Process and system for separation and recovery of perfluorocompound gases

• US 6,254,666 B1
• Filed: 03/28/2000
• Issued: 07/03/2001
• Est. Priority Date: 07/17/1995
• Status: Expired due to Fees

• Current Assignee: American Air Liquide Incorporated (L'Air Liquide SA), L'Air Liquide Societe Anonyme Pour L'Etude et L'Exploitation Des Procedes Georges Claude (L'Air Liquide SA)
• Original Assignee: American Air Liquide Incorporated (L'Air Liquide SA), L'Air Liquide Societe Anonyme Pour L'Etude et L'Exploitation Des Procedes Georges Claude (L'Air Liquide SA)
• Inventors: Li, Yao-En, Vassallo, David, Fleming, Gregory K., Paganessi, Jospeh E.
• Primary Examiner(s): Spitzer, Robert H.
• Application Number:
  US09/536,687
• Time in Patent Office: 462 Days
• Field of Search: 95/45, 95/47--49, 95/51--54, 95/90, 95/92, 951/49, 952/30, 952/37, 95/39, 96/4, 96/7--14, 961/08, 961/34, 963/61
• US Class Current: 95/39
• CPC Class Codes: B01D 2257/204 Inorganic halogen compounds
• CPC Class Codes: B01D 2257/2066 Fluorine
• CPC Class Codes: B01D 53/22 by diffusion manufacturing semi-permeable membranes B01D67/00; form, structure or properties of semi-permeable membranes B01D69/00; material for semi-permeable membranes B01D71/00
• CPC Class Codes: B01D 53/225 Multiple stage diffusion
• CPC Class Codes: B01D 53/226 in serial connexion
• CPC Class Codes: B01D 53/229 Integrated processes (Diffusion and at least one other process, e.g. adsorption, absorption)
• CPC Class Codes: C07C 17/38 Separation; Purification; Stabilisation; Use of additives
• CPC Class Codes: C07C 19/08 containing fluorine
• CPC Class Codes: Y02C 20/30 of perfluorocarbons [PFC], hydrofluorocarbons [HFC] or sulfur hexafluoride [SF6]
• CPC Class Codes: Y02P 20/151 Reduction of greenhouse gas [GHG] emissions, e.g. CO2
• CPC Class Codes: Y02P 20/155 Perfluorocarbons [PFC]; Hydrofluorocarbons [HFC]; Hydrochlorofluorocarbons [HCFC]; Chlorofluorocarbons [CFC]

Abstract

Processes and systems to recover at least one perfluorocompound gas from a gas mixture are provided. In one embodiment the inventive process comprises the steps of a) providing a gas mixture comprising at least one perfluorocompound gas and at least one carrier gas, the gas mixture being at a predetermined pressure; b) providing at least one glassy polymer membrane having a feed side and a permeate side; c) contacting the feed side of the at least one membrane with the gas mixture; d) withdrawing from the feed side of the membrane as a non-permeate stream at a pressure which is substantially equal to the predetermined pressure a concentrated gas mixture comprising essentially the at least one perfluorocompound gas; and e) withdrawing from the permeate side of the membrane as a permeate stream a depleted gas mixture comprising essentially the at least one carrier gas.

Claims

1. A process for the separation and recovery of perfluorocompound gases from a gas mixture comprising at least one perfluorocompound gas and at least one carrier gas, said process comprising the steps of:

(a) providing a first membrane having a feed side and a permeate side, the first membrane being permeable to the at least one carrier gas and being non-permeable to the at least one perfluorocompound gas;

(b) contacting the feed side of the first membrane with the gas mixture;

(c) withdrawing from the feed side of the first membrane a first non-permeate stream enriched in the at least one perfluorocompound gas;

(d) withdrawing from the permeate side of the first membrane a first permeate stream comprising primarily the at least one carrier gas;

(e) providing a second membrane having a feed side and a permeate side, the second membrane being permeable to the at least one carrier gas and being non-permeable to the at least one perfluorocompound gas;

(f) contacting the feed side of the second membrane with the first non-permeate stream;

(g) withdrawing from the feed side of the second membrane a second non-permeate stream enriched in the at least one perfluorocompound gas;

(h) withdrawing from the permeate side of the second membrane a second permeate stream comprising primarily the at least one carrier gas;

(i) passing the second non-permeate stream to a condensation process to liquefy at least a portion of the perfluorocompound gas; and

(j) recycling at least a portion of the second permeate stream to the feed side of the first membrane.

2. A process for the separation and recovery of perfluorocompound gases from a gas mixture comprising at least one perfluorocompound gas and at least one carrier gas, said process comprising the steps of:

(a) providing a first membrane having a feed side and a permeate side, the first membrane being permeable to the at least one carrier gas and being non-permeable to the at least one perfluorocompound gas;

(b) contacting the feed side of the first membrane with the gas mixture;

(c) withdrawing from the feed side of the first membrane a first non-permeate stream enriched in the at least one perfluorocompound gas;

(d) withdrawing from the permeate side of the first membrane a first permeate stream comprising primarily the at least one carrier gas;

(e) providing a second membrane having a feed side and a permeate side, the second membrane being permeable to the at least one carrier gas and being non-permeable to the at least one perfluorocompound gas;

(f) contacting the feed side of the second membrane with the first non-permeate stream;

(g) withdrawing from the feed side of the second membrane a second non-permeate stream enriched in the at least one perfluorocompound gas;

(h) withdrawing from the permeate side of the second membrane a second permeate stream comprising primarily the at least one carrier gas; and

(i) passing the second non-permeate stream to a condensation process to liquefy at least a portion of the perfluorocompound gas.