Techno-economic evaluation of carbonation as CO2 capture and utilization technology in the cement industry

Abstract

In the cement industry, CO2 emissions mainly proceed from limestone calcination and fossil fuel combustion in clinker production, which represents about 8% of the worldwide CO2 emissions. To avoid an increase of 2 °C in global temperature compare with pre-industrial global temperature proposed in the COP21 agreement in 2015, cement industry should reduce CO2 emissions 24% below current levels. Thus, the purpose of this study was to evaluate an indirect carbonation CO2 capture and utilization technology for CO2 emissions abatement in the clinker production. The indirect carbonation process was evaluated using different hydroxides (Na, Ba and Ca) as absorbent precursors. Through technical evaluation, carbonation process using Na and Ba hydroxides resulted viable between 50 to 70 °C, with CO2 capture efficiencies of 98 and 65%, respectively. Contrary, Ca-based process presented an efficiency of 0.5% due to the low solubility of Ca(OH)2 in water, which results in technical infeasibility. For Na and Ba processes, an estimated cost of CO2 capture was assessed at 65 and 140 USD/t CO2, respectively. Moreover, technical and economic evaluation was integrated through a system dynamics model; which was developed to appraise the effect of economic policies and market conditions in CO2 capture economic impact on a cement plant and CO2 emissions reduction. System dynamics results showed that the implementation of a CO2 taxing policy, with CO2 tax between 20 and 80 USD/t CO2 emitted, will encourage the implementation of CO2 capture technologies to reduce emissions by 24% in a cement plant.