Adsorption of water and ethanol vapors on 3A and 4A molecular sieve zeolites

The goal of this study was to conduct adsorption equilibrium gravimetric tests on Grace Davison molecular sieve zeolites used in industrial ethanol drying processes. Measurements were performed in a stream of inert carrier gas such as nitrogen for different partial pressures of water and ethanol at atmospheric pressure and at various temperatures. Experimentally determined adsorption equilibrium data for water was in reasonable agreement with equilibrium data found in the literature and with manufacturer provided data. The Langmuir isotherm equation was used to correlate single component experimental data and obtained parameters for pure components of water and ethanol were used to construct a multicomponent adsorption model.; Binary equilibrium data was established across a plurality of partial pressures for various ethanol and water mixtures. Yang's multiregional extended Langmuir model was used to predict binary adsorption uptakes. Only the two parameters of the Langmuir isotherm for each pure component are used. Results were in very good agreement with experimental data. Developed equilibrium model will be used in a simulation package for optimization and design of industrial PSA processes for fuel ethanol production.; Key Words. water, ethanol, adsorption equilibrium, 3A zeolite, 4A zeolite, gravimetric analysis.