Methanol production system

Abstract

Disclosed is a methanol production system including a methanol production reactor configured to produce methanol using a feed gas containing carbon dioxide and hydrogen, a gas-liquid separator configured to separate unreacted gas from a reaction product produced in the methanol production reactor, and a distillation column configured to distill methanol from the reaction product from which the unreacted gas has been separated in the gas-liquid separator, wherein at least a portion of waste water discharged after distillation of the methanol in the distillation column is supplied to the methanol production reactor as cooling water.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to Korean Patent Application No. 10-2025-0053885, filed on April 24, 2025, the entire contents of which are incorporated herein by reference for all purposes. Technical Field

[0003] This disclosure relates to methanol production systems, and more particularly to methanol production systems that can eliminate the need for separate purification facilities for wastewater treatment and reduce the amount of wastewater generated by utilizing wastewater separated after methanol production as cooling water for temperature control of the methanol production reactor, thereby achieving a compact equipment configuration. Background Technology

[0004] In conventional methanol production systems, wastewater (process water) separated after methanol production is purified through a separate purification facility to remove compounds generated during the reaction, such as hydroalcohols, esters, dimethyl ether (DME), and ketones. The wastewater (process water) purified to deionized (DI) water through this separate purification facility is then used for water electrolysis, and the green hydrogen produced through renewable energy-based water electrolysis is used in methanol production.

[0005] However, due to the land-based water electrolysis and complex equipment configuration, such conventional methanol production systems are difficult to apply to offshore platforms and have therefore been primarily used on shore-based platforms. Furthermore, when the methanol produced for marine applications is transported to ships, an additional problem arises: carbon emissions are generated during the transportation process. Summary of the Invention

[0006] One object of this disclosure is to provide a methanol production system that eliminates the need for a separate purification facility for wastewater treatment and reduces the amount of wastewater generated by utilizing wastewater separated after methanol production as cooling water for temperature control of the methanol production reactor, thereby achieving a compact equipment configuration.

[0007] The technical problems to be solved by this disclosure are not limited to those mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the following description.

[0008] One embodiment is a methanol production system comprising: a methanol production reactor configured to produce methanol using a feed gas containing carbon dioxide and hydrogen; a gas-liquid separator configured to separate unreacted gases from the reaction products generated in the methanol production reactor; and a distillation column configured to distill methanol from the reaction products from which unreacted gases have been separated in the gas-liquid separator, wherein at least a portion of the wastewater discharged after methanol distillation in the distillation column is supplied as cooling water to the methanol production reactor.

[0009] According to one implementation, the wastewater is not purified before being supplied to the methanol production reactor.

[0010] According to one embodiment, the methanol production system may further include a compressor configured to compress the feed gas and supply the compressed feed gas to the methanol production reactor.

[0011] According to one implementation, the compressor compresses the feed gas to a pressure of 30 to 70 bar.

[0012] According to one implementation, the unreacted gas separated in the gas-liquid separator can be supplied to a compressor or to a methanol production reactor.

[0013] According to one implementation scheme, carbon dioxide can be captured using direct air capture (DAC) technology.

[0014] According to one implementation plan, hydrogen can be produced by water electrolysis.

[0015] According to one embodiment, the methanol production system may also include a heat exchanger configured to preheat the feed gas or unreacted gas separated in a gas-liquid separator using the heat of reaction from the methanol production reactor.

[0016] According to one implementation, the heat exchange medium can be circulated between the methanol production reactor and the heat exchanger.

[0017] According to one implementation plan, the methanol production system can be set up on an offshore platform.

[0018] According to one embodiment, the methanol production system may further include a purification unit configured to purify seawater into distilled water, wherein the distilled water can be electrolyzed to produce hydrogen.

[0019] According to one implementation, the purification unit is a reverse osmosis (RO) device or a membrane device.

[0020] According to one embodiment, the methanol production system may further include a byproduct determination unit, to which the remaining portion of the wastewater is supplied and the byproduct determination unit determines whether the byproducts in the wastewater are equal to or less than a predetermined standard, wherein when the byproduct determination unit determines that the byproducts in the wastewater are equal to or less than the predetermined standard, the wastewater is supplied to a purification unit.

[0021] According to one implementation plan, when the by-product determination unit determines that the by-products in the wastewater exceed a predetermined standard, the wastewater is supplied to a wastewater storage tank.

