合成气加氢制甲醇铜基催化剂适配关系的研究

发布时间：2019-04-01 17:49

【摘要】：合成气催化反应制备甲醇对资源合理化利用及环境保护有着至关重要的作用,因此对Cu基催化剂组分与混合气适配关系的研究尤为关键,将有助于提高反应气的转化率及催化反应的产率。本论文通过X射线衍射(XRD)、热重-微商热重(TG-DTG)、红外光谱仪(FT-IR)、H2程序升温还原(H2-TPR)、CO2程序升温吸脱附(CO2-TPD)和X射线光电子能谱(XPS)等表征方法探究了不同助剂组成的二组分、三组分及四组分催化剂的催化活性及催化体系在三种混合气条件下的适配关系。具体内容如下:1、助剂的组成对催化性能的影响:不同组分含量的催化剂所表现的催化活性为:二组分(Cu-ZnO,Cu-Al2O3,Cu-ZrO2)三组分(Cu-ZnO-Al2O3,Cu-ZnO-ZrO2)四组分(Cu-ZnO-Al2O3-ZrO2)。而四组分催化剂体系中,当添加适当的ZrO2(6%),前驱体中出现绿铜锌矿相,而此时CuO和ZnO颗粒尺寸最小,比表面积、铜分散度增强,催化剂的催化效果最好,甲醇的选择性和收率以及CO2转化率最高。ZrO2含量过多或过少,不利于形成绿铜锌矿相,仅有锌孔雀石相形成。对于单组分氧化物载体催化剂来说,ZrO2载体更有利于CO2加氢反应,Al2O3载体更有利于CO加氢反应。对于复合氧化物载体催化剂来说,四组分Cu-ZnO-Al2O3-ZrO2中ZrO2掺杂量为2%时,CO加氢效果较好,ZrO2掺杂量为10%时,CO2加氢效果较好,ZrO2掺杂量为6%时,其CO和CO2混合气加氢效果较好。2、混合气组成对产率的影响:不同组成的反应气对甲醇的选择性和甲醇的收率影响很大。对于CO2和氢气的混合气反应来说,其CO2的转化率明显优于三元混合气。对于CO和氢气的混合气来说,其CO的转化率明显优于三元混合气,但三元混合气在催化过程中,其甲醇的选择性和收率最高,CO和CO2的适当混合可以有效提高产物的转化率。
[Abstract]:The synthesis of methanol by catalytic reaction of syngas plays an important role in the rational utilization of resources and environmental protection. Therefore, the study on the relationship between the composition of Cu-based catalyst and the mixture of methanol is especially critical. It will help to increase the conversion of reaction gas and the yield of catalytic reaction. In this paper, X-ray diffraction (XRD), thermogravimetry-derivative thermogravimetry (TG-DTG), infrared spectrometer (FT-IR), H2 temperature programmed reduction (H2-TPR), CO2 temperature programmed desorption (CO2-TPD) and X-ray photoelectron spectroscopy (XPS) were used to characterize the two components of different auxiliaries. The catalytic activity of three-component and four-component catalysts and the adaptation relationship of the catalyst system under the conditions of three kinds of gas mixture. The main contents are as follows: 1. The effect of promoter composition on catalytic performance: the catalytic activity of catalysts with different component contents is as follows: two components (Cu-ZnO,Cu-Al2O3,Cu-ZrO2) and three components (Cu-ZnO-Al2O3,). Cu-ZnO-ZrO2) four components (Cu-ZnO-Al2O3-ZrO2). In the four-component catalyst system, when the appropriate ZrO2 (6%) was added, the spruce phase appeared in the precursor, and the particle size of CuO and ZnO was the smallest, the specific surface area and copper dispersion were enhanced, and the catalytic effect of the catalyst was the best. The selectivity and yield of methanol and the conversion rate of CO2 are the highest. Too much or too little ZrO _ 2 content is not conducive to the formation of zincite phase, but only zinctachite phase. For single component oxide carrier catalyst, ZrO2 carrier is more favorable for CO2 hydrogenation, and Al2O3 carrier is more favorable for CO hydrogenation reaction. When the content of ZrO2 in the four-component Cu-ZnO-Al2O3-ZrO2 is 2%, the hydrogenation effect of CO is better, that of ZrO2 is 10%, that of CO2 is better, and that of ZrO2 is 6%. The mixture of CO and CO2 has a good hydrogenation effect. 2, the effect of mixture composition on the yield: the selectivity of methanol and the yield of methanol are greatly influenced by the reaction gas of different composition. For the mixed gas reaction of CO2 and hydrogen, the conversion of CO2 is obviously better than that of ternary mixture. For the mixture of CO and hydrogen, the conversion of CO is obviously better than that of ternary mixture, but the selectivity and yield of methanol are the highest in the catalytic process of ternary mixture. The proper mixing of CO and CO2 can effectively improve the conversion of the product.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ223.121;O643.36

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