Apparatus and method for synthesizing methanol

Abstract

An apparatus and a method for synthesizing methanol are disclosed. The apparatus includes a hydraulic pressure generator, a carbon-capturing device, an electrolysis device, and a reactor. The hydraulic pressure generator generates a pressurized water from ocean water. The carbon-capturing device has an electrodialysis unit and a carbon-capture unit. The electrodialysis unit generates an acid, a base, and a desalinated water from a first portion of the pressurized water. The carbon-capture unit generates carbon dioxide by acidification of a second portion of the pressurized water. The electrolysis device receives an input stream of water to generate hydrogen. The reactor receives the carbon dioxide from the carbon-capture unit and the hydrogen from the electrolysis device to synthesize methanol.

Description

APPARATUS AND METHOD FOR SYNTHESIZING METHANOLTECHNICAL FIELD

[0001] The present disclosure generally relates to the synthesis of methanol and, more particularly, to an apparatus and a method for synthesizing methanol from ocean water.BACKGROUND

[0002] Methanol (CH3OH) is a chemical compound produced conventionally from natural gas, coal, etc. In recent times, methanol can also be directly produced from the reaction of carbon dioxide (CO2) and hydrogen (H2). Methanol production has gained a lot of attention due to its wide applications in both the process and product industries, for example, in the chemical and pharmaceutical industries. Methanol can also be used as an alternative fuel in automobiles and marine vehicles. Methanol holds several advantages over other substances commonly used in industrial settings, notably its lower toxicity compared to ammonia. Further, methanol offers a cleaner emission profile compared to fossil fuels (e.g., gasoline), particularly in terms of particulate emissions, and having the ability to meet stringent emission limits of nitrogen oxide (NOx).

[0003] One promising way of methanol production lies in tapping into abundant natural gas reserves without the need for converting it first into synthetic. Additionally, several innovative processes are emerging for producing renewable methanol from different sources, such as municipal solid waste, sludges, etc. Moreover, methanol can be synthesized through the reaction of hydrogen and carbon dioxide, where the carbon dioxide can be captured directly from the atmospheric air ( / .e. a direct air capture (DAC)) or concentrated sources, such as flue gas from power or other industrial plants. However, these advancements come with challenges. For instance, the process and technologies involved demand substantial amounts of both electrical and thermal energy driving up the production cost. Additionally, the infrastructure required for methanol production entails high costs and is space-intensive. Therefore, there exists a need to find alternate ways of generating and storing methanol that are not only cost-effective and accessible but also minimize space requirements especially when compared to DAC.SUMMARY

[0004] In order to solve the foregoing problem and to provide other advantages, one aspect of the present disclosure is to provide an apparatus for synthesizing methanol. The apparatus includes a hydraulic pressure generator, a carbon-capturing device, an electrolysis device, and a reactor. The hydraulic pressure generator is configured to generate pressurized water from ocean water. In particular, the hydraulic pressure generator generates the pressurized water using the kinetic energy of the flow or current of the ocean water. The carbon-capturing device is fluidically connected or connectable to the hydraulic pressure generator. The carbon-capturing device has an electrodialysis unit and a carbon-capture unit. The electrodialysis unit is configured to generate an acid and a base from a first portion of the pressurized water and output a de-salinated water. Further, the carbon-capture unit is configured to generate carbon dioxide by acidification of a second portion of the pressurized water using the acid and output a carbon-depleted water. Furthermore, the electrolysis device is configured to receive an input stream of water to generate hydrogen. The reactor is fluidically connected or connectable to the carbon-capturing device and the electrolysis device. The reactor is configured to receive the carbon dioxide from the carbon- capture unit and the hydrogen from the electrolysis device, and a reaction of the carbon dioxide and the hydrogen synthesize methanol. Advantageously, the apparatus provides the advantage of generating carbon dioxide from ocean water instead of from atmospheric air. This provides the advantage of abundant availability of a source of ocean water for generating the carbon dioxide. Further, the base can be used for neutralizing the ocean water after the extraction of carbon dioxide, which then can be discharged to the ocean, thereby facilitating further absorption of atmospheric carbon dioxide. Furthermore, generating the carbon dioxide by the utilization of renewable energy sources including, but not limited to tidal, solar, and wind energy may reduce the energy demand and the overall carbon footprint of the apparatus. In other words, the process of synthesizing methanol by utilizing renewable energy sources lowers the carbon footprint of the apparatus. The ocean water provides the advantage of abundant availability of water sources for generating carbon dioxide. The ocean water has the natural ability to absorb enormous amounts of the carbon dioxide from the atmosphere, which helps mitigate the effects of climate change. Additionally, as the pressurized water is generated by the hydraulic pressure generator, there is no need for additional pumps to pressurize the ocean water to be supplied to the carbon capture device. This feature reduces the overall cost of synthesizing the methanol.

[0005] In an aspect of the apparatus, the input stream of water supplied to the electrolysis device is the de-salinated water. Advantageously, providing the de-salinated water to the electrolysisdevice eliminates the need for desalinating the water, thereby reducing the energy demand of the apparatus.

[0006] In an aspect of the apparatus, a first storage tank is configured to store the acid and a second storage tank is configured to store the base. The base can neutralize the ocean water subsequent to carbon dioxide extraction, enabling its safe discharge back into the ocean. This process promotes additional absorption of atmospheric carbon dioxide by the ocean. Storing the acid and the base in tanks is useful in case of the absence or fluctuation of electric power required to operate the carbon-capture unit.