[0022] According to one implementation plan, 30% to 50% of the wastewater can be recycled as cooling water.

[0023] According to this disclosure, wastewater separated after methanol production is used as cooling water for temperature control of the methanol production reactor, thereby eliminating the need for a separate purification facility for wastewater treatment and reducing the amount of wastewater generated. Therefore, the total number of process steps, including water electrolysis, can be reduced, and a compact equipment configuration can be achieved, making the system suitable for offshore platforms.

[0024] When the methanol production system is applied to offshore platforms as described above, carbon generated in the marine environment can be directly utilized, and methanol for marine use can be supplied to ships via coastal supply or fuel supply without generating additional carbon emissions after methanol production.

[0025] In addition, when methanol production systems are applied to offshore platforms, seawater can be purified into distilled water and used for water electrolysis, and in some cases, wastewater can also be purified and used for water electrolysis when the byproducts in the wastewater are determined to be equal to or less than predetermined standards.

[0026] The effects of this disclosure are not limited to those described above, and those skilled in the art can derive other effects not described herein from the following description of the embodiments of this disclosure. Attached Figure Description

[0027] Figure 1 A schematic diagram of a methanol production system according to a first embodiment of the present invention is shown.

[0028] Figure 2 A schematic diagram of a methanol production system according to a second embodiment of the present invention is shown.

[0029] Figure 3 A schematic diagram of a methanol production system according to a third embodiment of the present invention is shown. Detailed Implementation

[0030] In the following description, a preferred embodiment of the methanol production system according to this disclosure will be described with reference to the accompanying drawings.

[0031] Furthermore, the terms described below are defined in consideration of the functionality of one or more exemplary embodiments and may have different meanings depending on the intent or practice of the user or operator. Additionally, the exemplary embodiments described below are not intended to limit the scope of this disclosure, but rather to exemplify only the configuration elements defined in the claims.

[0032] For clarity in illustrating the invention, irrelevant details have been omitted, and similar components are indicated by similar reference numerals throughout the specification. Throughout the specification, when a part "comprises" or "includes" a component, unless otherwise stated, this indicates that other components are not excluded and may be included.

[0033] In this specification, regarding elements referred to as "units" or "modules," two or more elements may be combined into one element, or one element may be divided into two or more elements according to its subdivided functions. Furthermore, each element described below, in addition to its own main function, may additionally perform some or all of the functions performed by another element, and some of the main functions of each element may be performed entirely by another component.

[0034] Reference Figure 1 The following describes a methanol production system according to a first embodiment of the present invention.

[0035] The methanol production system according to this embodiment includes a compressor 100, a methanol production reactor 200, a gas-liquid separator 300, and a distillation column 400. In some cases, all components can be configured in multiple stages.

[0036] The methanol production reactor 200 uses a feed gas containing carbon dioxide (CO2) and hydrogen (H2) to produce methanol.

[0037] Compressor 100 compresses the feed gas and supplies it to methanol production reactor 200. Preferably, compressor 100 compresses the feed gas to a pressure of 30 bar to 70 bar.

[0038] The gas-liquid separator 300 separates unreacted gases from the reaction products generated in the methanol production reactor 200. The reaction products generated in the methanol production reactor 200 include unreacted gases, methanol, water, and byproducts.

[0039] The unreacted gas separated in the gas-liquid separator 300 is supplied to the compressor 100 or to the methanol production reactor 200 for reuse in methanol production.

[0040] Distillation column 400 distills methanol from the reaction products from which unreacted gases have been separated in gas-liquid separator 300. In some cases, the distilled methanol from distillation column 400 may be in the form of dimethyl ether (DME), sustainable aviation fuel (SAF), etc.

[0041] The present disclosure is characterized in that at least a portion of the wastewater discharged after methanol distillation in distillation column 400 is supplied as cooling water to methanol production reactor 200. In methanol production reactor 200, heat of reaction is generated during methanol production, and the supplied wastewater cools the reactor to control the temperature of methanol production reactor 200.

[0042] The wastewater is not purified before being supplied to the methanol production reactor 200. Although the wastewater contains byproducts other than water (e.g., hydrogen alcohols, esters, DME, ketones, etc.), unlike conventional systems, it is not used for water electrolysis. Instead, since the wastewater is used as cooling water to control the temperature of the methanol production reactor 200 (e.g., to maintain isothermal conditions), a separate purification facility is not required to remove the byproducts. Therefore, this can help reduce the load on the water treatment system.

