Marine carbon-neutral power generation system in floating type using marine carbon cycle

Abstract

To provide a marine offshore system and a method for power generation including a structure placed in an offshore location.SOLUTION: A marine offshore system and a method for power generation includes a structure placed in an offshore location. A power generation module is installed on the structure, the power generation module including a turbine, a power generator connected to the turbine, and a generation source of a turbine power fluid produced from the burning of fossil fuels. A recovery system connected to the generation source to transport carbon dioxide combustion gas is located in the underwater location for the CO2 sequestration.SELECTED DRAWING: Figure 1

Description

Cross - reference to related applications

[0001] This application claims priority to U.S. Patent Application No. 62 / 544,517, filed on August 11, 2017, the disclosure of which is hereby incorporated by reference in its entirety for all purposes.

Technical Field

[0002] The present invention relates to electric power generation, and more particularly to floating ocean power generation that utilizes artificial carbon dioxide capture and sequestration in the ocean.

Background Art

[0003] To date, power generation sources have been nuclear power, fossil fuels (coal, oil, natural gas), hydro - power, wind power, wave power, and solar power. Fossil fuels have a carbon footprint (e.g., CO2), while all of the other raw materials mentioned are generally free of such a carbon footprint, i.e., they are carbon neutral. As the problems related to climate change increase, power plants using fossil fuels are being retrofitted or established with technologies to reduce their carbon footprint. However, in recent years, there are no carbon - neutral power generation facilities using fossil fuels. This has drawn attention to the use of nuclear power for base - load power generation (BLPG). However, nuclear power generation is considered a high - risk option by many people, as proven by disasters such as Chernobyl and Fukushima Daiichi in Japan.

[0004]

Disclosure of the Invention

[0005] Summary of the Invention ​In one aspect, the present invention relates to carbon-neutral power generation.

[0006] In another aspect, the present invention relates to the use of fossil fuels for carbon-neutral power generation.

[0007] In yet another aspect, the present invention relates to ocean power generation.

[0008] In yet another aspect, the present invention relates to power generation that utilizes the Ocean Carbon Cycle (OCC) to mitigate the release of carbon dioxide into the atmosphere.

[0009] These and further features and advantages of the present invention will become apparent from the following detailed description, with reference to the figures in the accompanying drawings.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

[0011] Detailed Description of the Preferred Embodiment The present invention partly utilizes the role that the OCC (Ocean Carbon Cycle) plays in the overall carbon cycle. The ocean is generally recognized as a carbon sink because it takes in more carbon from the atmosphere than it releases. Therefore, carbon dioxide from the atmosphere dissolves in ocean water. Some of the carbon dioxide remains as dissolved gas, while some is converted into other substances. For example, photosynthesis by microscopic marine plants (phytoplankton) in the sunlit surface waters of the ocean converts the carbon into organic matter. Additionally, many organisms use carbon to produce calcium carbonate, a constituent of shells and skeletons. Another chemical process also forms calcium carbonate in seawater. The consumption of carbon by biological and chemical processes allows more carbon dioxide to enter the seawater from the atmosphere. That is, carbon from, for example, CO2 incorporates itself into marine organisms as organic matter or as calcium carbonate. incorporates itself into marine organisms as organic matter or as calcium carbonate.

[0012] The disposal of CO2 into the ocean surface (<1 km depth) will allow equilibrium with the atmosphere within years to decades and thus will provide little benefit, while disposal into ocean basins deeper than 3 km has been predicted based on mathematical models to delay equilibrium with the atmosphere over centuries and eliminate transient changes in atmospheric concentration. The resulting interaction with sediments rich in calcite could potentially reduce atmospheric concentration by a significant amount (~50%) over a long period (>2000 years). In any case, many of the bidirectional processes between marine organisms and CO2 could result in the locking up of carbon over millions of years. Additionally, since the solubility of carbon dioxide in water is known to increase with decreasing temperature, CO2 sequestration may be more effective in colder ocean waters. In any case, many of the bidirectional processes between marine organisms and CO2 could result in the locking up of carbon over millions of years. Additionally, since the solubility of carbon dioxide in water is known to increase with decreasing temperature, CO2 sequestration may be more effective in colder ocean waters. In any case, many of the bidirectional processes between marine organisms and CO2 could result in the locking up of carbon over millions of years. Additionally, since the solubility of carbon dioxide in water is known to increase with decreasing temperature, CO2 sequestration may be more effective in colder ocean waters.

