阅读说明：本技术 用于升级生物气的方法和系统 (Method and system for upgrading biogas ) 是由 帕特里克·J·福迪 约翰·德什曼 于 2019-07-09 设计创作，主要内容包括：提供可再生天然气(RNG)的方法,包括从生物气中去除硫化氢和/或二氧化碳以提供可以存储在移动储罐中的部分纯化生物气。将所述部分纯化生物气至少部分通过卡车、铁路或船运输至生物气升级设施。在生物气升级设施处,将所述部分纯化生物气进一步纯化以提供RNG,所述RNG能够被注入分配系统(例如天然气网络)和/或提供给交通运输使用。(A method of providing Renewable Natural Gas (RNG) includes removing hydrogen sulfide and/or carbon dioxide from a biogas to provide a partially purified biogas that can be stored in a mobile storage tank. Transporting the partially purified biogas at least partially by truck, rail or ship to a biogas upgrading facility. At the biogas upgrade facility, the partially purified biogas is further purified to provide RNGs that can be injected into a distribution system (e.g., a natural gas network) and/or provided for transportation use.)

1. A method for upgrading biogas, comprising:

(a) obtaining biogas from a plurality of biogas sources, the biogas comprising a first biogas from a first biogas source and a second other biogas from a second other biogas source;

(b) removing one or more components from the first biogas to produce a first partially purified biogas, the one or more components comprising hydrogen sulfide, carbon dioxide, or a combination thereof, the one or more components being removed using at least one stationary purification system;

(c) transporting a first vessel comprising the first portion of purified biogas to a biogas upgrading facility;

(d) removing one or more components from the second biogas to produce a second partially purified biogas, the one or more components comprising hydrogen sulfide, carbon dioxide, or a combination thereof, the one or more components being removed using at least one stationary purification system;

(e) optionally, transporting a second vessel containing the second portion of purified biogas to the biogas upgrading facility;

(f) removing at least one component from a gas stream comprising the first portion of purified biogas, the second portion of purified biogas, or a combination thereof at the biogas upgrading facility to produce a renewable natural gas having a heating value greater than a heating value of any one of the first portion of purified biogas and the second portion of purified biogas;

(g) providing the renewable natural gas produced in f) for injection into a distribution system, for use as a transportation fuel, or for use as a combination thereof.

2. The method of claim 1, wherein the one or more components removed in step (b) comprise carbon dioxide.

3. The method of claim 2, wherein the at least one component removed in step (f) comprises carbon dioxide.

4. The method of claim 3, wherein the first portion of the purified biogas has a heating value of at least 750BTU/scf and less than 925 BTU/scf.

5. The method of claim 2, wherein step (b) comprises removing at least 50% of the carbon dioxide in the first biogas.

6. The method of claim 2, wherein step (b) comprises removing at least 75% of the carbon dioxide in the first biogas.

7. The method of claim 2, wherein step (b) comprises removing at least 85% of the carbon dioxide in the first biogas.

8. The method of claim 2, wherein the first portion of purified biogas has a carbon dioxide content of less than 8%.

9. The method of claim 8, wherein the first portion of purified biogas has a nitrogen content of at least 5%, and step f) comprises removing nitrogen.

10. The method of claim 1, wherein the one or more components removed in steps (b) and (d) comprise carbon dioxide, water, and hydrogen sulfide.

11. The method of claim 4, wherein the one or more components removed in steps (b) and (d) comprise carbon dioxide, water, and hydrogen sulfide.

12. The method of claim 1, wherein the biogas upgrading facility is connected to the second biogas source via piping, and wherein the second biogas comprises landfill gas.

13. The method of claim 1, wherein the first vehicle is a truck, a rail car, or a boat.

14. The method of claim 1, wherein the first container in a trailer is transported to the biogas upgrading facility by truck.

15. The method of claim 1, wherein the first vessel is charged with the first portion of purified biogas to a pressure of at least 1000 psig.

