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Neutralization of Alkaline Wastewater with CO2 in a Continuous Flow Jet Loop Reactor

연속흐름형 Jet loop reactor에서 CO2를 이용한 알칼리폐수의 중화

  • Kang, Dae-Yeop (Department of Environmental Engineering, Pukyong National University) ;
  • Kim, Mi-Ran (Department of Environmental Engineering, Pukyong National University) ;
  • Lim, Jun-Heok (Department of Chemical Engineering, Pukyong National University) ;
  • Lee, Tae-Yoon (Department of Environmental Engineering, Pukyong National University) ;
  • Lee, Jea-Keun (Department of Environmental Engineering, Pukyong National University)
  • Received : 2015.10.06
  • Accepted : 2015.12.08
  • Published : 2016.02.01

Abstract

This paper investigates the feasibility of applying the jet loop reactor for the neutralization of alkaline wastewater using carbon dioxide ($CO_2$). In this study, pH changes and $CO_2$ removal characteristics were examined by changing influent flow rate of alkaline wastewater (initial pH=10.1) and influent $CO_2$ flow rates. Influent flow rates of alkaline wastewater ($Q_{L,in}$) ranged between 0.9 and 6.6 L/min, and inlet gas flow rate ($Q_{G,in}$) of 1 and 6 L/min in a lab-scale continuous flow jet loop reactor. The outlet pH of wastewater was maintained at 7.2 when the ratio ($Q_{L,in}/Q_{G,in}$) of $Q_{L,in}$ and $Q_{G,in}$ was 1.1. However, the $CO_2$ removal efficiency and the outlet pH of wastewater were increased when $Q_{L,in}/Q_{G,in}$ ratio was higher than 1.1. Throughout the experiments, the maximum $CO_2$ removal efficiency and the outlet pH of wastewater were 98.06% and 8.43 at the condition when $Q_{G,in}$ and $Q_{L,in}$ were 2 L/min and 4 L/min, respectively.

본 연구에서는 $CO_2$를 이용한 알칼리폐수의 중화처리 시 jet loop reactor의 적용가능성을 검토하고자 하였다. 이를 위해 연속식 jet loop reactor에서 pH=10.1인 알칼리 폐수의 유입유량($Q_{L,in}=0.9{\sim}6.6L/min$)과 유입가스유량($Q_{G,in}=1{\sim}6L/min$)을 변화시키면서 유출수의 pH 변화 및 $CO_2$ 제거특성을 살펴보았다. 중화반응 후 유출수의 pH는 $Q_{L,in}/Q_{G,in}$ 비가 1.1일 때는 $Q_{G,in}$$Q_{L,in}$이 증가하여도 pH가 7.2 정도로 일정하게 유지되었다. 그러나 $Q_{L,in}/Q_{G,in}$ 비가 1.1 이상에서는 $Q_{L,in}/Q_{G,in}$ 비가 증가할수록 $CO_2$ 제거효율 및 배출수의 pH가 증가하는 경향을 보였다. 본 연구범위에서 얻어진 최대 $CO_2$ 제거효율은 98.06%로 $Q_{G,in}=2L/min$, $Q_{L,in}=4L/min$인 조건이었으며, 이때의 유출수 pH는 8.43 이었다.

Keywords

References

  1. Ko, K. S., "A Study on Utilization of $CO_2$-rich Exhaust Gas for pH Control of Alkaline Wastewater," Ph. D. Dissertation, Sunchon National University, Sunchon, Korea(2010).
  2. Fleischer, C., Becker, S. and Eigenberger, G., "Detailed Modelling of the Chemisorption of $CO_2$ into NaOH in a Bubble Column," Chem. Eng. Sci., 51(10), 1715-1725(1996). https://doi.org/10.1016/0009-2509(96)00030-9
  3. Park, S. W., Sohn, I. J., Park, D. W. and Oh, K. J., "Absorption of Carbon Dioxide into Non-Newtonian Liquid. I. Effect of Viscoelasticity," J. Sep. Sci. Technol., 38(6), 1361-1384(2003). https://doi.org/10.1081/SS-120018814
  4. Mahamoudkhani, M., Heidel, K. R., Ferreira, J. C., Keith, D. W. and Cherry, R. S., "Low Energy Packed Tower and Caustic Recovery for Direct Capture of $CO_2$ from Air," Energy Procedia., 1(1), 1535-1542(2009). https://doi.org/10.1016/j.egypro.2009.01.201
  5. Gaddis, E. S., "Mass Transfer in Gas-liquid Contactors," Chem. Eng. Process., 38(4-6), 503-510(1999). https://doi.org/10.1016/S0255-2701(99)00046-X
  6. Bohner, K. and Blenke, H., "Gasgehalt und Flussigkeitumwalzung in Schlaufenreaktor," Verfahrenstechnik, 6, 50-57(1972).
  7. Chriastel, L. and Fadavi, A., "New Concept of Jet Loop Bioreactor," Nova Biotechnoligica, 4(1), 89-100(2006).
  8. Son, M. K., Sung, H. J. and Lee, J. K., "Neutralization of Synthetic Alkaline Wastewater with $CO_2$ in a Semi-batch Jet Loop Reac tor," J. Korean Society of Combustion, 18(2), 17-22(2013). https://doi.org/10.15231/jksc.2013.18.2.017
  9. Cha, G. E., Sung, H. J., Lim, J. H., Lee, T. Y. and Lee, J. K., "$CO_2$ Absorption Characteristics of a Jet Loop Reactor with a Two-fluid Swirl Nozzle in an Alkaline Solution," Korean J. Chem. Eng., 31(4), 701-705(2014). https://doi.org/10.1007/s11814-013-0275-5
  10. Darmana, D., Henket, R. L. B., Deen, N. G. and Kuipers, J. A. M., "Detailed Modelling of Hydrodynamics, Mass Transfer and Chemical Reactions in a Bubble Column using a Discrete Bubble Model : Chemisorption of $CO_2$ into NaOH Solution, Numerical and Experimental Study," Chem. Eng. Sci., 62(9), 2556-2575(2007). https://doi.org/10.1016/j.ces.2007.01.065

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