CFD modelling of CO₂ enhanced gasification of coal in a pressurized circulating fluidized bed reactor

Two CFD models of CO₂-enhanced coal gasification in pressurized circulating fluidized bed reactor were developed and applied to simulate the process and predict syngas composition at the reactor outlet. The models were developed using commercial codes ANSYS Fluent and CPFD Barracuda. The models allowed to predict the outlet syngas composition and give insight into the processes occurring in the reactor. Results of the analyses were compared with experimental data obtained from a small scale test facility. The predicted syngas compositions agreed well with the experimental data, however the local gas composition in some instances were different. The predicted temperature distribution in Fluent agreed well with the experimental data. The examined cases confirmed that addition of CO₂ to the gasifying agent in a pressurized reactor can increase the CO yield per unit of feedstock and reduce the oxygen demand.