Granted Patent B2

US 12,281,267 · App. 18/463,479 · Granted Apr 22, 2025

Inventor: Darren Schmidt (Williston, ND)

Assignee: Energy & Environmental Research Center Foundation

C10G5/06C10G2300/4012C10G2400/28

Abstract

Claims (39)

1. An apparatus for recovering gaseous hydrocarbons from tank headspace as a fuel on-site, the apparatus comprising:

a compressor that accepts a hydrocarbon gas composition from headspace of a tank fed by a separator, wherein the separator accepts a crude hydrocarbon input stream and outputs a crude liquid hydrocarbon stream to the tank;

a cooling unit that accepts a compressed mixture from the compressor and that forms a cooled composition comprising liquid hydrocarbons;

a flowline from the cooling unit for flowing the cooled composition to a buffer tank to form a buffered fuel composition; and

an outlet from headspace of the buffer tank that outputs a fuel gas composition for use as an on-site fuel.

2. The apparatus of claim 1 , wherein the compressor comprises an oilless compressor, wherein the oilless compressor comprises a crankcase that is free of oil that contacts material being compressed and is free of oil lubrication that requires regular changings.

3. The apparatus of claim 1 , wherein the separator comprises a primary separator or a secondary separator.

4. The apparatus of claim 1 , further comprising a primary recovery separator that accepts the hydrocarbon gas composition from headspace of the tank fed by the secondary-separator and that flows the hydrocarbon gas composition from the primary recovery separator to the compressor.

5. The apparatus of claim 1 , further comprising a secondary recovery separator that accepts the cooled composition comprising the liquid hydrocarbons and that outputs a liquid hydrocarbon stream from the secondary recovery separator to the buffer tank.

6. The apparatus of claim 1 , wherein the outlet from the headspace of the buffer tank outputs the fuel gas composition to one or more on-site combustors that combust the fuel gas composition.

7. The apparatus of claim 1 , wherein the outlet from the headspace of the buffer tank outputs the fuel gas composition to heat the separator, as a flare pilot, as gas assist, in an auxiliary internal combustion device for heat or power, or a combination thereof.

8. The apparatus of claim 1 , wherein the apparatus comprises a processor configured to:

cause water to be at least partially drained from the buffer tank as a response to determining a level transmitter in a lower portion of the buffer tank is immersed in water;

cause a variable frequency drive on the compressor to run at a lower speed or to shut off as a response to determining a level transmitter in an upper portion of the buffer tank is immersed;

cause the variable frequency drive on the compressor to run at a lower speed or to shut off as a response to determining that a pressure transducer or pressure transmitter in an upper portion of the tank fed by the secondary separator is detecting a pressure above a predetermined pressure threshold;

cause the variable frequency drive on the compressor to maintain speed or to run at a higher speed as a response to determining that the pressure transducer or pressure transmitter in the upper portion of the tank fed by the secondary separator is detecting a pressure below a predetermined pressure threshold;

cause the variable frequency drive on the compressor to slow or stop as a response to determining that a temperature transducer or temperature transmitter measuring temperature of the compressed mixture exiting the compressor is detecting a temperature above a compressed mixture temperature setpoint; or

a combination thereof.

9. The apparatus of claim 1 , wherein the separator is a secondary separator, wherein the separator accepts the crude liquid hydrocarbon input stream from another separator.

10. The apparatus of claim 9 , wherein the secondary separator comprises a heater-treater.

11. The apparatus of claim 9 , wherein the secondary separator accepts the crude hydrocarbon input stream from a primary separator.

12. The apparatus of claim 11 , wherein the primary separator comprises a two-phase separator.

13. The apparatus of claim 11 , wherein the primary separator comprises a crude hydrocarbon input stream and comprises an output stream that comprises the crude liquid hydrocarbon stream that is inputted to the secondary separator.

14. A method of recovering gaseous hydrocarbons from tank headspace as fuel on-site, the method comprising:

flowing a hydrocarbon gas composition from headspace of a tank fed by a separator comprising a secondary separator into a compressor to form a compressed mixture, wherein the separator accepts a crude hydrocarbon input stream and outputs a crude liquid hydrocarbon stream to the tank;

flowing the compressed mixture into a cooling unit to cool the compressed mixture, to form a cooled composition comprising liquid hydrocarbons;

flowing the cooled composition to a buffer tank to form a buffered fuel composition;

removing a fuel gas composition from headspace of the buffer tank; and

combusting the fuel gas composition as an on-site fuel.

15. The method of claim 14 , wherein the separator accepts the crude hydrocarbon input stream from another separator.

16. The method of claim 14 , wherein the secondary separator comprises a heater-treater.

17. The method of claim 14 , wherein the secondary separator accepts the crude hydrocarbon input stream from a primary separator.

18. The method of claim 17 , wherein the primary separator comprises a two-phase separator.

19. A method of recovering gaseous hydrocarbons from tank headspace as fuel on-site, the method comprising:

flowing a hydrocarbon gas composition from headspace of a tank fed by a heater-treater into a compressor to form a compressed mixture, wherein the heater-treater accepts a crude liquid hydrocarbon input stream from a two-phase separator, wherein the two-phase separator comprises a crude hydrocarbon input stream and comprises an output stream comprising the crude liquid hydrocarbon stream that is inputted to the heater-treater;

flowing the compressed mixture into a cooling unit to cool the compressed mixture, to form a cooled composition comprising liquid hydrocarbons;

flowing the cooled composition to a buffer tank to form a buffered fuel composition;

removing a fuel gas composition from headspace of the buffer tank; and

combusting the fuel gas composition as an on-site fuel.

Assignments (1)

Continuity (4)

References Cited (23)