Fluid clathrate system for continuous removal of heavy noble gases from mixtures of lighter gases

• US 5,743,944 A
• Filed: 10/11/1995
• Issued: 04/28/1998
• Est. Priority Date: 02/04/1994
• Status: Expired due to Term

• Current Assignee: University of Chicago
• Original Assignee: University of Chicago
• Inventors: Zawadzki, Mary T., Markun, Francis, Gross, Kenneth C.
• Primary Examiner(s): Bushey, C. Scott
• Application Number:
  US08/540,715
• Time in Patent Office: 930 Days
• Field of Search: 55/220, 55/227, 55/228, 55/256, 55/257.1, 55/257.7, 55/270, 95/149, 95/156, 95/178, 95/179, 95/180, 95/185, 95/186, 95/187, 95/226, 95/230, 95/260, 96/181, 96/218
• US Class Current: 96/181
• CPC Class Codes: B01D 2257/11 Noble gases
• CPC Class Codes: B01D 53/14 by absorption
• CPC Class Codes: B01D 53/1493 Selection of liquid materials for use as absorbents
• CPC Class Codes: B01D 53/18 Absorbing units; Liquid distributors therefor B01D3/16, B01D3/26, B01D3/30 take precedence; packing elements B01J19/30, B01J19/32
• CPC Class Codes: C01B 2210/0031 Helium
• CPC Class Codes: C01B 2210/0035 Krypton
• CPC Class Codes: C01B 2210/0037 Xenon
• CPC Class Codes: C01B 2210/0039 Radon
• CPC Class Codes: C01B 2210/004 Separation of a mixture of noble gases
• CPC Class Codes: C01B 23/00 Noble gases; Compounds thereof liquefying F25J ; noble gases obtained by rectification F25J3/028
• CPC Class Codes: C01B 23/0089 by absorption in liquids

Abstract

An apparatus and method for separation of heavy noble gas in a gas volume. An apparatus and method have been devised which includes a reservoir containing an oil exhibiting a clathrate effect for heavy noble gases with a reservoir input port and the reservoir is designed to enable the input gas volume to bubble through the oil with the heavy noble gas being absorbed by the oil exhibiting a clathrate effect. The gas having reduced amounts of heavy noble gas is output from the oil reservoir, and the oil having absorbed heavy noble gas can be treated by mechanical agitation and/or heating to desorb the heavy noble gas for analysis and/or containment and allow recycling of the oil to the reservoir.

Claims

1. A system for separation of a heavy noble gas entrained in a gas stream obtained from surrounding ambient air in an enclosed volume of air breathable by a person, comprising:

means for containing a fluid and having an input port, said means for containing coupled to a volume of air breathable by a person and said means also constructed for receiving a stream of the volume of air and said containing means enabling the stream of the volume of air to be input into said containing means to contact the fluid in said means for containing and be output therefrom;

said fluid in said containing means consisting essentially of an oil and the oil disposed within said containing means with said oil for contacting the stream of the volume of air and also for absorbing a heavy noble gas entrained in the stream of the volume of air; and

means coupled to said containing means for receiving said oil therefrom after said oil has absorbed the heavy noble gas and said means for receiving further for desorbing the heavy noble gas from said oil.

2. The system as defined in claim 1 wherein the oil is selected from the group consisting of corn oil and soybean oil and combinations thereof.

3. The system as defined in claim 1 wherein the oil exhibits a clathrate effect for absorption of a heavy noble gas selected from the group consisting of radon, krypton and xenon and in a temperature range of about 20°

C. to the freezing point of the oil.

4. The system as defined in claim 1 further including means, coupled to said means for receiving the oil, for receiving desorbed heavy noble gas.

5. The apparatus as defined in claim 1 further including means, coupled to said means for receiving oil, for desorbing heavy noble gas from the oil.

6. The apparatus as defined in claim 3 wherein the oil exhibits a clathrate desorption effect, of the heavy noble gas absorbed by the clathrate effect of the oil, for a temperature range above about 50°

C. to 60°

C.

7. The apparatus as defined in claim 1 wherein said containing means includes at least one of a diffuser for said gas stream for forming a fine bubble distribution of gas and a packed column scrubber.

8. The apparatus as defined in claim 1 wherein said means for receiving the oil and desorbing the heavy noble gas comprises means for mechanically agitating the oil.

9. The apparatus as defined in claim 1 wherein said means for receiving the oil and desorbing the heavy noble gas comprises means for applying heat to the oil.

10. The apparatus as defined in claim 9 further including means for cooling the oil for return to said containing means.

11. The apparatus as defined in claim 4 wherein said means for receiving the desorbed heavy noble gas comprises a heavy-noble-gas trap.

12. A system for absorption of a heavy noble gas entrained in a gas stream taken from a volume of breathable air in an enclosed space, comprising:

a reservoir coupled to a volume of breathable air in an enclosed space for containing a fluid consisting essentially of a liquid oil, the liquid oil absorbing a heavy noble gas from a first gas stream taken from the volume of breathable air, said reservoir holding the liquid oil and having an input port for receiving the first gas stream from the volume of breathable air and enabling the first gas stream to bubble through the liquid oil in said reservoir; and

said reservoir further including an output port through which is passed a second gas stream decontaminated of the heavy noble gas, thereby removing a portion of the heavy noble gas from the first gas stream.

13. The system as defined in claim 12 further including means for desorbing the heavy noble gas absorbed by the oil.

14. The system as defined in claim 13 further including means for trapping the heavy noble gas desorbed from the oil.

15. The system as defined in claim 13 wherein the oil exhibits a clathrate effect for absorption of a heavy noble gas selected from the group consisting of radon, krypton and xenon.

16. The system as defined in claim 15 wherein the oil exhibits a selective clathrate desorption of the heavy noble gas above about 60°

C.

17. A system for absorption of a heavy noble gas entrained in a gas stream taken from a volume of breathable air present in an enclosed space which can be occupied by a person, comprising:

a reservoir having an input port coupled to a volume of breathable air in an enclosed space which can be occupied by a person with said reservoir containing a liquid oil, the liquid oil in said reservoir absorbing a heavy noble gas in a gas stream taken from the volume of breathable air with the gas stream passed into said input port and through the liquid oil in said reservoir; and

said reservoir further including an output port through which is passed a decontaminated gas stream, thereby removing a portion of the heavy noble gas present in the gas stream taken from the volume of breathable air.

18. The system as defined in claim 17 further including means coupled to said reservoir for desorbing the heavy noble gas from the liquid oil.

19. The system as defined in claim 17 wherein the liquid oil exhibits a clathrate effect for absorption of the heavy noble gas.

20. The system as defined in claim 17 wherein the enclosed space is selected from the group consisting of a home, a mine, a school building and a government site.