二氧化碳加氫合成二甲醚催化劑的制備及性能研究
發(fā)布時間：2019-05-28 23:29
【摘要】：本文主要研究了二氧化碳加氫合成二甲醚催化劑的制備及性能。使用碳酸鈉作為沉淀劑的共沉淀法在不同的工藝條件下制備了鋯摻雜的二氧化碳加氫合成二甲醚的催化劑。在WFSM-3060型催化劑評價裝置中對不同工藝條件下制備的催化劑進行了催化性能的測試和評價,篩選出了最優(yōu)的制備工藝條件。并利用X-射線衍射(XRD)、比表面積測試(BET)、掃描電子顯微鏡(SEM)和熱重分析(TG)等技術對各種工藝條件制取的催化劑進行了表征,研究了催化劑性能與結構及成分的關系。主要的工作如下:(1)制備了不同Cu/Zn摩爾比、不同焙燒溫度、不同沉淀劑的Cu-Zn-Al/HZSM-5催化劑,通過正交試驗對焙燒溫度、Cu/Zn摩爾比、沉淀劑種類進行試驗,篩選出在350℃,Cu/Zn摩爾比為2:1,碳酸鈉為沉淀劑時,二甲醚的收率最高。在正交試驗的基礎上還使用單因素試驗分別對Cu/Zn比例以及焙燒溫度對催化劑催化性能的影響進行了進一步的研究,最終得出了最優(yōu)的制備工藝條件。最后在最優(yōu)的工藝條件下制取了催化劑并進行了不同量的Zr02摻雜,得出了最佳的ZtO2摻雜量。發(fā)現(xiàn)在最佳工藝條件下制備的鋯摻雜的Cu-Zn-Al/HZSM-5催化劑與傳統(tǒng)的催化劑比較對二氧化碳加氫合成二甲醚具有更高的二氧化碳轉化率以及二甲醚的收率反而有所降低。通過XRD、BET及SEM分析發(fā)現(xiàn)ZrO2的摻入使得催化劑中各衍射峰的強度增加,峰形變得更加尖銳。堆積程度增加,比表面積有一定程度的降低。(2)為了制備高選擇性的二氧化碳加氫合成二甲醚催化劑,選擇使用不同Cu/Mn摩爾比、不同焙燒溫度作為催化劑制備的工藝優(yōu)化項目。探索了不同Cu/Mn及不同焙燒溫度所制備的Cu-Mn-Al/HZSM-5催化劑在催化CO2加氫制取DME時對催化性能的影響。使用單因素試驗得出了最佳的Cu/Mn摩爾比和最佳的焙燒溫度。在最佳工藝條件下對所制備的催化劑進行ZrO2的摻雜,探究摻雜前后及摻雜量對該催化劑催化性能的影響,成功得出了最佳的2rO2的摻雜量。進一步的研究發(fā)現(xiàn)該鋯摻雜的Cu-Mn-Al/HZSM-5催化劑具有較高的二甲醚的選擇性,并且二甲醚的收率也很可觀達到11.96%。
[Abstract]:In this paper, the preparation and properties of catalysts for hydrogenation of carbon dioxide to dimethyl ether were studied. Zirconium-doped catalysts for hydrogenation of carbon dioxide to dimethyl ether were prepared by coprecipitation method with sodium carbonate as precipitator under different technological conditions. The catalytic performance of the catalysts prepared under different process conditions was tested and evaluated in WFSM- 3060 catalyst evaluation unit, and the optimal preparation conditions were selected. The catalysts prepared under various technological conditions were characterized by X-ray diffraction (XRD), specific surface area measurement (BET), scanning electron microscope (SEM) and thermogravimetric analysis (TG). The relationship between catalyst performance and structure and composition was studied. The main work is as follows: (1) Cu-Zn-Al/HZSM-5 catalysts with different Cu/Zn molar ratio, different calcination temperature and different precipitant were prepared. The calcination temperature and Cu/Zn molar ratio were determined by orthogonal test. The yield of dimethyl ether was the highest when the molar ratio of Cu/Zn was 2 鈮，
本文編號：2487452
[Abstract]:In this paper, the preparation and properties of catalysts for hydrogenation of carbon dioxide to dimethyl ether were studied. Zirconium-doped catalysts for hydrogenation of carbon dioxide to dimethyl ether were prepared by coprecipitation method with sodium carbonate as precipitator under different technological conditions. The catalytic performance of the catalysts prepared under different process conditions was tested and evaluated in WFSM- 3060 catalyst evaluation unit, and the optimal preparation conditions were selected. The catalysts prepared under various technological conditions were characterized by X-ray diffraction (XRD), specific surface area measurement (BET), scanning electron microscope (SEM) and thermogravimetric analysis (TG). The relationship between catalyst performance and structure and composition was studied. The main work is as follows: (1) Cu-Zn-Al/HZSM-5 catalysts with different Cu/Zn molar ratio, different calcination temperature and different precipitant were prepared. The calcination temperature and Cu/Zn molar ratio were determined by orthogonal test. The yield of dimethyl ether was the highest when the molar ratio of Cu/Zn was 2 鈮，
本文編號：2487452
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