Process Development and Pilot Demonstration of Cabon Capture Coupled Co-Production of Calcium Carbonate and Ammonium Sulfate

J. Zhu, S. Xia, J. Li, Y. Gong, J. Zhou
Sichuan University,

Keywords: carbon capture, coupled co-production, ammonium sulfate, calcium carbonate, flue gas, phospho-gypsum


Summary Carbon capture and storage (CCS) was affirmed to be a major component of a cost-effective portfolio of emission reduction strategies, by 2030 and beyond. However, there are still no full-scale applications on a commercial power plant up to now, owing to the high cost and large energy requirements of current CCS processes. There is a necessity to develop affordable technologies to help implementing global CO2 emission reduction, especially for developing countries to take a bigger portion of the task. The feasibility of a innovative process of carbon capture coupled co-production (CCCC), calcium carbonate (cement material) and ammonium sulfate (fertilizer) from mineralization of CO2 with industrial waste phosphor-gypsum (PG) in this study, was assessed technically and economically. It is a value added process from calculation of value balance between products and raw materials, a $4.1 net increase to each 44kg CO2 and 172kg PG mineralized with 34kg ammonia as agent, calculated on the fixed market price of 2012. There is no energy requirement according to the thermodynamic indicator, △G =-146.1 kJ•mol-1 based on the chemical reaction formula. Furthermore it is highly environment friendly by converting two wastes of CO2 and PG into valuable products without any pollutant generation. A verifying demonstration facility of 100 m3/h flue gas (slipstream, 15% CO2 ) at the site of Puguang Branch, Sino-PEC Co. was built and operated under realistic plant conditions through year 2013~2014. The performances were well verified by three critical parameters: CO2 capture ≥75% at the rate 481.9 kg•h-1•m-3 (reactor), NH3 escaped in tail gas≤10 ppmv, yield from PG to CaCO3 ≥90%. The result of verification indicated that the CCCC process is feasible and promising for commercial development. A full-scale demonstration project is putting forward by Sino-PEC, which is designed to match the demand of CO2 sequestration from a 5×104 m3•h-1 flue gas disposal, equivalent to a 20MW coal-fired power plant.