[0007] In an aspect of the apparatus, a distillation unit is fluidically connected or connectable to the reactor. The distillation unit is configured to use thermal energy generated from the reaction of the carbon dioxide and the hydrogen to distill the synthesized methanol. Advantageously, the heat generated during methanol generation in the reactor reduces the requirements for heat to distillate the methanol. This reduces the overall cost of synthesization of the methanol, thereby making the apparatus cost-effective.

[0008] In an aspect of the apparatus, the carbon-capture unit is further configured to supply the carbon dioxide to a first storage device enclosed in a first pressurized container below ocean water at a first predetermined hydraulic pressure. The distillation unit is further configured to supply the distilled methanol to a second storage device enclosed in a second pressurized container below the ocean water at a second predetermined hydraulic pressure. Advantageously, storage of the carbon dioxide and the methanol below the ocean water reduces its condensation cost and offers safe storage for a long term compared to on-shore storage.

[0009] In an aspect of the apparatus, the first portion is about 1% to 2% of the pressurized water and the second portion of the pressurized water is about 98% to 99% of the pressurized water. Advantageously, the first portion is about 1% to 2 % of the pressurized water utilizes very little amount of the pressurized water to generate the hydrogen and thus limits the energy requirements.

[0010] In an aspect, a method for synthesizing methanol is disclosed. The method includes generating pressurized water from ocean water. The hydraulic pressure generator generates the pressurized water using the kinetic energy of the flow or current of the ocean water. The methodfurther includes performing electrodialysis of a first portion of the pressurized water to generate an acid and a base and providing a de-salinated water. Furthermore, the method includes generating carbon dioxide by acidification of a second portion of the pressurized water using the acid and outputting a carbon-depleted water. Moreover, the method includes generating hydrogen from an input stream of water and synthesizing methanol from a reaction of the carbon dioxide and the hydrogen. Advantageously, the apparatus provides the advantage of generating carbon dioxide from ocean water instead of from atmospheric air. This provides the advantage of abundant availability of a source of ocean water for generating the carbon dioxide. Further, the base can be used for neutralizing the ocean water after the extraction of carbon dioxide, which then can be discharged to the ocean, thereby facilitating further absorption of atmospheric carbon dioxide. Furthermore, generating the carbon dioxide by the utilization of renewable energy sources including, but not limited to tidal, solar, and wind energy may reduce energy demand and the overall carbon footprint of the apparatus. In other words, the process of synthesizing methanol by utilizing renewable energy sources lowers the carbon footprint of the apparatus. Ocean water provides the advantage of abundant availability of water sources for generating carbon dioxide. Ocean water has the natural ability to absorb enormous amounts of carbon dioxide from the atmosphere, which helps mitigate the effects of climate change. Additionally, as pressurized water is generated by the hydraulic pressure generator, there is no need for additional pumps to pressurize the water to be supplied to the carbon capture device. This feature reduces the overall cost of synthesizing the methanol.

[0011] In an aspect of the method, the input stream of water supplied to the electrolysis device is the de-salinated water. Advantageously, providing the de-salinated water to the electrolysis device eliminates the need for desalinating the water, thereby reducing the energy demand of the apparatus.

[0012] In an aspect of the method, includes storing the acid in a first storage tank and storing the base in a second storage tank. The base can neutralize the ocean water subsequent to carbon dioxide extraction, enabling its safe discharge back into the ocean. This process promotes additional absorption of atmospheric carbon dioxide by the ocean. Storing the acid and the base in tanks is useful in case of the absence or fluctuation of electric power required to operate the carbon-capture unit.

[0013] In an aspect of the method, includes distilling the synthesized methanol through thermal energy generated from the reaction of the carbon dioxide and the hydrogen. Advantageously, the heat generated during methanol generation in the reactor reduces the requirements for heat to distillate the methanol. This reduces the overall cost of synthesization of the methanol, thereby making the apparatus cost-effective.

[0014] In an aspect of the method, includes supplying the carbon dioxide to a first storage device enclosed in a first pressurized container below ocean water at a first predetermined hydraulic pressure and supplying the distilled methanol to a second storage device enclosed in a second pressurized container below the ocean water at a second predetermined hydraulic pressure. Advantageously, storage of the carbon dioxide and the methanol below the ocean water reduces its condensation cost and offers safe storage for a long term compared to on-shore storage.

[0015] In an aspect of the method, the first portion is about 1 % to 2% of the pressurized water and the second portion is about 98% to 99% of the pressurized water. Advantageously, the first portion is about 1% to 2% of the pressurized water utilizes very little amount of the pressurized water to generate the hydrogen and thus limits the energy requirements.BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above and other features and advantages of the present disclosure will become readily apparent to those skilled in the art by the following detailed description of exemplary embodiments thereof with reference to the attached drawings, in which:

[0017] Figure 1 illustrates a block diagram representation of an apparatus related to various embodiments of the present disclosure;

[0018] Figure 2A illustrates a schematic representation of the apparatus, in accordance with one embodiment of the present disclosure;

[0019] Figure 2B illustrates a schematic representation of the apparatus, in accordance with another embodiment of the present disclosure;

[0020] Figure 2C illustrates a schematic representation of the apparatus, in accordance with yet another embodiment of the present disclosure;

