Simulation of Coal Gasification in Texaco Gasifier: Kinetics-Based Aspen Plus Model

Abstract

A kinetic model of coal gasification in a Texaco gasifier was developed using the software Aspen Plus, and the model was validated using experimental data from previously reported research. The effects of the gasification temperature, use of steam (H2O) or carbon dioxide (CO2) as the gasification agent (GA), and the gasification agent/carbon molar ratio (GA/C) on the composition, net CO2 emissions, and H2/CO molar ratio of the resulting syngas were evaluated. The results showed that for both H2O and CO2, CO was preferentially generated at high temperatures, whereas H2 and CO2 were dominant at low temperatures, although the carbon conversion was higher and the net CO2 emissions lower at high temperatures. On the other hand, the concentration of H2 was higher when H2O was employed as the GA, reaching 49% when the H2O/C ratio was 2.0, but the concentration of CO was higher with CO2 as the GA, reaching 72% at a CO2/C ratio of 2.0. The net CO2 emissions and the H2/CO ratio were lower with CO2 and higher with H2O as the GA. The concentration of CO in the syngas was the highest (72%) when the temperature was 1,600 K and the CO2/C ratio was 0.4, making it suitable as a raw material for the production of formic acid. The results of this study offer guidelines for the optimization of the operating parameters for entrained flow gasification and the application of H2O and CO2 gasification technology.