Experimental Research On Carbon Dioxide Reforming Of Methane To Synthetic Gas

The process of carbon dioxide reforming of methane to synthesis gas has received considerable attention in recent years, and it's an attractive way to utilize CO2 since it offers several advantages over steam reforming and partial oxidation of CH4:first, it offers a suitable H2/CO product ratio (nearly 1/1), which can be directly used as feedstock of syntheses of some oxidic compounds; second, it has important environmental implications as it reduces CO2 and CH4 emissions contributing to the greenhouse effect; third, it is better used in chemical energy transmission.However, the major obstacle preventing commercialization of this process is that, due to the endothermic nature of the process, a high operating temperature is required to attain high conversions. This condition is conducive to carbon deposition or coking and catalyst deactivation. For this reason, a number of studies have been focused on the development of a coke-resistant catalyst for the CO2 reforming of CH4.Ni-based catalysts are widely used for CO2 reforming of methane because of the high activity and low cost. However, a rapid deactivation due to carbon deposition and/or sintering of the metal particles has been reported on Ni/oxidic support catalysts. It's been reported that Ni-based catalysts' performance can be enhanced by choosing proper supporters, adding promoters to the catalysts, controlling the proper ratio of the components and also by improving the preparation methods.γ-Al2O3 has shown good performance and is widely used as supporters of Ni-based catalysts. Also, Ni-based catalysts'ability against carbon deposition can be greatly enhanced by adding proper amount of promoters. A lot of researches have been focused on the alkali metal and MgO has shown good results.In this paper, Ni-based catalyst supported onγ-Al2O3 with the promoter of MgO for or the carbon dioxide reforming of methane has been prepared. The experimental researches on how reaction parameters affect carbon dioxide of methane were carried out in a fixed-bed stainless steel reactor with an inner diameter of 12mm. First, the prepared Ni/Mg Al2O3 catalyst was tested for its catalytic activity and stability at 700℃,800℃under atmospheric pressure. The gas velocity was set at 1200h-1 with a CH4/CO2 ratio of 1:1. The results showed a maximum catalytic activity of 89% and 90% for methane and carbon dioxide conversion rates, respectively. Then the experiments were carried out and the effects of the reaction temperatures, the feedstock velocity and the different composition in the feedstock on the reaction performance were investigated.The results suggested that reaction temperature had a great effect on the reaction performance; the effects of the feedstock velocity and composition are less than the reaction temperature; the carbon dioxide reforming of methane received the highest synthesis gas yield rate when the volume rate of methane and carbon dioxide in the feedstock is about 1:1.