Marine methanol inert gas covering layer

Abstract

An inert coating system includes a reformer (128) that generates hydrogen (130) and carbon dioxide (135). The hydrogen gas (130) is separated from the carbon dioxide (135). Carbon dioxide (135) is delivered to the vapor region (122) of the canister (114) to reduce flammability of the gas in the vapor region (122) of the canister (114). The excess carbon dioxide (135) is fed to an overflow system (150) which is designed to store the excess carbon dioxide (135) for future use or to isolate the carbon dioxide (135).

Description

Technical Field

[0001] The present invention relates generally to marine fuel tanks and, more particularly, to blanketing a fuel tank using a gaseous inert product of a reformer. Background Art

[0002] Methanol fuel system can be used to provide power for the engine on board. However, if the vapor space above the liquid pipeline (or surface) of liquid methanol is not covered (or covered) by inert gas, so that the flammable methanol vapor gathers in the vapor space, storing methanol or other volatile fuels in the tank on board will bring safety risks. In such applications, it is hoped that the vapor space of the fuel tank and other parts of the fuel system will not be easy to catch fire or explode by using an inert covering layer, that is, reduce flammability. The jacket around the fuel tank or fuel line, such as nitrogen and / or carbon dioxide, can provide fireproof or explosion-proof protection. However, storing a large amount of such inert gases can cause additional costs and take up considerable space on ships.

[0003] An example of a system that uses a reformer to produce carbon dioxide and hydrogen is described in Chinese Patent No. 106741984B (hereinafter referred to as the "'984 patent"). The '984 patent discloses a system for catalytic reforming and decommissioning aircraft fuel tanks and a method of operating the system. The system is characterized in that a mixture of fuel vapor and air in the upper gas phase space of the fuel tank is dried and then compressed and condensed by a compressor. The liquid fuel is separated. The remaining mixed gas enters the catalytic reforming reactor and reacts under the action of the catalyst to produce carbon dioxide, hydrogen, nitrogen and water vapor. Hydrogen is separated from other gases. The remaining gas enters the gas phase space of the fuel tank for inerting after being cooled and reduced in pressure by a regenerator and a throttle valve. Hydrogen can be used in various systems, such as hydrogen fuel cells. The system described in the '984 patent achieves controllable automatic operation through an oxygen concentration sensor and a control switch.

[0004] However, the system described in the '984 patent is configured to draw outside air into the upper space of the tank and draw the upper space gas into its system so that the system consumes oxygen through chemical reactions. Such systems are characterized by changing the feed composition based on, for example, the timing of fuel replenishment and fuel consumption and temperature changes of the tank. In addition, because outside air is drawn into the upper space, water vapor is also drawn into the tank, which is problematic for marine methanol fuel storage systems because methanol absorbs water and violates the International Ship Safety Code ("IGF Code"), which requires an inert gas to cover the methanol in the tank and prevent methanol from absorbing water vapor. In addition, the system described in the '984 patent is not configured to provide an inert gas to the fuel line.

[0005] Examples of the present invention are directed to overcoming the deficiencies of such systems. Summary of the invention

[0006] In one aspect of the present invention, a method includes: reacting methanol with water vapor using a reformer to produce a mixture of hydrogen and carbon dioxide; directing the mixture from the reformer to a hydrogen selective membrane; separating the hydrogen contained in the mixture from the carbon dioxide contained in the mixture using the hydrogen selective membrane to produce a carbon dioxide / water mixture; cooling the carbon dioxide / water mixture in a condenser / cooler to condense water and cool the carbon dioxide, thereby separating water from the carbon dioxide / water mixture to form a carbon dioxide concentrated gas mixture; and directing the carbon dioxide concentrated gas mixture from the hydrogen selective membrane to a vapor region of a tank, the vapor region including a region within the tank located above a methanol liquid level within the tank, the carbon dioxide concentrated gas mixture forming an inert cover layer in the vapor region.

