Ti-Ce系列催化剂上乙酸的催化湿式氧化反应

采用Ti-Ce系列湿式氧化催化剂,研究模型反应物乙酸在催化湿式氧化反应中的动力学影响因素以及反应过程产物.结果表明,乙酸的催化湿式氧化受到催化剂用量、反应温度、反应体系酸度以及氧分压的影响较大.当反应温度230℃,氧分压2～2.5MPa,催化剂量5g/L,反应液初始pH3.0时,反应1h后即可使乙酸浓度(以COD计)去除率在90%以上.通过离子色谱,检测了反应过程中的甲酸中间体,结果表明,催化剂的存在不仅加速了湿式氧化反应速率,而且也改变了反应历程.

The Catalytic Wet Air Oxidation Reaction of Acetic Acid with Ti-Ce Series Catalyst

The influence factors and reaction mechanism during the catalytic wet air oxidation of acetic acid with Ti-Ce series catalyst was investigated in this paper. The results show that the reaction was influenced by the catalyst load, the reaction temperature, the pH of the reaction system and the partial pressure of oxygen. More than 90% removal efficiency of acetic acid (as COD) can be obtained at the reaction conditions as follow: temperature 230 degrees C, oxygen partial pressure 2-2.5 MPa, catalyst amount 5 g/L, initial pH of the system 3.0 and reaction time 1 h. With Ion Chromatography, the formic acid formed during the reaction process was detected. The formic was found during the wet air oxidation of acetic acid in the absence of catalyst, but can not be detected during the catalytic wet air oxidation process with Ti-Ce catalyst. It means that the presence of catalyst in the system not only improve the removal efficiency, but also change the oxidation pathway.