生物质气制二甲醚双功能催化剂的研究
发布时间：2019-06-03 23:44
【摘要】：本文以CuO-ZnO-Al_2O_3/HZSM-5双功能催化剂为基础,分别研究了 Li_2O含量和不同助剂(Ce、Y、Ga、Zr)对其催化生物质气制备二甲醚反应性能的影响。最后还研究了不同制备方法对CLuO-ZnO-Al_2O_3-ZrO_2/HZSM-5催化性能的影响。本实验采用加压固定床反应器对所制得的催化剂进行活性评价,并采用XRD、N2吸脱附、N2O化学吸附、SEM、XPS和H_2-TPR等一系列技术对催化剂进行表征。取得的主要结果如下:一、Li_2O 含量对 CuO-ZnO-Al_2O_3-Li_2O(x)/HZSM-5 催化性能的影响采用碳酸钠共沉淀法制备CuO-ZnO-Al_2O_3-Li_2O(CZAL-x),研究了 Li_2O含量对CuO-ZnO-A1_2O_3-Li_2O(x)/HZSM-5催化性能的影响。结果表明,添加适量的Li可以促进催化剂中活性组分的分散,提高Cu表面积,从而提高CO的转化率。在H_2/CO/CO_2=2:2: 1,P=3.0MPa,T=250 ℃,WHSV=2400mL·gcat-1·h-1 的反应条件下,在 CZAL-0.5+HZSM-5催化剂的作用下,CO的转化率和DME的选择性分别达到了 61.1%和63.4%。此外,Li的添加还可以有效地抑制Cu晶体的生长,从而明显提高催化剂的稳定性。二、助剂(Ce/Y/Ga/Zr)对 CuO-ZnO-Al_2O_3/HZSM-5 催化性能的影响采用碳酸钠共沉淀法制备CuO-ZnO-Al_2O_3-MOx(M=Ce/Y/Ga/Zr),研究了助剂Ce、Y、Ga、Zr对CuO-ZnO-Al_2O_3/HZSM-5催化性能的影响。结果表明,助剂种类的不同,对CuO-ZnO-Al_2O_3/HZSM-5催化性能的影响也不相同,其中助剂Zr的添加可以促进催化剂中活性组分Cu的分散,提高CuL比表面积,从而提高CO的转化率。此外,助剂Zr的添加也可以适当提高催化剂的稳定性。三、制备方法对CuO-ZnO-Al_2O_3-ZrO_2/HZSM-5催化性能的影响采用碳酸钠共沉淀、草酸胶态共沉淀、草酸固相反应法和燃烧法制备CuO-ZnO-Al_2O_3-ZrO_2 催化剂,研究制备方法对 CuO-ZnO-Al_2O_3-ZrO_2/HZSM-5 催化性能的影响。结果表明,用碳酸钠共沉淀法制备的CuO-ZnO-Al_2O_3-ZrO_2催化剂Cu的晶粒最小,Cu比表面积最大,与HZSM-5混合后的催化活性也最好。
[Abstract]:Based on CuO-ZnO-Al_2O_3/HZSM-5 bifunctional catalyst, the effects of Li_2O content and different auxiliaries (Ce,Y,Ga,Zr) on the catalytic preparation of dimethyl ether from biomass gas were studied. Finally, the effects of different preparation methods on the catalytic performance of CLuO-ZnO-Al_2O_3-ZrO_2/HZSM-5 were studied. In this experiment, the activity of the catalyst was evaluated by a pressurized fixed-bed reactor, and the catalyst was characterized by a series of techniques, such as XRD,N2 adsorption and desorption, N _ 2O chemical adsorption, SEM,XPS and H_2-TPR. The main results are as follows: 1. The effect of Li_2O content on the catalytic performance of CuO-ZnO-Al_2O_3-Li_2O (x) / HZSM-5 was prepared by sodium carbonate coprecipitation method. CuO-ZnO-Al_2O_3-Li_2O (CZAL-x) was prepared by sodium carbonate coprecipitation method. The effect of Li_2O content on the catalytic performance of CuO-ZnO-A1_2O_3-Li_2O (x) / HZSM-5 was studied. The results show that the addition of proper amount of Li can promote the dispersion of active components in the catalyst, increase the surface area of Cu, and thus increase the conversion of CO. Under the reaction conditions of H 2 CO 2 2 2: 1, P 3.0 MPA, T 250 鈩，
本文编号：2492312
[Abstract]:Based on CuO-ZnO-Al_2O_3/HZSM-5 bifunctional catalyst, the effects of Li_2O content and different auxiliaries (Ce,Y,Ga,Zr) on the catalytic preparation of dimethyl ether from biomass gas were studied. Finally, the effects of different preparation methods on the catalytic performance of CLuO-ZnO-Al_2O_3-ZrO_2/HZSM-5 were studied. In this experiment, the activity of the catalyst was evaluated by a pressurized fixed-bed reactor, and the catalyst was characterized by a series of techniques, such as XRD,N2 adsorption and desorption, N _ 2O chemical adsorption, SEM,XPS and H_2-TPR. The main results are as follows: 1. The effect of Li_2O content on the catalytic performance of CuO-ZnO-Al_2O_3-Li_2O (x) / HZSM-5 was prepared by sodium carbonate coprecipitation method. CuO-ZnO-Al_2O_3-Li_2O (CZAL-x) was prepared by sodium carbonate coprecipitation method. The effect of Li_2O content on the catalytic performance of CuO-ZnO-A1_2O_3-Li_2O (x) / HZSM-5 was studied. The results show that the addition of proper amount of Li can promote the dispersion of active components in the catalyst, increase the surface area of Cu, and thus increase the conversion of CO. Under the reaction conditions of H 2 CO 2 2 2: 1, P 3.0 MPA, T 250 鈩，
本文编号：2492312
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