| Description |
xix, 163 leaves : illustrations ; 29 cm |
| Summary |
"Experimental measurements of transient adsorption of pure components and binary mixtures of propylene and propane into 13X molecular sieves, at one atmosphere, have been used to estimate the diffusivities of both components for the transport models : pore diffusion, surface diffusion, and a model whose individual component (surface) diffusivities depend linearly upon the individual component concentrations. The binary results cover concentrations of 25, 50, 75 mole% propylene, at temperatures of 25°C, 50°C, and 70°C. While all models appear acceptable for pure component diffusion, only the interacting binary surface diffusion model offered reasonable fits to the binary data. The diffusion coefficients obtained by regression to this model could be used for design within their experimental ranges of temperature and composition. However, these coefficients do not exhibit the temperature and composition behavior expected of an activated surface diffusion process. The estimated diffusivities for pure component surface diffusion were 1.7x10⁻⁸ m²/sec for pure propylene and propane. At all temperatures, the four binary surface diffusivities varied with concentration. At 25°C the values ranged from D[subscript g11] = 2.59x10⁻⁹, D[subscript g12] = 2.67x10⁻⁹, D[subscript g21] = 1.84x10⁻⁸, D[subscript g22]= 2.57x10⁻⁸ m²/sec at 25 mole% propylene to 5.03x10⁻⁸, 1.44x10⁻⁸, 7x10⁻¹⁰, 3.81x10⁻⁹ m²/sec at 75 mole% propylene. Pure and binary pore diffusion coefficients for propylene at 25°C ranged from 3.04 to 3.32 x 10⁻⁷ m²/sec , while those for propane ranged from 3.26 to 2.84 x 10⁻⁷ m²/sec"--Abstract, leaf iii. |
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