Molecular sieving of n-butenes by zeolite erionite and by isostructural silicoaluminophosphate SAPO-17

Incorporation of Gallium into Zeolites: Syntheses, Properties and Catalytic Application

“…Erionite cavities are quite large (6.3 × 13.0 Å), but pore openings (windows) of the cavities are small (3.6 × 5.1 Å). The alkali form of the zeolite erionite was shown to exert molecular sieving effects for normal butenes differentiating between cis -but-2-ene and trans -but-2-ene due to their different sizes and polarities 53 Framework structure of erionite (ERI).…”

“…The alkali form of the zeolite erionite was shown to exert molecular sieving effects for normal butenes differentiating between cis-but-2-ene and trans-but-2-ene due to their different sizes and polarities. 340 Klyueva 341,342 reported the formation of [Ga]-erionite with 100% crystallinity from an initial synthesis gel comprising solutions of NaOH, KOH, gallium sulfate, and sodium silicate after 1-30 days of crystallization at 120 °C. The product had a Si/Ga ratio of 19.75, but only 50% of the gallium was tetrahedrally coordinated as proved by 71 Ga NMR spectroscopy.…”

Liquid phase separation of 1-butene from 2-butenes on all-silica zeolite RUB-41

“…The reverse order is observed when the separation is based on a true shape selective effect. Thus, 8-membered ring zeolites like NaCaA (LTA), 3 erionite or AlPO-17 (ERI), 4 and recently all-silica DD3R (DDR), 5,6 allsilica chabazite (CHA), 7 or ITQ-32 (IHW) 8 all prefer trans-2butene over 1-butene, simultaneously excluding cis-2-butene from the lattice. This order is consistent with the critical diameters of the isomers: trans-2-butene (0.431 nm) o 1-butene (0.446 nm) o cis-2-butene (0.494 nm).…”

“…This order is consistent with the critical diameters of the isomers: trans-2-butene (0.431 nm) o 1-butene (0.446 nm) o cis-2-butene (0.494 nm). 5 However, the application of such zeolites has exclusively been demonstrated in the gas phase, [3][4][5][6][7][8] while liquid phase operation offers the advantage of maximised bed utilisation, as indicated by a vast body of patented technology. 9,10 Here we report on the butene sorption properties of all-silica RUB-41 zeolite.…”

Separation of 1-Butene and 2-Butene Isomers via Nanoporous Graphene: A Molecular Simulation Study

“…Some endeavors have been made to tailor-make suitable MOFs and zeolites with preferential recognition of targeted butene isomers . For example, 8-membered ring zeolites (i.e., SAPO-17, all-silica DD3R (DDR), and ITQ-32) show the selective adsorption of trans -2-C 4 H 8 , but cis -2-C 4 H 8 is simultaneously excluded with 1-C 4 H 8 . All-silica zeolite RUB-41 also shows the preferential binding of 2-C 4 H 8 over 1-C 4 H 8 in the liquid phase operation at low concentrations .…”