AU2014200989A1

AU2014200989A1 - LNG Production

Info

Publication number: AU2014200989A1
Application number: AU2014200989A
Authority: AU
Inventors: Bretton Cooper
Original assignee: Individual
Current assignee: Individual
Priority date: 2013-03-22
Filing date: 2014-02-25
Publication date: 2014-10-09

Abstract

Abstract The present invention relates generally to the production of LNG by means of capturing widely distributed C02 emissions from stationary and mobile devices powered by gas derived from LNG. This LNG has been produced, in part, from those 5 distributed C02 emissions. The method generally comprises the steps of: 1. Recovering C02 from the atmosphere at C02 recovery 10; 2. Reacting the recovered C02 together with H2 to provide CH4 at 12; 3. Liquefying the CH4 to derive LNG at 14.

Description

1 LNG Production Field of the Invention The present invention relates broadly to a method of producing Liquid Natural Gas (LNG). The invention also relates generally to a plant assembly for producing LNG. 5 Summary of the Invention According to one aspect of the present invention there is provided a method of producing LNG, said method comprising the steps of: recovering carbon dioxide(C0 2 ) from the atmosphere; 10 reacting the recovered C02 together with hydrogen (H 2 ) to provide methane

(CH

4 ); liquefying the CH 4 to derive the LNG. Preferably the step of recovering C02 involves capture and concentration of C02 15 directly from the atmosphere. Preferably the step of liquefying the CH 4 to derive the LNG involves using the CH 4 as a feedstock for a liquefaction plant which produces the LNG. 20 Preferably the method also comprises the step of producing the H 2 via electrolysis of water (H 2 0). More preferably the electrolysis of H 2 0 is powered using a renewable energy source such as solar, tidal, wind or geothermal. Preferably the method is performed by key plant components being in close proximity 25 to one another. Preferably the method further comprises the step of remotely regasifying the LNG to provide

CH

4 . 30 According to another aspect of the invention there is provided a plant assembly for producing LNG comprising: a C02 recovery module for recovering C02 from the atmosphere; a reactor for combining the recovered C02 together with H 2 to provide CH 4 ; a liquefaction module for liquefying the CH 4 from which the LNG is derived.

2 Preferably the C02 recovery module is in the form of a direct air capture plant designed to capture and concentrate C02 directly from the atmosphere. 5 Preferably the reactor is a Sabatier reactor. Preferably the liquefaction module is one of a plurality of said modules included in a liquefaction plant which produces the LNG. More preferably the liquefaction plant is located either on-shore or floating off-shore. 10 Preferably the plant assembly also comprises an electrolysis plant which produces the H 2 from H 2 0. More preferably the electrolysis plant is powered by a renewable energy plant such as a solar, tidal, wind or geothermal plant. 15 Preferably the plant assembly includes key plant components comprising the electrolysis plant, the reactor and the direct air capture plant located in close proximity to one another. Preferably the plant assembly further comprises a remote regasification plant which 20 regasifies the LNG to provide CH 4 and other gaseous hydrocarbons. More preferably the remote regasification plant is provided at an export or overseas market. Brief Description of the Drawings In order to achieve a better understanding of the nature of the present invention a 25 preferred embodiment of a method of producing LNG will now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 is a process flow diagram of a method of producing LNG according to an embodiment of the invention; 30 Figure 2 is a schematic illustration of a plant assembly for producing LNG according to an embodiment of another aspect of the invention.

