MODELING AND SIMULATION OF CO-GASIFICATION OF COAL AND PETCOK.E1N A FLUIDIZED BED GASIFIER

Abstract

In this work we discuss the modeling and simulation of a fluidized bed coal gasifier which uses a mixture of coal and petcoke as its feed. A model where the fluidized bed reactor is assumed to function like a continuous stirred tank reactor (CSTR), because of vigorous mixing conditions prevalent in both these reactor, is used to describe the coal gasification process. We consider taking into account the effect of four heterogeneous reactions and four homogeneous reactions. We analyze the effect of various operating parameters such as composition of feed, ash content, temperature and volume of reactor, oxygen and steam flow rates on the performance of the gasifier. The results of predictions of the simulations have been found to be in good agreement with the experimental results in the literature. It has been found that increase in petcoke content in the feed mixture tends to lower the carbon conversion but increases the amount of syngas produced. Also, from the simulations, it has been found that increase in ash content of coal decreases the carbon conversion, while increasing the volume of reactor increases the carbon conversion. The optimum values of reactor temperature and steam to oxygen molar ratio have been found to be in good agreement with the experimental values given in literature.