【作者】 王莉萍；

【导师】 张永发；

【作者基本信息】 太原理工大学 ， 化学工艺， 2010， 硕士

【摘要】 近年来,环保要求日趋严格,节能减排步伐逐渐加快,同时,天然气资源短缺,焦炉煤气制天然气引起了人们的密切关注,此项工作也正在成为焦炉煤气利用的一项重要技术途径。且利用我国丰富的剩余焦炉煤气制天然气对解决天然气短缺,在能源安全、节能减排方面具有重要意义。许多文献已报道了少量CO和CO2甲烷化的钌系或镍系催化剂研究,但是,对焦炉煤气制天然气过程的钌基催化剂开发研究报道甚少。因此,本文选择负载型Ru催化剂为研究对象,系统考察了活性氧化铝载Ru催化剂的甲烷化性能。1、研究了不同载体对负载型钌催化剂的影响。结果表明,不同载体负载钌催化剂的活性顺序为：Ru／Al2O3>Ru／MgO>Ru／SiO2。2、研究了不同活性组分以γ-Al2O3为载体的催化剂性能,结果表明催化剂活性顺序为：Ru／Al2O3>Co／Al2O3>Ni／Al2O3,负载型钌催化剂不仅具有最低的活化能,而且具有较高的活性。3、研究了制备方法(等体积浸渍法和超声波浸渍法)、超声波浸渍时间、超声波频率、Ru负载量对催化剂活性的影响。结果表明,Ru负载量为0.5wt%,超声波浸渍不仅可以提高催化剂活性而且可以缩短浸渍时间,超声波浸渍法制备催化剂合适的超声浸渍时间为20min,超声波频率为40kHz。不同钌含量的Ru／Al2O3催化剂活性随着Ru负载量增加CO转化率和甲烷选择性先增加后逐渐降低,但副产物CO2的选择性也逐渐增加。Ru负载量为2wt%,CO转化率达98.33%,甲烷化选择性达83.29%,催化剂性达到最佳。4、研究了制备条件(焙烧温度和还原温度)、助剂等对催化剂活性的影响。结果表明,催化剂最佳制备的焙烧温度为500℃,还原温度为400℃。催化剂不论是添加Ni,Co等Ⅷ族金属还是添加Ce,La和K等非Ⅷ族助剂,催化剂活性改善不明显,甚至有不同程度地降低。另外,氯离子的去除对催化剂活性也有影响,催化剂浸渍后用去离子水结合氨水洗涤,可有效去除氯离子,提高催化剂活性。5、研究了空速、原料气配比和反应温度对Ru／Al2O3催化剂上CO甲烷化反应的影响,并对催化剂的热稳定性和耐毒性进行了初步的考察。结果表明,空速等于3000h-1时,CO转化率和CH4选择性达到最大；催化剂活性随着H2和CO比值的增加而急剧升高；CO的转化率和甲烷选择性随反应温度的升高先增加后略微下降,研究表明300-400℃为较适宜的反应温度；催化剂在测试时间26h内活性稳定高效,催化剂耐毒性测试其极限耐毒量为1.72μL.g-1。更多还原

【Abstract】 In recent years, cleanning coke oven gas conversion has stirred attention from both environmental protection and energy-saving emission reduction. At the same time, because of lack of nature gas, conversion coke oven gas to SNG (substitude nature gas) is becoming an important technology. It is of great significance to solve our future natural gas demand、energy security、energy saving and emission reduction. Many studies have reported Ru or Ni catalyst research for CO and CO2 methanation for purifying fuel cell or ammonia synthesis feed gas, but very few results for ruthenium-based catalyst for high CO concentrations about coke oven gas to natural gas. Therefore, this dissertation it has been highlighted that the tests of the methanation performance of Ru catalysts supported on oxides in coke oven gas.1、The effect of supports on the methanation of CO of Ru catalysts has been investigated. The order of activity is shown as follows:Ru/Al2O3> Ru/MgO> Ru/SiO2.2、The methanation performances of a series of y-Al2O3 supported transition metal catalysts have been explored by the employment of activity test. The order of catalytic activity is shown as follows:Ru/Al2O3> Co/Al2O3> Ni/Al2O3. Among the catalysts Ru/Al2O3 catalyst has the highest activity for the methanation of CO with the least activation energy.3、The influences of preparation method (wet impregnation and ultrasonic impregnation) and ultrasonic impregnation time and frequence, Ru loadings of Ru/Al2O3 on the activity of catalysts have been investigated. The results showed that when Ru loadings 0.5 wt%, compared with the catalyst prepared by impregnation method, the catalyst prepared by ultrasonic impregnation method performed higher activity and also save catalyst impregnation time, the right impregnation time was 20 min and ultrasonic frequence 40 kHz. As the Ru content increases, CO conversion not change significantly and seems to attain a plateau, while methane selectivity decreased gradually, CO2 selectivity increased gradually.2% wt% Ru is appropriate catalyst metal loading, the conversion of CO and CH4 selectivity are 98.33% and 83.29%, respectively.4、The influences of preparation condition (calcined temperature and reduction temperature)、addition of promoters and effect of Cl- on activity of Ru/Al2O3 catalyst have been investigated. A suitable catalyst calcination temperature was 500℃, reduction temperature was 400℃. The addition of promoters of VIII metal and non-VIII metal into the single Ru metal catalyst will result in more or less decrease of Catalytic activity. Addition, filtrating the sample after RuCl3 was impregnated, It can effectively remove Cl- and improve catalyst activity, in particular, the effect of washing with dilute ammonia and deionized water is evident.5、The influences of space velocity、ratio of CO and H2、reaction temperature on activity of Ru/Al2O3 catalyst have been investigated and then examined the catalyst thermal stability and sulfer resistance. The optimal reaction conditions are space velocity 3000 h-1; with ratio of CO and H2 increased, CO conversion and CH4 selectivity increaseed; as the reaction temperature increasing, CO conversion and CH4 selectivity firstly increased and then a little decreased, studies show that 300-400℃for the more appropriate reaction temperature. The study also found that the catalyst has good activity after 26 h, the catalyst sulfer-resistant amount limits was 1.72μL.g-1.更多还原