Study On Syngas Production From Landfill Gas In Porous Media Reactor

With the growing of city garbage, many large and medium-sized city fell into the trouble of garbage. The effective use of the energy in landfill gas not only can reduce greenhouse gas emissions, but also can effectively alleviate the energy shortage problem in china. The syngas is a kind of widely used chemical raw material, its main components are carbon monoxide and hydrogen. Utilization of landfill gas composed mostly of methane and carbon dioxide to produce syngas has the advantages of energy saving and environmental protection. In this paper, porous medium is applied to the process of the landfill gas to synthesis gas. A porous medium reactor is designed. This reactor has the advantages of stable combustion, high combustion temperature. Syngas can be gained from landfill gas in this reactor without heat source and catalyst.This paper mainly includes the following several aspects of the work:First of all, a thermodynamic equilibrium analysis on the multi-reaction system for the process of syngas production from landfill gas be performed based on minimization of Gibbs free energy of method, the aim of which is to found key factors that influences the reactions and obtain the suitable range of reaction conditions.The results revealed that 4CH conversion is significantly influenced by temperature. High temperature is helpful to 4CH and 2CO convering to 2H and CO and inhibit carbon production. The addition of 2O to landfill gas is useful to eliminate carbon deposit, but the syngas yields reduces. Accordinglg,the optimal equilibrium conditions for the 2 4 2O /CH /CO ratio were within the range of 0.1/1/0.8-0.2/1/1 and temperature of 1173K-1373 K.Then,a mathematical model for premixed gas combustion in porous media reactor is established in the paper and the mathematical model be certified through the experiments. The combustion characteristics of landfill gas in porous media is researched. The results show that divergent porous medium burner can offer superior advantages such as high combustion temperature and stable combustion.Based on the above results, a convolution type porous medium reactor is designed in the end of this paper and the calculation method for producing synthesis gas by reforming the landfill gas in this porous medium reactor is established. The syngas yields is calculated. The results showed that syngas yields is the highest corresponded to the operating feed ratio and excess air coefficient of 4 2CH /CO =1 and 0.4. 1 mol landfill gas could convert to 0.55mol2 H and 0.6mol CO. 2H and CO selectivity were 0.55 and 0.82 respectively.In addition, the higher the content of methane in landfill gas is beneficial to improve the production of syngas. The 2H /CO ratio increases with 4 2CH /CO ratio, different 2H /CO ratio can be obtained to meet different requirements of industrial formation by adjusting 4 2CH /CO ratio.