Statistical Analysis and Optimization of a Process for CO2 Capture
CO2 capture and storage technologies play a significant role in contributing to the control of climate change through the reduction of carbon dioxide emissions into the atmosphere. The present study evaluates and optimizes CO2 capture through a process, where carbon dioxide is passed into pH adjusted high salinity water and reacted with sodium chloride to form a precipitate of sodium bicarbonate. This process is based on a modified Solvay process with higher CO2 capture efficiency, higher sodium removal, and higher pH level without the use of ammonia. The process was tested in a bubble column semi-batch reactor and was optimized using response surface methodology (RSM). CO2 capture efficiency and sodium removal were optimized in terms of major operating parameters based on four levels and variables in Central Composite Design (CCD). The operating parameters were gas flow rate (0.5–1.5 L/min), reactor temperature (10 to 50 oC), buffer concentration (0.2-2.6%) and water salinity (25-197 g NaCl/L). The experimental data were fitted to a second-order polynomial using multiple regression and analyzed using analysis of variance (ANOVA). The optimum values of the selected variables were obtained using response optimizer. The optimum conditions were tested experimentally using desalination reject brine with salinity ranging from 65,000 to 75,000 mg/L. The CO2 capture efficiency in 180 min was 99% and the maximum sodium removal was 35%. The experimental and predicted values were within 95% confidence interval, which demonstrates that the developed model can successfully predict the capture efficiency and sodium removal using the modified Solvay method.
Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1123683Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1348
 C. Song, "Global challenges and strategies for control, conversion and utilization of CO2 for sustainable development involving energy, catalysis, adsorption and chemical processing," Catalysis Today, vol. 115, pp. 2-32, 6/30/ 2006.
 D. Holtz-Eakin and T. M. Selden, "Stoking the fires. CO2 emissions and economic growth," Journal of Public Economics, vol. 57, pp. 85-101, 5// 1995.
 J. Aboudi and M. Vafaeezadeh, "Efficient and reversible CO2 capture by amine functionalized-silica gel confined task-specific ionic liquid system," Journal of Advanced Research, vol. 6, pp. 571-577, 4// 2015.
 L. Li, N. Zhao, W. Wei, and Y. Sun, "A review of research progress on CO2 capture, storage, and utilization in Chinese Academy of Sciences," Fuel, vol. 108, pp. 112-130, 6// 2013.
 J. Le Dirach, S. Nisan, and C. Poletiko, "Extraction of strategic materials from the concentrated brine rejected by integrated nuclear desalination systems," Desalination, vol. 182, pp. 449-460, 11/1/ 2005.
 M. H. El-Naas, A. H. Al-Marzouqi, and O. Chaalal, "A combined approach for the management of desalination reject brine and capture of CO2," Desalination, vol. 251, pp. 70-74, 2// 2010.
 K. M. Ramachandran and C. P. Tsokos, "Chapter 9 - Design of Experiments," in Mathematical Statistics with Applications in R (Second Edition), K. M. R. P. Tsokos, Ed., ed Boston: Academic Press, pp. 459-494, 2015.
 S. García, M. V. Gil, C. F. Martín, J. J. Pis, F. Rubiera, and C. Pevida, "Breakthrough adsorption study of a commercial activated carbon for pre-combustion CO2 capture," Chemical Engineering Journal, vol. 171, pp. 549-556, 7/1/ 2011.
 A. Nuchitprasittichai and S. Cremaschi, "Optimization of CO2 capture process with aqueous amines using response surface methodology," Computers & Chemical Engineering, vol. 35, pp. 1521-1531, 8/10/ 2011.
 C. Song, Y. Kitamura, and S. Li, "Optimization of a novel cryogenic CO2 capture process by response surface methodology (RSM)," Journal of the Taiwan Institute of Chemical Engineers, vol. 45, pp. 1666-1676, 7// 2014.
 V. Mulgundmath and F. H. Tezel, "Optimisation of carbon dioxide recovery from flue gas in a TPSA system," Adsorption, vol. 16, pp. 587-598, 2010/12/01 2010.
 A. I. Khuri, "Ch. 6. Current modeling and design issues in response surface methodology: GLMs and models with block effects," in Handbook of Statistics. vol. Volume 22, R. K. a. C. R. Rao, Ed., ed: Elsevier, pp. 209-229, 2003.
 J. Antony, "6 - Full Factorial Designs," in Design of Experiments for Engineers and Scientists (Second Edition), J. Antony, Ed., ed Oxford: Elsevier, pp. 63-85, 2014.
 C. C. Shale, Simpson, D.G., Lewis, P.S., "Removal of sulfur and nitrogen oxides from stack gases by ammonia," ed. Chemical Engineering Progress Symposium Series 67, 52–57, 1971.
 J. E. Pelkie, Concannon, P.J., Manley, D.B., Poling, B.E., "Product distributions in the CO2–NH3–H2O system from liquid conductivity measurements," ed. Industrial and Engineering Chemistry Research, vol. 31, pp 2209–2215, 9// 1992.
 N. Greenwood, Chemistry of the Elements: Elsevier Science & Technology Books, ISBN: 9780080379418, 1996.
 J. T. Yeh, K. P. Resnik, K. Rygle, and H. W. Pennline, "Semi-batch absorption and regeneration studies for CO2 capture by aqueous ammonia," Fuel Processing Technology, vol. 86, pp. 1533-1546, 10// 2005.