[0007] In another aspect of the invention, a system includes: an internal combustion engine mechanically connected to a generator via a shaft, wherein the engine rotates the shaft to rotate windings of the generator to produce an electrical output; a methanol tank for providing methanol to the engine and a reformer, wherein the reformer produces hydrogen and carbon dioxide by reacting the methanol with water vapor; a hydrogen selective membrane that separates the hydrogen from the carbon dioxide to produce a carbon dioxide / water mixture; a condenser / cooler for cooling the carbon dioxide / water mixture to condense the water and cool the carbon dioxide to separate the water from the carbon dioxide / water mixture to form a carbon dioxide-rich gas mixture; and a blanket controller configured to manipulate a control valve to direct the carbon dioxide-rich gas mixture produced by the reformer into a vapor region of the tank to produce an inert blanket in the vapor region of the tank to reduce the flammability of the gas in the vapor region.

[0008] In yet another aspect of the invention, a vessel comprises an internal combustion engine mechanically connected to a generator via a shaft, wherein the engine rotates the shaft to rotate windings of the generator, thereby producing an electrical output; a methanol tank for providing methanol to the engine and a reformer, wherein the reformer produces a hydrogen and carbon dioxide concentrated gas mixture by reaction of the methanol with water vapor; a hydrogen selective membrane that separates the hydrogen from the carbon dioxide concentrated gas mixture; and a blanket controller configured to manipulate a control valve to direct the carbon dioxide concentrated gas mixture produced by the reformer into a vapor region of the tank to produce an inert blanket in the vapor region of the tank to reduce the flammability of the gas in the vapor region; or an overflow system for receiving excess carbon dioxide. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 is a schematic diagram of an onboard engine system according to one or more examples of the present invention that uses carbon dioxide produced by a reformer to provide an inert blanket in the vapor space of a methanol fuel tank.

[0010] Figure 2 is a cross-sectional view of a vessel utilizing an inert cover for various purposes in accordance with one or more examples of the present invention.

[0011] Figure 3 is a flow chart illustrating a method of providing an inert cover layer according to an example of the presently disclosed subject matter.

[0012] Figure 4 Depicted is a component level view of an overlay controller for use with the systems and methods described herein, according to an example of the presently disclosed subject matter. DETAILED DESCRIPTION

[0013] Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. Figure 1 1 is a schematic diagram of a system 100 for use in a ship or marine vessel (not shown) according to one or more embodiments of the present invention, the system using the product gas of the reformer to provide an inert gas blanket. System 100 includes an engine 104 and a generator 106. Engine 104 is mechanically connected to generator 106 via shaft 108. When engine 104 is running, engine 104 rotates shaft 108. Shaft 108 rotates windings within generator 106, thereby generating an electrical output 110. Engine 104 and generator 106 can be a single unit or can be separate units, and the subject matter disclosed herein is not limited to any particular engine / generator configuration. In addition, generator 106 can generate AC power or DC power, and the subject matter disclosed herein is not limited to any particular type of electrical output 110 generated. It should also be noted that the subject matter disclosed herein is not limited to the use of engine 104 for generating electricity through generator 106. The subject matter disclosed herein includes the use of engine 104, whereby engine 104 provides other forms of power, such as motive force for moving a vehicle, rotating a propeller, etc. through a powertrain.

