载体,浸渍法制备了系列Pd-Ni/δ-Al_2O_3催化剂,在滴流床反应器中,在温度80~120℃,压力3.0~5.0 MPa,氢油比3 000∶1(物质的量比)条件下,四氢苯酐(THPA)催化加氢制备六氢苯酐(HHPA)为探针反应,实验结果显示6%Ni-2%Pd/δ-Al_2O_3催化活性最高。采用δ-Al_2O_3负载型Pd、Ni二元金属催化剂,适当降低催化剂活性,加大氢气分压,有效提高了目的产物HHPA选择性和收率。氢气分上、中、中下三个位置,进入滴流床反应器,反应布局更加均匀可控,减少副反应发生。催化加氢为放热反应,加大反应器内氢气的内循环速度,氢气作为载热体,及时转移反应热,可以有效避免局部过热现象,减少副反应的发生。在温度180~230℃,压力为-0.098 MPa条件下,减压精馏,得到HHPA的纯度为99.5%,产物总转化率和收率分别为97.3%、84.1%。

In the study,δ-Al2O3 used as the support,a series of catalysts of Pd-Ni/δ-Al2O3 were produced by impregnation method.Under the conditions of a temperature 80-120 ℃,the pressure 3.0-5.0 MPa,mole ratio of hydrogen to oil 3 000∶1,Hexahydro phthalic anhydride（HHPA）was prepared by selective hydrogenation of cis-1,2,3,6-Tetrahydrophthalic anhydride（THPA）over Pd-Ni/δ-Al2O3 in a trickle bed reactor.The results show that 6%Ni-2%Pd/δ-Al2O3 possessed with the highest catalytic activity according with the probe reaction.The selectivity and yield of the product HHPA were effectively improved by adopting two metals of Pd and Ni overδ-Al2O3,meanwhile reducing the activity of catalyst and increasing the partial pressure of hydrogen.The hydrogen was divided into the upper,middle and lower three positions into a trickle bed reactor.The reaction layout was more uniform and controllable,and the side reactions were reduced.Catalytic hydrogenation was an exothermic reaction.Increasing the internal circulation speed of hydrogen in the reactor,the reaction heat could be transferred by hydrogen as the heat carrier in time.Under the conditions of a temperature 180-230 ℃,the pressure-0.098 MPa,the purity of HHPA was99.5%through vacuum distillation,and the total conversion and yield were 97.3% and 84.1%,which reached the national quality standard.