16. The method of claim 1, wherein step b) comprises membrane separating the first biogas from the first biogas source.

17. The method of claim 1, wherein the first and second vessels are powered by natural gas, renewable natural gas, or a combination thereof.

18. The method of claim 1, wherein the plurality of biogas sources are selected to provide biogas to the biogas upgrading facility at a rate of at least 2,000 SCFM.

19. The method of claim 1, wherein the plurality of biogas sources are selected to provide biogas to the biogas upgrading facility at a rate of at least 5,000 SCFM.

20. A method for upgrading biogas, comprising:

(a) obtaining biogas from a plurality of biogas sources, the biogas comprising a first biogas from a first biogas source and a second other biogas from a second other biogas source;

(b) feeding the first biogas to a first stationary purification system to remove hydrogen sulfide, carbon dioxide, or a combination thereof from the first biogas and produce a first partially purified biogas having a heating value of less than 950 BTU/scf;

(c) transporting a first vessel comprising the first portion of purified biogas to a biogas upgrading facility via a vehicle;

(d) feeding the second biogas to a second other stationary purification system to remove hydrogen sulfide, carbon dioxide, or a combination thereof from the second biogas and produce a second partially purified biogas having a heating value of less than 950 BTU/scf;

(e) optionally, transporting a second vessel containing the second portion of purified biogas to the biogas upgrading facility via a carrier;

(f) feeding the first and second portions of purified biogas to one or more purification systems at the biogas upgrading facility to remove carbon dioxide, nitrogen, oxygen, or any combination thereof and produce a renewable natural gas having a heating value of at least 950 BTU/scf;

(g) providing the renewable natural gas produced in (f) for injection into a distribution system, for use as a transportation fuel, or for use as a combination thereof.

21. A method for upgrading biogas, comprising:

(a) obtaining biogas from a biogas source;

(b) generating a partially purified biogas from said biogas, said generating comprising removing hydrogen sulfide, carbon dioxide, or a combination thereof from said biogas with at least one stationary purification system;

(c) filling the vessel with partially purified biogas;

(d) transporting the vessel containing the partially purified biogas to a destination;

(e) removing the partially purified biogas from the vessel at a destination;

(f) purifying a gas stream comprising partially purified biogas removed from the vessel to produce renewable natural gas; and

(g) the renewable natural gas is provided for injection into a natural gas distribution system, for use as a transportation fuel, or for use as a combination thereof.

22. The method of claim 21, wherein step (b) comprises removing carbon dioxide from the biogas.

23. The method as set forth in claim 22, wherein said renewable natural gas has a heating value of at least 950 BTU/scf.

24. The method of claim 21, wherein the partially purified biogas has a heating value of less than 900 BTU/scf.

25. The method of claim 22, wherein step (b) comprises removing 0% to 5% of the carbon dioxide in the biogas.

26. The method of claim 22, wherein step (b) comprises removing 10% to 90% of the carbon dioxide in the biogas.

27. The method of claim 22, wherein step (b) does not include removing nitrogen from the biogas, and wherein step (f) includes removing nitrogen from the partially purified biogas.

28. The method of any one of claims 21 to 27, wherein the destination is a biogas upgrading facility connected to a natural gas distribution system by a pipeline.

29. The method of any one of claims 21 to 27, wherein steps (a), (b), and (c) are performed at a pretreatment site, wherein the destination is a biogas upgrading facility, and wherein the pretreatment site is located at least 1 mile from the biogas upgrading facility.

30. The method of claim 29, comprising transporting a vessel containing partially purified biogas from a plurality of other pretreatment sites to the biogas upgrading facility, wherein each other pretreatment site includes a respective biogas source.

31. The method of claim 29, wherein the containers are transported from the plurality of pretreatment sites to the biogas upgrading facility using trucks, rails, ships, or any combination thereof.

32. The method of claim 21, wherein step (c) is performed when the partially purified biogas is produced.

33. The method of claim 21, wherein step (c) comprises filling the vessel with the partially purified biogas to a pressure of at least 1500 psig.

