Interphase Mass Transfer with Bulk Flow Normal to the Phase Boundary

Gilsoo Han; Hong Yong Sohn

Korean Journal of Chemical Engineering, Vol.21, No.1, 34-40, January, 2004

DOI10.1007/BF02705378 Export Citation

Interphase Mass Transfer with Bulk Flow Normal to the Phase Boundary

Gilsoo Han¹, and Hong Yong Sohn^{1, 2, †}

¹Departments of Metallurgical Engineering, University of Utah, Salt Lake City, Utah 84112, USA
²Departments of Chemical and Fuels Engineering, University of Utah, Salt Lake City, Utah 84112, USA

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The effect of bulk flow normal to the interface on the interphase mass transfer rate is analyzed by using a convective mass transfer coefficient, and a method of deriving the correct choice of the reference mole fraction in the bulk flow term is developed. The effect of the bulk flow and the definition of the proper reference mole fraction have been derived based on diffusion in a binary gas mixture across the boundary layer and expanded to the system of an interfacial gas-solid reaction. The results show that the bulk flow effect together with the proper choice of the reference mole fraction in the bulk flow term is important in obtaining an accurate expression of interphase mass transfer rate. In an extreme situation, the bulk flow effect can cause mass transfer to occur in the direction of increasing concentration. The theoretical development is applied to the rate analysis of the hydrogen reduction of silica.

Keywords:Boundary Layer;Bulk Flow Effect;Diffusion;Interphase;Mass Transfer;Volume Change

[References]

Benitez J, "Principles and Modern Applications of Mass Transfer Operations," John Wiley & Sons, Inc., New York, 85 (2002)
Bird RB, Stewart WE, Lightfoot EN, "Transport Phenomena," 1st ed., John Wiley, Sons, New York, 563 (1960)
Bird RB, Stewart WE, Lightfoot EN, "Transport Phenomena," 2nd., John Wiley & Sons, Inc., New York, 536 (2002)
Bird RB, Stewart WE, Lightfoot EN, "Transport Phenomena," 2nd ed., John Wiley & Sons, Inc., New York, 671 (2002)
Gardner RA, J. Solid State Chem., 9, 336 (1974)
HSC Chemistry, Version 4.0, Outokumpu Research Oy, Finland (1999)
Lewis SD, "Reduction of Fused Silica in Hydrogen," Thesis, University of Utah (1979)
Schwerdtfeger K, Trans. Met. Soc. AIME, 236, 1152 (1966)
Sohn HY, Sohn HJ, Ind. Eng. Chem. Process Des. Dev., 19, 237 (1980)
Szekely J, Evans JW, Sohn HY, "Gas-Solid Reactions," Academic Press, New York, 66 (1976)
Tso ST, Park JA, J. Am. Ceram. Soc., 65, 457 (1982)

[1] Benitez J, "Principles and Modern Applications of Mass Transfer Operations," John Wiley & Sons, Inc., New York, 85 (2002)

[2] Bird RB, Stewart WE, Lightfoot EN, "Transport Phenomena," 1st ed., John Wiley, Sons, New York, 563 (1960)

[3] Bird RB, Stewart WE, Lightfoot EN, "Transport Phenomena," 2nd., John Wiley & Sons, Inc., New York, 536 (2002)

[4] Bird RB, Stewart WE, Lightfoot EN, "Transport Phenomena," 2nd ed., John Wiley & Sons, Inc., New York, 671 (2002)

[5] Gardner RA, J. Solid State Chem., 9, 336 (1974)

[6] HSC Chemistry, Version 4.0, Outokumpu Research Oy, Finland (1999)

[7] Lewis SD, "Reduction of Fused Silica in Hydrogen," Thesis, University of Utah (1979)

[8] Schwerdtfeger K, Trans. Met. Soc. AIME, 236, 1152 (1966)

[9] Sohn HY, Sohn HJ, Ind. Eng. Chem. Process Des. Dev., 19, 237 (1980)

[10] Szekely J, Evans JW, Sohn HY, "Gas-Solid Reactions," Academic Press, New York, 66 (1976)

[11] Tso ST, Park JA, J. Am. Ceram. Soc., 65, 457 (1982)