Numerical and experimental investigations of converter gas improvement inside a flue using its waste heat and CO2 by pulverized coal injection

To explore how to use the waste heat and reduce the CO2 emissions of converter flue gas, a new process is proposed in this paper, performed by injecting pulverized coal into the hot gas using its waste heat to generate CO and further to achieve a secondary recovery of flue gas. Numerical simulations and industrial investigations are conducted. By comparing the injecting rate, the particle size, and the injecting velocity of the pulverized coal, an optimized scheme was obtained. The testing results show that, with increasing the injecting rate, the O-2 and CO2 contents in the flue gas are reduced, while the CO and H-2 contents are increased. When the injecting rate is 20 kg min(-1), the O-2 and CO2 contents are decreased by 72.16% and 50%, respectively, yet the CO and H-2 contents are raised by 21.08% and 171.8%, respectively. The gas recovery time is extended by 10.12% and the carbon conversion is increased as much as 55%. Thus, the new process will be of great benefit to reduce CO2 emissions and increase the energy of converter gas. (c) 2017 American Institute of Chemical Engineers Environ Prog, 37: 1503-1512, 2018