A Systematic Approach to Evaluating Environmental-Economic Benefits of High-Gravity Technology for Flue Gas Purification and Municipal Solid Waste Incineration Fly Ash Utilization

Abstract This study proposed a systematic approach to evaluating the environmental-economic benefits of multiple air pollution control, CO2 mineralization, and municipal solid waste incineration (MSWI) fly ash stabilization-utilization with high-gravity (HiGee) technology. MSWI fly ash due to its high alkalinity and calcium-rich compositions could be used to absorb acid gas pollutants and mineralize CO2 simultaneously. HiGee system can be deployed to eliminate the mass-transfer limit to accelerate the reaction kinetics. Technical-economic analysis (TEA) and life cycle analysis (LCA) were integrated with the technique to order preference by similarity to ideal solution (TOPSIS) approach and comprehensively evaluate the prioritized alternatives. Compared to existing wet-scrubber and fly ash landfill, the combination of fly ash slurry and further utilization of cementitious material can generate additional profits of direct/indirect carbon credit, calcium carbonate byproduct, reduction of air pollution fees and fly ash utilization revenue. In terms of environmental benefits, the installed HiGee system can reduce water and energy consumption to avoid water depletion and greenhouse gas emissions. TOPSIS results prioritized the various alternatives of HiGee operation modes and provided a technological evaluation for substituting the existing scrubber in an MSWI plant.