[0021] Figure 3A illustrates a block diagram representation of a power balance of the apparatus, in accordance with an embodiment of the present disclosure;

[0022] Figure 3B illustrates a block diagram representation of a thermal balance of the apparatus, in accordance with an embodiment of the present disclosure; and

[0023] Figure 4 illustrates a flow diagram of an example representation of a method for synthesizing methanol, in accordance with an embodiment of the present disclosure.DETAILED DESCRIPTION

[0024] Various exemplary embodiments and details are described hereinafter, with reference to the figures when relevant. It should be noted that the figures may or may not be drawn to scale and that elements of similar structures or functions are represented by like reference numerals throughout the figures. It should also be noted that the figures are only intended to facilitate the description of the embodiments. They are not intended as an exhaustive description of the disclosure or as a limitation on the scope of the disclosure. In addition, an illustrated embodiment does not have all the aspects or advantages shown. An aspect or an advantage described in conjunction with a particular embodiment is not necessarily limited to that embodiment and can be practiced in any other embodiments even if not so illustrated, or if not so explicitly described.

[0025] The Figures are schematic and simplified for clarity, and they merely show details which aid in understanding the disclosure, while other details have been left out. Throughout, the same reference numerals are used for identical or corresponding parts.

[0026] Various embodiments of the present disclosure relate to an apparatus and a method for synthesizing methanol. The apparatus includes a hydraulic pressure generator, a carbon- capturing device, an electrolysis device, and a reactor. These devices of the apparatus are arranged in one or more sequences to generate methanol from ocean water. The hydraulic pressure generator generates pressurized water from the ocean water by receiving electric power from a suitable power source, such as a renewable power source. The carbon-capturing devicereceives the pressurized water from the hydraulic pressure generator at least to generate carbon dioxide therefrom. The pressurized water received by the carbon-capturing device channelizes into a first portion and a second portion. An electrodialysis unit of the carbon-capturing device receives the first portion to generate an acid, a base, and a de-salinated water therefrom. A carbon-capture unit of the carbon-capturing device receives the second portion to generate the carbon dioxide by acidification using the acid and outputs a carbon-depleted water using a pH swing process. The electrolysis device can be arranged in a variety of configurations to receive one of the de-salinated water, the carbon-depleted water, or a portion of the pressurized water to generate the hydrogen. The reactor synthesizes the methanol from a reaction of the carbon dioxide and the hydrogen. The methanol generated by the apparatus can be used in different domains, such as on-shore, off-shore, and the like., to which direct ocean capture (DOC) can be applied.

[0027] Various example embodiments of the present disclosure are described hereinafter with reference to Figure 1 to Figure 4.

[0028] Figure 1 illustrates a block diagram representation of an apparatus 100 related to various embodiments of the present disclosure. The apparatus 100 mainly includes a hydraulic pressure generator 102, a carbon-capturing device 104, an electrolysis device 106, and a reactor 108. These devices of the apparatus 100 may be arranged sequentially to generate methanol 110 from ocean water 112.

[0029] The hydraulic pressure generator 102 is configured to generate pressurized water 114 from the ocean water 112. In particular, the hydraulic pressure generator 102 generates the pressurized water 114 using the flow or current of the ocean water 112. The carbon-capturing device 104 is fluidically connected or connectable to the hydraulic pressure generator 102. The carbon-capturing device 104 receives the pressurized water 114 from the hydraulic pressure generator 102 and is configured at least to generate carbon dioxide 116 therefrom. In particular, the carbon-capturing device 104 includes an electrodialysis unit 118 and a carbon-capture unit 120. The pressurized water 114 received by the carbon-capturing device 104 is channelized into a first portion 122A and a second portion 122B. The electrodialysis unit 118 receives the first portion 122A and is configured to generate an acid 124, a base 126, and a de-salinated water 128 therefrom. The term “de-salinated water 128” disclosed herein refers to water having diluted salt.

[0030] On the other hand, the carbon-capture unit 120 receives the second portion 122B and is configured to generate the carbon dioxide 116 by acidification (using the acid 124) and output a carbon-depleted water 130. The carbon-capture unit 120 generates the carbon dioxide 116 by strategically changing the potential of hydrogen (hereinafter “potential of hydrogen” is referred to as “pH”) of the second portion 122B of the pressurized water 114. In the disclosed embodiment, the carbon dioxide 116 is generated from the second portion 122B of the pressurized water 114 using a “pH swing” process.

[0031] The electrolysis device 106 is fluidically connected or connectable to the carbon-capturing device 104 to receive an input stream of water 132 required to generate hydrogen 134. In one embodiment of the disclosure, the input stream of water 132 is the de-salinated water 128 discharged from the electrodialysis unit 118 of the carbon-capturing device 104. In another embodiment of the disclosure, the input stream of water 132 is the carbon-depleted water 130 discharged from the carbon-capture unit 120. In yet another embodiment of the disclosure, the input stream of water 132 is a portion (not shown in Figure 1) of the pressurized water 114 discharged from the hydraulic pressure generator 102.

