Exploring the use of modified copper slag by copper concentrate in chemical chain gasification: Oxygen absorption and release kinetics

This study focuses on the performance of Copper concentrate with Copper Slag (CC-CS) oxygen carriers within the Chemical Looping Gasification (CLG) process, revealing the significant impacts of temperature, doping ratio, and reaction conditions on their effectiveness. It was found that an enhancement in the reactivity of the oxygen carriers is observed with the increase in temperature, attributed to the formation of the copper-iron composite oxide, CuFe2O4, which plays a crucial role in the chemical looping reactions. Additionally, a doping ratio of 5 % copper was determined to be the most effective for creating an ideal porous structure(105 m2/g surface area, 3.32 nm pore size) that reduce oxygen release activation energy to 24.02 kJ/mol, significantly improving the reactive performance of the carriers and enhancing their resistance to sintering. Through detailed investigations into the kinetics of oxygen absorption and release, the microscopic mechanisms involving oxygen atom migration and O-O bond formation on the surface of the carriers were elucidated. When the carbon to oxygen ratio is 0.3:1, the gasification efficiency and syngas selectivity are at their highest, reaching 69 % and 70 % respectively.