Separation of Propylene/Propane Mixtures Using Faujasite-Type Zeolite Membranes

Abstract

Faujasite-type zeolite membranes, having a thickness of approximately 20 µm, were synthesized on porous R-alumina supports using the secondary growth method. For the first time, a detailed investigation of the faujasite membrane's ability to separate propylene/propane mixtures has been performed. Single-component and binary mixture permeation experiments indicated that the membranes are propylene permselective. The maximum separation factor (13.7 ( 1 at 100 °C) and the maximum ideal selectivity (28 at 35 °C) indicate that the membranes have improved performance, compared to previously reported results. Membrane permselective behavior was maintained over the entire range of feed compositions examined (P total ) 101 kPa and P propylene ) 12-93 kPa). The temperature dependence differences between the single-component and binary mixture permeation fluxes indicate that the presence of propylene enhances propane transport through the membrane.

FT-IR study of the adsorption of carbon monoxide and of some nitriles on Na-faujasites: Additional insight on the formation of complex interactions

“…Either in the form of powder packed beds or of membranes, alkali metal zeolites may allow the drying of air [3], the separation of air components (N 2 /O 2 ) by pressure/vacuum swing adsorption procedures [4], the separation of CO 2 from different gaseous streams [5], the alkene/alkane [6], the benzene/cyclohexane [7] and the xylene isomers separations [8].…”

Recovery of hydrocarbons from mixtures containing C3H6, C3H8 and N2 using NaX membranes

“…The supports were prepared following a procedure described in the literature [16,21]. Prior to hydrothermal treatment, NaY (Aldrich) crystals were deposited on the support using a dip-casting technique.…”

“…The duration of the synthesis was 7 days and resulted in the formation of a membrane having an estimated thickness between 15 and 18 m [21]. Details about the preparation of the synthesis gel can be found in an earlier publication [16]. After hydrothermal growth, the membranes were thoroughly washed several times with hot distilled water and were then calcined in air at 420 • C (heating rate 2 • C min −1 ) for 6 h.…”

“…Faujasite membranes have shown promising results for the separation of CO 2 /N 2 [10][11][12], CO 2 /CH 4 [11,13] [14] and saturated/unsaturated hydrocarbon mixtures [15][16][17]. FAU crystals adsorb larger amounts of light hydrocarbons than N 2 [18][19][20], and as a result FAU membranes are ideal candidate materials for the separation of light olefins or paraffins from a N 2 rich polyolefin vent stream.…”

Propylene/propane Permeation Properties of Metal-doped Organosilica Membranes with Controlled Network Sizes and Adsorptive Properties

“…Those published papers suggest the importance of tailoring the pore size for improved molecular sieving separation, and controlling the adsorptive properties, particularly for olefin molecules. For example, although FAU-type zeolite membranes show Knudsen selectivity for C3H6/C3H8, due to the fact that the channel size is too large for separation, the separation factor can, however, be dramatically enhanced by exchanging ions for increased molecular sieving and affinity of C3H6 molecules with cations in the FAU zeolite 9) . The network structure of organosilica utilizing bis (triethoxysilyl) methane (BTESM) via a sol-gel method was suggested to be suitable for C3H6/C3H8 separation 17), 18) , due to the fact that these membranes showed , Shinjiro HAYAKAWA 2) , Hiroki NAGASAWA 1) , Tomohisa YOSHIOKA 1) , and Toshinori TSURU 1) comparable C3H6/C3H8 permeation properties with ZIF-8 membranes 11) 15) , which showed high diffusive separation of C3H6/C3H8 through six-ring cages that are 0.4 nm in size.…”