CO2 concentration measurement in dry gas mixtures

Patent metadata

Field	Value
Publication number	US-9804117-B2
Application number	US-201313966093-A
Country	US
Kind code	B2
Filing date	Aug 13, 2013
Priority date	Aug 13, 2013
Publication date	Oct 31, 2017
Grant date	Oct 31, 2017

Abstract

Described herein is an apparatus and methods for characterizing a fluid composition including exposing electrolyte to one fluid mixture, collecting a signal from an electrode in contact with the electrolyte, and simultaneously exposing the electrolyte to a second fluid, collecting a signal from a second electrode in contact with the electrolyte exposed to the second fluid, and comparing the signal difference between the electrodes with the Nerst equation wherein the temperature of the electrolyte is above 488° C. Carbon dioxide, nitrogen, and/or oxygen may be present in the fluid and/or the second fluid.

First claim

We claim:

1. An apparatus for observing a gas composition, the apparatus comprising:
a housing comprising alumina configured to contain molten electrolyte, wherein (i) the housing is configured to direct a first fluid through a first flow pathway such that the first fluid contacts the molten electrolyte and (ii) the housing is configured to direct a second fluid through a second flow pathway such that the second fluid contacts the molten electrolyte;
a first electrode in contact with the molten electrolyte; and
a second electrode in contact with the molten electrolyte; and
a pressure balanced sampling system configured to pressure balance the first flow pathway and the second flow pathway.

2. The apparatus of claim 1 , wherein the housing comprises a wall to divide the first flow pathway and the second flow pathway.

3. The apparatus of claim 1 , further comprising a nontransitory computing device to measure an electrical signal output from the first electrode and the second electrode.

4. The apparatus of claim 1 , wherein the housing comprises a first port for the first fluid and a second port for the second fluid, wherein the first port is connected to a first source of the first fluid and the second port is connected to a second source of the second fluid.

5. The apparatus of claim 4 , wherein a first flowmeter controls flow of the first fluid to the first port inlet.

6. The apparatus of claim 4 , wherein a second flowmeter controls flow of the second fluid to the second port.

7. The apparatus of claim 1 , further comprising a heater.

8. The apparatus of claim 7 , wherein the heater heats the housing to a temperature above 480° C.

9. The apparatus of claim 1 , wherein the molten electrolyte is selected from the group consisting of lithium carbonate, potassium carbonate, and a combination thereof.

10. The apparatus of claim 1 , wherein a portion of the housing containing the molten electrolyte permits molar flux across the molten electrolyte and the portion of the housing.

11. The apparatus of claim 1 , wherein a housing volume is suitably dimensioned for use with at least one of a lab bench, wellbore, carbon dioxide pipeline, and flue gas.

12. The apparatus of claim 1 , wherein the first fluid comprises a sample gas with carbon dioxide of unknown concentration, and the second fluid comprises a reference gas with carbon dioxide of known concentration.

13. The apparatus of claim 12 , further comprising:
a nontransitory computing device configured to determine a concentration of carbon dioxide in the sample gas based on an electrical potential signal output from the first electrode and the second electrode.

14. The apparatus of claim 1 , wherein the pressure balanced sampling system comprises a piston configured to pressure balance the first flow pathway and the second flow pathway.

15. The apparatus of claim 1 , wherein the pressure balanced sampling system comprises a bellows configured to pressure balance the first flow pathway and the second flow pathway.

16. The apparatus of claim 1 , wherein the pressure of the first fluid and the pressure of the second fluid are within 0.5 psi of each other.

17. The apparatus of claim 1 , wherein the housing defines a first section and a second section and the molten electrolyte is disposed within the first section and the second section.

18. The apparatus of claim 17 , wherein the first flow path flows along the first section such that the first fluid contacts the molten electrolyte in the first section and the the second flow path flows along the second section such that the second fluid contacts the molten elctrolyte in the second section.

19. The apparatus of claim 18 , further comprising:
a wall that separates the first flow pathway and the first section from the second flow pathway and the second section.

20. The apparatus of claim 19 , wherein the wall comprises a trapezoidal cross-section.

21. The apparatus of claim 19 , wherein the wall is configured to maintain electrolyte continuity between the first section and the second section.

22. An apparatus for observing a gas composition, the apparatus comprising:
a housing configured to contain molten electrolyte having a first surface and a second surface;
a first port in the housing for directing a first fluid such that the first fluid contacts the first surface of the molten electrolyte;
a second port in the housing for directing a second fluid such that the second fluid contacts the second surface of the molten electrolyte;
a first electrode in the housing in contact with the first surface of the molten electrolyte; and
a second electrode in the housing in contact with the second surface of the molten electrolyte; and
means for pressure balancing the first fluid and the second fluid.

23. The apparatus of claim 22 , wherein the pressure of the first fluid and the pressure of the second fluid are within 0.5 psi of each other.

24. The apparatus of claim 22 , wherein the housing defines a first section and a second section and the molten electrolyte is disposed within the first section and the second section.

25. The apparatus of claim 24 , wherein the first fluid contacts the first surface of molten electrolyte in the first section and the second fluid contacts the second surface of the molten elctrolyte in the second section.

26. The apparatus of claim 22 , wherein the housing comprises alumina.

27. The apparatus of claim 22 , wherein the first fluid comprises a sample gas with carbon dioxide of unknown concentration, and the second fluid comprises a reference gas with carbon dioxide of known concentration.

28. The apparatus of claim 27 , further comprising:
a nontransitory computing device configured to determine a concentration of carbon dioxide in the sample gas based on an electrical potential signal output from the first electrode and the second electrode.

Assignees

• Schlumberger Technology Corp

Inventors

• Perez Albert
• Ramakrishnan Terizhandur S
• Zhang Wenlin
• Jiang Li
• Koveleski Roy
• Elias Quincy K

Classifications

• G01N27/4074

  for detection of gases other than oxygen · CPC title

• G01N27/403 Primary

  Cells and electrode assemblies · CPC title