Modeling and optimization of a two-stage limestone contactor: An application to carbon capture

• Main Authors: Villavert, Ricardo T., De Leon, Rizalinda L., Pilario, Karl E.
• Format: text
• Published: Animo Repository 2013
• Subjects: Carbon sequestration; Carbon dioxide mitigation; Chemical weathering; Chemical Engineering
• Online Access: https://animorepository.dlsu.edu.ph/faculty_research/13288
• Institution: De La Salle University

Carbon Capture and Sequestration (CCS) is a mid-term approach to the climate change problem. One of the most economically promising CCS technologies is the Advanced Weathering of Limestone (AWL) which uses limestone and water to remove CO2. This research aims to augment the earlier findings by evaluating the CO, removal performance of a two-stage limestone contactor, a water treatment technology akin to AWL. Preliminary experiment on the fabricated reactor showed a relatively poor CO, removal performance. A computer simulation model was developed to assist in locating the maximum Percentage of CO, Removal (PCR). Simulation showed maximum values pointing towards bed height to reactor diameter ratio (H/D) > 1, gas to liquid ratio (G/L) < 1, and superficial velocity (Us) < 30 cm/min. Subsequent experiment demonstrated similar CO, removal trends with the computer model and a 12-fold improvement to the initial experiment. The optimum conditions of the reactor were obtained as a function of the Limestone Dissolution Rate (LDR), Water Consumption Rate (WCR), CO, Removal Rate (CRR), and Pressure Drop (PD): maximum PCR and CRR at 64.45% and 83.37 mg/min, and minimum LDR, WCR and PC at 189.47 mg/min, 34.10 mg/min, and 4.03 mm Hg respectively using a H/D = 1.5, G/L = 0.10, and Us = 10 cm/min. These new findings showed a new understanding to the CO, removal performance of a limestone contactor, which may be particularly helpful to energy firms planning to implement CCS.