【摘要】：本文以CuO-ZnO-Al_2O_3/HZSM-5雙功能催化劑為基礎(chǔ),分別研究了 Li_2O含量和不同助劑(Ce、Y、Ga、Zr)對(duì)其催化生物質(zhì)氣制備二甲醚反應(yīng)性能的影響。最后還研究了不同制備方法對(duì)CLuO-ZnO-Al_2O_3-ZrO_2/HZSM-5催化性能的影響。本實(shí)驗(yàn)采用加壓固定床反應(yīng)器對(duì)所制得的催化劑進(jìn)行活性評(píng)價(jià),并采用XRD、N2吸脫附、N2O化學(xué)吸附、SEM、XPS和H_2-TPR等一系列技術(shù)對(duì)催化劑進(jìn)行表征。取得的主要結(jié)果如下:一、Li_2O 含量對(duì) CuO-ZnO-Al_2O_3-Li_2O(x)/HZSM-5 催化性能的影響采用碳酸鈉共沉淀法制備CuO-ZnO-Al_2O_3-Li_2O(CZAL-x),研究了 Li_2O含量對(duì)CuO-ZnO-A1_2O_3-Li_2O(x)/HZSM-5催化性能的影響。結(jié)果表明,添加適量的Li可以促進(jìn)催化劑中活性組分的分散,提高Cu表面積,從而提高CO的轉(zhuǎn)化率。在H_2/CO/CO_2=2:2: 1,P=3.0MPa,T=250 ℃,WHSV=2400mL·gcat-1·h-1 的反應(yīng)條件下,在 CZAL-0.5+HZSM-5催化劑的作用下,CO的轉(zhuǎn)化率和DME的選擇性分別達(dá)到了 61.1%和63.4%。此外,Li的添加還可以有效地抑制Cu晶體的生長(zhǎng),從而明顯提高催化劑的穩(wěn)定性。二、助劑(Ce/Y/Ga/Zr)對(duì) CuO-ZnO-Al_2O_3/HZSM-5 催化性能的影響采用碳酸鈉共沉淀法制備CuO-ZnO-Al_2O_3-MOx(M=Ce/Y/Ga/Zr),研究了助劑Ce、Y、Ga、Zr對(duì)CuO-ZnO-Al_2O_3/HZSM-5催化性能的影響。結(jié)果表明,助劑種類(lèi)的不同,對(duì)CuO-ZnO-Al_2O_3/HZSM-5催化性能的影響也不相同,其中助劑Zr的添加可以促進(jìn)催化劑中活性組分Cu的分散,提高CuL比表面積,從而提高CO的轉(zhuǎn)化率。此外,助劑Zr的添加也可以適當(dāng)提高催化劑的穩(wěn)定性。三、制備方法對(duì)CuO-ZnO-Al_2O_3-ZrO_2/HZSM-5催化性能的影響采用碳酸鈉共沉淀、草酸膠態(tài)共沉淀、草酸固相反應(yīng)法和燃燒法制備CuO-ZnO-Al_2O_3-ZrO_2 催化劑,研究制備方法對(duì) CuO-ZnO-Al_2O_3-ZrO_2/HZSM-5 催化性能的影響。結(jié)果表明,用碳酸鈉共沉淀法制備的CuO-ZnO-Al_2O_3-ZrO_2催化劑Cu的晶粒最小,Cu比表面積最大,與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，

本文編號(hào)：2492312