Numerical Simulation and Process Optimization of Fluidized Bed Coal Gasification
Key Laboratory of Coal Cleaning Conversion and Chemical Engineering Process, Xinjiang Uygur Autonomous Region, College of Chemical Engineering, Xinjiang University, Urumqi 830046, China
Abstract Taking an experimental bubbling fluidized bed gasifier as the simulation object, the numerical simulation of coal gasification reaction was carried out by multiphase particle element method. And the simulation value was consistent with the experimental data, which proved the accuracy of the simulation. The gas-solid flow pattern, gas composition and reaction rate distribution were studied. The effects of the mass ratio of oxygen to coal, the mass ratio of steam to coal and the particle diameter of coal on the gasification index were investigated taking the gasification efficiency and carbon conversion as the gasification indexes. Based on the orthogonal experiment results, the response surface methodology was used to explore the influence of multiple factors on the gasification efficiency, and the optimal process conditions were obtained. The results showed that the influence weight of each factor was as follows: mass ratio of oxygen to coal > the particle diameter of coal > the mass ratio of steam to coal. The optimal process conditions by response surface method were as follows: the mass ratio of oxygen to coal was 0.474, the mass ratio of steam to coal was 0.376 and the particle diameter of coal was 3.055 mm, at such conditions the maximum gasification efficiency was 0.707.
