Ethene/Ethane and Propene/Propane Separation via the Olefin and Paraffin Selective Metal–Organic Framework Adsorbents CPO-27 and ZIF-8

Abstract

Two types of metal-organic frameworks (MOFs) have been synthesized and evaluated in the separation of C2 and C3 olefins and paraffins. Whereas Co2(dhtp) (=Co-CPO-27 = Co-MOF-74) and Mg2(dhtp) show an adsorption selectivity for the olefins ethene and propene over the paraffins ethane and propane, the zeolitic imidazolate framework ZIF-8 behaves in the opposite way and preferentially adsorbs the alkane. Consequently, in breakthrough experiments, the olefins or paraffins, respectively, can be separated.

Ethane/ethylene separation on a copper benzene-1,3,5-tricarboxylate MOF

“…The ethylene affinity on this material was also observed, in a previous work performed by Wang et al [36]. In Table S1 are also summarized the literature results for the olefin/paraffin separation potential MOFs [32,33,37,38].…”

“…Indeed, an interesting feature of some MOFs in the separation of olefin/paraffin, is how the structure reacts in presence of the adsorbate at a given pressure inducing the so-called "gate opening" effect [25,[31][32][33][34]. This effect can originate in some cases to paraffin selective adsorbents.…”

Amine-modified Mg-MOF-74/CPO-27-Mg membrane with enhanced H 2 /CO 2 separation

“…Due to its high gas adsorption ability, many studies have been focused on the gas separation efficiency of Mg- MOF-74 (Mason et al, 2011;Yang et al, 2012;Dietzel et al, 2010;Herm et al, 2012;Yu and Balbuena, 2013;Böhme et al, 2013;Mundstock et al, 2013).…”

“…simulation (Kong et al, 2012;Dzubak et al, 2012;Remy et al, 2013), to date no Mg-MOF-74 membrane with successful gas separation performance has been reported. In a first attempt, a supported Mg-MOF-74 membrane with a mean tilt angle of 31° of the 1D pore system from the direction perpendicular to the membrane surface could be developed (Mundstock et al, 2013). Lee et al (2012) have prepared a Ni-MOF-74 membrane by using the layer-by-layer synthesis technique with a H 2 /CO 2 selectivity of 9.1 at 25 °C.…”

Synthesis and crystallographic characterisation of Mg(H 2 dhtp)(H 2 O) 5 ·H 2 O

“…[2,10] The desolvation of this family of compounds generates metal centres with vacant coordination sites, onto which gas adsorbents such as NO, [11] CO, [12] CO 2 , [13,14] H 2 S, [15,16] H 2 [2,7] and C 2 H 2 [12,17] may be bound. The CPO-27-Mg structure has particularly good properties for the adsorption of CO 2.…”