I 1 I I I I I I 0 0.2 0.4 0.6 0.8 I .o MOLE FRACTION CO I N VAPOR Fig. 3. Phase diagram for adsorption of carbon monoxide and nitrogen on molecular sieve 5A at -200°F. Circles: experimental data. Solid line: theory of ideal adsorbed solutions.spreading pressure of carbon monoxide. Spreading pressures of carbon monoxide and nitrogen calculated by Equation (1) and the integration constant at one atmosphere are shown as a function of pressure on Figure 2. Calculation of phase equilibria for adsorption at a particular pressure requires adsorption data on the more volatile adsorbate (here, nitrogen) at higher pressure.Unfortunately Danner and Wenzel failed to measure the adsorption of nitrogen at pressures greater than atmospheric. However, the selectivity may be calculated at lower pressure. On Figure 3, adsorbed and gas compositions predicted by the theory of ideal adsorbed solutions at 100 mm Hg are compared with experimental points of Danner and Wenzel at atmospheric pressure. It is known that selectivity decreases weakly with increasing pressure (Myers, 1968). The theoretical curve should shift somewhat closer to the 45" line, and therefore closer to the experimental points, at atmospheric pressure. Even if differences in pressure are ignored, these data can be explained quantitatively by activity coefficients in the adsorbed phase no larger than 1.5 at infinite dilution. We picked the CO-N2-zeolite 5A system for discussion because the discrepancy between theory and experiment is greatest. For other mixtures (CO + 02, N2 + 0 2 ) adsorbed on zeolites 5A and 1OX the theory of ideal adsorbed solutions predicts the observed selectivity (xlyz/ x2yl) within 2 10%. Organic Liquids at 25' and 5OoCThe influence of diffusivity on the mass transfer of gases into both nonturbulent and turbulent liquids is now well established ( Davies, 1972) so accurate diffusivity values are needed for the interpretation and calculation of mass transfer rates. Recently Akgerman and Gainer ( 1972a,b) showed that previously developed diffusivity correlations did not entirely satisfactorily predict the diffusivities of gases in liquids and proposed an improved equation based on significant liquid structure and absolute rate theory. However, only 41 of the 268 data points used to test their equation were for gases in organic liquids and J. M. Woollen is with Amoco, Chicago, Illinois.

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Aspergillus fumigatus was cultured in disc-turbine-agitated vessels and in an air-lift fermentor. In the agitated vessels the yield of cellulase was reduced when the agitation rate was increased, although extracellular protein levels rose. The enzyme complex itself was shown to be exceptionally stable under conditions similar to those in the agitated vessels, so probably shear damage to the mycelium had occurred, liberating intracellular contents. These appeared to contain an inhibitor that could be removed by fabricated inorganic protein absorbents, such as kieselguhr and alumina. However, the inhibitor was not likely to be protease, since only relatively low levels could be detected and its identity has not been established. The use of an air-lift fermentor avoided the shear effects due to use of the disc turbine agitator in the conventional fermentors, and yields of enzyme were then found to increase by about 20%, maximum yields being obtained at maximum K(L)a values.

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