Diffusivities in the micropore and adsorption equilibrium constants were determined for neon, argon, krypton, xenon, nitrogen, methane, ethylene, ethane, propylene, propane, n‐butane, and benzene on molecular sieving carbon by chromatographic measurement and moment analysis. Isosteric heat of adsorption was found to be 2.6 times heat of vaporization for the gases examined here. Two separate linear relations were obtained between activation energies of diffusion in micropore and isosteric heats of adsorption for rare gases, methane, and benzene, and for n‐paraffin and n‐olefin except methane.

Nonisothermal pressure swing adsorption is simulated by numerical calculation, by accounting for mass transfer as well as heat transfer in the column, where linear driving force for adsorption rate and linear isotherm were assumed. 40 cycles of PSAoperation from start-up are iterated in the computer as a case study of air drying by activated alumina. Assuming that volumetric ratio of purge to feed is 2, steady mode is observed after 30 cycles and almost constant distribution of amount adsorbed in the bed is found to be established. Condition for isothermal, nonisothermal or adiabatic assumption can be determined by this simulation in terms of column diameter. Bed length, cycle time and purge to feed ratio have significant effects on product concentration in the simulations. Further, optimizations are discussed as for the relation between column length and purge-to-feed ratio and as for cycle time in the case of air drying by silica gel.

Air drying experiments by pressure swing adsorption (PSA) were carried out, using two columns packed with silica gel as adsorbent. Measurements were also madeof batch adsorption of water vapor on silica gel to obtain input data for the authors' PSAsimulation program. Experimental PSAresults were compared with this computer simulation. Good agreement was obtained and the trend of experimental results was well explained by simulation for both isothermal and non-isothermal cases. In the simulation, however, mass transfer coefficients two or three times larger than those estimated conventionally from batch measurement were used to obtain good coincidence. These larger masstransfer coefficients were determined by a recently developed methodfor short adsorption and desorption cycle.5} The simulation method is useful in predicting the performance of air drying PSA.