| With the decrease of oil resources and the rising of the price of oil resources, the development and utilization of natural gas has been got more and more attention. Indirect conversion method has become the focus of research in the world's natural gas industry, the natural gas is converted to syngas by methane catalytic reforming reaction, and then the liquid fuel or chemical raw material is synthesized by using syngas as raw material. Methane catalytic reforming to generate syngas including steam reforming of methane(SRM), methane and carbon dioxide reforming(CDR), partial oxidation of methane(POM), etc. The method's advantage is obvious, but there are also some disadvantages.For the problems of low methane conversion and syngas yield, high energy consumption and uncontrolled temperature runaway in methane catalytic reforming reaction, we put forward a plate micro reactor with regenerative and wall-intake structure based on the structure of a conventional plate micro reactor. The oxygen can be preheated and the progress of the reaction can be controlled well by using regenerative structure to avoid the problem of temperature runaway because of intense exothermic reaction. Meanwhile, the use of wall-intake structure can increase disturbance of the flow field and promote the methane catalytic reforming reaction effectively. Simultaneously, it can control reaction speed and improve the safety of the reaction process to advantage. The angle of reaction channel, and the structure parameters such as layout columns, radius size, gap size and marshalling pattern of small holes in the wall are all designed optimally by numerical simulation.This paper studied the characteristics of catalytic partial oxidation of methane to syngas in an optimized diverging plate micro reactor with regenerative and wall-intake structure by investigating the influence of the basic operation conditions such as different mole ratio of O2 and CH4, inlet velocity, inlet temperature and catalyst surface site density on the reaction characteristics. In order to gain a higher methane conversion rate and a higher yield and selectivity of CO, the appropriate O/C was chosen at 0.8. For consideration of the influence of distribution along the flow direction on different main inlet velocity to conversion of reactants, product yield, selectivity and mass fraction, the main inlet velocity was selected as 0.25m/s. At the same time, by considering that the preheating intake air in high temperature will significantly increase the energy consumption of the system and increase the difficulty of the follow-up study, the optimal main inlet temperature was set at 800 K. And the suitable catalyst load density was 2.72×10-8 kmol/m2 under the consideration of the catalyst preparation cost when the response system had higher H2 yield and CO yield.With the addition of water vapor in the feed gas, characteristics of catalytic partial oxidation of methane to syngas with coupling methane steam reforming was studied by investigating the influence of the basic operation conditions such as different mole ratio of O2 and CH4, mole ratio of water vapor and CH4, inlet velocity, inlet temperature and catalyst loading density on the reaction characteristics. Then optimal operating conditions were obtained. The use of catalytic partial oxidation of methane to syngas with coupling methane steam reforming can not only increase the selectivity and yield of hydrogen with partial self-heating in reaction system but also adjust mole ratio of H2 and CO in synthesis gas.The research in this paper provides further theoretical basis for the improvement of the syngas technology, and has obtained some research results which have important significance and practical reference value. |
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