[0032] Further, the reactor 108 is fluidically connected or connectable to the carbon-capturing device 104 and the electrolysis device 106. The reactor 108 is fluidically connected or connectable to the carbon-capturing device 104 to receive the carbon dioxide 116 and the electrolysis device 106 to receive the hydrogen 134. The reactor 108 synthesizes the methanol 110 from a reaction of the carbon dioxide 116 and the hydrogen 134. The reactor 108 disclosed herein is configured to be a catalytic reactor, without limiting the scope of the disclosure. The methanol 110 generated by the apparatus 100 can be used in different domains, such as on-shore, off-shore, and the like, to which direct ocean capture (DOC) can be applied.

[0033] In another embodiment, the apparatus 100 may be installed off-shore of the ocean, without limiting the scope of the disclosure. Off-shore installation of the apparatus 100 involves colocation with offshore platforms, such as but not limited to oil rigs, offshore energy farms, and the like. The methanol 110 generated from the ocean water 112 can be routed to facilities that permanently store the methanol 110 in subseafloor, such as in saline aquifers or depleted oil and gas reservoirs. The apparatus 100 has the potential for off-shore installation that offers a variety of useful potential benefits, such as reducing the need for useful land, allowing access to themethanol 110 storage sites, and producing the methanol 110 streams offshore for a number of potential uses, including a feedstock for fuel and chemical synthesis.

[0034] In yet another embodiment, the apparatus 100 may be installed on-shore of the ocean, without limiting the scope of the disclosure. On-shore installation of the apparatus 100 involves co-location with facilities that take ocean water 112 as input, such as desalination plants and power plants. The methanol 110 thus generated may be potentially utilized as raw material for alternative fuel production and chemical manufacturing.

[0035] Figure 2A illustrates a schematic representation of the apparatus 100, in accordance with one embodiment of the present disclosure. Figure 2B illustrates a schematic representation of the apparatus 100, in accordance with another embodiment of the present disclosure. Figure 2C illustrates a schematic representation of the apparatus 100, in accordance with yet another embodiment of the present disclosure.

[0036] Referring to Figures 2A to 2C, the hydraulic pressure generator 102 is configured to generate the pressurized water 114 from the ocean water 112. The hydraulic pressure generator 102 harnesses the kinetic energy of ocean current or flow to generate the pressurized water 114. The ocean current and flow contain significant kinetic energy due to the movement of water masses over long distances in the ocean. The hydraulic pressure generator 102 is placed in the path of flow to capture and convert this kinetic energy into mechanical energy. The hydraulic pressure generator 102 disclosed herein can be any suitable device or unit that is designed to increase pressure (i.e., hydraulic pressure) of the ocean water 112.

[0037] In an embodiment, the hydraulic pressure generator 102 may include a plurality of pressure pumps (not shown) configured to increase the pressure (i.e., hydraulic pressure) of the ocean water 112. The plurality of pressure pumps may be disposed below the ocean surface such that the kinetic energy of the ocean water is used for generating the pressurized water 114. Each pressure pump of the plurality of pressure pumps is connected or connectable to an impeller assembly. The receiving end of each pressure pump may be provided with a foot valve 202 and a strainer 204 to filter large debris, sediments, solid objects (e.g., fish, seawood), etc., present in the ocean water 112. Blades of the impeller assembly are angled to transform the kinetic energy of flowing water into rotational energy. The plurality of pressure pumps may be connected to a main pipe (not shown) through a plurality of secondary pipes (not shown). The main pipe directsthe pressurized water 114 from the plurality of secondary pipes to a receiving station (not shown). At the receiving station, the potential energy in the pressurized water 114 can be released by operating turbines for the generation of electric energy.

[0038] In addition to an increase in the hydraulic pressure of the ocean water 112, the hydraulic pressure generator 102 may also be configured to generate electric power by driving a turbine using the pressurized water 114. In an embodiment, the hydraulic pressure generator 102 may be a hydromill that rotates through the kinetic energy of the ocean waves. The hydromill is a mechanical pump providing the pressurized water 114 (using kinetic energy of the ocean waves) that can be directed to the turbine. The electric power is then utilized to operate other devices (e.g., the electrolysis device 106) of the apparatus 100. Utilizing the kinetic energy of the ocean water to generate the pressurized water 114 reduces the energy demand of the apparatus 100.

[0039] In another embodiment, the plurality of pumps can be operated through one or more motors (not shown). In one embodiment where the apparatus 100 is installed onshore of the ocean, the respective motors of the plurality of pumps may receive electric power from renewable power sources, such as solar power (e.g., solar panels). In another embodiment where the apparatus is installed at the off-shore of the ocean, the motors of the plurality of pumps may receive electric power from renewable power sources, such as wind power, tidal power, thermal power, and the like.

[0040] The hydraulic pressure generator 102 is fluidically connected to the carbon-capturing device 104. As shown, the carbon-capturing device 104 is located downstream of the hydraulic pressure generator 102. Such a mounting arrangement eliminates the requirement of additional energy to generate the pressurized water 114 to be supplied to the carbon-capturing device 104. The electrodialysis unit 118 receives the first portion 122A of the pressurized water 114 from the hydraulic pressure generator 102. According to an aspect, the pressurized water 114 is pretreated before being discharged into the electrodialysis unit 118. In this regard, an ion exchange water filter 206 is provided before an entry of the electrodialysis unit 118. The ion exchange water filter 206 softens the pressurized water 114 through filtration and ion exchange. For instance, the ion exchange water filter 206 removes heavy metal ions, such as calcium ions (Ca+2), magnesium ions (Mg+2), etc., present in the pressurized water 114. The ion exchange water filter 206 may employ one or more techniques including chemical precipitation, membrane separation, ionexchange, etc., for removing the heavy metal ions from the pressurized water 114, without limiting the scope of the invention.

