多孔介质反应器内填埋气重整制合成气的研究

发布时间：2018-08-30 19:17

【摘要】：有效地利用垃圾填埋气,不仅能减少温室气体的排放,而且能有效地缓解我国能源短缺问题。合成气是一种用途广泛的化工原料,其主要成分是一氧化碳和氢气。利用填埋气中的甲烷和二氧化碳制合成气,具有节能、环保双重意义。本文将多孔介质运用到填埋气制合成气的过程中,设计了一种多孔介质反应器。利用多孔介质反应器具有燃烧稳定好、燃烧温度高等特点,在不加热源和催化剂的条件下,实现填埋气的再生利用。本文主要包括以下几个方面的工作:首先,采用吉布斯自由能最小法对填埋气重整制合成气的热力学过程进行计算,分析各因素对重整制合成气过程的影响,找出填埋气重整反应合适的条件范围。研究结果表明:高温条件不仅有利于4CH和2CO转化为2H和CO,而且可以抑制积碳的产生;往填埋气中加入少量的2O,有助于消除积碳,但是加入2O会导致合成气的产量减少,二氧化碳转化率降低。综合考虑,填埋气重整在温度为1173K-1373K范围内,2 4 2O/CH/CO=0.1/1/0.8-0.2/1/1条件下转化率高,合成气产量大,积碳少。其次,建立预混气体在多孔介质内反应的数学模型,通过实验验证了模型的可靠性,并分析了填埋气在多孔介质内的燃烧特性。研究表明:进口气体当量比以及流速是影响火焰驻定的关键因素;渐变型多孔介质具有燃烧温度高、燃烧稳定性好等特点。综合以上研究结果,本文最后设计了一种渐变型多孔介质反应器,探究了多孔介质反应器内填埋气重整制合成气的计算过程,并对填埋气重整制合成气的产量进行分析。结果表明:4 2CH/CO=1,过量空气系数为0.4时,填埋气制合成气的产量最高。1mol的填埋气制0.55mol2H、0.60mol CO,氢气和一氧化碳的选择性分别为0.55和0.82。此外,填埋气中甲烷含量越高越有利于合成气的产量的提高。2H/CO摩尔比随4 2CH/CO增大而增大,可以通过调节4 2CH/CO来制不同2H/CO摩尔比来满足不同的工业生成要求。
[Abstract]:The effective use of landfill gas can not only reduce the greenhouse gas emissions, but also effectively alleviate the energy shortage in China. Syngas is a widely used chemical raw material, its main components are carbon monoxide and hydrogen. Using methane and carbon dioxide in landfill gas to produce syngas has the dual significance of energy saving and environmental protection. In this paper, a porous medium reactor is designed by applying porous medium to landfill gas to produce syngas. The porous medium reactor has the characteristics of good combustion stability and high combustion temperature. The landfill gas can be regenerated without heating the source and catalyst. This paper mainly includes the following aspects: firstly, the thermodynamic process of landfill gas reforming to syngas is calculated by Gibbs free energy minimization method, and the influence of various factors on the process of reforming to syngas is analyzed. Find out the suitable condition range of landfill gas reforming reaction. The results show that the high temperature condition is not only favorable to the conversion of 4CH and 2CO to 2H and CO, but also to the inhibition of carbon deposition, and the addition of a small amount of 2O to the landfill gas will help to eliminate the carbon deposition, but the addition of 2O will lead to a decrease in the production of syngas. The conversion rate of carbon dioxide decreased. Considering synthetically, the landfill gas reforming has high conversion rate, large synthetic gas output and less carbon deposition under the condition of 1173K-1373K temperature of 24 2O/CH/CO=0.1/1/0.8-0.2/1/1. Secondly, the mathematical model of the reaction of premixed gas in porous media is established. The reliability of the model is verified by experiments, and the combustion characteristics of landfill gas in porous media are analyzed. The results show that the inlet gas equivalent ratio and the flow rate are the key factors affecting the flame setting, and the gradual porous media has the characteristics of high combustion temperature and good combustion stability. Based on the above results, a kind of gradual porous medium reactor is designed, and the calculation process of landfill gas reforming to syngas in porous medium reactor is explored, and the output of landfill gas reforming to syngas is analyzed. The results showed that when the excess air coefficient was 0.4, the selectivity of landfill gas to 0.55 mol / CO, hydrogen and carbon monoxide was 0.55 and 0.82, respectively. In addition, the higher the methane content in landfill gas is, the higher the yield of syngas is. 2H / CO molar ratio increases with the increase of 4 2CH/CO. Different 2H/CO molar ratio can be prepared by adjusting 4 2CH/CO to meet different industrial production requirements.
【学位授予单位】：华南理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE665.3

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