3 Detailed Description of the Preferred Embodiment In its preferred form the invention relates to the production of LNG by means of capturing widely distributed C02 emissions from stationary and mobile devices powered by gas derived from LNG. This LNG has been produced, in part, from those 5 distributed C02 emissions. As shown in figure 1 there is according to one embodiment of the invention a method of producing LNG. The method generally comprises the steps of: 10 1. recovering C02 from the atmosphere at C02 recovery 10; 2. reacting the recovered C02 together with H 2 to provide CH 4 at 12; 3. liquefying the CH 4 to derive LNG at 14. In this embodiment the H 2 is produced from H 2 0 at 16. This H 2 production is effected 15 by electrolysis of H 2 0. The electrolysis is powered using a renewable energy source such as solar photovoltaic (PV), tidal, wind or geothermal. The recovery of C02 at 10 in this example involves capture and concentration of C02 directly from the atmosphere. This operation can be performed by direct air capture 20 and recovery of the C02. In this example the reaction of the recovered C02 together with H 2 is performed at elevated temperatures and pressures in the presence of a catalyst. The H 2 0 produced from this catalytic reaction may also be recirculated as part of the H 2 0 25 supply to the H 2 recovery operation at 16 in the electrolysis of H 2 0. In this embodiment the CH 4 is used at 14 as a feedstock for a liquefaction plant which produces the LNG. This liquefaction involves condensing the CH 4 into liquid form by effectively refrigerating it. 30 The LNG is transported, for example shipped in cryogenic LNG carriers, to its export market. The LNG may then be regasified to provide CH 4 typically for use in natural gas vehicles, centralised electricity generating plants and distributed gas fired fuel cells.

4 Figure 2 schematically depicts a plant assembly designated generally as 20 for producing LNG according to another aspect of the invention. In this embodiment the LNG is produced according to the methodology of the preceding paragraphs. 5 The plant assembly 20 of this example generally comprises: 1. a C02 recovery module 22 for recovering C02 from the atmosphere; 2. a reactor 24 for combining the recovered C02 together with H 2 to provide CH 4 ; 3. a liquefaction module 26 for liquefying the CH 4 from which the LNG is derived. 10 In this embodiment the C02 recovery module 22 is in the form of a direct air capture plant. The direct air capture plant 22 is designed to capture and concentrate C02 directly from the atmosphere. 15 In this example the reactor 24 is in the form of a Sabatier reactor. The Sabatier reactor 24 operates at elevated temperatures and pressures in the presence of a catalyst to produce methane and water from the recovered C02 together with the H 2 . In this example the H 2 is produced via an electrolysis plant 28 which produces the H 2 20 from H 2 0. Some of the H 2 0 may be sourced from the Sabatier reactor 24 as a by product of the reaction between C02 and H 2 . The electrolysis plant 28 is powered by a renewable energy plant 30 such as solar PV plant, wind turbine, tidal or geothermal plant. 25 In this example the waste heat from the Sabatier reactor 24 and/or the electrolysis plant 28 is delivered to the direct air capture plant 22 to assist in powering its function. In this example the liquefaction module 26 is a floating LNG plant which is located off shore and connected via pipe to the on-shore Sabatier reactor 24 to enable it to 30 liquefy the methane produced from the Sabatier reactor 24. In this example the key components of the total plant assembly 20 which are closely located to each other are the electrolysis plant 28, the Sabatier reactor 24 and the direct air capture plant 22.The other components of the assembly being the 5 renewable energy plant 30 and the liquefaction plant 26 can be more distantly located. For example the renewable energy plant 30 may be located some distance from the electrolysis plant 28 and connected to it by high voltage power lines and the liquefaction plant 26 could be located off-shore some distance from the Sabatier 5 reactor 24 and connected to it via gas pipe lines. In this embodiment the transport infrastructure 32 is associated with a regasification plant 34 located at the distant or export market. The regasification plant 34 regasifies the LNG to provide CH 4 . The CH 4 is utilised at the export market to, for example, 10 power natural gas vehicles or a centralised gas-fed power plant or decentralised gas fired fuel cells. It will be understood that the method of producing LNG is effectively a closed carbon loop insofar as C02 emitted from combustion of the LNG sourced CH 4 is recovered 15 directly from the atmosphere in the C02 recovery operation. This recovered C02 is then utilised in the reactor together with H 2 to provide the CH 4 .Therefore the use of direct air capture in manufacturing LNG enables distributed C02 emissions to be captured from any source in the world. These distributed C02 emissions could be sourced from transport vehicles and fuel cells powered by LNG sourced gas, where 20 these emissions are captured for recycling in the manufacture of that same LNG so as to close the carbon loop. This distinguishes from the prior art of, for example the applicant's innovation patent no. 2011101411, which sources C02 emissions from large plant, single point, stationary C02 emitters. 25 Now that a preferred embodiment of the present invention has been described it will be apparent to those skilled in the art that the method of producing LNG has at least the following advantages: 1. the process effectively combines C02 recovery directly from the atmosphere with a Sabatier reaction to provide CH 4 from which LNG is produced; 30 2. the process and plant assembly in the production of LNG enables flexibility regarding the location as between assembly components with some components being able to be distantly located from other components; 6 3. the renewable energy plant in powering the recovery of H 2 from for example the electrolysis of water effectively stores the renewable energy in the form of the LNG produced; 4. the close proximity of key plant components of the plant assembly enables 5 efficient operation of the assembly because the direct air capture plant at least partly, if not wholly, powers its operation by harnessing waste heat from the electrolysis plant and/or the reactor. Those skilled in the art will appreciate that the invention described herein is 10 susceptible to variations and modifications other those specifically described. For example, the unit operations of C02 recovery and the CH 4 reactor need not be limited to the specific embodiments of direct air capture and the Sabatier reactor, respectively. The H 2 recovery need not be limited to electrolysis and in the case of electrolysis need not be necessarily powered by a renewable energy source. The 15 plant assembly may extend across multiple locations depending on existing infrastructure, such as an existing LNG plant, and natural resources, such as wind or solar energy. All such variations and modifications are to be considered within the scope of the 20 present invention the nature of which is to be determined from the foregoing description.