[0041] In an example, the first portion 122A discharged into the electrodialysis unit 118 is about 1 % to 2% of the pressurized water 114. Based on the feasibility and hydrogen 134 generation requirement, the first portion 122A discharged into the electrodialysis unit 118 can be adjusted within the scope of the disclosure. The electrodialysis unit 118 unit uses an electrodialysis process to generate the acid 124 (e.g., hydrochloric acid (HCI)) and the base 126 (e.g., sodium hydroxide (NaOH)) out of the sodium chloride, and to output the de-salinated water 128. In an example, the electrodialysis process is a membrane-based process involving the transport of ions through semipermeable membranes using an applied electric field. The electric field generated by the electric power is received from one or more electric power generating sources, such as but not limited to the hydraulic pressure generator 102, renewable power sources (e.g., tidal, wind, solar, etc.), and the like. The geometrical configuration and operating aspects of the electrodialysis unit 118 are well-known in the art, and therefore not extensively discussed here for the sake of brevity.

[0042] In a specific embodiment, the apparatus 100 includes a first storage tank 208 and a second storage tank 210. Each of the first storage tank 208 and the second storage tank 210 is fluidically connected or connectable to the electrodialysis unit 118. The first storage tank 208 is designed to store the acid 124 (e.g., hydrochloric acid (HCI)) and the second storage tank 210 is designed to store the base 126 (e.g., sodium hydroxide (NaOH)). Such a provision of storing the acid 124 and the base 126 is useful in case of the absence or fluctuation of electric power required to operate the carbon-capture unit 120. In a non-limiting example, the solar panels generate electric power in the daylight to operate the electrodialysis unit 118. Therefore, during daylight, the electrodialysis unit 118 receives the first portion 122A of the pressurized water 114 to generate the acid 124 and the base 126, and output the de-salinated water 128. On the other hand, during nighttime, the solar panels could not generate electric power. The acid 124 and the base 126 stored respectively in the first storage tank 208 and the second storage tank 210 can be used to operate the carbon-capture unit 120.

[0043] Additionally or alternatively, instead of storing the acid 124 in the first storage tank 208 and the base 126 in the second storage tank 210, it can be directly supplied to the carbon-capture unit 120 for continuous usage, without limiting the scope of the invention.

[0044] Further, in the disclosed embodiment, the second portion 122B, discharged into the carbon-capture unit 120, is about 98% to 99% of the pressurized water 114. Based on the feasibility and requirement of the generation of the carbon dioxide 116, the volume of the second portion 122B, discharged into the carbon-capture unit 120, can be varied in another embodiment of the disclosure. The carbon-capture unit 120 uses the pH swing process to generate the carbon dioxide 116 from the second portion 122B of the pressurized water 114. In the illustrated embodiment, the acid 124 is used for the pH swing of the second portion 122B of the pressurized water 114. In an alternate embodiment, both the acid 124 and the base 126 can be used for the pH swing of the second portion 122B of the pressurized water 114. In the pH swing process, the acid 124 reduces the pH of the second portion 122B of the pressurized water 114 thereby acidifying the second portion 122B of the pressurized water 114. In other words, the acid 124 makes the second portion 122B of the pressurized water 114 acidic by reducing its pH. By reducing the pH of the second portion 122B of the pressurized water 114, the carbon dioxide 116 can be extracted from the pressurized water 114. After extracting the carbon dioxide 116, the second portion 122B of the pressurized water 114 turns into the carbon-depleted water 130.

[0045] Further, in order to make the carbon-depleted water 130 more alkaline, the base 126 is added to it. The base 126 has ability to neutralize the carbon-depleted water 130 as the second portion of the pressurized water 114 was made acidic. Thus, the pH of the carbon-depleted water 130 is increased, making it more alkaline. The alkaline carbon-depleted water 130 being discharged in the ocean is more suspectable to capture the carbon dioxide 116. It is to be noted the pH swing process is well-known in the art, and therefore not described here for the sake of brevity.

[0046] According to an embodiment, in order to extract the carbon dioxide 116, a membrane (not shown in Figures 2A, 2B, and 2C) and a vacuum pump (not shown in Figures 2A, 2B, and 2C) are used. The process involves passing the second portion 122B of the pressurized water 114 through a selective membrane (e.g., polymeric membrane, ceramic membrane, hollow fiber membrane, etc.) that allows the molecules of the carbon dioxide 116 to pass while blocking other components present therein. The carbon dioxide 116 permeates through the membrane and is then collected on the other side. The vacuum pump is configured to create a pressure gradient across the membrane, which helps in the efficient movement of the carbon dioxide molecules through the membrane.

[0047] The carbon-capture unit 120 is further configured to supply the carbon dioxide 116 to a first storage device 211 below the ocean water 112 at a first predetermined hydraulic pressure. The first predetermined hydraulic pressure may be a condensation pressure of the carbon dioxide 116. By changing the potential head of the first storage device 211 , the hydraulic pressure of the carbon dioxide 116 can be changed. The first storage device 211 may be enclosed in a first pressurized container 213 to sustain the first predetermined hydraulic pressure at which the first storage device 211 is disposed in the ocean water. Storage of the carbon dioxide 116 below the ocean water 112 (i.e., off-shore) provides cost-saving in construction of the first storage device 211. Additionally, this arrangement ensures the safe and secure storage of the first storage device 211 compared to on-shore storage. The storage of carbon dioxide 116 below the ocean water 112 can be stored for a long term without consuming land space. However, in another embodiment (not shown), the carbon dioxide 116 can be stored at ocean level (i.e., ground level), without departing from the scope of the disclosure. Condensation of the carbon dioxide gas at ground level typically involves reducing its temperature and / or increasing pressure to the point where the transition from the gaseous state to the liquid state takes place.

