合成气低温合成二甲醚催化剂的研究

Study of Catalyst for Dimethyl Ether Synthesis under Low Temperature

采用共沉淀法制备了Cu Zn Al甲醇合成催化剂,在此基础上采用机械混合法和共沉淀沉积法制备了Cu Zn Al/HZSM 5+Al2O3二甲醚合成催化剂。以BET、XRD、TPR和XRF对催化剂进行了表征并采用高压微反对催化剂活性进行了评价。结果表明,所制备的Cu Zn Al甲醇合成催化剂同Topse公司的MK 101商业甲醇合成催化剂相比,前者具有更高的低温催化活性和稳定性。采用共沉淀沉积法制备的催化剂对于二甲醚合成的活性明显高于机械混合法制备的催化剂。以HZSM 5与酸性Al2O3(质量比4/1)作为复合脱水组分,当w(Cu Zn Al)/w(HZSM 5+Al2O3)=3 6时,以共沉淀沉积法制备的催化剂对于二甲醚合成具有高活性,特别是低温活性明显高于机械混合法制备的催化剂。

A Cu-Zn-Al catalyst for methanol synthesis was prepared by co-precipitation method and the Cu-Zn-Al/HZSM-5+Al_2O_3 catalysts for DME synthesis were prepared by mechanical mixing method and precipitation sedimentation method. The catalysts were characterized by means of BET, XRD, TPR and XRF and activities of catalysts were measured by micro-reactor under a high pressure. The results indicated that the prepared Cu-Zn-Al catalyst for methanol synthesis possessed a higher catalytic activity and a higher stability than the MK-101 catalyst produced by Topsφe. The catalyst prepared by precipitation sedimentation method had a higher catalytic activity for DME synthesis than the catalyst prepared by mechanical mixing method. The catalyst prepared by precipitation sedimentation method with the Cu-Zn-Al/HZSM-5+Al_2O_3 mass ratio of 3.6/1, using HZSM-5+Al_2O_3 (HZSM-5/Al_2O_3 mass ratio 4/1) as dehydration component, had a high activity for DME synthesis especially an excellent activity even under a low temperature.