Enhanced CO2 capture through reaction with steel-making dust in high salinity water

Abstract

Mineral carbonation (MC) is evolving as a possible technology for sequestering CO2 from medium-sized emission point sources. Industrial wastes have been recently used as an effective source for MC that have higher reactivity than natural minerals; they are also inexpensive and readily available in proximity to CO2 emitters. In this work, accelerated carbonation of electric arc furnace (EAF) baghouse dust (BHD) in a reject brine medium was evaluated in a novel reactor system, specially designed for contacting gases and liquids. This approach is environmentally friendly and eliminates the cost associated with pre-treatment. Experimental design was utilized to determine the effect of the operating parameters (solid to liquid ratio, CO2 gas flowrate and inert particles fraction) on the CO2 uptake. Analysis of the experimental results indicated that the studied factors had a significant impact on CO2 uptake, which was observed to be in the range of 0.1–0.18 gCO2/g BHD. At ambient conditions (24 °C and 1 atm) and at optimum operating parameters, the optimum CO2 uptake was 0.22 g CO2/g BHD. A higher CO2 uptake performance of 1 ± 0.04 gCO2/g BHD was achieved at ambient temperature and pressure of 5 bar. Thermal gravimetric analysis of the solid products revealed that a variety of carbonate products have been produced, particularly, calcium and magnesium carbonates.