[0048] Further, an electrolysis device 106 may be configured to receive the input stream of water 132 to generate the hydrogen 134. The input stream of water 132 can be one of the de-salinated water 128 that is discharged from the electrodialysis unit 118, the carbon-depleted water 130 that is discharged from the carbon-capture unit 120, or the portion 212 of the pressurized water 114 that is discharged from the hydraulic pressure generator 102.

[0049] In one embodiment disclosed in Figure 2A, the electrolysis device 106 is fluidically connected or connectable to the electrodialysis unit 118 of the carbon-capturing device 104. The electrolysis device 106 receives the de-salinated water 128 from the electrodialysis unit 118 to generate the hydrogen 134. The electrolysis device 106 uses an electrolysis process to generate the hydrogen 134 from the de-salinated water 128 that is received from the electrodialysis unit 118. As the water supplied to the electrolysis device 106 is de-salinated (i.e., contains no salt or dilute salt), further de-salination is not required. Advantageously, providing the de-salinated water 128 to the electrolysis device 106 eliminates the need for desalinating the water, thereby reducing the energy demand of the apparatus 100.

[0050] In another embodiment disclosed in Figure 2B, the electrolysis device 106 is fluidically connected or connectable to the carbon-capture unit 120 of the carbon-capturing device 104. Theelectrolysis device 106 receives the carbon-depleted water 130 from the carbon-capture unit 120 to generate the hydrogen 134. The electrolysis device 106 uses the electrolysis process to generate the hydrogen 134 from the carbon-depleted water 130 that is received from the carbon- capture unit 120. As the carbon-depleted water 130 may contain salt and other contaminants, desalination of the carbon-depleted water 130 is required. One or more techniques, such as reverse osmosis, ion exchange, etc., can be used to filter out the salt and other contaminants from the carbon-depleted water 130 before being supplied to the electrolysis device 106.

[0051] In yet another embodiment disclosed in Figure 2C, the electrolysis device 106 is fluidically connected or connectable to an outlet of the hydraulic pressure generator 102. The electrolysis device 106 receives the portion 212 of the pressurized water 114 to generate the hydrogen 134. The electrolysis device 106 uses the electrolysis process to generate the hydrogen 134 from the portion 212 of the pressurized water 114.

[0052] In one configuration, the electrolysis device 106 may receive the portion 212 of the pressurized water 114 before an entry of the ion exchange water filter 206. As the pressurized water 114 may contain salt and other contaminants, de-salination of the pressurized water 114 is required. One or more techniques, such as reverse osmosis, ion exchange, etc., can be used to filter out the salt and other contaminants from the pressurized water 114 before being supplied to the electrolysis device 106. However, in another configuration, the ion exchange water filter 206 may receive the portion 212 of the pressurized water 114 after an exit of the ion exchange water filter 206 (i.e. , before the entry of the electrodialysis unit 118). In such a configuration, filtration, and ion exchange of the portion 212 of the pressurized water 114 are not required.

[0053] Referring now to Figures 2A, 2B, and 2C, the electrolysis device 106 consists of two electrodes, viz. cathode and anode. The cathode is a negatively charged electrode, while the anode is positively charged. Both cathodes are separated by a membrane called an electrolyte and surrounded by the input stream of water 132 (i.e., one of the de-salinated water 128, the carbon-depleted water 130, or the portion 212 of the pressurized water 114).

[0054] The reactions that occur in the electrolysis device 106 are as follows:3H2O -> 3H2+ 3 / 2O2

[0055] Electrolysis is the decomposition of the input stream of water 132 (i.e., one of the desalinated water 128, the carbon-depleted water 130, or the portion 212 of the pressurized water 114) into its basic components, the hydrogen 134 and oxygen by passing electric current. Through this process, electrical energy can be stored as chemical energy in the resulting hydrogen 134. During the electrolysis process, a considerable amount of electrical power is dissipated into heat. The heat energy can be utilized for other purposes. In a non-limiting example, the heat energy can be supplied to the carbon-capture unit 120 to reduce the need for lowering the pH of the second portion 122B of the pressurized water 114 for generating the carbon dioxide 116.

[0056] Further, the reactor 108 is fluidically connected or connectable to the carbon-capturing device 104 and the electrolysis device 106. The reactor 108 is fluidically connected or connectable to the carbon-capturing device 104 to receive the carbon dioxide 116 and to the electrolysis device 106 to receive the hydrogen 134. The reactor 108 disclosed herein is a methanol reactor that synthesizes the methanol 110 from a reaction of the carbon dioxide 116 and the hydrogen 134. The reactor 108 used for the synthesis of methanol 110 may include, but is not limited to a boiling water reactor.

[0057] The reaction of the carbon dioxide 116 and the hydrogen 134 in the reactor 108 is as follows:Wherein, CO2is carbon dioxide, H2is Hydrogen, CH3OH is methanol, and H2O is water.