[0013] First, in FIG. 1, it may be a barge, a platform, etc. , and a floating structure 10 is shown that may be dynamically or statically positioned at a suitable ocean location. Placement of the structure 10 in deep water may be carried out using well-known methods utilized for deep water placement and mooring of work barges for drilling and production in the oil and gas industry. Mounted on the structure 10 is a gas treatment / optimization module 12 connected by a conduit 14 to a pipeline 16 lying on the sea floor 18. Generally, the gas pipeline 16 will be for the transport of light hydrocarbon gas, such as natural gas, which mainly contains methane. In the gas treatment module 12, the gas transported from the pipeline 16 and the line 14 may be treated by various methods well known to those skilled in the art to remove undesirable contaminants, water, and other components that may adversely affect downstream operations. The module 12 may also include a separation / concentration system for optimizing the BTU content of the gas from the pipeline 16.

[0014] Furthermore, on the structure 10, there is a power station module shown generally as 20 and including a drive device, for example, both well-known to those skilled in the art, both directly in the present invention or indirectly powered by the combustion products of a fuel, for example, processed natural gas transported from the processing module 12 via line 24, such as a gas turbine or a steam turbine. The combustion gas (flue gas) generated in the power generation area 22 of the drive device or module 20 is sent to a gas recovery system consisting of a compression station 26 for compressing the combustion exhaust gas and transporting it to a conduit or line 28 leading to an undersea location at a desired optimal depth, which may be in seawater exposed to sunlight but preferably is in a deeper ocean pool more than about 3 km below the ocean surface for the reasons considered above. In a preferred embodiment, before compression at the compression station 26, the combustion exhaust gas is sent to a carbon dioxide separation station 25 where the carbon dioxide is separated from the combustion exhaust gas by absorption, adsorption, thin-film gas separation, or other methods well-known to those skilled in the art. Next, only the carbon dioxide is sent to the compression station 26 and finally transported to the undersea location by the conduit 28. Next, the components of the combustion exhaust gas other than carbon dioxide are treated and discarded by means well-known to those skilled in the art.

[0015] The turbine including the drive device 22 is mechanically connected to the generator 24 in a well-known manner, where electricity is generated and transmitted to a power substation 30 via line 28. The substation 30 generally has switching, protection and control devices, and transformers, and the output from the substation 30 is transmitted via a power transmission line 32 to a remote onshore location, preferably where it may be distributed as required.

[0016] Turning now to FIG. 2, another aspect of the present invention is shown. The aspect shown in FIG. 2 is substantially the same as that shown in FIG. 1, except that gas from the pipeline 16 is transported via line 14 to the gas storage tank 15 disposed on the structure 10. The gas in the storage tank 15 is transported via line 13 to the gas treatment module 12. The aspect of FIG. 2 is the same as the aspect of FIG. 1 in all other respects and functions in a similar manner.

[0017] Turning now to FIG. 3, another aspect of the present invention is shown which is the same as the aspects shown in FIGS. 1 and 2, except that it utilizes liquefied natural gas (LNG) as a fuel source. To this end, there is a barge or ship 42 having a room or container 44 for carrying the LNG, and the LNG is transported from the room 44 via line 48 to a storage vessel 46 on the structure 10. The LNG is transported via line 47 to the regasification module 50, and then the regasified liquefied natural gas (RLNG) is transported via line 52 to the gas treatment module 12. The LNG may be used as a fuel without regasification using fuel injection techniques. In all other respects, the aspect of FIG. 3 is the same as the aspects of FIGS. 1 and 2 and functions in a similar manner. 2 exists, and the LNG is transported from the room 44 via line 48 to a storage vessel 46 on the structure 10. The LNG is transported via line 47 to the regasification module 50, and then the regasified liquefied natural gas (RLNG) is transported via line 52 to the gas treatment module 12. The LNG may be used as a fuel without regasification using fuel injection techniques. In all other respects, the aspect of FIG. 3 is the same as the aspects of FIGS. 1 and 2 and functions in a similar manner.

[0018] Next, in FIG. 4, a schematic arrangement of a typical gas turbine system that may be used in the power generation system, and the method of the present invention are shown. The gas turbine system of FIG. 4 includes a compressor 60 connected to a turbine 64 by a shaft 62. Air is introduced into the compressor 60 via line 66 in a well-known manner, the air is compressed, and then transported via line 68 to a combustion chamber 70 where it is mixed with a suitable fuel, such as natural gas, LNG, and the fuel is ignited within the combustion chamber 70 to produce a high-temperature, high-pressure gas stream that is induced via line 74 into the turbine 64 to drive the turbine 64 where it expands to exhaust pressure to provide a shaft work output via shaft 76 and may then drive an electric generator, such as generator 24. Next, the carbon dioxide combustion gas from the turbine 64 is captured for transport via line 28 for isolation at a suitable depth below the ocean surface as described above for the embodiments of FIGS. 1 - 3.

