Combination of Combustion and Catalytic Reactors for Syngas Product: Modeling and Simulation

Autothermal reforming (ATR) is the preferred technology used to produce syngas that is applied in the gas-to-liquid process. The main objective of this paper is to develop a mathematical model to consider a new autothermal reformer which is a combination of two distinct sections; a combustion section and a catalytic section including three packed bed layers. In the combustion section, a 0-D transient model for constant-volume reactor is solved to achieve the temperature and the concentration of species. The GRI-3.0 chemical mechanism consisting 325 elementary reactions and 53 species is used to increase the accuracy of solution. In order to solve equation system including 54 ordinary differential equations the CHEMKIN package is used. The results of combustion section are applied as initial conditions for the catalytic section which is modeled by a one-dimensional plug flow model. Results of the model are compared by domestic plant data of the ATR process. In spite of model simplifications, good agreement is observed between results of modeling and industrial. The proposed model is used for studying the effects of feed temperature, the initial O-2/CH4 ratio and H2O/CH4 ratio on the stoichiometric number and methane conversion. The results revealed that initial O-2/CH4 ratio and initial H2O/CH4 ratio have the most significant contribution to the reformer performance. Increase in both initial O-2/CH4 ratio and H2O/CH4 ratio increase the conversion of methane. The optimal stoichiometric number can be achieved by adjusting the O-2/CH4 and H2O/CH4 ratios in the feed stream.

Automated summary

The paper develops a mathematical model for a new autothermal reformer, which consists of a combustion section and a catalytic section. The model shows good agreement with industrial data and reveals the significant contribution of the initial O2/CH4 and H2O/CH4 ratios on the reformer performance.