[0058] In an embodiment, the reaction of the carbon dioxide 116 and hydrogen 134 in the reactor 108 may generate methanol 110 and the water in the ratio of 1 : 1 , without limiting the scope of the invention. The water generated by the reactor 108 may be separated in a distillation unit 214. The apparatus 100 is provided with the distillation unit 214 fluidically connected or connectable to the reactor 108. The distillation unit 214 may be configured to use thermal energy generated from the reaction of the carbon dioxide 116 and the hydrogen 134 to distill the synthesized methanol 110. The distilled water separated from the methanol 110 in the distillation unit 214 may be pure water. In an embodiment, the distilled water of the distillation unit 214 may be supplied to the electrolysisdevice 106 to generate the hydrogen 134. It is to be noted that the distillation process is well- known in the art, and therefore not discussed herein for the sake of brevity.

[0059] The distillation unit 214 is further configured to supply the distilled methanol 110 to a second storage device 216 below the ocean water surface at a second predetermined hydraulic pressure. The second predetermined hydraulic pressure may be the condensation pressure of the methanol 110. By changing the potential head of the second storage device 216, the hydraulic pressure of the methanol 110 can be changed. The second storage device 216 may be enclosed in a second pressurized container 218 to sustain the second predetermined hydraulic pressure at which the second storage device 216 is disposed in the ocean water 112. Storage of the methanol 110 below the ocean water 112 (i.e. , off-shore) reduces its condensation cost and can ensure its safe and secure storage compared to on-shore storage. The storage of the methanol 110 below the ocean water 112 can be stored for a long term without consuming land space. However, in another embodiment (not shown), the distillation unit 214 may supply the distilled methanol 110 to a methanol tanker, without departing from the scope of the disclosure. The methanol tanker may be constructed with features tailored to safely carry and deliver large volumes of methanol from one location to another, typically via sea routes.

[0060] Figure 3A illustrates a block diagram representation of a power balance 300 of the apparatus 100, in accordance with an embodiment of the present disclosure. For the power balance 300 of the apparatus 100, in addition to the hydraulic pressure generator 102, renewable power generating sources, such as a wind power 302, a solar power 304, and a tidal power 306 can be used. The electric power generated by these sources can be stored in at least one battery 308 and utilized by the one or more devices of the apparatus 100 whenever required. Therefore, the power balance 300 allows the apparatus 100 to generate the methanol 110 in case of power failure or fluctuation in electric power.

[0061] For instance, the solar panels generate the solar power 304 in the daylight to operate the electrodialysis unit 118, whereas, during nighttime, the solar panels cannot generate the solar power 304. The acid 124 and the base 126 stored respectively in the first storage tank 208 and the second storage tank 210 can be used to operate the carbon-capture unit 120. The power balance 300 of the apparatus 100 makes the operational cost of the apparatus 100 more economical. Based on the power balance 300 of the apparatus 100, it can be stated that theapparatus 100 synthesizes the methanol 110 from the ocean water 112 using renewable power sources.

[0062] Figure 3B illustrates a block diagram representation of a thermal balance of the apparatus 100, in accordance with an embodiment of the present disclosure. Herein, the term “thermal balance” refers to the utilization of the heat generated during operation of the one device of the apparatus 100 for operating another device of the apparatus 100. In the representative example, the electrolysis device 106 generates a considerable amount of heat while generating the hydrogen 134. This heat (i.e., thermal energy) can be supplied to the carbon-capture unit 120 through a first fluidic channel 352. Furthermore, the reaction of the carbon dioxide 116 and the hydrogen 134 in the reactor 108 generates heat which is supplied to the distillation unit 214 through a second fluidic channel 354. The thermal balance of the apparatus 100 significantly reduces the requirement of thermal power. Consequently, the thermal balance of the apparatus 100 makes the operational cost of the apparatus 100 more economical.

[0063] Figure 4 illustrates a flow diagram of an example representation of a method 400 for synthesizing the methanol 110, in accordance with an embodiment of the present disclosure. At step 402, the method 400 includes generating the pressurized water 114 from the ocean water 112. The hydraulic pressure generator 102 is configured to generate the pressurized water 114 from the ocean water 112. The operating aspects of the hydraulic pressure generator 102 are already described with reference to Figures 2A to 2C, and therefore not reiterated here for the sake of brevity.

[0064] At step 404, the method 400 includes performing electrodialysis of the first portion 122A of the pressurized water 114 to generate the acid 124 and the base 126, and providing the desalinated water 128. In the disclosed embodiment, the first portion 122A discharged into the electrodialysis unit 118 is about 1% to 2% of the pressurized water 114. The electrodialysis unit 118 unit uses an electrodialysis process to generate the acid 124 (e.g., hydrochloric acid (HCI)) and the base 126 (e.g., sodium hydroxide (NaOH)) out of the sodium chloride, and output the desalinated water 128.

[0065] At step 406, the method 400 includes generating the carbon dioxide 116 by acidification of the second portion 122B of the pressurized water 114 using the acid 124 and outputting the carbon-depleted water 130. In the disclosed embodiment, the second portion 122B dischargedinto the carbon-capture unit 120 is about 98% to 99% of the pressurized water 114. In the illustrated embodiment, the acid 124 is used for the pH swing of the second portion 122B of the pressurized water 114. Alternatively, both the acid 124 and the base 126 can be used for the pH swing of the second portion 122B of the pressurized water 114. After extracting the carbon dioxide 116, the second portion 122B of the pressurized water 114 turns into the carbon-depleted water 130. Afterward, the method 400 includes storing the acid 124 in the first storage tank 208 and storing the base 126 in the second storage tank 210.

