Mass Transfer Characteristics in Pressurized Three-phase Slurry Bubble Columns with Variation of Column Diameter

가압 삼상슬러리 기포탑에서 직경변화에 따른 기체-액체 물질전달 특성

  • Seo, Myung Jae (School of Chemical Engineering, Chungnam National University) ;
  • Lim, Dae Ho (School of Chemical Engineering, Chungnam National University) ;
  • Shin, Ik Sang (School of Chemical Engineering, Chungnam National University) ;
  • Son, Sung Mo (School of Chemical Engineering, Chungnam National University) ;
  • Kang, Yong (School of Chemical Engineering, Chungnam National University)
  • 서명재 (충남대학교 화학공학과) ;
  • 임대호 (충남대학교 화학공학과) ;
  • 신익상 (충남대학교 화학공학과) ;
  • 손성모 (충남대학교 화학공학과) ;
  • 강용 (충남대학교 화학공학과)
  • Received : 2009.04.20
  • Accepted : 2009.05.11
  • Published : 2009.08.31

Abstract

Gas-liquid mass transfer characteristics were investigated in pressurized three-phase slurry bubble columns with variation of column diameter. Effects of gas velocity, operating pressure, liquid viscosity, solid content in the slurry phase and column diameter on the gas-liquid volumetric mass transfer coefficient($k_La$) were determined. The effects of operating variables on the mass transfer coefficient tended to change with variation of column diameter. The mass transfer coefficient increased with increasing gas velocity or operating pressure but decreased with increasing column diameter, liquid viscosity or solid concentration in the slurry phase. The increase trend of $k_La$ value with increasing gas velocity and the decrease trend of $k_La$ value with increasing liquid viscosity, tended to decrease gradually with increasing column diameter. However, the effects of operating pressure and solid concentration in the slurry phase on the $k_La$ value did not change considerably with variation of column diameter. The values of $k_La$ were well correlated with operating variables with in this experimental conditions as $k_La=0.02D^{-0.26}U_G^{0.28}P^{0.43}{\mu}_L^{-0.04}S_c^{-0.35}$.

가압 삼상슬러리 기포탑에서 탑의 직경변화에 따라 기체-액체 물질전달 특성을 고찰하였다. 기체 유속, 운전압력, 액체점도, 슬러리상에서 고체입자의 양 그리고 탑의 직경이 기체-액체 부피물질전달계수에 미치는 영향을 결정하였다. 운전변수들이 물질전달계수에 미치는 영향은 기포탑의 직경이 변화함에 따라 다르게 나타났다. 기체-액체 부피물질전달계수는 기체유속이나 운전압력이 증가함에 따라 증가하였으나, 기포탑의 직경, 액체의 점도 그리고 슬러리상에 고체입자의 농도가 증가함에 따라 감소하였다. 기체-액체 물질전달계수가 기체유속 증가에 따라 증가하는 경향과 액체의 점도가 증가함에 따라 감소하는 경향은 기포탑의 직경이 증가함에 따라 점차 감소하였다. 그러나, 운전압력과 슬러리상에 포함된 고체입자의 농도가 기체-액체 물질전달계수에 미치는 영향은 기포탑의 직경이 변화함에 따라 큰 영향을 받지 않았다. 본 연구의 실험범위에서 기체-액체 물질전달계수는 다음 식과 같은 실험변수의 상관식으로 나타낼 수 있었다. $k_La=0.02D^{-0.26}U_G^{0.28}P^{0.43}{\mu}_L^{-0.04}S_c^{-0.35}$.

Acknowledgement

Supported by : 한국에너지기술연구원

References

  1. Deckwer, W. D., Bubble Column Reactors, John wiley and Sons. Newyork(1992)
  2. Krichma, R. and Sie, S. T., "Design and Scale-up of the Fischer- Tropsch Bubble Column Slurry Reactor," Fuel Processing Technol., 64, 73-105(2000) https://doi.org/10.1016/S0378-3820(99)00128-9
  3. Fan, L. S., Gas-Liquid-Solid Fluidization Engineering, Butterworths, Boston(1989)
  4. Kim, S. D. and Kang, Y., "Heat and Mass Transfer in Threephase Fluidized-Bed Reactors-An Overview," Chem. Eng. Sci., 52, 3639-3660(1997) https://doi.org/10.1016/S0009-2509(97)00269-8
  5. Kim, S. D. and Kang, Y., "Hydrodynamics, Heat and Mass Transfer in Inverse and Circulating Three-phase Fluidized-Bed Reactors for Waste water Treatment," Studies Surface Science and Catalyst, 159, 103-108(2006) https://doi.org/10.1016/S0167-2991(06)81545-4
  6. Shin, I. S., Son, S. M., Kim, U. Y., Kang, Y., Kim, S. D. and Jung, H., "Multiple Effects of Operating Variables on the bubble Properties in Three-phase Slurry Bubble Columns," Korean J. Chem. Eng., 26, 587-591(2009) https://doi.org/10.1007/s11814-009-0100-3
  7. Kang, Y., Cho, Y. J., Woo, K. J. and Kim, S. D., "Diagnosis of Bubble Distribution and Mass Transfer in Pressurized Bubble Columns mwith Viscous Liquid Medium," Chem. Eng. Sci., 54, 4887-4893(1993) https://doi.org/10.1016/S0009-2509(99)00209-2
  8. Kang, Y., Lee, K. I., Shin, I. S., Son, S. M., Kim, S. D. and Jung, H., 'Characteristics of Hydrodynamics, Heat and Mass Transfer in Three-phase Inverse Fluidized Beds', Korean Chem. Eng. Res., 46, 451-464(2008)
  9. Kang, S. H., Son, S. M., Kang, Y., Bae, J. W. and Jun, K. W., "Effects of Pressure Fluctuations on the Heat Transfer Characteristics in a Pressurized Slurry Bubble Column," Korean J. Chem. Eng., 25, 897-904(2008) https://doi.org/10.1007/s11814-008-0148-5
  10. Son, S. M., Kang, S. H., Kim, U. Y., Shin, I. S., Kang, Y. and Kim, S. D., "Oxygen Transfer in Three-phase Circulating Fluidized Bed with viscous Luquid Medium," J. Chem. Eng. Japan, 41, 655-661(2008) https://doi.org/10.1252/jcej.07WE119
  11. Davis, B. H., "Overview of Reactors for Liquid phase Fischer-Tropsch Synthesis," Catalysis Today, 71, 249-300(2002) https://doi.org/10.1016/S0920-5861(01)00455-2
  12. Maretto, C. and Krishna, R., "Modelling of a Bubble Column Slurry Reactor for Fischer-Tropsch Synthesis," Catalysis Today, 52, 279-289(1999) https://doi.org/10.1016/S0920-5861(99)00082-6
  13. Bakapoulos, A., "Multiphase Fluidization in a Large-Scale Slurry Jet Loop Bubble Columns for Methanol and of Dimethyl Ether production," Chem. Eng. Sci., 61, 538-557(2006) https://doi.org/10.1016/j.ces.2005.06.035
  14. Behkish, A., Lemoine, R., Sehabiague, L., Oukaci, R. and Morsi, B. I., "Gas Holdup and Bubble Size Behavior in a Large-Scale Slurry Bubble Column Reactor Operating with an Organic Liquid under Elevated Pressures and Temperature," Chem. Eng. J., 128, 69-84(2007) https://doi.org/10.1016/j.cej.2006.10.016