Method and apparatus for analyzing gases containing volatile organic compounds by use of tetraglyme

• US 5,650,560 A
• Filed: 05/17/1995
• Issued: 07/22/1997
• Est. Priority Date: 05/17/1995
• Status: Expired due to Fees

• Current Assignee: Southern Petroleum Laboratories, Inc. (SPL Holdings LLC (Delaware))
• Original Assignee: Southern Petroleum Laboratories, Inc. (SPL Holdings LLC (Delaware))
• Inventors: Troost, John R.
• Primary Examiner(s): Williams, Hezron E.
• Assistant Examiner(s): LARKIN, DANIEL SEAN
• Application Number:
  US08/443,366
• Time in Patent Office: 797 Days
• Field of Search: 73/23.41, 73/23.38, 73/31.01, 73/31.02, 73/31.03, 73/31.07, 55/356, 95/226, 261/121.1, 422/88, 422/89, 436/178
• US Class Current: 73/23.41
• CPC Class Codes: G01N 1/2294 Sampling soil gases or the like
• CPC Class Codes: G01N 2001/2217 using a liquid
• CPC Class Codes: G01N 30/06 Preparation
• CPC Class Codes: G01N 30/7206 interfaced to gas chromatograph interfaces in general for introducing or extracting samples to be analysed with specially adapted mass spectrometer, see H01J49/04
• CPC Class Codes: G01N 33/0011 Sample conditioning preparing specimens for investigation G01N1/28
• CPC Class Codes: G01N 33/0047 Organic compounds
• CPC Class Codes: G01N 33/24 Earth materials G01N33/42 takes precedence
• CPC Class Codes: Y10T 436/255 including use of a solid sorbent, semipermeable membrane, or liquid extraction

Abstract

A method and apparatus for sampling and analyzing gas. In particular landfill gas, which consists primarily of methane and contains volatile organic components, is passed through a quantity of liquid tetraglyme to cause the volatile organic components to be absorbed in the tetraglyme. The tetraglyme containing the absorbed volatile organic components, is then disposed in a sealed container and transported to a laboratory testing facility. At the testing facility, at least a portion of the tetraglyme is withdrawn from the container, dispersed in water, and subjected to a gas chromatography/mass spectrometry procedure to analyze the volatile organic components.

Claims

1. A method of sampling and analyzing a gas containing volatile organic compounds, comprising the steps of passing the gas through a quantity of liquid tetraglyme to cause the volatile organic compounds to be absorbed in the tetraglyme, removing at least a portion of the tetraglyme from the container and mixing said tetraglyme with water to form a dispersion, and thereafter subjecting the dispersion to gas analysis to identify the volatile organic compounds.

2. The method of claim 1, and including the step of maintaining the tetraglyme at a temperature below 0°

C. when the gas is passed through said tetraglyme.

3. The method of claim 1, and including the step of passing a preselected volume of gas through said tetraglyme.

4. The method of claim 1, and including the step of disposing the tetraglyme in an impinger, said step of passing the gas through the tetraglyme comprises percolating the gas through the tetraglyme in said impinger.

5. The method of claim 1, and including the step of disposing the tetraglyme in a plurality of individual impingers, said step of passing the gas through the tetraglyme comprising percolating the gas through each impinger.

6. A method of sampling and analyzing landfill gas, comprising conducting gas comprising methane and containing volatile organic compounds from a landfill site, passing a preselected volume of said gas through a quantity of liquid tetraglyme in a container to thereby absorb said volatile organic compounds in said tetraglyme, withdrawing at least a portion of the tetraglyme from the container and mixing the tetraglyme with water to form a mixture, and subjecting the mixture to a gas chromatography/mass spectrometry analysis to analyze the composition of said volatile organic compounds.

7. The method of claim 6, and including the step of maintaining the temperature of said tetraglyme at a value in the range of 0°

C. to -30°

C.

8. The method of claim 6, and including the step of removing water vapor from said gas prior to passing the gas through said tetraglyme.

9. The method of claim 6, wherein said gas is passed through said quantity of tetraglyme at a flow rate of about 50 to 500 ml/minute.

10. A method of sampling and analyzing landfill gas, comprising conducting landfill gas composed of methane and volatile organic compounds from a landfill site, removing water vapor from said gas, passing a preselected volume of said gas through a quantity of liquid tetraglyme contained within an impinger and flowing the gas upwardly through said quantity of tetraglyme to thereby cause the volatile organic compounds to be absorbed in said tetraglyme, transferring the tetraglyme with the absorbed volatile organic compounds to a container, icing down the container, transferring the container to an analysis site, withdrawing at least a portion of the tetraglyme from the container at the analysis site, and subjecting the withdrawn tetraglyme to a gas chromatography/mass spectrometry procedure to analyze the composition of said volatile organic compounds.

11. An apparatus for extracting volatile organic impurities from a gas sample;

said apparatus comprising;

a plurality of impingers, said impingers containing an amount of tetraglyme;

means for introducing said gas sample into each impinger;

means for placing said gas in contact with the tetraglyme;

means for controlling the temperature of said tetraglyme; and

means for recovering the gas sample from the impingers, subsequent to contact with the tetraglyme.

12. The apparatus of claim 11, wherein said temperature controlling means is an insulated container containing a substance at a temperature of less than 0°

C.

13. The apparatus of claim 11, wherein said apparatus is portable.

14. The apparatus of claim 11, further comprising a means for controlling the flow rate of said gas into said impingers.