钙钛矿型复合氧化物催化剂用于焦炉煤气二氧化碳重整反应的研究

发布时间：2018-05-28 13:38

本文选题：合成气 + 干重整　；参考：《上海大学》2015年硕士论文

【摘要】：焦炉煤气二氧化碳重整制合成气是近年来研究的热点和难点,其意义在于:(l)可以充分利用冶金废气,缓解能源危机,实现经济的可持续发展;(2)减少温室气体排放,缓解全球气候变暖,有利于环境保护;(3)其H2/CO比更适合与F-T及甲醇的合成;(4)焦炉煤气二氧化碳重整可作为能量储存介质。但是由于焦炉煤气二氧化碳重整反应过程中会产生严重的积碳,造成催化剂(尤其是非贵金属催化剂)失活,进而限制了其在工业中的应用。尽管贵金属催化剂具有良好的催化活性和抗积碳性能,但其成本昂贵且需要回收。因此,焦炉煤气二氧化碳重整反应研究和工业化的关键就是开发高活性、良好抗积碳性能的非贵金属催化剂。本论文首先研究了Ni的掺杂量和煅烧温度对溶胶凝胶法制备的La0.6Sr0.4NixCo1-xO3钙钛矿型复合氧化物催化剂催化活性的影响。通过XRD、TPR、TEM、SEM等表征手段对其性能进行研究。XRD结果显示在La0.6Sr0.4Co O3中掺杂Ni离子之后,La0.6Sr0.4NixCo1-xO3仍保持钙钛矿的结构。Ni的掺杂显著提高了催化剂的活性,其中La0.6Sr0.4Ni O3显示出了最好的催化性能,CH4和CO2的转化率分别达到93.3%和96.3%。反应后的XRD结果显示产物中生成了Ni0、Co0和La2O2CO3,其中La2O2CO3作为重要的中间产物,对焦炉煤气二氧化碳重整催化剂的催化活性和抗积碳性能有重要的影响。研究还发现,焦炉煤气的富氢特性对催化剂中的积碳有一定的消除作用。其次,研究了La Ni O3负载在五种不同的载体Al2O3、Ce O2、Mg Al2O4、Si O2和SBA-15上的负载型催化剂LN-M(M=Al2O3,Ce O2,Mg Al2O4,Si O2,SBA-15)的催化活性,发现LN-Al2O3的催化活性最低,CH4和CO2的转化率分别只有80.2%和96.1%,通过XRD和TPR发现还原后生成的Ni离子与Al2O3发生固相反应生成了难以还原的Ni Al2O4尖晶石相,进而降低了催化剂的活性。LN-Ce O2显示出最高的催化活性,说明Ce O2和La Ni O3有着良好的相互作用,改良了催化剂的催化活性和抗积碳性能。最后,对LN-Ce O2催化剂进行进一步的研究,制备了一系列不同Ni含量的LN-Ce O2催化剂,并用于焦炉煤气二氧化碳重整中。实验结果表明当Ni含量从5wt%增加到15wt%时,催化剂的催化活性显著增加,继续增加Ni含量到20 wt%,催化活性反而降低到81%。TG-DSC结果表明,20wt%Ni/LNC的积碳量最高,导致其催化剂活性下降。
[Abstract]:Carbon dioxide reforming of coke oven gas to syngas has been a hot and difficult point in recent years. Its significance lies in that it can make full use of metallurgical waste gas, alleviate energy crisis, realize sustainable economic development and reduce greenhouse gas emissions. H2/CO is more suitable for carbon dioxide reforming with F-T and methanol than that with F-T and methanol) carbon dioxide reforming of coke oven gas can be used as energy storage medium. However, due to the serious carbon deposition in the process of carbon dioxide reforming of coke oven gas, the catalyst (especially non-precious metal catalyst) is deactivated, which limits its application in industry. Although noble metal catalysts have good catalytic activity and resistance to carbon deposition, they are expensive and need to be recovered. Therefore, the key to the research and industrialization of carbon dioxide reforming reaction of coke oven gas is to develop non-precious metal catalysts with high activity and good resistance to carbon deposition. In this paper, the effects of doping amount of Ni and calcination temperature on the catalytic activity of La0.6Sr0.4NixCo1-xO3 perovskite-type composite oxide catalyst prepared by sol-gel method were studied. The XRD results showed that the doping of La0.6Sr0.4NixCo1-xO3 with perovskite structure significantly improved the activity of the catalyst after doping Ni ions in La0.6Sr0.4Co O3. Among them, La0.6Sr0.4Ni O3 showed the best catalytic activity, the conversion of Ch 4 and CO2 reached 93 3% and 96 .3%, respectively. The results of XRD show that Ni0 Co0 and La2O2CO3 are formed in the products. La2O2CO3, as an important intermediate product, has an important effect on the catalytic activity and anti-carbon deposition of coke oven gas carbon dioxide reforming catalyst. It is also found that the hydrogen-rich properties of coke oven gas can eliminate the carbon deposition in the catalyst. Secondly, the catalytic activity of La Ni O 3 supported on five different supports of Al _ 2O _ 3, ce _ 2O _ 2, mg, Al _ 2O _ 4, Sio _ 2 and SBA-15 was studied, and the catalytic activity of the supported catalyst LN-MU Al _ 2O _ 3O _ 2O _ 2C _ 2O _ 2mg Al _ 2O _ 4 O _ 2O _ 2O _ 2SBA-15 was studied. It was found that the catalytic activity of LN-Al2O3 was the lowest, the conversion of CH4 and CO2 were only 80.2% and 96.1%, respectively. It was found by XRD and TPR that the Ni ~ (2 +) formed by the reduction reacted with Al2O3 in solid state to form a refractory Ni Al2O4 spinel phase. Thus, the activity of the catalyst. LN-CeO2 showed the highest catalytic activity, which indicated that there was a good interaction between ce O2 and La Ni O 3, and the catalytic activity and the resistance to carbon deposition of the catalyst were improved. Finally, a series of LN-Ce O 2 catalysts with different Ni content were prepared and used in carbon dioxide reforming of coke oven gas. The experimental results show that when Ni content increases from 5 wt% to 15 wt%, the catalytic activity of the catalyst increases significantly, and the catalytic activity decreases to 81%.TG-DSC, which leads to the decrease of the catalytic activity of Ni / LNC, which leads to the decrease of catalyst activity.
【学位授予单位】：上海大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：O643.36;TE665.3

【共引文献】