Ce-Mn复合氧化物上PTA尾气的催化燃烧

CATALYTIC COMBUSTION OF PTA OFF-GAS OVER Ce-Mn COMPOSITE OXIDES

研究了在Ce-Mn复合氧化物上对苯二甲酸(PTA)生产尾气中有机杂质的催化燃烧效果。考察了W/V杂质、床层入口温度、有机杂质体积分数和总体积空速等对对二甲苯、醋酸甲酯催化燃烧的影响,结果表明:以空气作为氧化剂,当W/V杂质大于200 g.min/L,有机杂质体积分数低于0.8%,反应气体总空速低于30 000 h-1,反应温度分别为350,280℃时,对二甲苯、醋酸甲酯的去除率均大于95%。分别研究了对二甲苯、醋酸甲酯和二溴甲烷所组成的二元、三元混合杂质的催化燃烧,发现前两者组成的二元混合杂质均完全去除的温度取决于对二甲苯;由于醋酸甲酯与对二甲苯燃烧所产生的CO2和H2O与二溴甲烷在催化剂活性位上形成竞争吸附,使三元混合杂质的完全去除温度比单组分均高,达到440℃。

Catalytic combustion of PTA off-gas was studied over Ce-Mn composite oxides.The effect of W/Vimpurities,the inlet temperature of catalyst bed,the concentration of organic impurities and total space velocity on combustion performance of p-xylene and methyl acetate were investigated.The results showed that 95% removal rate of p-xylene and methyl acetate was obtained while air was used as the oxidant,the reaction condition was as follows： W/Vimpurities was above 200 g·min/L,volume fraction of organic impurity was below 0.8 vol %,the total space velocity was less than 30 000 h-1,and the reaction temperature was 350 ℃ and 280℃ respectively.The combustion of binary and ternary mixture consisting of p-xylene,methyl acetate and dibromomethane was researched separately.It was found that the complete removing temperature of binary mixture consisting of p-xylene and methyl acetate depends on p-xylene,and the complete removing temperature of the ternary mixture is 440 ℃,higher than any single component because of the competition adsorption of CO2 and H2O generated from combustion of methyl acetate and p-xylene with dibromomethane on the catalyst active site.