1. Optimization of accelerated weathering of limestone for CO2 capture in cement industry.
- Author
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Chai, Slyvester Yew Wang, Damu, Daniel Nyuin Alfred, How, Bing Shen, Chin, Mei Yun, Adini, Mohd. Jamil Bin Anong, Kassim, Alzian Mohamad, Peter, Catriena, and Ngu, Lock Hei
- Subjects
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CEMENT industries , *LIMESTONE , *OCEAN acidification , *COUNTERCURRENT processes , *RF values (Chromatography) , *WEATHERING , *GREENHOUSE gases - Abstract
Tremendous CO2 emissions from various industries cause environmental complications such as ocean acidification and global warming. The cement industry contributes to 2.53 billion tCO2/yr emissions globally. In an effort to remedy this problem, this research aims to implement the accelerated weathering of limestone (AWL) process to capture CO2 from cement industry emissions. The AWL absorption process utilizes a counter-current flow with a limestone-packed-bed column height of 0.876 m, a diameter of 0.102 m, and a working limestone packing volume of 0.0056 m3. A correlation study was conducted to study the effect of the liquid-to-gas (L/G) ratio on effluent alkalinity and CO2 capture efficiency. It was found that when the L/G ratio decreases (1 to 0.003), a significant increase in the alkalinity (0.62 to 2.43 mM) and pH (6.34 to 7.32) of the calcium bicarbonate (Ca(HCO3)2) effluent was observed. This was due to the longer retention time under a lower L/G ratio operation. On the flip side, the CO2 capture efficiency (70.82 to 16.98 %) of the AWL system responded negatively to the decrease in the L/G ratio. During a low L/G ratio configuration, the rate at which the system reaches equilibrium is more rapid. Results from the correlation study were used to determine the optimum operating condition simulated via the Design of Expert (DoE) software. Two optimized conditions to obtain maximum alkalinity and maximum CO2 capture efficiency were identified and validated experimentally. The highest possible alkalinity and CO2 capture efficiency obtainable were 2.43 mM and 73.51 %, respectively. Overall, this research serves as a preliminary study for the potential future commercialization of the AWL process. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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