Equilibrium adsorption of light alkanes and their mixtures at high pressure on 5A, 13X and S-115 adsorbents.

Abstract

Pure and Multicomponent equilibrium data are reported for Linde 5A, 13X and S-115 adsorbents at pressure up to 2.50 psia and in the temperature rage of 275 to 350 K. The intrinsic Henry constants are extracted from the data using virial isotherm techniques. The pure and component data are modelled by four simple isotherm (LRC, Toth, Mathews and Weber, Jaroniec) and one statistical thermodynamic isotherm(Ruthven). The multicomponent form of Ruthven's isotherm is developed, and used to model 5A and 13X data. The multicomponent Toth model is used the S-115 data. For the 5A pellets, the Toth model fits the data for all four components. The Ruthven model is best for methane, ethane and propane. The four simple isotherms (LRC, Toth, Mathews and Weber, Jaroniec) fit the data for silicalite (S-115) but the Ruthven model is not applicable. Only isotherms of methane and propane have been measured for 13X zeolite. All models fit the methane data but the propane is not well fitted by any model. Toth, Mathews and Weber and Ruthven models are the best. Binary, ternary and quaternary data are reported at 300 K and at 50 and 95 psia. For the 5A and 13X pellets these data are analyzed and modelled with the multicomponent form of Ruthven's model and the fit is reasonable with intrinsic Henry constant for 5A and with optimized Henry constant for 13X pellets. The multicomponent Toth model is used to fit the multicomponent data for the silicalite pellets and the fit is reasonable. Considering equilibrium only the separation of methane is greater in silicalite than in 13X or in 5A pellets.