Separation of C3/C4 hydrocarbon mixtures by adsorption using a mesoporous iron MOF: MIL-100(Fe)

In this work an iron MOF, MIL-100(Fe) is proposed as a plausible adsorbent to carry out C3/C4 separation by adsorption. The adsorption equilibrium of pure propane, propylene and isobutane over MIL-100(Fe) was studied by means of a magnetic suspension balance in a wide range of temperature and pressure (323-423 K and 0-500 kPa). Propane and propylene present nearly linear isotherms at high temperature, while isobutane present steeper isotherms at low pressures, showing higher adsorption capacity than that of propane and propylene in most of the studied range. Multicomponent fixed-bed adsorption experiments confirmed the preferential adsorption of isobutane over propane and propylene, with an adsorption separation factor of 3. A non-isothermal, non-adiabatic, bidisperse mass transfer model that describes satisfactorily the single and multicomponent breakthrough experiments is proposed. (C) 2012 Elsevier Inc. All rights reserved.