DESIGNS FOR ENHANCED RELIABILITY AND CALIBRATION OF LANDFILL GAS MEASUREMENT AND CONTROL DEVICES

• US 20170254787A1
• Filed: 03/20/2017
• Published: 09/07/2017
• Est. Priority Date: 03/01/2016
• Status: Active Grant

• Current Assignee: Loci Controls, Inc.
• Original Assignee: Peter Quigley
• Inventors: Campanella, Andrew, Martin, Ian, Michels, Joseph G., Pallo, Nathan, Quigley, Peter
• Granted Patent: US 10,705,063 B2
• Time in Patent Office: Days
• CPC Class Codes: B09B 1/006 Shafts or wells in waste dumps
• CPC Class Codes: B09B 3/80 involving an extraction step
• CPC Class Codes: E21B 36/00 Heating, cooling or insulating arrangements for boreholes or wells, e.g. for use in permafrost zones
• CPC Class Codes: E21B 36/003 Insulating arrangements
• CPC Class Codes: E21B 47/06 Measuring temperature or pressure
• CPC Class Codes: E21B 47/07 Temperature
• CPC Class Codes: E21B 49/08 Obtaining fluid samples or testing fluids, in boreholes or wells
• CPC Class Codes: E21B 49/0875 determining specific fluid parameters
• CPC Class Codes: G01N 1/2294 Sampling soil gases or the like
• CPC Class Codes: G01N 33/0006 Calibrating gas analysers
• CPC Class Codes: G01N 33/0036 specially adapted to detect a particular component physical analysis of gaseous biological material G01N33/497
• CPC Class Codes: G01N 33/004 CO or CO2
• CPC Class Codes: Y02C 20/20 of methane
• CPC Class Codes: Y02W 30/20 Waste processing or separation

Abstract

An apparatus for sampling landfill gas from a landfill flowing through a pipe. The apparatus may comprise: an enclosure configured to receive a section of the pipe; a gas sampling port in the section of the pipe; at least one sensor device disposed in a region of the enclosure, the at least one sensor being coupled to the section of the pipe through the gas sampling port; and thermal insulation positioned to retain heat from the section of the pipe in the region of the enclosure. A method of operating a landfill gas recovery system. The method may comprise: flowing gas from a well riser pipe through a sampling subsystem to a collection system; and heating a portion of the sampling subsystem with the gas flowing from the well riser pipe to the collection system.

Claims

1. A sensor calibration method performed by an apparatus for sampling landfill gas flowing through a pipe, the apparatus comprising a region configured to receive a section of the pipe having a gas sampling port, at least one sensor, and at least one calibration port, the method comprising:

isolating the at least one sensor from the gas sampling port;

while the at least one sensor is isolated from the gas sampling port,

obtaining at least one sample of a gas having a known composition through the at least one calibration port;

measuring, using the at least one sensor, at least one concentration of at least one constituent gas in the at least one sample of the gas having the known composition; and

automatically calibrating the at least one sensor based on a comparison between the at least one measured concentration of the at least one constituent gas and an expected concentration of the at least one constituent gas in the at least one sample gas having the known composition.

2. The sensor calibration method of claim 1, wherein the apparatus further comprises at least one valve connected between the at least one calibration port and the region configured to receive the section of the pipe having the gas sampling port, and wherein isolating the at least one sensor from the gas sampling port comprises actuating the at least one valve.

3. The sensor calibration method of claim 2, wherein actuating the at least one valve is performed in response to a command.

4. The sensor calibration method of claim 2, wherein actuating the at least one valve is performed in response to detection of a fitting being connected to the at least one calibration port.

5. The sensor calibration method of claim 1, wherein obtaining the at least one sample comprises obtaining a sample of ambient air outside the apparatus.

6. The sensor calibration method of claim 1, wherein obtaining the at least one sample comprises obtaining a gas sample from a gas canister coupled to the at least one calibration port.

7. The sensor calibration method of claim 1, wherein obtaining the at least one sample comprises obtaining a gas sample of a mixture of at least two gasses of known composition.

