浆态床反应器中Cu-Co合金催化剂用于合成气制低碳醇的研究

Synthesis of higher alcohols from syngas over Cu-Co alloy catalyst in slurry reactor

采用柠檬酸络合-等体积浸渍法将钙钛矿型复合氧化物LaCo0.7Cu0.3O3担载于SiO2表面,得到催化剂前驱体。利用X射线衍射(XRD)、N2吸附-脱附(BET)、程序升温还原(TPR)、透射电镜(TEM)等技术对催化剂进行表征。对还原后的催化剂,在加压浆态床反应器中测试了合成气制低碳醇的催化性能,并与固定床反应器中催化性能进行了对比。结果表明:还原后形成了La2O3修饰的SiO2负载Cu-Co合金颗粒(CuCo-Alloy/La2O3-SiO2)催化剂。浆态床反应器中,由于液体石蜡浆液的作用和对热点形成的抑制,C2+醇的选择性显著提高。在所考察的实验条件下,空速为900至1 500mL/(gcat·h)、压力3MPa、H2∶CO∶N2=8∶4∶1和温度为250℃时,总醇中C2+醇的选择性达到95%以上。

LaCo0.7Cu0.3O3 was supported on SiO2according to the incipient wetness impregnation method combined with citrate complexing method.The prepared catalyst precursors were characterized by XRD,BET,H2-TPR and TEM.The catalytic performance for higher alcohols synthesis from syngas was conducted in a slurry reactor,which was compared with that in fixed-bed reactor.After reduction,the catalyst precursor favoured to form nanoparticles of Cu-Co alloy highly dispersed on SiO2and modified with La2O3.In slurry reactor,the selectivity to C2+OH was much higher,which may be attributed to the effect of liquid slurry of paraffin for suppressing the desorption of methanol and the formation of hot-spots.Under the experimental condition of 900to 1 500mL/(gcat·h),3MPa,H2∶CO∶N2=8∶4∶1and 250℃,C2+OH in the total alcohols was more than 95%in weight.