34. The method of claim 21, wherein the partially purified biogas produced in step (b) has a non-methane content of at least 10%.

35. The method of claim 21, wherein the partially purified biogas produced in step (b) has a carbon dioxide content of 5% to 30%.

36. The method of claim 21 wherein the partially purified biogas produced in step (b) has a heating value of less than 950BTU/scf and is at least 25BTU/scf higher than the heating value of the biogas obtained in step (a), and wherein the renewable natural gas produced in step (f) has a heating value of at least 950BTU/scf and is at least 25BTU/scf higher than the heating value of the partially purified biogas produced in step (b).

37. The method of claim 21, wherein step (b) comprises removing carbon dioxide from the biogas to produce the partially purified biogas, and wherein step (f) comprises removing carbon dioxide.

38. The method of claim 21, wherein step (b) comprises removing carbon dioxide from the biogas at a pressure of at least 90 psig.

39. The method of claim 21, wherein during step (c), the container is installed with a trailer separate from the truck.

40. The method of claim 30, comprising feeding the partially purified biogas removed from the vessel directly to one or more purification systems, and wherein the vessel containing the partially purified biogas from the plurality of other pretreatment sites is arranged to reach the biogas upgrading facility to provide a continuous flow of partially purified biogas to the biogas upgrading facility.

41. A method for upgrading biogas, comprising:

obtaining a partially purified biogas from a plurality of pre-treatment sites, each pre-treatment site comprising a biogas source, a stationary purification system for producing the partially purified biogas, and a vessel for storing the partially purified biogas at a pressure of at least 1000 psig;

transporting each vessel containing partially purified biogas directly to a biogas upgrading facility;

removing the partially purified biogas from each vessel at the biogas upgrading facility;

further purifying the partially purified biogas removed from each vessel to provide a renewable natural gas having a heating value of at least 950BTU/scf and used for injection into a distribution system, as a transportation fuel, or as a combination thereof.

42. The method of claim 41, wherein the partially purified biogas collected from the plurality of pretreatment sites has a non-methane content of at least 10%.

43. The method of claim 42, wherein the partially purified biogas is removed from each vessel in sequence at the biogas upgrading facility to provide a continuous flow of partially purified biogas.

44. A method for upgrading biogas, comprising:

in a first place, providing a first stationary biogas purification system to process biogas from a first biogas source;

at a second location, providing a second other stationary biogas purification system to process biogas from a second other biogas source;

collecting or arranging for collection of partially purified biogas produced at the first and second locations respectively, the collecting comprising coupling a container or container supporting a container to a truck, rail car or boat, wherein the container comprises partially purified biogas produced at the first or second locations; and

generating renewable natural gas from the transported partially purified biogas, the generating comprising removing carbon dioxide, nitrogen, oxygen, or any combination thereof from the transported partially purified biogas.

45. A method for upgrading biogas, comprising:

removing water, hydrogen sulfide, carbon dioxide, or any combination thereof from the raw biogas at the pretreatment site to produce a partially purified biogas, compressing the partially purified biogas, and filling a container with the compressed partially purified biogas while producing the compressed partially purified biogas, the container being separate from the vehicle;

transporting the partially purified biogas to a biogas upgrade facility, the transporting comprising moving the container by a vehicle;

at a biogas upgrade facility, separating the vessel from the vehicle and removing the partially purified biogas therefrom;

further purifying the removed partially purified biogas to produce a renewable natural gas; and

the renewable natural gas is provided for injection into a natural gas distribution system, for use as a transportation fuel, or for use as a combination thereof.

Technical Field

The present disclosure relates to methods and systems for upgrading biogas, and more particularly to methods and systems for upgrading biogas to Renewable Natural Gas (RNG), which includes partial purification of biogas followed by transportation.

Background

Biogas is a mixture of several gases, usually produced by decomposing organic matter under low oxygen conditions. It can be produced, inter alia, by anaerobic digestion or fermentation of organic matter, such as fertilizers, sludges, municipal solid waste, biodegradable raw materials, etc.