8. The sensor calibration method of claim 1, wherein obtaining the at least one sample comprises obtaining a gas sample including at least CO₂ and CH₄.

9. The sensor calibration method of claim 7, wherein obtaining the gas sample including at least CO₂ and CH₄ comprises obtaining a gas sample comprising 35% CO₂, 50% CH₄, and 15% N₂.

10. The sensor calibration method of claim 1, wherein obtaining the at least one sample comprises obtaining a first gas sample of ambient air outside the apparatus and a second gas sample including at least CO₂ and CH₄.

11. The sensor calibration method of claim 1, wherein obtaining the at least one sample comprises obtaining a first gas sample of a first mixture of gasses of known composition and obtaining a second gas sample of a second mixture of gasses of known composition, the second mixture of gasses having a composition of gasses than that of the first mixture.

12. The sensor calibration method of claim 1, wherein the at least one sensor includes a gas composition sensor configured to sense oxygen, methane, and/or carbon dioxide.

13. The sensor calibration method of claim 1, wherein measuring the at least one concentration of the at least one constituent gas comprises measuring at least one of oxygen concentration in the at least one sample of the gas, methane concentration in the at least one sample of the gas, and carbon dioxide concentration in the at least one sample of the gas.

14. The sensor calibration method of claim 1, wherein automatically calibrating the at least one sensor comprises determining at least one parameter for processing measurements obtained by the at least one sensor.

15. The sensor calibration method of claim 14, wherein determining the at least one parameter for processing measurements obtained by the at least one sensor comprises:

determining at least one parameter for linearly compensating measurements obtained by the at least one sensor.

16. The sensor calibration method of claim 15, wherein determining the at least one parameter for linearly compensation measurements obtained by the at least one sensor comprises determining at least one of a gain and an offset to apply to measurements obtained by the at least one sensor.

17. The sensor calibration method of claim 14, wherein determining the at least one parameter for processing measurements obtained by the at least one sensor comprises:

determining at least one parameter for non-linearly compensating measurements obtained by the at least one sensor.

18. The sensor calibration method of claim 1,

wherein the at least one sensor comprises an oxygen sensor;

wherein obtaining the at least one sample comprises obtaining a sample of ambient air outside the apparatus;

wherein the measuring comprises using the oxygen sensor to measure concentration of oxygen in the sample of ambient air; and

wherein the automatically calibrating comprises automatically calibrating the oxygen sensor by;

comparing the measured concentration of oxygen in the sample of ambient air to an expected concentration of oxygen in ambient air; and

determining at least one parameter for processing measurements obtained by the oxygen sensor.

19. The sensor calibration method of claim 18, wherein the automatically calibrating further comprises calibrating a methane sensor and/or a carbon dioxide sensor based on the determined at least one parameter for processing measurements obtained by the oxygen sensor.

20. An apparatus for sampling landfill gas flowing through a pipe, the apparatus comprising:

an enclosure configured to receive a section of the pipe, the section of the pipe having a gas sampling port;

at least one sensor disposed in a region of the enclosure, the at least one sensor being coupled to the section of the pipe through the at least one gas sampling port;

a calibration port configured for connection to at least one source of gas of known composition; and

a valve connected between the calibration port and the at least one sensor so as to enable gas to flow from the calibration port to the at least one sensor while isolating the at least one sensor from the gas sampling port.

21. An apparatus for sampling landfill gas flowing through a pipe, the apparatus comprising:

a sampling subsystem comprising;

a gas inlet port and a gas outlet port;

a region configured to receive a section of the pipe, the section of the pipe having a gas sampling port;

at least one sensor coupled to the gas outlet port; and

a gas flow passage from the gas inlet port, over the at least one sensor, and to the gas outlet port, the gas flow passage passing adjacent to and in thermal contact with a thermoelectric condenser;

at least one calibration port configured for connection to at least one source of gas of known composition; and

at least one valve connected between the at least one calibration port and the sampling subsystem so as to enable gas to flow from the at least one calibration port to the at least one sensor while isolating the at least one sensor from the gas sampling port.