Modeling and simulation of coal gasification on an entrained flow coal gasifier

Abstract

In this paper, the recent researches and developments on coal gasification modeling and simulation are described. Numerical models for the three chemical processes such as devolatilization, char gasification, and gas-phase reaction are reviewed and discussed for further development to improve accuracy. Recently the devolatilization models to describe the coal chemical structure with a simple expression have been proposed and validated on the laboratory-scale flames. It is essential to precisely model char gasification reaction as a rate-determining step and the formulation of the active sites sharing by the mixture and the pore structure formation are important in the modeling. It will become significant to take the elementary reactions into account in the gas phase reaction model. Large-eddy simulation of coal gasification on the laboratory-scale entrained flow gasifier is performed to demonstrate the numerical procedure. Results show the predicted temperature distribution qualitatively agrees with the experiment. Moreover, the gas-liquid-solid three-phase reacting flow simulation is preliminarily performed to capture the molten slag flow behavior within the gasifier. It is revealed that the three-phase simulation can give insight into the complex multiphase and multiphysics phenomena taking place within the gasifier to assess the design and the operating condition.