Modelling DME production from synthetic gases with a fluidized bed reactor: A CFD approach

Abstract

Dimethyl ether (DME) is one of the most sought-after automotive fuels. Catalyst is generally preferred in direct dime production from synthesis gas. 0In our study, Computational Fluid Dynamics is used for reactor modeling of DME production from syngas in a fluid bed model. It is aimed to determine the necessary conditions to ensure maximum gas-solid contact for the production of zeolite-catalyzed DME in a fluidized reactor, especially for the syngas produced by gasification method from domestic wastes. A distinctive feature of this approach is the physical optimisation simulation. The calculation of the bed density at which the catalyst active surface is provided at maximum contact has a very important place in determining the reactor operating conditions. In the study, firstly, the simulation model is compared with a real experimental fluidized bed model. In the subsequent optimization study, the conditions where the maximum solid-gas contact surface was achieved was sought. For this reason, the results obtained in the case of a bed density of 2200 kg/m3 showed that the pressure drop increased positively across the bed. This means that the reaction time is reduced. Therefore, the bed density value of 2200 kg/m3 (with a maximum volume fraction of 55%), is the ideal density value to ensure maximum gas-solid contact compared to 2300 (with a maximum volume fraction of 55,8%), 2400 (with a maximum volume fraction of 59,5%), 2500 (with a maximum volume fraction of 58,9%), and 2600 (with a maximum volume fraction of 57,2%) kg/m3.