对羧基苯甲醛在钯炭催化剂上串联加氢反应宏观动力学  

Apparent Kinetics of 4-CBA Tandem Hydrogenation over Pd/C Catalyst

作　　者：张少钢[1,2] 周静红[1] 徐笑春[1] 隋志军[1] 周兴贵[1] 袁渭康[1] 

机构地区：[1]华东理工大学化学工程国家联合重点实验室,上海200237 [2]中国石油化工股份有限公司催化剂上海分公司,上海201208

出　　处：《化学反应工程与工艺》2008年第6期509-515,共7页Chemical Reaction Engineering and Technology

摘　　要：在高压间歇反应釜中研究了对苯二甲酸中杂质对羧基苯甲醛(4-CBA)在钯炭催化剂上进行加氢反应的特性,考察了反应温度、氢气分压、内扩散对4-CBA 加氢反应的影响。结果表明,4-CBA 的加氢反应是一个中间产物为对羟甲基苯甲酸(4-HMBA)的串联反应,加氢反应内扩散影响严重;温度和氢气分压提高,反应速率增大;温度和氢气分压对4-HMBA 加氢生成对甲基苯甲酸(PT)的影响大于对4-CBA 加氢生成4-HMBA 的影响。采用幂函数动力学模型拟合得到了4-CBA 串联加氢反应体系的宏观动力学方程。4-CBA 加氢生成4-HMBA 反应的表观活化能为16.98 kJ/mol,对4-CBA 和 H_2的反应级数分别为0.96和0.24;4-HMBA 加氢生成 PT 反应的表观活化能为23.44 kJ/mol,对4-HMBA 和 H_2的反应级数分别为0.61和0.75。The hydrogenation of 4-carboxybenzaldehyde （4-CBA） over commercial Pd/C catalyst in a batch autoclave was studied, and effects of temperature, hydrogen pressure and internal diffusion resistance on hydrogenation of 4-CBA were carefully investigated. The results showed that the hydrogenation of 4-CBA was a tandem reaction, in which 4-CBA was first hydrogenated to 4-hydroxymethylbenzoic acid （4-HMBA） and then to p-toluic acid （PT）. hydrogenation of 4-CBA over Pd/C catalyst. The There was strong internal diffusion resistance for hydrogenation rate increased with the increase of temperature and hydrogen pressure, however, the hydrogenation rate of 4-HMBA to PT was more sensitive to temperature and hydrogen pressure than that of 4-CBA to 4-HMBA. As a result, Apparent kinetics for the tandem hydrogenations of 4-CBA under different conditions were obtained from the experimental data using the power-law kinetics model. The apparent activation energy for hydrogenation of 4-CBA to 4-HMBA was 16.98 kJ/mol, and the reaction orders for 4-CBA and H2 were 0.96 and 0.24 respectively. The apparent activation energy for hydrogenation of 4-HMBA to PT was 23.44 kJ/mol, and the reaction orders for 4-HMBA and H2 were 0.61 and 0.75 respectively.

关 键 词：对羧基苯甲醛 加氢 钯炭催化剂 宏观动力学 

分 类 号：O643.1[理学—物理化学]