Process Simulation Of Methanation From Synthesis Gas

Simulation of methanation reactor and methanation flow were studied in this paper. The reaction net was established on the basis of thermodynamic data, and thermodynamics calculation was also analysed. With actual operating data, the simulations of methanation reactor and process were carried out in the three-stage process with adiabatic fixed-bed reactor and product gas recycling cooling. The effects of operating conditions on the outlet temperature and composition of methanation reactor were also researched in the simulation.The methanation reactors and process were simulated in Aspen Plus, with BWRS as the property method. Take Lurgi methanation process for example, three adiabatic fixed-bed methanation reactors were substituted with the models of RPlug when constructed flow sheet. Taking the methanation of carbon monoxide and shift reaction as two separate reactions, the kinetics model of the former was chosen as power law, the latter was chosen as LHHW. Simulation results of different values of each operating conditions showed the effects on the outlet temperature and composition. The details of each material stream and reaction conversions were calculated in process simulation.The simulation results of the first methanation reactor can be concluded that the inlet temperature, pressure and space velocity had a great effect on the methanation and shift reaction. Meanwhile, inlet composition and space velocity were both changed when changing recycle ratio. The effects were reflected in the change of outlet temperature and composition. From the above, the best reaction conditions were determined by these effect factors.