Mass transfer coefficients nonreactive measurement

Some of this theoretical thinking may be utilized in reactor analysis and design. Illustrations of gas-liquid reactors are shown in Fig. 19-26. Unfortunately, some of the parameter values required to undertake a rigorous analysis often are not available. As discussed in Sec. 7, the intrinsic rate constant kc for a liquid-phase reaction without the complications of diffusional resistances may be estimated from properly designed laboratory experiments. Gas- and liquid-phase holdups may be estimated from correlations or measured. The interfacial area per unit reactor volume a may be estimated from correlations or measurements that utilize techniques of transmission or reflection of light, though these are limited to small diameters. The combined volumetric mass-transfer coefficient kLa, can be also directly measured in reactive or nonreactive systems (see, e.g., Char-pentier, Advances in Chemical Engineering, vol. 11, Academic Press, 1981, pp. 2-135). Mass-transfer coefficients, interfacial areas, and liquid holdup typical for various gas-liquid reactors are provided in Tables 19-10 and 19-11. 

Snider and Perona3 measured Ksas, the volumetric liquid-solid mass-transfer coefficient, for the case of hydrogenation of a-methyl styrene on 3-mm alumina spheres coated with palladium catalyst. The results were obtained in the bubble-flow regime. The measurements of Ks, the liquid-solid mass-transfer coefficient in a nonreacting system, were first reported by Mochizuki and Matsui.20 They... 

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