Fixed bed of methanation reactor was simulated by inserting methanation reaction into simulation process in the form of the source term by using the CFD software to write CEL language. Then

by comparing the simulation accuracy of porous model and packed pebble-bed model

and choosing the packed pebble-bed model to simulate

the velocity field

the concentration of the components and the temperature field distribution in bed layer were obtained. The results showed that using the porous model to simulate fixed bed reactor caused greater error with the reason that porous model ignore the internal pore structure. The effect of wall in fixed bed significantly influenced on the field distribution. For example

20% of the mass flowed through the area near the wall that shared only 10% of the total area. The axial temperature rose from 250℃ to 685℃ significantly and the radial temperature distribution was not uniform with a fluctuating range of within 20℃ to 40℃.