The biogas collected at its source (e.g., a landfill or anaerobic digester) may be referred to as raw biogas. The composition of the raw biogas may vary depending on the type of organic matter from which it is derived, primarily methane (CH)₄) And carbon dioxide (CO)₂) And a small and/or negligible amount of nitrogen (N)₂) Hydrogen sulfide (H)₂S), water (H)₂O), ammonia (NH)₃) Hydrogen (H)₂) Carbon monoxide (CO), oxygen (O)₂) Volatile Organic Compounds (VOCs) and/or silicones. For example, but not limiting of, the composition of the raw biogas may include about 60% CH₄(e.g., about 35% to 75%), about 35% CO₂(e.g., about 15% to 65%), about 0% to 20% N₂And about 0% to 5% O₂。

Although the raw biogas may have sufficient energy content for combustion (e.g., in an engine, turbine, or boiler) without the need to remove inert components (e.g., CO)₂And/or N₂) Yet another option is to upgrade the raw biogas for injection into the natural gas distribution system. Biogas upgrading refers to the removal of at least CO₂And/or N₂And certain other typical contaminants, thereby increasing CH₄To increase the biogas heatingAnd (4) the process of measuring. When raw biogas is upgraded to the point of meeting applicable specifications (e.g., pipeline standards) for natural gas distribution systems and/or being applicable to the transportation sector, it is referred to as "renewable natural gas". Renewable Natural Gas (RNG) is essentially interchangeable with natural gas and thus can be used as a substitute for fossil natural gas, can be injected into natural gas distribution systems, and/or can be used as a transportation fuel when it qualifies for fuel credit.

Generally, biogas upgrading is associated with relatively high capital investment costs when upgrading raw biogas to RNG. Thus, it is often economically unfeasible for low volume production biogas producers (e.g., small farms, small landfills, or small wastewater treatment facilities).

SUMMARY

The present disclosure describes improved methods and/or systems for biogas upgrading in which raw biogas is partially purified (e.g., at a pre-treatment site near the source of the raw biogas) prior to being transported to a centralized biogas upgrading facility that further purifies the partially purified biogas into Renewable Natural Gas (RNG). The RNG can be injected into a natural gas distribution system or can be used to provide compressed natural gas (bio-CNG) or liquefied natural gas (bio-LNG) to an off-grid industrial site or filling station, such as a commercial gas station.

Advantageously, biogas upgrading can benefit from economies of scale since a centralized biogas upgrade facility can receive biogas from multiple sources (e.g., multiple pretreatment sites and/or raw biogas from one or more other sources).

Further advantageously, the process/system is more efficient as it enables partial purification prior to transportation to a centralized biogas upgrading facility. For example, when the partial purification involves removal of a gas such as H₂O and H₂S, this can reduce corrosion problems and/or safety issues. When the partial purification involves removing CO₂This can improve the compression process and/or allow more methane to be transported per unit volume at a given pressure, thereby reducing costs.

According to an aspect of the present invention, there is provided a method comprising: a) obtaining biogas from a plurality of biogas sources, the biogas comprising a first biogas from a first biogas source and a second other biogas from a second other biogas source; b) removing one or more components from the first biogas to produce a first partially purified biogas, the one or more components comprising hydrogen sulfide, carbon dioxide, or a combination thereof, the one or more components being removed using at least one stationary purification system; c) transporting a first vessel comprising the first portion of purified biogas to a biogas upgrading facility; d) removing one or more components from the second biogas to produce a second partially purified biogas, the one or more components comprising hydrogen sulfide, carbon dioxide, or a combination thereof, the one or more components being removed using at least one stationary purification system; e) optionally, transporting a second vessel containing the second portion of purified biogas to the biogas upgrading facility; f) removing at least one component from a gas stream comprising the first portion of purified biogas, the second portion of purified biogas, or a combination thereof at the biogas upgrading facility to produce a renewable natural gas having a heating value greater than the heating value of either of the first and second portions of purified biogas; g) providing the renewable natural gas produced in f) for injection into a distribution system, for use as a transportation fuel, or for use as a combination thereof.

