二氧化碳加氢合成二甲醚催化剂的制备及性能研究
发布时间：2019-05-28 23:29
【摘要】：本文主要研究了二氧化碳加氢合成二甲醚催化剂的制备及性能。使用碳酸钠作为沉淀剂的共沉淀法在不同的工艺条件下制备了锆掺杂的二氧化碳加氢合成二甲醚的催化剂。在WFSM-3060型催化剂评价装置中对不同工艺条件下制备的催化剂进行了催化性能的测试和评价,筛选出了最优的制备工艺条件。并利用X-射线衍射(XRD)、比表面积测试(BET)、扫描电子显微镜(SEM)和热重分析(TG)等技术对各种工艺条件制取的催化剂进行了表征,研究了催化剂性能与结构及成分的关系。主要的工作如下:(1)制备了不同Cu/Zn摩尔比、不同焙烧温度、不同沉淀剂的Cu-Zn-Al/HZSM-5催化剂,通过正交试验对焙烧温度、Cu/Zn摩尔比、沉淀剂种类进行试验,筛选出在350℃,Cu/Zn摩尔比为2:1,碳酸钠为沉淀剂时,二甲醚的收率最高。在正交试验的基础上还使用单因素试验分别对Cu/Zn比例以及焙烧温度对催化剂催化性能的影响进行了进一步的研究,最终得出了最优的制备工艺条件。最后在最优的工艺条件下制取了催化剂并进行了不同量的Zr02掺杂,得出了最佳的ZtO2掺杂量。发现在最佳工艺条件下制备的锆掺杂的Cu-Zn-Al/HZSM-5催化剂与传统的催化剂比较对二氧化碳加氢合成二甲醚具有更高的二氧化碳转化率以及二甲醚的收率反而有所降低。通过XRD、BET及SEM分析发现ZrO2的掺入使得催化剂中各衍射峰的强度增加,峰形变得更加尖锐。堆积程度增加,比表面积有一定程度的降低。(2)为了制备高选择性的二氧化碳加氢合成二甲醚催化剂,选择使用不同Cu/Mn摩尔比、不同焙烧温度作为催化剂制备的工艺优化项目。探索了不同Cu/Mn及不同焙烧温度所制备的Cu-Mn-Al/HZSM-5催化剂在催化CO2加氢制取DME时对催化性能的影响。使用单因素试验得出了最佳的Cu/Mn摩尔比和最佳的焙烧温度。在最佳工艺条件下对所制备的催化剂进行ZrO2的掺杂,探究掺杂前后及掺杂量对该催化剂催化性能的影响,成功得出了最佳的2rO2的掺杂量。进一步的研究发现该锆掺杂的Cu-Mn-Al/HZSM-5催化剂具有较高的二甲醚的选择性,并且二甲醚的收率也很可观达到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，
本文编号：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，
本文编号：2487452
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