SIMULATION OF A MULTI-STAGE ADIABATIC REACTOR WITH INTER-STAGE QUENCHING FOR DIMETHYL ETHER SYNTHESIS

Adiabatic fixed-bed reactors have proven commercially successful in large-scale catalytic dehydration of methanol to dimethyl ether. A one-dimensional pseudo-homogeneous model of an industrial reactor of dimethyl ether synthesis has been established. To verify the proposed model, the simulation results have been compared to available data from an industrial reactor, showing good agreement. The distribution of the catalyst bed temperature and concentration of each component was obtained under conditions of inlet temperature 260 degrees C, reaction pressure 1.2 MPa and gaseous hourly space velocity 950.7 h(-1). With inlet catalyst bed temperature 240-280 degrees C, operating pressure 0.6-1.8 MPa and gaseous hourly space velocity 831.8-1069.5 h(-1), the influence of these reaction conditions on temperature distribution of the reactor catalytic bed, outlet methanol conversion and the dimethyl ether yield were calculated. The results show that, with the rise of inlet temperature (240-280 degrees C) and operating pressure (0.6-1.8 MPa), the outlet conversion of methanol, the hot spot temperature and the DME yield increased. The increase of gaseous hourly space velocity (831.8-1069.5 h(-1)) lead to a decrease in the hot spot temperature of catalytic bed and the outlet conversion of methanol, but the DME yield increased initially and then decreased.