[0019] In the case of a steam turbine, the natural gas is used to convert water to steam, the steam is used in turn to drive the turbine, and the output shaft of the turbine is connected to a generator as in the case of the gas turbine. Further, it is also envisioned that there may be a combination of gas and steam turbines similar in form to a land-based combined cycle power plant well-known to those skilled in the art.

[0020] In all of the aspects considered above, either natural gas or LNG has been utilized as the fuel source. However, it is within the scope of the present invention for the fuel source to include petroleum, heating oil, and other hydrocarbon liquids. Further, the fuel source may include coal that may be transported to the ocean structure from the shore by barge, and the coal that forms the fuel for the boiler generates steam to drive a steam turbine. The use of coal clearly presents a greater combustion gas capture problem, but as described above with respect to the embodiments shown in FIGS. 1 - 3, harmful gases other than CO2 are captured and the remaining CO2 is transported into the ocean. Known techniques exist for recovering combustion gases from the combustion of coal or similar solid fossil fuels with a certain composition. Such systems may be useful when the situation makes it difficult for the system to supply natural gas, LNG, or other similar liquid fossil fuels, and when there are abundant coal deposits in adjacent land areas. Furthermore, used paper products may also be utilized as a fuel source.

[0021] Furthermore, it is assumed that the carbon dioxide recovery system may include a system for adding additives before undersea transportation, if necessary, in order to mitigate the potential for local ocean acidification through the ocean sequestration of point sources of carbon dioxide.

[0022] As described above, the structure may be a floating structure similar to an offshore oil and gas work platform that forms a semi-permanent structure thereby, or a fixed structure similar to a relatively shallow offshore oil and gas work platform recently. However, the use of some types of floating structures is preferred because it allows for the discretionary transfer of the system from one location to another in order to optimize cost issues.

[0023] Furthermore, the feed stock and power or export connections It will be understood that they are of a type that can be quickly detached to move the structure during weather-related events such as typhoons.

[0024] Furthermore, depending on what type of one or more turbines are utilized, it will be understood that the power plant may also include boilers, steam generators, pumps, and typical devices used in onshore power plants and systems well-known to those skilled in the art.

[0025] Furthermore, it is assumed that the system may also include another container or structure with energy storage capacity.

[0026] In this specification, although some specific embodiments of the present invention have been described in some detail, this has been done solely for the purpose of illustrating various embodiments of the present invention and is not intended to limit the scope of the present invention as defined in the following claims. Those skilled in the art will understand that the illustrated and described embodiments are exemplary and that various other alternatives, variations, and modifications, including alternatives to the designs specifically contemplated herein, may be made in the practice of the present invention without departing from its scope.

Claims

1. 1. A system for generating electricity, comprising: an offshore marine structure; and a power generation system mounted on the structure, The power generation system includes: Generator and a drive device powered by a fossil fuel combustion process, said drive device being connected to said generator; a capture system connected to said combustion process for transporting carbon dioxide flue gas from said combustion process to a subsea location; A power generation system comprising:

2. The system of claim 1 , wherein the driver comprises a turbine.

3. The system of claim 2 , wherein the driver comprises a gas turbine.

4. 2. The system of claim 1, wherein the capture system includes a conduit having a first end operably connected to the drive device for receiving the carbon dioxide combustion gas therefrom and a second end disposed at a subsea location.

5. The system of claim 4 , wherein the capture system further comprises a compression system for compressing the carbon dioxide combustion gas introduced into the conduit.

6. 10. The system of claim 1, further comprising a power substation mounted on said offshore structure for receiving electrical power output from said generator.

7. 7. The system of claim 6, further comprising an electric power transmission system operably connected to said substation and to said remote location for transmitting electric power to said remote location. Hmm.

8. placing a structure at an offshore marine location; mounting a power generation system on the structure, the power generation system comprising a generator and a drive drivingly connected to the generator; burning a fossil fuel and using a carbon dioxide combustion gas by-product to power said drive device; capturing and transporting the carbon dioxide combustion gas to a subsea location; and Including, the Electricity Generation Act.

9. The method of claim 8 , wherein the driving device is one of a gas combustion turbine or a steam turbine.

10. 10. The method of claim 8, further comprising compressing said carbon dioxide gas prior to transporting said carbon dioxide gas to said subsea location.

11. The method of claim 8 further comprising transmitting electrical power from the power generation system to a remote location.

12. The method of claim 11 , wherein the remote location is on land.

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