[0043] Therefore, this disclosure eliminates the need for a separate purification facility for wastewater and reduces the volume of wastewater, thereby reducing the total number of process steps (including those related to water electrolysis) and allowing for a compact equipment configuration. Consequently, the methanol production system of this disclosure can be applied not only to onshore platforms but also, in particular, to offshore platforms.

[0044] In the following description, the methanol production system of this disclosure is described with reference to its installation on an offshore platform. Considering domestic and international environments, the offshore platform of the floating facility can be fixed, floating, or coastal-connected. When the methanol production system of this disclosure is applied to an offshore platform, the methanol produced for marine applications can be supplied to the vessel via coastal supply or fuel supply without additional carbon emissions.

[0045] The remainder of the wastewater discharged from distillation column 400 that is not supplied to methanol production reactor 200 is stored in a wastewater storage tank for separate treatment. Since at least a portion of the wastewater is recycled as cooling water, the volume of the wastewater storage tank can be minimized.

[0046] Preferably, 30% to 50% of the wastewater is recycled as cooling water. For example, when producing 300,000 TPY of methanol (43,611 kg / h), the amount of wastewater generated can correspond to 170,000 TPY (23,933 kg / h). When using a boiling water reactor (BWR) as the methanol production reactor, 51,500 kg / h of cooling water is required, therefore approximately 40% of the wastewater can be used as cooling water for reactor temperature control.

[0047] In this implementation, carbon dioxide is captured using direct air capture (DAC) technology. While carbon dioxide captured on shore may be transported in some cases, it is more efficient when captured via DAC, as carbon from the marine environment can be directly utilized without additional transportation. The carbon dioxide captured via DAC can be stored in a separate carbon dioxide tank and supplied to compressor 100.

[0048] Furthermore, in this embodiment, hydrogen is generated through the electrolysis of distilled water (DI water). The electricity used for electrolysis can be supplied by renewable energy sources, an energy storage system (ESS), an external power source, or a combination thereof. Since methanol production requires a high hydrogen-to-carbon dioxide molar ratio, additional hydrogen from nuclear energy, reforming, or other sources can be used when the hydrogen produced by electrolysis is insufficient. The hydrogen produced by electrolysis can be stored in a hydrogen tank and supplied to compressor 100.

[0049] The methanol production system disclosed herein includes eco-friendly processes, and the methanol produced therefrom corresponds to electro-methanol.

[0050] Reference Figure 2 The following describes a methanol production system according to a second embodiment of the present invention.

[0051] like Figure 1 In this embodiment, the methanol production system includes a compressor 100, a methanol production reactor 200, a gas-liquid separator 300, and a distillation column 400, and also includes a heat exchanger 500.

[0052] The heat exchanger 500 uses the heat of reaction from the methanol production reactor 200 to preheat the feed gas or unreacted gas separated in the gas-liquid separator 300. In this embodiment, the heat exchanger 500 is installed between the compressor 100 and the methanol production reactor 200 to preheat the feed gas supplied to the methanol production reactor 200.

[0053] In some cases, a heat exchanger may be installed between the gas-liquid separator 300 and the compressor 100 or between the gas-liquid separator 300 and the methanol production reactor 200 to preheat unreacted gases.

[0054] In this embodiment, the heat exchange medium circulates between the methanol production reactor 200 and the heat exchanger 500. Therefore, the heat exchange medium absorbs the reaction heat in the methanol production reactor 200, transfers the heat to the feed gas in the heat exchanger 500, and circulates back to the methanol production reactor 200, thereby effectively utilizing the reaction heat within the system.

[0055] Reference Figure 3 The following describes a methanol production system according to a third embodiment of the present invention.

[0056] like Figure 1 In this embodiment, the methanol production system includes a compressor 100, a methanol production reactor 200, a gas-liquid separator 300, and a distillation column 400, and also includes a purification unit 600 and a byproduct determination unit 700.

[0057] Since the methanol production system of this embodiment is applied to an offshore platform, hydrogen is produced through the electrolysis of seawater. Specifically, purification unit 600 purifies seawater into distilled water, and the distilled water is electrolyzed to produce hydrogen. Purification unit 600 is primarily used for salt removal and differs in type from purification facilities used to remove byproducts from wastewater, occupying a much smaller space within the system. Purification unit 600 can be a reverse osmosis (RO) unit or a membrane unit. Byproducts separated in purification unit 600 can be stored and subsequently disposed of onshore.

