合成气制乙醇铜基催化剂的研究

发布时间：2018-04-26 03:06

本文选题：合成气 + 钴改性　；参考：《华东理工大学》2017年硕士论文

【摘要】：乙醇作为一种重要的基础化工原料,在化工及其他领域都有着广泛的用途。作为煤化工的一部分,合成气化工的发展对于煤炭资源的洁净应用意义重大。采用共沉淀、浸渍法及两者相结合的方法制备了催化剂,研究了在改性甲醇合成催化剂和改性费托合成催化剂上CO加氢制混合醇的催化活性。通过低温N2吸附-脱附、X射线衍射(XRD)、CO程序升温脱附(CO-TPD)、程序升温还原(H2-TPR)和X射线光电子能谱分析(XPS)等手段对催化剂进行表征。通过筛选,确定了以Cu为活性组分的改性低温甲醇合成催化剂体系。载体考察结果表明,碱性载体MgO较Al2O3、ZrO_2、SiO_2更有利于乙醇的合成,适宜的Cu/Mg摩尔比为1。对于Cu/MgO催化剂,较其他金属助剂而言,Mn具有更强的链增长能力以及C_(2+)醇收率。表征结果显示,Mn的加入增大了 Cu/MgO催化剂的比表面积,使Cu、Mg物种更加分散,为催化反应提供了更多的活性位,同时也增加了催化剂表面碱性位数量并增强了其强度。在Mn/Cu比为0.3时,总醇中C2H5OH/C1OH由0.08增至0.31,C2H5OH 时空收率由 2.69 g(kgcat·h)-1 增至 5.65 g(kgcat·h)-1。Mn/Cu/MgO催化剂上C_(2+)OH合成能力有限,Co的加入形成Co2Mg、MnCo2O4相,有利于Cu、Mn及Mg物种的分散,为C_(2+)OH的生成提供了更多活性位。适量Co的加入有助于提高催化剂对总醇中C_(2+)OH的选择性。对于Co0.3/Mn/Cu/MgO催化剂,在260℃,3.0MPa,2000mL(gcat·h)-1,V(H2)/V(CO)=2.0 的条件下,C_(2+)OH/C1OH 比值由未加Co时的0.31增至3.12,C_(2+)OH的时空收率则由15.83 g·(kgcat·h)-1增至50.32 g·(Kgcat·h)-1。讨论了 Co-Cu基催化剂上混合醇的合成机理,该过程中Co的插碳效应对混合醇的选择性起着重要作用,但同时也提高了烃类产物的选择性。
[Abstract]:As an important basic chemical raw material, ethanol is widely used in chemical and other fields. As a part of coal chemical industry, the development of synthetic gas chemical industry is of great significance for the clean application of coal resources. The catalyst is prepared by means of co precipitation, impregnation and the combination of the two methods, and the synthesis of modified methanol is studied. The catalytic activity of mixed alcohols from CO hydrogenation on the catalyst and modified Fisher synthesis catalyst was characterized by low temperature N2 adsorption desorption, X ray diffraction (XRD), CO programmed temperature desorption (CO-TPD), temperature programmed reduction (H2-TPR) and X ray photoelectron spectroscopy (XPS). The modification of Cu was selected to determine the modification of active components by Cu. The results show that the basic carrier MgO is more beneficial to the synthesis of ethanol than that of Al2O3, ZrO_2 and SiO_2. The suitable Cu/Mg molar ratio is 1. for Cu/MgO catalyst and Mn has stronger chain growth ability and C_ (2+) alcohol yield than the other metal additives. The characterization results show that Mn addition increases Cu/Mg. The specific surface area of the O catalyst makes the Cu, Mg species more dispersed, provides more active sites for the catalytic reaction, and increases the surface alkalinity of the catalyst and strengthens its strength. At the Mn/Cu ratio of 0.3, the C2H5OH/C1OH in total alcohol increases from 0.08 to 0.31, and the time and space yield of C2H5OH is increased from 2.69 g (kgcat h) -1 to 5.65 g (kgcat. The synthesis ability of C_ (2+) OH on MgO catalyst is limited, and Co is added to form Co2Mg, MnCo2O4 phase, which is beneficial to the dispersion of Cu, Mn and Mg species, which provides more active sites for the production of C_ 2+. 2) under the condition of /V (CO) =2.0, the ratio of C_ (2+) OH/C1OH increased from 0.31 without Co to 3.12, and the time and space yield of C_ (2+) OH increased from 15.83 g (kgcat.) to 50.32. The selectivity of hydrocarbon products is higher.

【学位授予单位】：华东理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ223.122;TQ426

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