导　　师： 吕永康

学科专业： G0304

授予学位： 硕士

作　　者： ;

机构地区： 太原理工大学

摘　　要： 甲烷二氧化碳重整制取合成气反应，不仅为天然气资源的合理利用及缓解温室气体排放量提供了有效的解决途径，还因其为一可逆的强吸热过程，可作为能量传输系统，用来贮存太阳能、核能等。因而，近年来引起全世界学术界及工业界的广泛关注。该过程工业化的一个关键性问题，就是高活性、高稳定性实用型催化剂的研制开发。目前大量的研究集中于贵金属及镍基催化剂。前者价格昂贵，后者因积炭严重稳定性差。本论文重点对CO催化剂体系进行研究，经过合理设计，得到了一系列既具有优良的催化活性，又有独特的抗积炭性能的CO催化剂。
　　 本论文采用溶胶-凝胶法制备了CO/BATIO3及CO-MGO/BATIO3 系列催化剂并研究了钴基催化剂的组成、制备及反应条件对甲烷二氧化碳重整反应的影响。在常压固定床反应器上考察了负载型CO基催化剂的焙烧温度、钴含量以及还原温度对甲烷二氧化碳重整过程的影响；并考察了以溶胶-凝胶法引入助剂MGO对CO/BATIO3 催化剂的催化反应性能影响，采用程序升温还原(TPR)、X 射线衍射(XRD)、扫描电子显微镜(SEM)、热分析(TG)技术对催化剂进行了表征；探讨了催化剂的积炭机理。
　　 实验结果表明：经过700℃焙烧3H 后的7[％]CO/BATIO3催化剂在反应温度为700℃，压力为0.1MPA，N(CO2)：N(CH4)为1：1，气相空速为12000 ML/(H. G. CAT)的条件下表现出相对良好的催化活性，CH4的转化率可达到87.68[％]、CO的选择性达到75.37[％]和H2的收率可达68.31[％]；CO/BATIO3，CO-MGO/BATIO3 催化剂的XRD和TPR表征结果表明，助剂MGO 使得催化剂中的活性CO2O3组分增多，还原性和分散性能较好。在N(CO2)：N(CH4)为1/1，气相空速为12000 ML/(H. G. CAT)，反应温度为700 ℃的条件下，催化剂CO-MGO/BATIO3表现出良好的催化性能，且反应初期CH4转化率可达到94.87[％]、CO 选择性可达85.21[％]、H2 收率可达74.08[％]；同时利用热分析技术对积炭进行了考察，结果发现反应10 H 后的CO-MGO/BATIO3 催化剂上并未出现导致催化剂失活的炭物种。 The catalytic reforming of CH4 with CO2 has received extensive attention of industrial and academic circles all over the world. This reaction has also important environmental implications because both CH4 and CO2 are regarded as the main factors leading to the green-house effect. Thus, this process exhibits certain potential to be used as thermochemical heat-pipe for recovery, storage and transmission of solar and other renewable energy sources. At present, one of the key problems for the application of this process is the development of practical catalysts with high activity and high stability. But the catalyst for the reaction at home and abroad studies have been largely focused on precious metals and nickel-based catalysts, precious metal catalyst is expensive , carbon deposition of nickel-based catalysts at the same time is serious and has low stability. The work is focused on the study of Co-based catalysts, which has a series of excellent catalytic activity and unique resistance of Co catalysts by rational design. In this paper, it is mainly concerned that the effect of the different contents of cobalt-supported catalysts, calcinations temperature, reaction conditions and assistant on the catalysis is preperties of methane carbon dioxide reforming in a fixed-bed reactor. The catalysts were characterized by means of XRD, TPR, SEM, FESEM and TGA. The results showed that the reaction performance was optimum, under the condition of n/(CO2/):n/(CH4/) of 1:1 with a GHSV 12000 ml// /(h. g. cat/) at 700℃, and 7/% content of cobalt-supported catalyst, the methane conversion and CO selectivity were 87.68/% and 75.37/% respectively. The calcinations temperature of 700 oC and the calcinations time of 3h were the best preparation conditions to Co-based catalysts. Results showed that MgO promoter on Co-based catalyst had the best performance, which was methane conversion 94.87/%, CO selectivity 85.21/% and H2 yield 74.08/% in the condition of n/(CO2/): n/(CH4/) of 1:1 with a GHSV 12000 mL///(h. g. cat/) at 700 oC. Results from XRD and TPR experiments showed that the addition of MgO enhanced the activity of catalyst, and the catalyst had the best reducibility and dispersibility. The type of carbonaceous species Cγ, which may cause catalyst deactivation, was unfound to exist on the Co-MgO//BaTiO3 catalyst after reaction in 10h by using TG techniques.

关 键 词： 甲烷二氧化碳 重整反应 钴基催化剂 制备工艺 催化活性

分 类 号： [TQ426.8]

领　　域： [化学工程]