[0014] The engine 104 is a reciprocating piston internal combustion engine based on hydrocarbon fuel, but other engine types may also be used, such as a continuous combustion engine or a turbine engine. In addition, the engine 104 may be a pure methanol engine (spark ignition) or a dual fuel engine, such as running on both methanol and one of diesel, renewable diesel, and biodiesel. The engine 104 may also be any other engine that runs on a fuel combination including methanol. Figure 1In the example shown, the fuel for the engine includes methanol 112 received via a methanol input 115. The methanol 112 is stored in a methanol tank 114. Air 116 and the methanol 112 are supplied to the engine 104 for combustion using a fuel pump 119 for the methanol 112. The methanol 112 is stored primarily as a liquid in a liquid region 120 of the methanol tank 114, however some of the methanol 112 may evaporate into a vapor region 122 of the methanol tank 114. The liquid level 124 is the upper surface of the methanol 112 in liquid form and generally depicts a boundary between the vapor region 122 and the liquid region 120 of the methanol tank 114. As described above, the description of the use of the methanol 112 as a fuel is described in terms of Figure 1 The system 100 , however, may use other types of fuels and are considered within the scope of the presently disclosed subject matter. The exhaust gas 126 is produced by the combustion of the methanol 112 and the air 116 in the engine 104 .

[0015] The system 100 also includes a reformer 128 for producing hydrogen 130. The reformer 128 can be various types of reformers, such as a steam reformer and a partial oxidation reformer. The presently disclosed subject matter is not limited to any particular type of reformer. Figure 1 The reformer 128 is a methanol 112 reformer that produces hydrogen 130 according to the following reaction:

[0016] CH3OH+H2O→CO2+3H2 (Reaction 1),

[0017] Where CH3OH is methanol 112 received via reformer input 129, H2O is water 132 (usually in vapor form), CO2 is carbon dioxide, and H2 is hydrogen 130. Figure 1The reformer 128 shown in FIG. 1 uses a catalyst 136 to support reaction 1 in the reformer 128. The catalyst 136 can be various types of catalysts, including but not limited to nickel, Cu / ZnO / Al2O3 and other types of catalysts. Depending on the input of the reformer 128, the product gas 138 of the reformer 128 may include carbon dioxide, hydrogen, and water vapor, nitrogen and other fluids. The product gas 138 is supplied to the hydrogen selective membrane 140. The hydrogen selective membrane 140 receives the product gas 138 from the reformer 128, which can be heated. In some examples, the hydrogen selective membrane 140 extracts 0% to 90% (or more) of hydrogen (providing hydrogen 130) from the product gas 138. The extracted hydrogen 130 is pure hydrogen (H2), provided in a dedicated pipeline, and can be collected for storage, use or removal. The remaining gas from the hydrogen selective membrane is a carbon dioxide / water mixture 134. The hydrogen selective membrane 140 may use various metal membranes, such as but not limited to palladium (Pd), vanadium (V), niobium (Nb) and tantalum (Ta) or alloys thereof. Other hydrogen separation techniques, such as pressure swing adsorption and cryogenic distillation, may be used, and these techniques are considered within the scope of the presently disclosed subject matter.

[0018] In some examples, water (in the form of water vapor) may be present in the product gas 138 and the carbon dioxide / water mixture 134. If a certain amount of water enters the methanol tank 114, the water may be absorbed and absorbed by the methanol 112, which may degrade the methanol 112. Therefore, in some examples, the system 100 may also include a cooler / condenser 141. The cooler / condenser 141 is designed to cool the carbon dioxide / water 134 to allow the water vapor to be cooled and separated as water 143 and a carbon dioxide concentrated gas mixture 135, which is cooled before entering the methanol tank 114.

[0019] The carbon dioxide concentrated gas mixture 135 obtained after separating hydrogen 130 and water 143 from the product gas 138 is provided to the methanol tank 114 through the control valve 142. The control valve 142 is an electrically actuated valve that receives a control signal 144 from a blanket controller 146. The blanket controller 146 is configured to control the amount of the carbon dioxide concentrated gas mixture 135 entering the methanol tank 114 to provide an inert blanket 148 in the vapor region 122 of the methanol tank 114. In some examples, the blanket controller 146 is a component, software, hardware, module or other entity that receives one or more inputs (such as pressure explained in more detail below) and provides one or more outputs to control the amount of the carbon dioxide concentrated gas mixture 135 entering the methanol tank 114. As described above, some portion of the methanol 112 can evaporate and collect in the vapor region 122. If the conditions in the vapor region 122 are stoichiometrically correct to support combustion, the presence of methanol 112 in the vapor region can pose a safety hazard. Furthermore, if the heat source contacts the methanol 112 in either the vapor region 122 or the liquid region 120 , the heat source (eg, a spark, a flame, etc.) may cause the methanol 112 to combust.

