제올라이트 A의 결정화 속도에 대한 결정화 조건의 영향

정경환; 서곤

Journal of the Korean Industrial and Engineering Chemistry, Vol.4, No.1, 94-102, March, 1993

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제올라이트 A의 결정화 속도에 대한 결정화 조건의 영향

The Effect of Crystallization Condition on the Crystallization Rate of Zeolite A

정경환, 서곤

초록

제올라이트 A의 결정화 과정에서 온도, Na₂O와 SiO₂ 조성의 영향을 조사하였다. 각 결정화 조건에서 결정화 곡선과 최종 생성물의 결정크기 분포를 조사하고 반응 경로 모델을 이용하여 결정화 속도를 구하였다. 결정화 과정은 길이 성장 속도상수가 결정 크기와 무관하게 일정하고 무정형 고형 겔과 용해된 반응물이 평형을 이룬다는 가정으로 잘 모사되었으며, 실험결과와 비교하여 길이성장 속도상수 등을 결정할 수 있었다. 온도가 높아지면 길이성장 단계와 용해된 반응물의 분율이 커져서 결정화 속도가 커졌다. 반면 Na₂O/H₂O 몰비가 커지면 성장단계는 촉진되지 않으나 용해된 반응물의 분율이 커졌으며 핵심생성이 촉진되었다. SiO₂/Al₂O₃ 몰비에 따라 용해된 반응물 분율과 핵심생성 속도가 달라진다. 각 결정화 조건에서 제올라이트 A의 길이성장 속도상수는 0.07∼0.24 ㎛·min^-1로 추정되었으며 겉보기 활성화에너지는 49 kJ·mol^-1이었다.

The effects of temperature and of Na₂O and SiO₂ contents on the crystallization of zeolite A were studied, by examining crystallization curves and particle size distributions of final products at various crystallization conditions. Crystallization process could be simulated adopting the assumptions of constant linear growth rate and equilibrium between amorphous solid phase and soluble species. Rate constants were determined by comparing the simulated crystallization curves with experimental data. Rate constant for linear growth increased with temperature and crystallization rate at different mole ratio of Na₂O/H₂O correlated reasonably well with increase of soluble species. The rate constant of crystallization did not increase with increase in mole ratio of Na₂O/H₂O, but the rate of nuclei formation and the fraction of soluble species were enhanced. The rate constants for linear growth of zeolite A were determined as 0.07∼024 ㎛·min^-1 at these experimental conditions Apparent activation energy was estimated as 49 kJ·mol^-1.

[References]

Lenado RA, Proc. 6th Intern. Zeolite Conf., 940 (1983)
Kravetz L, Proc. 6th Intern. Zeolite Conf., 966 (1983)
Ciric J, J. Colloid Interface Sci., 28, 315 (1968)
Angell CL, Flank WH, ACS Symp. Ser., 40, 194 (1977)
Zhdanov SP, Adv. Chem. Ser., 101, 20 (1971)
Meier WM, Proc. 7th Intern. Zeolite Conf., 134 (1986)
Meise W, Schwochow FE, Adv. Chem. Ser., 121, 169 (1972)
Kostinko JA, ACS Symp. Ser., 218, 3 (1983)
Cournoyer RA, Kranich WL, Sand LB, J. Phys. Chem., 79, 15 (1975)
Barrer RM, "Hydrothermal Chemistry of Zeolites," Academic Press, p. 46 (1982)
Seo G, Chung K, Park T, HWAHAK KONGHAK, 30(3), 285 (1992)
Breck DW, "Zeolite Molecular Sieves," John Wiley & Sons, New York, p. 353 (1974)
Seo G, HWAHAK KONGHAK, 23(5), 295 (1985)
Barrer RM, Zeolites, 1, 130 (1981)
Kacirek H, Lechert H, J. Phys. Chem., 79, 1589 (1975)
Kacirek H, Lechert H, J. Phys. Chem., 80, 1291 (1976)
Kerr GT, J. Phys. Chem., 70, 1047 (1966)
Breck DW, Flanigen EM, "Molecular Sieves," Society of Chemical Industry, London, p. 47 (1968)
Chung K, Kim K, Seo G, Korean J. Chem. Eng., 9(3), 144 (1992)
ref. 10, p. 141
Jacobs PA, Martens JA, "Synthesis of High-Silica Aluminosilicate Zeolites," Elsevier, New York, p. 58 (1987)
Bronic J, Subotic B, Smit I, Despotovic LJA, "Innovation in Zeolite Material Science," P.J. Gorbet et al., Eds., Studies in Surface Science and Catalysis No. 37, Elsevier, Amsterdam, p. 107 (1988)

[Referenced By]

[1] Lenado RA, Proc. 6th Intern. Zeolite Conf., 940 (1983)

[2] Kravetz L, Proc. 6th Intern. Zeolite Conf., 966 (1983)

[3] Ciric J, J. Colloid Interface Sci., 28, 315 (1968)

[4] Angell CL, Flank WH, ACS Symp. Ser., 40, 194 (1977)

[5] Zhdanov SP, Adv. Chem. Ser., 101, 20 (1971)

[6] Meier WM, Proc. 7th Intern. Zeolite Conf., 134 (1986)

[7] Meise W, Schwochow FE, Adv. Chem. Ser., 121, 169 (1972)

[8] Kostinko JA, ACS Symp. Ser., 218, 3 (1983)

[9] Cournoyer RA, Kranich WL, Sand LB, J. Phys. Chem., 79, 15 (1975)

[10] Barrer RM, "Hydrothermal Chemistry of Zeolites," Academic Press, p. 46 (1982)

[11] Seo G, Chung K, Park T, HWAHAK KONGHAK, 30(3), 285 (1992)

[12] Breck DW, "Zeolite Molecular Sieves," John Wiley & Sons, New York, p. 353 (1974)

[13] Seo G, HWAHAK KONGHAK, 23(5), 295 (1985)

[14] Barrer RM, Zeolites, 1, 130 (1981)

[15] Kacirek H, Lechert H, J. Phys. Chem., 79, 1589 (1975)

[16] Kacirek H, Lechert H, J. Phys. Chem., 80, 1291 (1976)

[17] Kerr GT, J. Phys. Chem., 70, 1047 (1966)

[18] Breck DW, Flanigen EM, "Molecular Sieves," Society of Chemical Industry, London, p. 47 (1968)

[19] Chung K, Kim K, Seo G, Korean J. Chem. Eng., 9(3), 144 (1992)

[20] ref. 10, p. 141

[21] Jacobs PA, Martens JA, "Synthesis of High-Silica Aluminosilicate Zeolites," Elsevier, New York, p. 58 (1987)

[22] Bronic J, Subotic B, Smit I, Despotovic LJA, "Innovation in Zeolite Material Science," P.J. Gorbet et al., Eds., Studies in Surface Science and Catalysis No. 37, Elsevier, Amsterdam, p. 107 (1988)