CFD simulation for coal gasification in fluidized bed gasifier

The present work deals with CFD simulation for coal gasification in a fluidized bed gasifier. Different design parameters were checked to validate the stability of the reactor. 8 reactions were taken into consideration for the simulation of gasification. A mixture of pure oxygen, water vapor, and nitrogen entering through the bottom of the distributor was used as the gasifying agent. The coal sample was fed from the side wall of the reactor 20 cm above the gas distributor. Three Australian coal samples having different compositions were simulated using CFD simulation and results were validated to justify the modeling of the reactor. The effect of the oxygen-to-carbon ratio on coal gasification was studied to get the maximum yield of synthesis gas. The cold gas efficiency of the reactor was found to be within 45-60% which was agreeing well with the literature data. The carbon conversion was also found to be between 40 and 50%. The yield of synthesis gas was measured and the mass fraction of outlet gases was calculated through simulation. These results imply that the gasifier modeling is satisfactory. Thus, it can be concluded that the CFD-modeled reactor can be used as a base design for an industrial gasifier.