[0020] In an attempt to reduce the possibility of uncontrolled or accidental combustion of a portion of the methanol 112 in the tank 114, the blanket controller 146 delivers a carbon dioxide concentrated gas mixture 135 produced in the reformer 128 due to the production of hydrogen 130 to the vapor region 122 of the methanol tank 114. The introduction of the carbon dioxide concentrated gas mixture 135 into the vapor region 122 produces an inert blanket 148 in the vapor region 122. The inert blanket 148 is formed by the carbon dioxide concentrated gas mixture 135 and is used to extinguish and / or prevent the occurrence of conditions that can support combustion in the tank 114, such as oxygen (air), methanol 112 gas in the vapor region 122, and displacement of other potential fuels for combustion. It should be noted that depending on the operating conditions in the reformer 128, the inert blanket 148 may also include other gases, such as nitrogen and water vapor. Various techniques, such as temperature swing separation, can be used to remove water vapor or reduce its concentration from the carbon dioxide concentrated gas mixture 135. The subject matter currently disclosed is not limited to any specific water separation technology.

[0021] The blanket controller 146 uses the control signal 144 to control the operation of the control valve 142. The control signal 144 may be an electrical signal or a data signal that, when received by the control valve 142, causes the operation of the control valve 142 according to the control signal 144. In some examples, the blanket controller 146 may use the control signal 144 to reduce or eliminate the flow of the carbon dioxide concentrated gas mixture 135 to the vapor region 122, and to start or increase the amount of the carbon dioxide concentrated gas mixture 135 entering the overflow system 150 by opening or closing the control valve 142, rather than directing (or delivering) the carbon dioxide concentrated gas mixture 135 to the vapor region 122. In some examples, the control valve 142 may also be a pressure relief valve that releases gas in the methanol tank 114 to the overflow system 150 when it is higher than the pressure in the methanol tank 114. In some examples, the amount of hydrogen 130 generated may exceed the amount of carbon dioxide concentrated gas mixture 135 required to generate or maintain the inert blanket 148. The blanket controller 146 can change the position of the control valve 142 to direct the excess carbon dioxide 152 to the overflow system 150 instead of venting the excess carbon dioxide 152 to the atmosphere. The overflow system 150 receives and stores the excess carbon dioxide 152 for future use or processing. For example, the overflow system 150 can be used to compress the excess carbon dioxide 152 into a liquid or gas and store it in a tank, as follows Figure 2 In other examples, the overflow system 150 may be used in other systems, such as an inert cover for other tanks or within a double hull design, also in the following Figure 2 150 . The presently disclosed subject matter is not limited to any type of overflow system 150 . In some examples, when the reformer 128 is started up and / or shut down, the blanket controller 146 can use the control signal 144 to position the control valve 142 to allow the carbon dioxide concentrated gas mixture 135 to be transferred to the exhaust device 153, thereby allowing the system 100 to reach operating efficiency before transferring the carbon dioxide concentrated gas mixture 135 to the methanol tank 114 or the overflow system 150 . The system 100 can also include a hydrogen sensor 157. The hydrogen sensor 157 senses the hydrogen concentration in the carbon dioxide / water 134. The hydrogen sensor 157 sends a hydrogen sensor signal 159 to the blanket controller 146. The blanket controller 146 receives the hydrogen sensor signal 159 and determines whether the hydrogen concentration is above a set point, which means that the carbon dioxide / water 134 has a sufficient level of hydrogen concentration that it may be unsafe to introduce the carbon dioxide concentrated gas mixture 135 into the methanol tank 114 and / or the overflow system 150. Thus, in this example, if the hydrogen concentration is above the set point, blanket controller 146 uses control signal 144 to position control valve 142 to allow the carbon dioxide concentrated gas mixture 135 to be diverted to exhaust 153 .

