화학공학소재연구정보센터
HWAHAK KONGHAK, Vol.34, No.3, 369-378, June, 1996
이산화탄소-나프탈렌 계에 대한 임계 이하 및 초임계 조건하의 물질전달
Subcritical to Supercritical Mass Transfer in Carbon Dioxide-Naphthalene System
초록
이산화탄소의 임계점 이하 초임계 조건에서 나프탈렌의 기-고 물질전달 거동을 실험적으로 조사하였다. 펠렛형 나프탈렌의 충진탑을 대상으로 다양한 온도(308.15-328.15K), 압력(10-200bar) 및 유속(0.9-33.5 STDl/min)범위에서 이산화탄소-나플탈렌의 물질전달 특성을 측정하였으며, 셀 모델을 적용하여 이산화탄소 내의 나프탈렌 물질전달 계수를 얻어내었다. 수직 방향으로 설치된 충진탑을 통과하는 이산화탄소의 흐름은 중력 방향과 역중력 방향으로 구분할 수 있으며, 본 연구에서는 중력 방향에 대한 물질전달 특성을 조사하였으며, 이 결과를 기초로 자연 대류와 강제 대류의 영향이 고려된 물질전달 상관식을 제안하였다. 본 연구 결과에 의하면 중력 방향 흐름에서 물질전달 속도가 역중력 방향 흐름에 비하여 6-15% 증가되는 것을 확인할 수 있었다. 또, 임계점 부근의 이산화탄소의 경우 자연 대류가 물질전달의 지배적인 기구로 작용하는 것을 확인하였으며, 특히 318.15K, 100bar에서 가장 높은 자연 대류 효과를 나타내었다.
Gas-solid mass transfer in Co2-naphthalene system was studied under critical to supercritical conditions. An experimental apparatus of packed bed which contains pelletized naphthalene was constructed and the amounts of naphthalene transferred to carbon dioxide fluid phase are measured at various temperatures(308.15-328.55K), pressures(10-200bar), and flow rates of carbon dioxide(0.9-33.5 STDl/min). Based on the experimental data, mass transfer coefficient of naphthalene was examined by the cell model. The mode of flow of carbon dioxide through the vertical packed bed can be classified as the gravity-assisted direction(downward flow) and the gravity-opposed direction(upward flow). However, the experimental study is limited to the gravity-assisted flow and the result is examined according to the correlation of mass transfer with natural and forced mode of flow. The results were compared with the case of gravity-opposed flow reported in the literature and accordingly we found that the assisted flow can enhance the mass transfer rate about 6-15% over the case of opposed flow. The natural convection is dominantly important in the vicinity of critical region of carbon dioxide and particularly at 318.15 K and 100bar.
  1. Hannay JB, Hogarth J, Proc. Roy. Soc., 29, 324 (1879)
  2. Rozclius W, Vitzthum O, Hubert P, U.S. Patent, 3,848,824 (1974)
  3. DeFillipi RP, Krukonis VJ, Modell M, Environ. Protect. Agency Rept. No. EPA-600/2-80-054 (1980)
  4. List GR, Friedrich JP, Pominski J, J. Am. Chem. Soc., 61, 1847 (1984)
  5. Patrick JR, Palmer F, "Supercritical Fluid Technology," Elsevier, Amsterdam (1985)
  6. Kumar SK, Suter VW, Reid RC, Fluid Phase Equilib., 29, 373 (1986) 
  7. Yonker CR, Wright RW, Frye SI, Smith RD, Am. Chem. Soc. Symp. Ser.(329), 172 (1987)
  8. Debenedetti PG, Reid RC, AIChE J., 32, 2034 (1986) 
  9. Triday J, Smith JM, AIChE J., 4, 658 (1988) 
  10. Knaff G, Schlunder U, Chem. Eng. Process., 21, 151 (1987) 
  11. Lim GB, Holder GD, Shah YT, J. Supercrit. Fluids, 3, 186 (1990) 
  12. Kramers H, Alberda G, Chem. Eng. Sci., 2, 173 (1953) 
  13. Danckwerts PV, Chem. Eng. Sci., 2, 1 (1953) 
  14. Wen CY, Fan LT, "Model for Flow Systems and Chemical Reactors," Marcel Dekker Inc., N.Y. (1975)
  15. Deans HA, Lapidus LA, AIChE J., 6, 656 (1960) 
  16. Chung SF, Wen CY, AIChE J., 14, 857 (1968) 
  17. Paulaitis ME, Krukonis VJ, Kurnix RT, Reid RC, Rev. Chem. Eng., 1, 179 (1983)
  18. Tsekhanskaya YV, Iomtev MB, Mushkina EV, Russ. J. Phys. Chem., 38, 1173 (1964)
  19. Debenedetti PG, Chem. Eng. Sci., 42, 2203 (1987) 
  20. Morozov VS, Vinkler EG, Russ. J. Phys. Chem., 49, 1404 (1975)
  21. Vinker EG, Morozov VS, Russ. J. Phys. Chem., 49, 1405 (1975)
  22. Iomtev MB, Tsekhanskaya YV, Russ. J. Phys. Chem., 38, 485 (1964)
  23. Mohamed RS, Holder GD, Fluid Phase Equilib., 32, 295 (1987) 
  24. McHugh MA, Paulaitis ME, J. Chem. Eng. Data, 25, 257 (1980) 
  25. Sonnefeld WJ, Zoller WH, Anal. Chem., 55, 275 (1983)
  26. Fuchs N, J. Phys. U.S.S.R., 6, 224 (1934)
  27. Langmuir I, Phys. Rev., 12, 368 (1918) 
  28. Whitelaw-Gray R, Patterson HS, "Smoke," Edward Arnold Company, London (1932)
  29. Eckert ERG, "Introduction to Heat and Mass Transfer," McGraw-Hill Inc., N.Y. (1950)
  30. Chilton TH, Colburn AP, Ind. Eng. Chem., 26, 1183 (1934) 
  31. Colburn AP, AIChE J., 29, 174 (1933) 
  32. Merk HJ, Prins JA, Appl. Sci. Res., A4, 11 (1954)
  33. Karabelas AJ, Wegner TH, Hanratty TJ, Chem. Eng. Sci., 26, 1581 (1971) 
  34. Churchill SW, AIChE J., 23, 10 (1977) 
  35. Ruckenstein E, Rajagopalan R, Chem. Eng. Commun., 4, 15 (1980)
  36. Jorne J, Chem. Eng. Sci., 39, 1701 (1984) 
  37. Chen TS, Armaly BF, Aung W, "Mixed Convection in Laminar Boundary Flow: Natural Convection, Fundamentals and Applications," Hemisphere, N.Y. (1985)
  38. Acrivos A, Chem. Eng. Sci., 21, 343 (1966)