경막형 용융결정화에 의한 벤젠-사이클로헥산 혼합물로부터 벤젠의 결정화-결정의 불순물 내포현상-

김광주; 이정민; 유승곤

Journal of the Korean Industrial and Engineering Chemistry, Vol.8, No.3, 389-394, June, 1997

Export Citation

경막형 용융결정화에 의한 벤젠-사이클로헥산 혼합물로부터 벤젠의 결정화-결정의 불순물 내포현상-

Crystallization of Benzene from Benzene-Cyclohexane Mixtures by Layer Melt Crystallization

김광주, 이정민, 유승곤

초록

경각형 결정화에 의하여 벤젠-사이클로헥산 혼합물로부터 벤젠의 결정화에서 결정에 내포된 불순물(사이클로헥산)의 분포가 조사되었다. 결정의 순도에 미치는 결정성장속도의 영향을 파악하였으며 모든 실험결과는 Wintermantel 모델에 의해 도시될 수 있었다. 결정의 순도는 과냉각 정도가 클수록, 주입조성이 낮을 수록, 결정성장속도가 클 수록 낮았으며 결정성장속도는 불순물의 내포를 지배하는 가장 중요한 변수이다. 결정화 초기에 형성된 결정은 불순물을 많이 내포하고 있으며 결정의 두께가 증가함에 따라 불순물은 잔여용융액쪽으로 이동되어 배제됨을 알 수 있었다. 경막결정화에서 결정에 내포된 불순물은 일정두께의 결정층에 온도구배를 이용하여 결정을 부분용해시키면 불순물의 확산에 의하여 제거될 수 있음을 알 수 있었다.

The distribution of impurity included in benzene layer crystal was explored in layer crystallization of cyclohexane and benzene mixtures. The influence of crystal growth rate on crystal purity was investigated. All experimental results for bezene-cyclohexane system obtained in layer crystallizer have been evaluated with the criterion of Wintermantel. The purity of crystal decreases with increasing degree of subcooling, decreasing feed concentration and increasing crystal growth rate. The crystal growth rate was a key parameter to determine the inclusion of impurity in crystals. The results obtained from runs performed at increasing crystallization time(i.e. crystal thickness) have clearly shown that migration of inclusions within crystal layer to the melt, leading to the removal of impurity occurs. The diffusion of impurity which takes place during the crystallization from the beginning, enhances a further purification of the crystal layer if that underwent a thermal gradient after growth of the layer crystal stops.

[References]

Yamazaki Y, Watanuma Y, Enomoto Y, Toyokura K, Kag. Kog. Ronbunshu, 12, 610 (1986)
Schildknecht H, Zone Melting, Academic Press, New York (1966)
Hunken I, Ulrich J, Chem. Ing. Tech., 65, 58 (1993)
Schalz R, Ulrich J, Genthner K, Proc. 12th Symp. Ind., Cryst., Warsaw, Poland(E.h. Rokowski ed.), 1, 25 (1993)
Delannoy C, Ulrich J, Fanconet M, Proc. 12th Symp. Inc., Cryst., Warsaw, Poland(E.H. Rokowski ed.), 1, 49 (1993)
Ulrich J. Ozoguz MY, Proc. 12th Symp. Ind, Cryst., Garmisch-Partenkirchen (A, Mersmann ed.), 821 (1990)
Wintermantel K, Wellinghoff G, Int. Chem. Eng., 34, 171 (1994)
Jancic ST, Tech. Rev., Sulzer, Winterthur, Switz (1986)
Kim KJ, Lee JM, Mersmann A, Sep. Sci. Technol., 31(13), 1859 (1996)
Kim KJ, Mersmann A, Chem. Eng. Res. Des., 75(2), 176 (1997)
Kim KJ, Lee JM, Ryu SK, J. Korean Ind. Eng. Chem., 7(2), 308 (1996)
Arnold R, Ph.D. Dissertation, Univ. of Michigan, Ann Arbor, Michigan (1967)
Burton JA, Prim RC, Slichter WP, J. Chem. Phys., 21, 1987 (1953)
Henry R, Powers JE, AIChE J., 16, 1055 (1970)
Gates WC, Powers JE, AIChE J., 16, 648 (1970)
Wintermantel K, Chem. Ing. Tech., 58, 498 (1986)

[Referenced By]

[1] Yamazaki Y, Watanuma Y, Enomoto Y, Toyokura K, Kag. Kog. Ronbunshu, 12, 610 (1986)

[2] Schildknecht H, Zone Melting, Academic Press, New York (1966)

[3] Hunken I, Ulrich J, Chem. Ing. Tech., 65, 58 (1993)

[4] Schalz R, Ulrich J, Genthner K, Proc. 12th Symp. Ind., Cryst., Warsaw, Poland(E.h. Rokowski ed.), 1, 25 (1993)

[5] Delannoy C, Ulrich J, Fanconet M, Proc. 12th Symp. Inc., Cryst., Warsaw, Poland(E.H. Rokowski ed.), 1, 49 (1993)

[6] Ulrich J. Ozoguz MY, Proc. 12th Symp. Ind, Cryst., Garmisch-Partenkirchen (A, Mersmann ed.), 821 (1990)

[7] Wintermantel K, Wellinghoff G, Int. Chem. Eng., 34, 171 (1994)

[8] Jancic ST, Tech. Rev., Sulzer, Winterthur, Switz (1986)

[9] Kim KJ, Lee JM, Mersmann A, Sep. Sci. Technol., 31(13), 1859 (1996)

[10] Kim KJ, Mersmann A, Chem. Eng. Res. Des., 75(2), 176 (1997)

[11] Kim KJ, Lee JM, Ryu SK, J. Korean Ind. Eng. Chem., 7(2), 308 (1996)

[12] Arnold R, Ph.D. Dissertation, Univ. of Michigan, Ann Arbor, Michigan (1967)

[13] Burton JA, Prim RC, Slichter WP, J. Chem. Phys., 21, 1987 (1953)

[14] Henry R, Powers JE, AIChE J., 16, 1055 (1970)

[15] Gates WC, Powers JE, AIChE J., 16, 648 (1970)

[16] Wintermantel K, Chem. Ing. Tech., 58, 498 (1986)