DEVICES AND TECHNIQUES RELATING TO LANDFILL GAS EXTRACTION

• US 20170216892A1
• Filed: 03/13/2017
• Published: 08/03/2017
• Est. Priority Date: 11/04/2013
• Status: Active Grant

• Current Assignee: Loci Controls, Inc.
• Original Assignee: Loci Controls, Inc.
• Inventors: Campanella, Andrew, Sims, Melinda, Pallo, Nathan, Martin, Ian
• Granted Patent: US 10,639,687 B2
• Time in Patent Office: Days
• CPC Class Codes: B09B 1/00 Dumping solid waste
• CPC Class Codes: B09B 1/006 Shafts or wells in waste dumps
• CPC Class Codes: E21B 43/12 Methods or apparatus for controlling the flow of the obtained fluid to or in wells E21B43/25 takes precedence; valve arrangements E21B34/00
• CPC Class Codes: G01N 33/0004 Gaseous mixtures, e.g. polluted air gaseous biological material G01N33/497; exhaust gas of internal combustion engines G01M15/102
• CPC Class Codes: G01N 33/0047 for organic compounds
• CPC Class Codes: G01N 33/0063 using a threshold to release an alarm or displaying means alarm arrangements G08B, e.g. fire alarm actuated by the presence of smoke or gases G08B17/10, for other abnormal conditions G08B21/00

Abstract

Devices and techniques related to landfill gas extraction are disclosed. A technique for controlling extraction of landfill gas from a landfill through a gas extraction system is described. The method may include measuring a plurality of values indicating conditions associated with the landfill; computing, based at least in part on the plurality of values and on a model of the landfill, a predicted future state of the landfill; determining, based at least in part on the predicted future state of the landfill, one or more control parameters for one or more respective control devices configured to control operation of the gas extraction system; applying the one or more control parameters to the one or more respective control, and with the one or more control devices, controlling extraction of the landfill gas from the landfill based, at least in part, on the one or more respective control parameters.

Claims

1. A control system for controlling extraction of landfill gas from a landfill via a gas extraction system, the gas extraction system comprising at least one vacuum source, well piping, and at least one well coupled to the at least one vacuum source through the well piping, the control system comprising:

at least one sensor configured to measure one or more characteristics of landfill gas extracted from the landfill;

at least one flow control mechanism disposed in the well piping and configured to control flow rates of the landfill gas extracted from the landfill; and

at least one processor configured to;

obtain at least one measurement, obtained using the at least one sensor, of concentration of a first gas in landfill gas extracted from the landfill;

determine whether the measured concentration of the first gas is different from a target concentration of the first gas; and

when it is determined that the measured concentration of the first gas is different from the target concentration of the first gas, automatically controlling the at least one flow control mechanism to change concentration of the first gas in landfill gas being extracted from the landfill.

2. The control system of claim 1, wherein the at least one sensor comprises:

a sensor to detect partial pressure or concentration of methane, a sensor to detect partial pressure or concentration of oxygen, a sensor to detect partial pressure or concentration of carbon monoxide,

a sensor to detect partial pressure or concentration of carbon dioxide, a sensor to detect partial pressure or concentration of hydrogen sulfide, and/or a sensor to detect partial pressure or concentration of nitrogen.

3. The control system of claim 1, wherein the first gas is one of methane, oxygen, carbon dioxide, carbon monoxide, hydrogen sulfide, and nitrogen.

4. The control system of claim 1,

wherein the measuring comprises using the at least one sensor to measure the concentration of methane in landfill gas extracted from the landfill;

wherein the determining comprises determining whether the measured concentration of methane is different from a target concentration of methane; and

when it is determined that the measured concentration of methane is different from the target concentration of methane, automatically controlling the at least one flow control mechanism to change concentration of methane in landfill gas being extracted from the landfill.

5. The control system of claim 1, wherein determining whether the measured concentration of the first gas is different from the target concentration of the first gas comprises determining whether the measured concentration of the first gas is less than a first threshold concentration of the first gas.

