Numerical Investigation of Hematite Flash Reduction-biomass Steam Gasification Coupling Process

Abstract

The flash ironmaking process is a novel ironmaking technology; the direct use of biomass as the reductant and fuel in this process can take full advantage of the heat and syngas produced during the biomass gasification. This study establishes a three-dimensional computational fluid dynamics model that incorporates turbulent flow, mass transfer, and heat transfer to describe the complex gas-particle reaction behavior of the hematite flash reduction-biomass steam gasification (FR-BSG) coupling process in an entrained flow reactor to explore its feasibility. The temperature and species distributions in the FR-BSG coupling process are analyzed, and the effects of steam/carbon molar ratio (S/C) and ore/biomass mass ratio (O/B) are investigated. The results show that the reduction degree of hematite particles reaches 76.67% in the residence time of 1.65 s under the conditions of S/C = 0.1, O/B = 1.0 and T = 1 673 K. The increase of S/C can enhance the production of H 2 but reduce the molar fractions of H 2 and CO in biomass syngas, which leads to the decrease of hematite reduction degree. A higher reduction degree of hematite and lower carbon conversion of biomass can be obtained at lower O/B values. These results provide a theoretical basis for the use of biomass as energy in flash ironmaking technology.

Numerical Simulation of Combustion Characteristics in the Dome Zone of the COREX Melter-Gasifier: The Effect of Rising Gas

“…Although the simulation process is established based on production conditions, some extremely complicated behaviors are simplified. It is inevitable that there are some small discrepancies that appear between the simulation and experimental data. , It can be explained that iron oxides in the recycling dust may consume some reducing gas. However, these phenomena are not considered in the simulation, so the percentage of effective components in the simulation is slightly higher than that in the experiment.…”

Numerical Analysis of the Dust Control Performance of a Counter-current Swirling Configuration in the Flash Ironmaking Reactor

“…Different fuels have different combustion mechanisms and gas compositions. [6][7][8][9][10] It is assumed that the upper cavity of the settler can be used as the location of gas generation, which is outside the computational zone. Therefore, the gas generation process was not considered in this study, and a simplified gas composition with pure H 2 : CO ratio was directly used as Fig.…”

“…4,5) The second one is based on fuel-oxygen flame generating heat and reducing gas at the same time, such as H 2 -O 2 , 6) CH 4 -O 2 , 7) coal-O 2 , 8,9) and biomass-O 2 . 10) These oxidation-reduction (Received on March 9, 2022; accepted on July 8, 2022; J-STAGE Advance published date: August 25, 2022) Flash ironmaking technology (FIT) is a potential alternative ironmaking process reducing energy consumption and environmental pollution. The newly proposed counter-current flash ironmaking process has a more reasonable temperature and concentration distribution, while the high dust rate cannot be avoided.…”