According to an aspect of the present invention, there is provided a method comprising: a) obtaining biogas from a plurality of biogas sources, the biogas comprising a first biogas from a first biogas source and a second other biogas from a second other biogas source; b) feeding the first biogas to a first stationary purification system to remove hydrogen sulfide, carbon dioxide, or a combination thereof from the first biogas and produce a first partially purified biogas having a heating value of less than 950 BTU/scf; c) transporting a first vessel comprising the first portion of purified biogas to a biogas upgrading facility via a vehicle; d) feeding the second biogas to a second other stationary purification system to remove hydrogen sulfide, carbon dioxide, or a combination thereof from the second biogas and produce a second partially purified biogas having a heating value of less than 950 BTU/scf; e) optionally, transporting a second vessel containing the second portion of purified biogas to the biogas upgrading facility via a carrier; f) feeding the first and second portions of purified biogas to one or more purification systems at the biogas upgrading facility to remove carbon dioxide, nitrogen, oxygen, or any combination thereof and produce a renewable natural gas having a heating value of at least 950 BTU/scf; and g) providing the renewable natural gas produced in f) for injection into a distribution system, for use as a transportation fuel, or for use as a combination thereof.

According to an aspect of the invention, there is provided a method for upgrading biogas, comprising: (a) obtaining biogas from a biogas source; (b) generating a partially purified biogas from said biogas, said generating comprising removing hydrogen sulfide, carbon dioxide, or a combination thereof from said biogas with at least one stationary purification system; (c) filling a vessel with the partially purified biogas; (d) transporting the vessel containing the partially purified biogas to a destination; (e) removing the partially purified biogas from the vessel at a destination; (f) purifying a gas stream comprising partially purified biogas removed from the vessel to produce renewable natural gas; and (g) providing the renewable natural gas for injection into a natural gas distribution system, for use as a transportation fuel, or for use as a combination thereof.

According to an aspect of the invention, there is provided a method for upgrading biogas, comprising: obtaining a partially purified biogas from a plurality of pre-treatment sites, each pre-treatment site comprising a biogas source, a stationary purification system for producing the partially purified biogas, and a vessel for storing the partially purified biogas at a pressure of at least 1000 psig; transporting each vessel containing partially purified biogas directly to a biogas upgrading facility; removing the partially purified biogas from each vessel at the biogas upgrading facility; further purifying the partially purified biogas removed from each vessel to provide a renewable natural gas having a heating value of at least 950BTU/scf and used for injection into a distribution system, as a transportation fuel, or as a combination thereof.

According to an aspect of the invention, there is provided a method for upgrading biogas, comprising: in a first place, providing a first stationary biogas purification system to process biogas from a first biogas source; at a second location, providing a second other stationary biogas purification system to process biogas from a second other biogas source; collecting or arranging for collection of partially purified biogas produced at the first and second locations respectively, the collecting comprising coupling a container or container supporting a container to a truck, rail car or boat, wherein the container comprises partially purified biogas produced at the first or second locations; and generating renewable natural gas from the transported partially purified biogas, the generating comprising removing carbon dioxide, nitrogen, oxygen, or a combination thereof from the transported partially purified biogas.

According to an aspect of the invention, there is provided a method for upgrading biogas, comprising: removing water, hydrogen sulfide, carbon dioxide, or any combination thereof from the raw biogas at the pretreatment site to produce a partially purified biogas, compressing the partially purified biogas, and filling a container of the compressed partially purified biogas that is separate from the vehicle when the compressed partially purified biogas is produced; transporting the partially purified biogas to a biogas upgrade facility, the transporting comprising moving the container by a vehicle; at a biogas upgrade facility, separating the vessel from the vehicle and removing the partially purified biogas therefrom; further purifying the removed partially purified biogas to produce a renewable natural gas; and providing the renewable natural gas for injection into a natural gas distribution system, for use as a transportation fuel, or for use as a combination thereof.