Methanol synthesis from CO/CO2 hydrogenation over Cu/Zn/Al/Mn catalyst

Abstract

Cu/Zn/Al/Mn, Cu/Zn/Al/Ce, and Cu/Zn/Al catalysts were prepared by co-precipitation method. Their activities were evaluated using a feed gas composed of H 2 (66%), CO (27%), CO 2 (3%), and N 2 (4%). Manganese was an effective promoter to improve the activity and thermal stability of Cu/Zn/Al catalyst. Mn promoter was favorable for the dispersion of CuO. The activity of Cu/Zn/Al/Mn catalyst was further evaluated using a CO 2-rich feed gas composed of H 2 (50%), CO (25%), CO 2 (20%), and N 2 (5%). Space time yield and selectivity of methanol were decreased when CO 2-rich synthesis gas was used.

利用共沉淀法制备了四组分的Cu-Zn-Al-Mn和Cu-Zn-Al-Ce催化剂以及三组分的Cu-Zn-Al催化剂。利用组成 H2/CO/CO2/N2=66/27/3/4(体积比)的富CO原料气对催化剂进行了活性评价, 并研究了温度、压力和空速等反应条件对催化剂活性的影响。结果发现添加适量的锰助剂能显著提高催化剂的活性和热稳定性。利用SEM和XRD方法进行了催化剂的结构和形貌表征, 同样表明锰助剂可以起到阻止CuO晶粒长大和促进CuO分散作用。利用富CO2的生物质原料气体积比为H2/CO/CO2/N2=50/25/20/5对Cu-Zn-Al-Mn催化剂进行的评价表明:Cu-Zn-Al-Mn催化剂上CO/CO2加氢合成甲醇的甲醇产率和选择性均有下降, 在试验范围内, 甲醇产率下降11%-25%, 选择性为93%-95%。