Performance Prediction of Entrained Flow Coal Gasifier for IGCC System Using a Steady-State Process Model

In an Integrated-coal Gasification Combined-Cycle (IGCC) plant, the gasifier is one of the most important units, since it converts solid fossil fuels such as gaseous fuel, liquid fuel or chemical feedstocks into clean syngas. The entrained-flow coal gasifiers have been widely used in IGCC plants due to the high gasification rate achievement and the relatively clean gas production.

This study focuses on finding optimum operating conditions for the given entrained flow coal gasifiers using a steady-state process model to predict the process performance. The process model includes two-stage equilibrium submodels and a carbon burnout mechanism for which a kinetic model is used to calculate the amount of combusted coal and the heat released to provide the gasification process. The stoichiometric equilibrium model for char gasification and gas phase reactions is used to calculate the temperature and composition of the syngas at the gasifier exit. The parametric effects of operating pressure, oxygen/carbon ratio and steam/carbon ratio on the gasification performance are also studied.