在Cu-Zn-Al-Ti-K催化剂上合成低碳混合醇的反应网络结构

REACTION NETWORK OF HIGHER ALCOHOL SYNTHESIS ON A Cu-Zn-AI-Ti CATALYST PROMOTED WITH K_2CO_3

用动力学方法系统地考察了在Cu-Zn-Al-Ti-K催化剂上合成低碳混合醇的反应网络结构,在此基础上提出了较完整的反应网络构造图。研究结果表明,甲醇是由CO加H_2和CO_2加H_2两条途径生成的,其它醇是从甲醇出发经过碳链增长过程生成的。甲烷是CO和H_2反应的产物,其它烃经由甲烷按碳链增长方式产生,其中乙烷也可能经乙醇产生。在经过很短的一段反应时间之后,就发生了逆变换向变换反应的转变,变换反应起了向CO_2加H_2合成甲醇这一途径提供反应物CO_2的作用。

This paper presents a scheme of reaction network of higher alcohols synthesis from CO/CO_2/H_2 over a Cu-Zn-Al-Ti catalyst promoted with K_2CO_3, based on the kinetic measurements carried out in a single-pass differential tubular reactor. The plots of product concentration-contact time suggest that methanol is produced by both reactions CO+2H_2=CH_3OH and CO_2+3H_2=CH_3OH + H_2O but higher alcohols car hydrocarbon products are basically formedvia methanol and methane respectively according to the chain growthmechanism. Respective chain growth pathwaysare also supported by the relations between product concentration and temperature which were experimentally obtained in a wide temperature range from 230-350℃. An optimal reaction temperature producing maximum amount of the total alcohols or C_2^+OH exists due to the chain growth mechanism and the reversibility of methanol synthesis in the range of temperature studied.