[0066] The carbon dioxide 116 is then supplied to the first storage device 211 that is enclosed in the first pressurized container 213 below the ocean water 112 at the first predetermined hydraulic pressure.

[0067] At step 408, the method 400 includes generating the hydrogen 134 from the input stream of water 132, The electrolysis device 106 is fluidically connected or connectable to the carbon- capturing device to receive the input stream of water 132 to generate the hydrogen 134. As described with reference to Figure 2A, the input stream of water 132 is the de-salinated water 128 discharged from the electrodialysis unit 118 of the carbon-capturing device 104. In another example as described with reference to Figure 2B, the input stream of water 132 is the carbon- depleted water 130 discharged from the carbon-capture unit 120. Alternatively or additionally, as described with reference to Figure 2C, the input stream of water 132 is the portion 212 of the pressurized water 114 discharged from the hydraulic pressure generator 102.

[0068] At step 410, the method 400 includes synthesizing the methanol 110 from the reaction of the carbon dioxide 116 and the hydrogen 134. The reactor 108 is fluidically connected or connectable to the carbon-capturing device 104 to receive the carbon dioxide 116 and to the electrolysis device 106 to receive the hydrogen 134. The reactor 108 synthesizes the methanol 110 from a reaction of the carbon dioxide 116 and the hydrogen 134. The methanol 110 is distilled through thermal energy generated from the reaction of the carbon dioxide 116 and the hydrogen 134. The distilled methanol 110 is then supplied to the second storage device 216 that is enclosed in the second pressurized container 218 below the ocean water 112 at the second predetermined hydraulic pressure.

[0069] Although features have been shown and described, it will be understood that they are not intended to limit the claimed disclosure, and it will be made obvious to those skilled in the art thatvarious changes and modifications may be made without departing from the scope of the claimed disclosure. The specification and drawings are, accordingly to be regarded in an illustrative rather than restrictive sense. The claimed disclosure is intended to cover all alternatives, modifications, and equivalents.

Claims

CLAIMS1 . An apparatus for synthesizing methanol, comprising: a hydraulic pressure generator configured to generate pressurized water from ocean water; a carbon-capturing device fluidically connected or connectable to the hydraulic pressure generator, the carbon-capturing device comprising: an electrodialysis unit configured to generate an acid and a base from a first portion of the pressurized water and output a de-salinated water; a carbon-capture unit configured to generate carbon dioxide by acidification of a second portion of the pressurized water using the acid and output a carbon-depleted water; and an electrolysis device configured to receive an input stream of water to generate hydrogen; and a reactor fluidically connected or connectable to the carbon-capturing device and the electrolysis device, the reactor configured, at least in part, to: receive the carbon dioxide from the carbon-capture unit; receive the hydrogen from the electrolysis device; and synthesize methanol from a reaction of the carbon dioxide and the hydrogen.

2. The apparatus as claimed in claim 1 , wherein the input stream of water is the de-salinated water3. The apparatus as claimed in claim 1 , further comprising a first storage tank configured to store the acid and a second storage tank configured to store the base.

4. The apparatus as claimed in claim 1 , further comprising a distillation unit fluidically connected or connectable to the reactor, the distillation unit configured to use thermal energy generated from the reaction of the carbon dioxide and the hydrogen to distill the synthesized methanol.

5. The apparatus as claimed in claim 4, wherein the carbon-capture unit is further configured to supply the carbon dioxide to a first storage device enclosed in a first pressurized container below the ocean water at a first predetermined hydraulic pressure, and wherein the distillation unit is further configured to supply the distilled methanol to a second storagedevice enclosed in a second pressurized container below the ocean water at a second predetermined hydraulic pressure.

6. The apparatus as claimed in any one of the claims 1 to 5, wherein the first portion is about 1% to 2% of the pressurized water and the second portion is about 98% to 99% of the pressurized water.

7. A method for synthesizing methanol, comprising: generating pressurized water from ocean water; performing electrodialysis of a first portion of the pressurized water to generate an acid and a base, and providing a de-salinated water; generating carbon dioxide by acidification of a second portion of the pressurized water using the acid and outputting a carbon-depleted water; generating hydrogen from an input stream of water; and synthesizing methanol from a reaction of the carbon dioxide and the hydrogen.

8. The method as claimed in claim 7, wherein the input stream of water is the de-salinated water.

9. The method as claimed in claim 7, further comprising: storing the acid in a first storage tank; and storing the base in a second storage tank.

10. The method as claimed in claim 7, further comprising distilling the synthesized methanol through thermal energy generated from the reaction of the carbon dioxide and the hydrogen.11 . The method as claimed in claim 10, further comprising: supplying the carbon dioxide to a first storage device enclosed in a first pressurized container below ocean water at a first predetermined hydraulic pressure; and supplying the distilled methanol to a second storage device enclosed in a second pressurized container below the ocean water at a second predetermined hydraulic pressure.

12. The method as claimed in claim 7, wherein the first portion is about 1% to 2% of the pressurized water and the second portion is about 98% to 99% of the pressurized water.

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