Effective Separation of Prime Olefins from Gas Stream Using Anion Pillared Metal Organic Frameworks: Ideal Adsorbed Solution Theory Studies, Cyclic Application and Stability

Abstract

The separation of C3H4/C3H6 is one of the most energy intensive and challenging operations, requiring up to 100 theoretical stages, in traditional cryogenic distillation. In this investigation, the potential application of two MOFs (SIFSIX-3-Ni and NbOFFIVE-1-Ni) was tested by studying the adsorption–desorption behaviors at a range of operational temperatures (300–360 K) and pressures (1–100 kPa). Dynamic adsorption breakthrough tests were conducted and the stability and regeneration ability of the MOFs were established after eight consecutive cycles. In order to establish the engineering key parameters, the experimental data were fitted to four isotherm models (Langmuir, Freundlich, Sips and Toth) in addition to the estimation of the thermodynamic properties such as the isosteric heats of adsorption. The selectivity of the separation was tested by applying ideal adsorbed solution theory (IAST). The results revealed that SIFSIX-3-Ni is an effective adsorbent for the separation of 10/90 v/v C3H4/C3H6 under the range of experimental conditions used in this study. The maximum adsorption reported for the same combination was 3.2 mmolg−1. Breakthrough curves confirmed the suitability of this material for the separation with a 10-min gab before the lighter C3H4 is eluted from the column. The separated C3H6 was obtained with a 99.98% purity.

A review on modified MOFs as CO2 adsorbents using mixed metals and functionalized linkers

“…Hence, in order to achieve an equilibrium-based separation, the porous material must have a large pore size that allows all of the molecules to pass through [23]. The insertion of significant interaction areas on the MOF framework creates comparable thermodynamic attractions between the gas molecules and the MOF material in equilibrium separations [28].…”

Metal Organic Frameworks for Advanced Applications

“…This Special Issue includes outstanding studies focused on the synthesis of new MOF-based materials with enhanced properties in terms of behavior and/or stability for adsorption and catalytic applications. In this sense, Khraisheh et al [3] analyzed the potential application of two MOFs (SIFSIX-3-Ni and NbOFFIVE-1-Ni) for the separation of prime olefins from gas streams at different temperatures and pressures. Dynamic adsorption breakthrough tests were also conducted, and the stability and regeneration ability of the MOFs were established after eight consecutive cycles.…”