Method for the integration of liquefied natural gas and syngas production

• US 10,393,431 B2
• Filed: 01/24/2017
• Issued: 08/27/2019
• Est. Priority Date: 08/05/2016
• Status: Active Grant

• Current Assignee: L'Air Liquide Societe Anonyme Pour L'Etude et L'Exploitation Des Procedes Georges Claude (L'Air Liquide SA)
• Original Assignee: L'Air Liquide Societe Anonyme Pour L'Etude et L'Exploitation Des Procedes Georges Claude (L'Air Liquide SA)
• Inventors: Roesch, Alexander, Guillard, Alain, Turney, Michael A.
• Primary Examiner(s): Ma, Kun Kai
• Application Number:
  US15/414,100
• Publication Number:
  US 20180038643A1
• Time in Patent Office: 945 Days
• Field of Search: 62613
• CPC Class Codes: C01B 2203/0205 containing a reforming step
• CPC Class Codes: C01B 2203/0233 the reforming step being a steam reforming step
• CPC Class Codes: C01B 2203/0244 the reforming step being an autothermal reforming step, e.g. secondary reforming processes
• CPC Class Codes: C01B 2203/042 Purification by adsorption on solids
• CPC Class Codes: C01B 2203/0475 the impurity being carbon dioxide
• CPC Class Codes: C01B 2203/0495 the impurity being water
• CPC Class Codes: C01B 2203/061 Methanol production
• CPC Class Codes: C01B 2203/1241 Natural gas or methane
• CPC Class Codes: C01B 2203/84 Energy production
• CPC Class Codes: C01B 3/34 by reaction of hydrocarbons with gasifying agents
• CPC Class Codes: C01B 3/384 the catalyst being continuously externally heated
• CPC Class Codes: C01B 3/56 by contacting with solids; Regeneration of used solids C01B3/508 takes precedence
• CPC Class Codes: F25J 1/0022 Hydrocarbons, e.g. natural gas
• CPC Class Codes: F25J 1/0035 by gas expansion with extraction of work
• CPC Class Codes: F25J 1/0037 of a return stream
• CPC Class Codes: F25J 1/005 by expansion of a gaseous refrigerant stream with extraction of work
• CPC Class Codes: F25J 1/0052 by vaporising a liquid refrigerant stream
• CPC Class Codes: F25J 1/0072 Nitrogen
• CPC Class Codes: F25J 1/0204 as a single flow SCR cycle
• CPC Class Codes: F25J 1/0229 Integration with a unit for using hydrocarbons, e.g. consuming hydrocarbons as feed stock
• CPC Class Codes: F25J 1/023 : for the combustion as fuels, i.e. integration with the fuel gas system
• CPC Class Codes: F25J 1/0231 : for the working-up of the hydrocarbon feed, e.g. reinjection of heavier hydrocarbons into the liquefied gas
• CPC Class Codes: F25J 1/0232 : integration within a pressure letdown station of a high pressure pipeline system
• CPC Class Codes: F25J 1/0282 : Steam turbine as the prime mechanical driver
• CPC Class Codes: F25J 1/0288 : using work extraction by mechanical coupling of compression and expansion of the refrigerant, so-called companders
• CPC Class Codes: F25J 1/0292 : Refrigerant compression by cold or cryogenic suction of the refrigerant gas
• CPC Class Codes: F25J 1/0294 : Multiple compressor casings/strings in parallel, e.g. split arrangement
• CPC Class Codes: F25J 2210/06 : Splitting of the feed stream, e.g. for treating or cooling in different ways
• CPC Class Codes: F25J 2210/60 : Natural gas or synthetic natural gas [SNG]
• CPC Class Codes: F25J 2230/20 : Integrated compressor and process expander; Gear box arrangement; Multiple compressors on a common shaft
• CPC Class Codes: F25J 2230/30 : Compression of the feed stream
• CPC Class Codes: F25J 2230/60 : the fluid being hydrocarbons or a mixture of hydrocarbons
• CPC Class Codes: F25J 2240/02 : Expansion of a process fluid in a work-extracting turbine (i.e. isentropic expansion), e.g. of the feed stream
• CPC Class Codes: F25J 2240/04 : Multiple expansion turbines in parallel
• CPC Class Codes: F25J 2240/12 : the fluid being nitrogen
• CPC Class Codes: F25J 2240/70 : Steam turbine, e.g. used in a Rankine cycle
• CPC Class Codes: F25J 2260/60 : Integration in an installation using hydrocarbons, e.g. for fuel purposes
• CPC Class Codes: F25J 2270/04 : Internal refrigeration with work-producing gas expansion loop
• CPC Class Codes: F25J 2270/12 : External refrigeration with liquid vaporising loop
• CPC Class Codes: F25J 2270/16 : with mutliple gas expansion loops of the same refrigerant

