Chemical Engineering Research & Design, Vol.160, 454-464, 2020
A novel simulation for gasification of Shenmu Coal in an entrained flow gasifier
An entrained flow gasification of Shenmu coal was modeled in this work. The conventional gasification reaction process was split into two stages - pyrolysis and gasification. The model was comprised of various unit operations including preheating of feed-stock, mixing, pyrolysis, gasification, heat exchanging, separation, and quenching, which were correlated to an actual gasification process. Both direct and indirect heat exchanging among the feedstock, the product, the reaction system, the cooling water and the quench water were taken into consideration. The investigation included the influence of water/coal ratio, oxygen/coal ratio, and temperature on the composition of the product gas, the yield of the product and the quench water amount. The results showed that H-2 concentration in gas product was favored at higher water/coal ratios and lower temperatures, which was opposite to the trend of CO. CO2 concentration would be lower at lower temperature and lower water/coal ratio. A novel cooling loop was proposed in this work to recycle the cooling water and to stabilize the process. The analysis showed that the quenching water affected the synthesis gas indirectly and the amount of the loop water. The extra quenching water would be drained off from the recycling system. The investigation results are meaningful for controlling of the gasification system and the desired products. (C) 2020 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.