6. The control system of claim 5, wherein, when it is determined that the concentration of the first gas is less than the first threshold concentration, automatically controlling the at least one flow control mechanism comprises controlling the at least one flow control mechanism to increase concentration of the first gas in landfill gas being extracted from the landfill.

7. The control system of claim 5, wherein determining whether the measured concentration of the first gas is different from the target concentration of the first gas comprises determining whether the measured concentration of the first gas is greater than a second threshold concentration of the first gas.

8. The control system of claim 7, wherein, when it is determined that the measured concentration of the first gas is greater than the second threshold concentration, automatically controlling the at least one flow control mechanism comprises controlling the at least one flow control mechanism to increase the concentration of the first gas in landfill gas being extracted from the landfill.

9. The control system of claim 8, wherein the first gas is methane, and wherein determining whether the measured concentration of the first gas is greater than the second threshold concentration comprises determining whether the measured concentration of methane is greater than 55 percent of methane by volume.

10. The control system of claim 1, wherein the at least one flow control mechanism comprises at least one valve, and wherein automatically controlling the at least one flow control mechanism comprises changing at least one valve position of the at least one valve.

11. The control system of claim 1, wherein the at least one processor is located remotely from the at least one flow control mechanism and is configured to wirelessly communicate with the at least one flow control mechanism.

12. The control system of claim 1, wherein the at least one sensor is coupled to the at least one flow control mechanism.

13. A method for controlling extraction of landfill gas from a landfill through a gas extraction system, the gas extraction system comprising at least one flow control mechanism, the method comprising:

measuring, using at least one sensor, a concentration of a first gas in landfill gas extracted from the landfill;

determining whether the measured concentration of the first gas is different from a target concentration of the first gas; and

when it is determined that the measured concentration of the first gas is different from the target concentration of the first gas, automatically controlling the at least one flow control mechanism to change concentration of first gas in landfill gas being extracted from the landfill.

14. The method of claim 13, wherein the first gas is one of methane, oxygen, carbon dioxide, carbon monoxide, hydrogen sulfide, and nitrogen.

15. The method of claim 13,

wherein the measuring comprises using the at least one sensor to measure the concentration of methane in landfill gas extracted from the landfill;

wherein the determining comprises determining whether the measured concentration of methane is different from a target concentration of methane; and

when it is determined that the measured concentration of methane is different from the target concentration of methane, automatically controlling the at least one flow control mechanism to change concentration of methane in landfill gas being extracted from the landfill.

16. The method of claim 13, wherein determining whether the measured concentration of the first gas is different from the target concentration of the first gas comprises determining whether the measured concentration of the first gas is less than a first threshold concentration of the first gas.

17. The method of claim 16, wherein the first gas is methane, and wherein determining whether the measured concentration of the first gas is less than the first threshold concentration comprises determining whether the measured concentration of methane is less than 45 percent of methane by volume.

18. The method of claim 16, wherein, when it is determined that the concentration of the first gas is less than the first threshold concentration, automatically controlling the at least one flow control mechanism comprises controlling the at least one flow control mechanism to increase concentration of the first gas in landfill gas being extracted from the landfill.

19. The method of claim 13, wherein determining whether the measured concentration of the first gas is different from the target concentration of the first gas comprises determining whether the measured concentration of the first gas is greater than a second threshold concentration of the first gas.

20. The method of claim 19, wherein the first gas is methane, and wherein determining whether the measured concentration of the first gas is greater than the second threshold concentration comprises determining whether the measured concentration of methane is greater than 55 percent of methane by volume.

21. The method of claim 19, wherein, when it is determined that the measured concentration of the first gas is greater than the second threshold concentration, automatically controlling the at least one flow control mechanism comprises controlling the at least one flow control mechanism to increase the concentration of the first gas in landfill gas being extracted from the landfill.

22. The method of claim 13, wherein the at least one flow control mechanism comprises at least one valve, and wherein automatically controlling the at least one flow control mechanism comprises changing at least one valve position of the at least one valve.