Influence of propane on CO2/CH4 and N2/CH4 separations in CHA zeolite membranes

Molecular sieve membranes for N2/CH4separation

“…The authors reported a N 2 /CH 4 selectivity of 5-7 for a feed pressure of 350 kPa and N 2 permeance of ;300 GPU. Although the separation selectivity was ; half of that observed for SSZ-13 membranes, 24 the observed N 2 permeance was ;5 times higher. The higher N 2 permeance of SAPO-34 membranes as compared to SSZ-13 membranes was likely related to the membrane thicknesses (;3 lm for SAPO-34 membranes versus ;8 lm for SSZ-13 membranes).…”

“…Wu et al synthesized SSZ-13 zeolite membranes via secondary seeded growth on the outer surface of mullite porous tubes. 24 The resultant membranes displayed remarkably high N 2 /CH 4 separation selectivities of 13 but relatively low N 2 permeances [2.2 Â 10 À8 mol/(m 2 s Pa) 5 66 GPU] at 20°C for a feed pressure of 270 kPa. Of all the reported molecular sieve membranes for N 2 /CH 4 separation, SAPO-34 membranes have displayed the best overall separation performance for this binary gas mixture.…”

“…All reported SAPO-34 membranes for N 2 /CH 4 separation have been successfully grown via secondary seeded growth on porous alumina supports. 12,24,[40][41][42] These porous tubes were typically 6 cm long with effective permeation areas between 6.5 and 7.5 cm 2 . Wu et al 24 prepared SAPO-34 membranes by secondary seeded growth on the inside of seeded, porous Al 2 O 3 tubes (1-cm O.D., 100 nm average pore size, 40-55% porosity).…”

“…12,24,[40][41][42] These porous tubes were typically 6 cm long with effective permeation areas between 6.5 and 7.5 cm 2 . Wu et al 24 prepared SAPO-34 membranes by secondary seeded growth on the inside of seeded, porous Al 2 O 3 tubes (1-cm O.D., 100 nm average pore size, 40-55% porosity). The membrane synthesis was carried out at 180°C for 6 h using a gel composition of 0.85 Al 2 O 3 :1.0 P 2 O 5 :0.3 SiO 2 :2.0 TEAOH:155 H 2 O.…”

The effect of zeolite suspension concentration on the formation of seed layer via vacuum seeding prior to NaX zeolite membranes growth

“…However, processing high pressure natural gas can be expensive for amine absorption [2] and polymeric membranes are known to be susceptible to plasticization by CO 2 resulting in reduction of selectivity [3]. Porous inorganic membrane such as zeolite membrane which contain nano pores, are favourable for CO 2 separation from CH 4 because of their chemical resistance to CO 2 induced plasticization and superior selectivity compared to polymeric membranes [2,[4][5]. N 2 presence in natural gas also reduces the heating value of the gas, and thus required removal.…”