Pure silica CHA-type zeolite membranes for dry and humidified CO2/CH4 mixtures separation

Kida, Koji; Maeta, Yasushi; Yogo, Katsunori

doi:10.1016/j.seppur.2017.12.060

Cited by 102 publications

(77 citation statements)

References 25 publications

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“…Al‐containing zeolite frameworks have a stronger interaction with the polar water molecules, leading to higher water uptake and pore blockage . The CO 2 permeance reduction here is even less than the all‐silica CHA (88 % reduction) and DD3R (68 % reduction) zeolite membranes (Table S8). The cationic SDAs ( N , N , N ‐trimethyl‐1adamantammonium hydroxide and methyltropinium iodide) lead to Si‐O‐Si bond breakage for charge balance, resulting in the formation of hydroxyl groups after SDAs removal.…”

Section: Resultsmentioning

confidence: 87%

Xenon Recovery by DD3R Zeolite Membranes: Application in Anaesthetics

et al. 2019

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Xe is only produced by cryogenic distillation of air, and its availability is limited by the extremely low abundance. Therefore,Xerecovery after usage is the only way to guarantee sufficient supply and broad application. Herein we demonstrate DD3R zeolite as ab enchmark membrane material for CO 2 /Xe separation. The CO 2 permeance after an optimized membrane synthesis is one order magnitude higher than for conventional membranes and is less susceptible to water vapour.T he overall membrane performance is dominated by diffusivity selectivity of CO 2 over Xe in DD3R zeolite membranes,whereby rigidity of the zeolite structure playsakey role. Forr elevant anaesthetic composition (< 5% CO 2 )a nd condition (humid), CO 2 permeance and CO 2 /Xe selectivity stabilized at 2.0 10 À8 mol m À2 s À1 Pa À1 and 67, respectively,d uring long-term operation (> 320 h). This endows DD3R zeolite membranes great potential for on-stream CO 2 removal from the Xe-based closed-circuit anesthesia system. The large cost reduction of up to 4o rders of magnitude by membrane Xerecycling (> 99 + %) allows the use of the precious Xe as anaesthetics gas av iable general option in surgery.

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Section: Resultsmentioning

confidence: 87%

Xenon Recovery by DD3R Zeolite Membranes: Application in Anaesthetics

et al. 2019

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“…Chemie contrast with Xe,o nly am inor difference in CO 2 permeance between single and mixed gas was observed for the separation of CO 2 /N 2 and CO 2 /CH 4 using small pore zeolite membranes of SSZ-13, [20] Si-CHA, [21] SAPO-34, [22] and DD3R [10b,d] (Table S4). Molecular simulation also revealed CO 2 diffusion in DD3R is weakly affected by the presence of CH 4 because these two molecules prefer different adsorption locations.…”

Section: Methodsmentioning

confidence: 99%

“…Thep ure CO 2 permeance decreased but only by 45 % ( Figure S12 a), far better than high-silica SSZ-13 (66-75 %r eduction) [8a,20] and SAPO-34 (99 %reduction) [7] zeolite membranes.Al-containing zeolite frameworks have as tronger interaction with the polar water molecules,l eading to higher water uptake and pore blockage. [20] TheCO 2 permeance reduction here is even less than the all-silica CHA (88 %r eduction) [21] and DD3R (68 %r eduction) [10d,12] zeolite membranes (Table S8). The cationic SDAs (N,N,N-trimethyl-1adamantammonium hydroxide and methyltropinium iodide) [12,21] lead to Si-O-Si bond breakage for charge balance,resulting in the formation of hydroxyl groups after SDAs removal.…”

Section: Methodsmentioning

confidence: 99%

Xenon Recovery by DD3R Zeolite Membranes: Application in Anaesthetics

et al. 2019

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Xe is only produced by cryogenic distillation of air, and its availability is limited by the extremely low abundance. Therefore, Xe recovery after usage is the only way to guarantee sufficient supply and broad application. Herein we demonstrate DD3R zeolite as a benchmark membrane material for CO2/Xe separation. The CO2 permeance after an optimized membrane synthesis is one order magnitude higher than for conventional membranes and is less susceptible to water vapour. The overall membrane performance is dominated by diffusivity selectivity of CO2 over Xe in DD3R zeolite membranes, whereby rigidity of the zeolite structure plays a key role. For relevant anaesthetic composition (<5 % CO2) and condition (humid), CO2 permeance and CO2/Xe selectivity stabilized at 2.0×10−8 mol m−2 s−1 Pa−1 and 67, respectively, during long‐term operation (>320 h). This endows DD3R zeolite membranes great potential for on‐stream CO2 removal from the Xe‐based closed‐circuit anesthesia system. The large cost reduction of up to 4 orders of magnitude by membrane Xe‐recycling (>99+%) allows the use of the precious Xe as anaesthetics gas a viable general option in surgery.

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“…To avoid difficulty and complexity, an excess amount of feed, which often reaches 100‐fold that of the permeated gas, is generally fed to a membrane module in the quest for a negligible change in the upstream flow rate and concentration along the membrane, 11,18 while single‐gas permeance can be obtained without the use of a significant amount of feed due to the lack of a change in the upstream partial pressure. Due to active research in recent years, membrane permeance has improved significantly to reach values larger than 10 −6 mol/(m 2 s Pa) 19‐21 . Recently, we also reported water vapor permeance of 5.5 × 10 −6 mol/(m 2 s Pa) and water flux of 37 kg/(m 2 h) during water/nitrogen separation at 150°C using a 1,2‐bis(triethoxysilyl) ethane‐derived silica membrane, which corresponds to permeated water flow rate of 2.4 L/min (standard temperature and pressure), even though the experiment was performed with a moderate partial pressure difference across the membrane of 107 kPa and a small membrane area of 0.00314 m 2 10 .…”

Section: Introductionmentioning

confidence: 92%

Evaluation of experimentally obtained permeance based on module simulation: How should permeance be evaluated?

et al. 2020

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Permeance and permeance ratio in binary separation generally are obtained from experimental data using an analytical permeance equation consisting of the logarithmic average of the partial pressure difference (hereafter, approximate permeance equation). The aim of the present study was to clarify the applicable range for this equation. First, the separation performance of a membrane module was calculated with various given membrane properties (permeance, permeance ratio) and operation conditions (pressure, flow rate) via numerical computation. The obtained concentrations and flow rates in the retentate and permeate were used to calculate permeances via approximate permeance equation, and the validity was discussed by comparing permeances used for numerical computation with obtained ones. The present work clarifies the validity of the approximate permeance equation, and yields a general guideline stipulating that the partial pressure difference across the membrane at the inlet and outlet should maintain more than 60% to obtain the correct permeance.

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Pure silica CHA-type zeolite membranes for dry and humidified CO2/CH4 mixtures separation

Cited by 102 publications

References 25 publications

Xenon Recovery by DD3R Zeolite Membranes: Application in Anaesthetics

Xenon Recovery by DD3R Zeolite Membranes: Application in Anaesthetics

Xenon Recovery by DD3R Zeolite Membranes: Application in Anaesthetics

Evaluation of experimentally obtained permeance based on module simulation: How should permeance be evaluated?

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