Claims

1. A method of producing LNG, said method comprising the steps of: recovering carbon dioxide(CO0 2 ) from the atmosphere; reacting the recovered C02 together with hydrogen (H 2 ) to provide methane 5 (CH 4 ); liquefying the CH 4 to derive the LNG.

2. A method as defined in claim 1 wherein the step of recovering C02 involves capture and concentration of C02 directly from the atmosphere. 10

3. A method as defined in either of claims 1 or 2 wherein the step of liquefying the CH 4 to derive the LNG involves using the CH 4 as a feedstock for a liquefaction plant which produces the LNG. 15

4. A method as defined in any one of the preceding claims also comprising the step of producing the H 2 via electrolysis of water (H 2 0).

5. A method as defined in claim 4 wherein the electrolysis of H 2 0 is powered using a renewable energy source including solar, tidal, wind or geothermal. 20

6. A method as defined in any one of the preceding claims performed by key plant components in close proximity to one another.

7. A method as defined in any one of the preceding claims further comprising the 25 step of remotely regasifying the LNG to provide CH 4 .

8. A plant assembly for producing LNG comprising: a C02 recovery module for recovering C02 from the atmosphere; a reactor for combining the recovered C02 together with H 2 to provide CH 4 ; 30 a liquefaction module for liquefying the CH 4 from which the LNG is derived.

9. A plant assembly as defined in claim 8 wherein the C02 recovery module is in the form of a direct air capture plant designed to capture and concentrate C02 directly from the atmosphere. 8

10. A plant assembly as defined in either of claims 8 or 9 wherein the reactor is a Sabatier reactor. 5

11. A plant assembly as defined in any one of claims 8 to 10 wherein the liquefaction module is one of a plurality of said modules included in a liquefaction plant which produces the LNG.

12. A plant assembly as defined in claim 11 wherein the liquefaction plant is 10 located either on-shore or floating off-shore.

13. A plant assembly as defined in claim 9 also comprising an electrolysis plant which produces the H 2 from H 2 0. 15

14. A plant assembly as defined in claim 13 wherein the electrolysis plant is powered by a renewable energy plant including a solar, tidal, wind or geothermal plant.

15. A plant assembly as defined in either of claims 13 or 14 including key plant 20 components comprising the electrolysis plant, the reactor and the direct air capture plant located in close proximity to one another.

16. A plant assembly as defined in any one of claims 8 to 15 further comprising a remote regasification plant which regasifies the LNG to provide CH 4 and other 25 gaseous hydrocarbons.

17. A plant assembly as defined in claim 16 wherein the remote regasification plant is provided at an export or overseas market.