CFD study of bio-syngas and coal co-injection in a blast furnace with double lance

Abstract

To rationally utilize biomass as an auxiliary fuel for pulverized coal injection (PCI) technology, the process of co-injection of bio-syngas/coal into the blast furnace (BF) is designed. In this paper, a 3D CFD model with double lance is established to investigate the co-injection of bio-syngas/coal in the BF. The effects of bio-syngas injection rates and the location of double-lance on the in-furnace thermochemical behavior of pulverized coal (PC) are systematically analyzed. The results show that the combustion of the bio-syngas promotes the devolatilization of the PC, but hinders the volatile matter (VM) combustion. As the bio-syngas injection rate increases, the volume-average temperature of the raceway and the endpoint burnout of PC increases; In addition, a reduction in the distance between the bio-syngas lance and the tuyere, or an increase in the distance between the two lances, can facilitate the PC to obtain more oxygen and have a better endpoint burnout. However, the rise of the coal plume reduces the space for the particles to recirculate, resulting in a reduction in the overall burnout of the PC.