Computational fluid dynamics study of the effects of coal properties on pulverized coal gasification in the dome zone of COREX melter gasifier

Pulverized coal injection (PCI) in the dome zone of COREX is benefit to increasing the amount of reducing gas and improve the metallization rate of the pre-reduction shaft furnace, which can reduce the overall fuel consumption and CO2 emissions. In this work, a 3-D steady-state CFD model was developed to study the influence of coal properties, such as coal type and particle size on the flow, temperature and species distribution. The results showed that when the injection fuel changed from bituminous coal to biomass charcoal, the highest concentration of volatile matter at the front end of the oxygen coal burner (OCB) decreased from 1.5% to 1.1%. Simultaneously, there was a progressive increase in the concentration of CO, while the gas flow rate decreased. It was recommended to employ a high proportion of bituminous coal in conjunction with a certain quantity of semi-anthracite for mixed injection, thereby facilitating the rational utilization of resources. As the size of the injected coal expanded from 60 mu m to 150 mu m, the average dome temperature decreased by 16.22 K, while the proportion of effective components in the export gas increased by 0.69%. The size of the pulverized coal injected in the dome zone of COREX melter gasifier can moderately increase compared with that injection in the tuyere of blast furnace.