US4762535A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ammonia separation using semipermeable membranes
Assignee: Air Products and Chemicals Inc
•
Filing: 1987-06-02
•
Granted: 1988-08-09
•
Expires: 2007-06-02
Abstract
Abstract The present invention is a process for separating ammonia from mixtures of other gases or from aqueous streams. The ammonia-containing mixture is contacted with a membrane containing, as the active component, a salt having the structural formula: NR 4 + X - , wherein each R is independently H or a straight chain or branched alkyl group and X - is an organic or inorganic anion. The membrane is useful for the selective permeation of ammonia from mixtures of gases containing ammonia, nitrogen and hydrogen.
Inventors
- 👤 Guido P. Pez
- 👤 Daniel V. Laciak
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 22:54
CPC Classifications
B; B01; B01D; B01D61/00; B01D61/38; B01D69/00; B01D69/14; B01D69/141; C; C01; C01C; C01C1/00; C01C1/02; C01C1/04; C01C1/0405; C01C1/0458; C01C1/12; C01C3/00; C01C3/02; C01C3/0208; C01C3/0212; Y; Y02; Y02P; Y02P20/00; Y02P20/50; Y02P20/52
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
71 words
A process for separating ammonia from a mixture of gases containing ammonia and at least one other component, the process comprising: contacting said ammonia-containing mixture with a membrane containing a salt having the structural formula: NR.sub.4.sup.+ X.sup.- wherein each R is independently H or a straight chain or branched alkyl group and X - is an organic or inorganic anion, such that said membrane selectively permeates ammonia from the ammonia-containing mixture.
Claim 2
Dependent Claim
71 words
A process for separating ammonia from a mixture of gases containing ammonia and at least one other component, the process comprising: contacting said ammonia-containing mixture with a membrane containing a salt having the structural formula: NR.sub.4.sup.+ X.sup.- wherein each R is independently H or a straight chain or branched alkyl group and X - is an organic or inorganic anion, such that said membrane selectively permeates ammonia from the ammonia-containing mixture.
Claim 3
Dependent Claim
49 words
A process in accordance with claim 1 wherein X - is selected from the group consisting of Cl - , Br - , I - , TeCN - , SeCN - , NO 3 - and SCN - and carboxylate R'CO 2 - where R'=H or an alkyl hydrocarbon.
Claim 4
Dependent Claim
33 words
A process in accordance with claim 1 wherein at least one R is H and said salt is incorporated into a polymeric structure to form a physical mixture which functions as a membrane.
Claim 5
Dependent Claim
13 words
A process in accordance with claim 3 wherein said polymeric structure is polyvinylalcohol.
Claim 6
Dependent Claim
27 words
A process in accordance with claim 4 wherein said polyvinylalcohol has been functionalized with methacrylic acid and cross-linked with tetraethylene glycol diacrylate prior to incorporating the salt.
Claim 7
Dependent Claim
31 words
A process in accordance with claim 1 wherein each R is H and said salt is incorporated into a polymeric structure to form a physical mixture which functions as a membrane.
Claim 8
Dependent Claim
33 words
A process in accordance with claim 6 wherein the said physical mixture comprising the salt is utilized as a thin film on a suitable support, or is immobilized in a thin porous support.
Claim 9
Dependent Claim
32 words
A process in accordance with claim 7 wherein the said physical mixture either as a thin film or an immobilized liquid is encapsulated in non-porous, gas permeable polymer or polymer blend material.
Claim 10
Dependent Claim
13 words
A process in accordance with claim 1 wherein said salt is ammonium thiocyanate.
Claim 11
Dependent Claim
35 words
A process in accordance with claim 1 wherein a solution of said salt in liquid NH 3 is utilized as a thin film on a suitable support, or is immobilized in a thin porous support.
Claim 12
Dependent Claim
12 words
A process in accordance with claim 10 wherein each R is H.
Claim 13
Dependent Claim
40 words
A process in accordance with claim 10 wherein the solution of the salt in liquid NH 3 , either as a thin film or as an immobilized liquid, is encapsulated in a non-porous, gas permeable polymer or polymer blend material.
Claim 14
Dependent Claim
32 words
A process in accordance with claim 1 wherein ammonia is separated from ammonia synthesis plant recycle loop gas comprising NH 3 , N 2 , H 2 , CH 4 and Ar.
Claim 15
Dependent Claim
22 words
A process in accordance with claim 1 wherein said salt is encapsulated in a non-porous, gas permeable polymer or polymer blend material.
Claim 16
Dependent Claim
23 words
A process of claim 1 where the membrane may be in the configuration of a flat sheet, spiral wound sheet or hollow fiber.
References Cited (Backward Citations)
US2681319A
Cited
GB790510A
Cited
GB866723A
Cited
US3723306A
Cited
US3475330A
Cited
US3545931A
Cited
US3554905A
Cited
US3948769A
Cited
US4125462A
Cited
US4156597A
Cited
US4262041A
Cited
SU1063774A1
Cited
US4180553A
Cited
US4537760A
Cited
US4439351A
Cited
US4547293A
Cited
GB2145702A
Cited
EP0194483A1
Cited
US4661257A
Cited
US4608060A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-08-09 | 1992-02-08 | 1992-08-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-08-09 | 1996-02-08 | 1996-08-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-08-09 | 2000-02-08 | 2000-08-09 | $7700.00 | Window Closed / Lapsed |