Binary liquid diffusion coefficients

Abstract

Dividing Equation (A6) by Equation (A7) and then using Equation (A9) to eliminate (dya,/dL)/( dT,/dL) one gets where FF is the average value of r in the film. Thus Equation (A10) can be written I+-There remains the problem of evaluating the first term in Equation (A12). This term is the ratio of the energy absorbed For given values of (x,/xp), m, q, and q' by the chemical reaction within the film Equation (A14) can be solved simulto the wall heat flux, and it is given by taneously with Figure A1 [or Equation (A5) with no heterogeneous reaction] to v -yield the value of E .With this simplification for q = 11 and N L~ = 1, q' = 11. The solution to Equation (A14) for this case is shown in Table Al The foregoing analysis leads to the conclusion that for cases of practical importance the steady state value of ro required to account for the imbalance in heat transfer to the bulk and diffusion of reactants from the bulk is so small that it has a negligible effect upon the results as presented in Figure 1. It is also clear that if ro is not equal to its steady state value at the leading edge of the wall (that is the i d o w boundary condition), it will rapidly approach that steady state value as the gas flows down in the L direction. This basic conclusion is unaltered if the foregoing analysis is repeated for other values of q and for other values of the Lewis number.On the other hand if the heterogeneous reaction is rapid enough to prodnce a large value of ( + -1) while the homogeneous reaction is so slow that it would, in the absence of the heterogeneous reaction, produce a small value of ( + -l ) , then clearly the assumption of chemical equilibrium in the bulk is not justified in general. The available correlations for the be divided into two classes. In the prediction of diffusion coefficients may first class theoretical correlations based = a R. Kanial is at Stamford Laboratories, on the works of Einstein (11), Eyring Binary Liquid Diffusion Coefficients

The mutual diffusion coefficient for binary mixtures of water and the isomers of propanol

“…The engineering requirement for the reliable prediction of liquid diffusivity data is manifested by the large number of correlations available (Darken 1948;Wilke & Chang 1955;Tyrell 1961;Kamal & Canjar 1962;Ratcliff & Lusis 1971;Reid & Sherwood 1966); however, none of these formulations is capable of even approxi mately representing our data. Therefore, in order to facilitate the use of the present results in heat and mass transfer studies, equation ( 27) has been chosen as the basis for a correlation scheme.…”

Liquid Phase Diffusion of Non-electrolytes at High Dilution.

“…Despite this fact, empirical or semiempirical methods will likely continue to provide the most convenient and the most reliable estimation methods for liquid diffusivities for some time to come. The most widely used correlation for diffusion at high dilution is that of Wilke and Chang (50, 51); several others have put forward modifications or other equations (17,29,39,41). All of these correlations have shortcomings when applied to the entire spectrum of available data; for example, difficulties have been encountered when the solute is highly polar (10,27), when the solute has a low molecular weight, and when the solvent has a relatively large viscosity.…”

Diffusion of Non-Polymeric and Polymeric Molecule in Chain Polymer Liquid

“…When the size of penetrant molecule is approximately equal to that of a segmental unit of the polymer medium, we can substitute v*«v* and further <fi01« (hosto Eq. (17) to obtain (18) yp2,p2…”