Engineering, environmental and economic performance evaluation of high-gravity carbonation process for carbon capture and utilization

摘要

Multi-waste treatment of slag and wastewater can be combined with CO2 capture in the steelmaking industry by the high-gravity carbonation (i.e., HiGCarb) process using a rotating packed bed. In this study, the HiGCarb process is comprehensively evaluated by an engineering, environmental and economic (3E) triangle model. The feedstock CO2 for the HiGCarb process can be obtained directly from the industrial stacks, eliminating the need for additional CO2 concentration and transportation. The reacted steelmaking slag, i.e., basic oxygen furnace slag (BOFS), is suited as cement substitution material, avoiding environmental burden from the cement industry, also a CO2-intensive emission source. Significant environmental benefits can be realized by establishing the waste-to-resource supply chain between the steelmaking and cement industries. The life-cycle assessment shows a net CO2 capture amount by the HiGCarb process of 282 kg-CO2/t-BOFS, accompanied by a CO2 avoidance of 997 kg-CO2/t-BOFS due to the product utilization. Moreover, the amount of revenue gained was estimated to be 20.2-23.2 USD/t-BOFS treated by the HiGCarb process. According to the 3E triangle model, the HiGCarb process is shown to be environmentally promising and economically feasible due to its high overall engineering performance, which makes it suitable as a potential CO2 sink in industry. (C) 2016 Elsevier Ltd. All rights reserved.