CFD Modeling of Indirectly Fired Integrated Oxygen-Free Gasification and Steam Generation System

This paper introduces a novel gasification reactor that uses a process of steam gasification of the carbonaceous feedstock by indirectly heating the reacting flow through a high temperature heat exchanger without the need for partial with pure oxygen. It demonstrates the importance of gasification as a method for increasing power plant efficiency and reducing emissions. A computational fluid dynamics (CFD) model was created to model this novel gasifier and the results of the model that illustrates the efficiency and advantages of the new gasifier. The heating fuel was assumed to be fully combusted at the inlet. The adiabatic flame temperature was assumed to be the inlet temperature of the heating gas. The gasification stream was modeled as a laminar flow, where the reaction is kinetically controlled. The standard Shrinking Core Model (SCM) included in the commercial CFD package Fluent was used to predict the char consumption. The coal conversion rates were found to be higher than expected. The results indicate that the gasification of coal with steam without partial combustion with pure oxygen using this new concept is feasible.