浆态床中Cu/ZnO/Al_2O_3/ZrO_2+γ-Al_2O_3双功能催化剂一步法合成二甲醚

Single-step dimethyl ether synthesis on a Cu/ZnO/Al_2O_3/ZrO_2+γ-Al_2O_3 bifunctional catalyst in slurry reactor

采用共沉淀法,制备了纤维状CD501甲醇合成催化剂,采用SEM、TEM、XRD和BET等手段对催化剂进行了表征;并将其进一步和γ-Al2O3进行混合,获得了Cu/ZnO/Al2O3/ZrO2+γ-Al2O3双功能催化剂,考察了其在浆态床中一步法合成二甲醚过程的催化特性。结果表明,相比商业催化剂(COM)和LP201催化剂,新型的CD501催化剂具有更大的比表面积和Cu/Zn分散性。对于浆态床中一步法合成二甲醚过程,采用CD501与γ-Al2O3双功能催化剂,相比采用COM或LP201与γ-Al2O3双功能催化剂,CO转化率提高了一倍,且经过270 h测试,CO转化率从61%降至57%,二甲醚时空产率从0.54 g/(g.h)降至0.48 g/(g.h),稳定性显著优于COM催化剂。当反应温度为250℃,压力为4.0 MPa,空速为3 000 mL/(g.h),氢碳比为1.0时,该催化剂应用在浆态床一步法合成二甲醚时,CO转化率为61%,DME时空产率达到0.54 g/(g.h)。

A fibrous CD501 methanol synthesis catalyst was prepared by a novel coprecipation method and characterized by SEM,TEM,XRD and BET.For Cu/ZnO/Al2O3/ZrO2＋γ-Al2O3 bifunctional catalyst which is a mixture of CD501 and γ-Al2O3,the catalytic performance for dimethyl ether（DME） synthesis was evaluated in a slurry reactor.The characterization showed that the CD501 catalyst had a larger specific surface area and a higher Cu/Zn dispersion than those of a commercial catalyst（COM） and LP201 catalyst.For the DME synthesis in a slurry reactor using CD501＋γ-Al2O catalyst,the CO conversion is twice as that on the COM＋γ-Al2O3 or LP201＋γ-Al2O3 catalyst.After 270h test,the CO conversion decreased from 61% to 57%,the space time yield of DME decreased from 0.54g/（g·h） to 0.48g/（g·h）,respectively.Compared with COM catalyst,the stability of the present reported catalyst was much improved.When reaction temperature is 250℃,pressure 4.0MPa,space velocity 3000mL/（g·h）,and H/C mol ratio 1.0,the CO conversion reached 61%,and space time yield of DME reached 0.54g/（g·h）.