[0058] In addition, a portion of the wastewater discharged from distillation column 400 that is not supplied to methanol production reactor 200 is supplied to by-product determination unit 700. By-product determination unit 700 determines whether the by-products in the wastewater are equal to or less than predetermined standards. These standards may vary according to environmental regulations or other conditions, and by-products may be assessed in ppm units.

[0059] When hydrogen is produced by seawater electrolysis, chloride ions are oxidized at the electrolytic oxidation electrode, generating other byproducts such as chlorine. Therefore, after identifying the byproducts, the wastewater can be purified for reuse in the process steps as needed.

[0060] If the byproduct determination unit 700 determines that the byproducts in the wastewater are equal to or less than a predetermined standard, the wastewater is supplied to the purification unit 600. In this case, the wastewater is purified together with seawater and can be used for electrolysis, thereby increasing hydrogen production and further reducing wastewater volume.

[0061] Conversely, if the byproduct identification unit 700 determines that the byproducts in the wastewater exceed a predetermined standard, the wastewater is not supplied to the purification unit 600, but instead to the wastewater storage tank for storage.

[0062] This disclosure is not limited to the specific embodiments and descriptions described above, and those skilled in the art can make various modifications without departing from the spirit of this disclosure as claimed in the claims. Such variations are within the scope of protection of this disclosure.

[0063] Figure Labels

[0064] 100: Compressor

[0065] 200: Methanol Production Reactor

[0066] 300: Gas-Liquid Separator

[0067] 400: Distillation column

[0068] 500: Heat exchanger

[0069] 600: Purification Unit

[0070] 700: By-product identification unit

Claims

1. A methanol production system, comprising: A methanol production reactor configured to produce methanol using a feed gas containing carbon dioxide and hydrogen; A gas-liquid separator configured to separate unreacted gas from the reaction products generated in the methanol production reactor; as well as A distillation column configured to distill methanol from the reaction products from which the unreacted gas has been separated in the gas-liquid separator. At least a portion of the wastewater discharged after methanol is distilled in the distillation tower is supplied as cooling water to the methanol production reactor.

2. The methanol production system according to claim 1, The wastewater was not purified before being supplied to the methanol production reactor.

3. The methanol production system according to claim 1 further includes: A compressor configured to compress the feed gas and supply the compressed feed gas to the methanol production reactor.

4. The methanol production system according to claim 3, The compressor compresses the feed gas to a pressure of 30 bar to 70 bar.

5. The methanol production system according to claim 3, The unreacted gas separated in the gas-liquid separator is supplied to the compressor or to the methanol production reactor.

6. The methanol production system according to claim 1, The carbon dioxide mentioned therein is captured using direct air capture (DAC) technology.

7. The methanol production system according to claim 1, The hydrogen gas is produced by water electrolysis.

8. The methanol production system according to claim 1, further comprising: A heat exchanger configured to preheat the feed gas or the unreacted gas separated in the gas-liquid separator by using the heat of reaction from the methanol production reactor.

9. The methanol production system according to claim 8, The heat exchange medium circulates between the methanol production reactor and the heat exchanger.

10. The methanol production system according to claim 2, The methanol production system is located on an offshore platform.

11. The methanol production system according to claim 10, further comprising: A purification unit configured to purify seawater into distilled water, and The distilled water is electrolyzed to produce the hydrogen gas.

12. The methanol production system according to claim 11, The purification unit is a reverse osmosis (RO) device or a membrane device.

13. The methanol production system according to claim 11, further comprising: A byproduct determination unit is supplied with the remaining portion of the wastewater, and the byproduct determination unit determines whether the byproducts in the wastewater are equal to or less than a predetermined standard. When the byproduct determination unit determines that the byproduct in the wastewater is equal to or less than the predetermined standard, the wastewater is supplied to the purification unit.

14. The methanol production system according to claim 13, in, When the byproduct determination unit determines that the byproducts in the wastewater exceed the predetermined standard, the wastewater is supplied to the wastewater storage tank.

15. The methanol production system according to claim 1, 30% to 50% of the wastewater is recycled as cooling water.

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