Industrial test of CO₂ capture and utilization from flue gas in thermal power plant based on chemical looping mineralization technology

Chemical looping mineralization of carbon dioxide (CO₂) with industrial waste to produce fine calcium carbonate is a potential way of CO₂ capture and utilization for thermal power plants. An industrial test plant for the mineralization of CO₂ with carbide slag was established and run at Datong Thermal Power Plant of China National Energy Group. Here, we reported the process, running conditions and results, carbon emission reduction, and the characteristics of calcium carbonate products of the pilot test. In the pilot process, with ammonia chloride as the looping extraction chemicals, the absorption and mineralization of CO₂ were integrated in one three-phase reactor. The pilot plant was designed with a scale of 1 000 t/a (calculated by CO₂), running more than 3 000 hours cumulatively. The longest continuous operation time reached 768 hours, with the maximum operating load reaching 148% of the design value. The results showed that the CO₂ absorption rate was beyond 90% and over 90% of calcium in the carbide slag had been converted into CaCO₃. According to third-party evaluations, the net CO₂ emission reduction was 68.6%. Calcium carbonate products could meet the standard of precipitated calcium carbonate for industrial use with particle size of D₅₀<20 μm.