Modeling of a pressurized entrained-flow coal gasifier for power plant simulation

Abstract

Now and in the mid-term future, coal remains an important energy source for electricity generation for reasons of energy supply security and economics. The expectation to get low CO2-emissions and high plant efficiencies, particularly independently of coal quality, makes coal gasification an essential part of numerous innovative power plant concepts. For that reason, simplified and flexible models for coal gasifiers are needed, which can be implemented easily in complex power plant system simulations. A model for an entrained-flow coal gasifier, the Prenflo coal gasification process, based on an equilibrium approach is developed. The created model is validated with operation data published in literature of a demonstration plant in Furstenhausen (Germany). For all published plant parameters, the calculated values of the model reproduce the operating data fairly precisely. Parametric study for the target application in a hybrid power plant including high temperature fuel cells regarding the gasification temperature and pressure as well as the mass flow ratios of the gasifying agent to coal is presented. Influences of these parameters on product gas composition and efficiency of gasification are investigated. By means of these, the model of the coal gasifier is qualified for implementation in system models such as those of integrated gasification combined cycle and hybrid power plants including high temperature fuel cells.