METHOD FOR THE SEPARATION OF GASES

• US 20120055385A1
• Filed: 03/26/2010
• Published: 03/08/2012
• Est. Priority Date: 03/26/2009
• Status: Abandoned Application

• Current Assignee: ECO Technol Pty., Ltd.
• Original Assignee: Eco-Geo Bio-Technology Company Limited
• Inventors: Lien, Larry Allen, Picaro, Tony
• Application Number:
  US13/259,643
• Publication Number:
  US 20120055385A1
• Time in Patent Office: Days
• US Class Current: 110/345
• CPC Class Codes: B01D 2257/302 Sulfur oxides
• CPC Class Codes: B01D 2257/404 Nitrogen oxides other than dinitrogen oxide
• CPC Class Codes: B01D 2257/504 Carbon dioxide
• CPC Class Codes: B01D 2257/80 Water
• CPC Class Codes: B01D 53/226 in serial connexion
• CPC Class Codes: Y02C 20/40 of CO2
• CPC Class Codes: Y02E 20/32 Direct CO2 mitigation

Abstract

A method (10) for the separation of gases involving the method steps of: i) passing an exhaust gas stream (27) containing CO₂ through a first membrane separation system (30) to produce a pre-concentrated gas stream (34) containing at least carbon dioxide; and a reject stream; and ii) directing the pre-concentrated gas stream to at least one purification step (50) to produce a purified CO₂ stream (55); wherein, sulphur-containing gases (SO_x) are also substantially separated from the exhaust gas (27) by the first membrane separation step (30) into the pre-concentrated gas stream (34), and the purified CO₂ stream (55) is substantially free of nitrogen gas.

Claims

1-46. -46. (canceled)

47. A method for the separation of gases comprising the method steps of:

(i) passing an exhaust gas stream containing CO₂ through a first membrane separation system to produce a pre-concentrated gas stream containing at least carbon dioxide and a reject stream; and

(ii) directing the pre-concentrated gas stream to at least one purification step to produce a purified CO₂ stream;

wherein sulphur-containing gases (SO_x) are also substantially separated from the exhaust gas stream by the first membrane separation step into the pre-concentrated gas stream, and the purified CO, stream is substantially free of nitrogen gas.

48. A method according to claim 47, wherein the first membrane separation system further:

(i) separates nitrogen containing gases (NO_x) and water vapour into the pre-concentrated gas stream;

(ii) comprises at least one membrane having a flat sheet or spiral wound constniction;

(iii) comprises at least one membrane having a CO₂ permeability within the range of 10 to 40,000 Barrer;

or

(iv) comprises at least one membrane having a CO₂ permeability within the range of 100 to 20,000 Barrer.

49. A method according to claim 48, wherein the at least one membrane is:

(i) formed from any one or a blend of polysulfone, polyacetylene polysiloxane, poly-arylate, polycarbonate, poly(aryl ether), poly(aryl ketone) or polyimide;

(ii) an inorganic membrane in the form of a ceramic, or metal or metal oxide;

or

(iii) formed from polydimethyl siloxane.

50. A method according to claim 48, wherein at least one membrane is in the form of a high temperature membrane suitable for use at temperatures above 120°

C. and optionally is formed from a polymer membrane coated onto a high temperature tolerant substrate.

51. A method according to claim 48, wherein:

(i) 30% to 90% of the NO_x present in the exhaust gas stream is separated into the pre-concentrated gas stream;

or

(ii) 50% to 80% of the NO_x present in the exhaust gas stream is separated into the pre-concentrated gas stream.

52. A method according to claim 48, wherein NO_x comprises one or more of NO, N₂O and NO₂.

53. A method according to claim 47, wherein the purification step comprises at least one membrane.

54. A method according to claim 53, wherein the at least one membrane has:

(i) a selectivity for CO₂ over nitrogen, within the range of 4 to 200;

(ii) a selectivity for CO₂ over nitrogen within the range of 8 to 100;

or

(iii) a hollow fibre construction.

55. A method according to claim 47, wherein the purification step is operated at a temperature of less than 100°

C.

56. A method according to claim 47, wherein the purified CO₂ stream contains:

(i) 70%-99% (v/v) CO₂;

or

(ii) 90%-95% (v/v) CO₂.

57. A method according to claim 47, wherein the first membrane separation system retains:

(i) between 95%-100% of dust and particulate matter contained in the exhaust gas stream;

(ii) 99% of dust and particulate matter contained in the exhaust gas stream;

(iii) at least 50% of the nitrogen (N₂) contained in the exhaust gas stream;

or

(iv) between 60% to 90% of the nitrogen contained in the exhaust gas stream into a reject stream.

58. A method according to claim 47, wherein the temperature of the exhaust gas passing through the first membrane separation system is within the range of:

(i) 50°

C. and 300°

C.;

or

(ii) 120°

C. and 250°

C.

59. A method according to claim 47, wherein the exhaust gas stream:

(i) has a CO₂ concentration in the exhaust gas stream within the range of 1% and 50% (v/v);

(ii) has a CO, concentration within the range of 2% and 20% (v/v);

(iii) has 70% to 95% of the CO, present separated into the pre-concentrated gas stream;

(iv) has at least 90% of the CO, present separated into the pre-concentrated gas stream;

(v) has 70% to 99% of the SOx present separated into the pre-concentrated gas stream;

(vi) has 90% to 95% of the SOx present separated into the pre-concentrated gas stream;

(vii) has 30% to 90% of the water vapour in the exhaust gas is separated into the pre-concentrated gas stream;

(viii) has 40% to 80% of the water vapour present in the exhaust gas is separated into the pre-concentrated gas stream;

or

(ix) is a flue gas.

60. A method according to claim 47, wherein SOx is predominantly comprised of SO₂.

61. A method according to claim 47, wherein the pre-concentrated gas stream:

(i) has a volume within the range of 20% to 40% of the original exhaust gas volume;

or

(ii) is directed to a gas cooling step prior to the purification step.

62. A method according to claim 47, wherein the method further comprises:

(i) combusting a gas in a combustor in the presence of a fuel to produce the exhaust gas stream;

or

(ii) enriching the oxygen content of a combustion gas entering a combustor to form an enriched oxygen stream and combusting the combustion gas in the presence of a fuel to produce the exhaust gas stream.

63. A method according to claim 62, wherein the fuel is a carbon-containing fuel.

64. A method according to claim 62, wherein the oxygen enrichment of step (ii):

(i) is performed using a secondary membrane system;

(ii) raises the concentration of oxygen to within the range of 22% to 50% (v/v);

or

(iii) raises the concentration of oxygen to within the range of 22% to 40% (v/v).