Abstract

An integrated method for the production of liquefied natural gas (LNG) and syngas is provided. The method can include the steps of: utilizing letdown energy of a high pressure natural gas stream that is withdrawn from a natural gas pipeline to provide a warm temperature cooling; utilizing a refrigeration cycle to provide a cold temperature cooling, wherein the refrigeration cycle comprises a refrigerant recycle compressor that is powered utilizing a steam turbine; and cooling a second high pressure natural gas stream using the warm temperature cooling and the cold temperature cooling to produce an LNG product stream. The second high pressure natural gas stream is withdrawn from the natural gas pipeline, and the steam turbine is powered by high pressure steam that is produced from a syngas production facility.

Claims

1. A method for a production of liquefied natural gas (“

LNG”

), the method comprising the steps of;

a) operating a syngas production facility that is configured to convert a first natural gas stream into a syngas stream, wherein the syngas production facility is further configured to produce a pressurized steam, wherein the pressurized steam is fed to a steam turbine, wherein during said operating step, the syngas production facility uses a second natural gas stream at a lower pressure than the first natural gas stream;

b) cooling and liquefying a third natural gas stream using refrigeration provided by at least two different sources to produce an LNG product stream;

c) providing a first source for the refrigeration used in step b) by expanding the second natural gas stream in a natural gas expander and then warming the second natural gas stream, prior to being used in the syngas production facility in step a), against the third natural gas stream; and

d) providing a second source for the refrigeration used in step b) using a nitrogen refrigeration cycle, wherein the nitrogen refrigeration cycle comprises a nitrogen recycle compressor and at least one turbine, wherein the nitrogen recycle compressor is driven by the steam turbine of the syngas production facility.

2. The method as claimed in claim 1, wherein the first natural gas stream, the second natural gas stream, the second natural gas stream, and the third natural gas stream all originate from a common source, wherein the common source is a pressurized natural gas pipeline.

3. The method as claimed in claim 1, wherein the nitrogen refrigeration cycle comprises the steps of compressing nitrogen refrigerant in the nitrogen recycle compressor, further compressing the nitrogen refrigerant in at least one booster, cooling the nitrogen refrigerant in a heat exchanger, withdrawing the nitrogen refrigerant from an intermediate portion of the heat exchanger and then expanding the nitrogen refrigerant in the at least one turbine to produce a cold nitrogen refrigerant;

and warming the cold nitrogen refrigerant against the third natural gas stream.

4. The method as claimed in claim 1, wherein the second natural gas stream is warmed against the third natural gas stream in a first heat exchanger and the nitrogen refrigerant is warmed against the third natural gas stream in a second heat exchanger.

5. The method as claimed in claim 4, wherein the first heat exchanger and the second heat exchanger are disposed within one heat exchanger unit.

6. The method as claimed in claim 1, wherein an outlet temperature of the natural gas turbine is warmer than a temperature at an outlet of the at least one turbine of the nitrogen refrigeration cycle.

7. The method as claimed in claim 1, wherein the first source for the refrigeration is provided in step c) at a first temperature, wherein the second source for the refrigeration is provided in step d) at a second temperature, wherein the second temperature is colder than the first temperature.

8. The method as claimed in claim 1, wherein the first source for the refrigeration provided in step c) and the second source for the refrigeration provided in step d) are provided without using externally provided electricity.

9. The method as claimed in claim 1, wherein the refrigeration used to liquefy the third natural gas stream during step b) is produced without the use of externally provided electricity.

10. The method as claimed in claim 1, wherein the refrigeration used to liquefy the third natural gas stream during step b) is produced with reduced amounts of externally provided electricity.

11. The method as claimed in claim 1, wherein the second natural gas stream and/or the third natural gas stream are boosted in a natural gas booster prior to steps b) and c).

12. The method as claimed in claim 11, wherein the natural gas expander comprises a natural gas expansion turbine.

13. The method as claimed in claim 12, wherein the natural gas expansion turbine powers the natural gas booster.