[0022] During operation of the system 100, it may be desirable to monitor the pressure in the vapor region 122 of the tank 114. The pressure may be an indication of the presence or absence of an inert blanket 148 in the vapor region. If an excess of the carbon dioxide concentrated gas mixture 135 is provided to the vapor region 122, the pressure in the vapor region 122 may increase to a point above the operating parameters of the tank 114. To detect the pressure, a pressure sensor 154 is used to detect and provide a pressure reading 156 of the pressure in the vapor region 122 of the tank 114. The pressure reading 156 is sent to the blanket controller 146. If the pressure reading 156 is above the high set point, the blanket controller 146 may send a control signal 144 to change the position of the control valve 142 to provide more carbon dioxide concentrated gas mixture 135 to the overflow system 150 and less carbon dioxide concentrated gas mixture 135 to the vapor region 122 of the tank. If pressure reading 156 is below the low set point, blanket controller 146 may send control signal 144 to change the position of control valve 142 to provide less carbon dioxide concentrated gas mixture 135 to overflow system 150 and more carbon dioxide concentrated gas mixture 135 to vapor region 122 of the tank.

[0023] In some examples, the hydrogen production pump 158 may also be used to control the amount of carbon dioxide concentrated gas mixture 135 produced. If the pressure reading 156 is above the high set point, the blanket controller 146 may send a pump control signal 160. If the pressure reading 156 is below the low set point, the blanket controller 146 may send a pump control signal 160 to increase the speed of the hydrogen production pump 158 or start the hydrogen production pump 158, thereby increasing the amount of hydrogen 130 produced by the reformer 128 and subsequently increasing the amount of carbon dioxide concentrated gas mixture 135. In some examples, when the engine 104 is shut down, it may be necessary to backwash or reflux carbon dioxide through the engine 104 to remove methanol 112 still present in the engine 104 and related piping. Therefore, the system 100 also includes a backwash valve 162. When opened, the backwash valve 162 delivers the carbon dioxide concentrated gas mixture 135 sent to the overflow system 150 to the outlet 164 of the engine 104. After the engine 104 is shut down, the carbon dioxide concentrated gas mixture 135 from the overflow system 150 pushes the remaining methanol 112 back into the tank 114. Once the backwash (or reflux) process is complete, the backwash valve 162 is closed.

[0024] In other examples, the reformer 128 may not be in operation, whereby the carbon dioxide concentrated gas mixture 135 used to produce the inert blanket 148 is not produced by the reformer 128. In these examples, an auxiliary source of carbon dioxide 168 is used. When the reformer 128 is not in operation but it is needed or required to maintain the inert blanket 148, the auxiliary source 168 or the overflow system 150 provides an auxiliary source of carbon dioxide. The auxiliary source 168 may include, but is not limited to, carbon dioxide in a tank, such as compressed carbon dioxide. In some examples, the overflow system 150 may be used to supply carbon dioxide to the auxiliary source 168. In some examples, the auxiliary source 168 and the overflow system 150 are the same system or different systems.

[0025] As described above, the system 100 is described as being used on a ship. When hydrogen 130 is produced, the carbon dioxide concentrated gas mixture 135 output by the reformer 128 is used to provide an inert blanket 148 in the vapor region 122 of the tank 114. However, the carbon dioxide concentrated gas mixture 135 can be used in other systems and uses on the ship, such as Figure 2 as shown in the example.

[0026] Figure 2 2 is a cross-sectional view of a vessel 200 that utilizes an inert blanket for various purposes in accordance with one or more examples of the present invention. Figure 2 The example hull 202 shown is a double hull design having a first hull 204 as an outer hull and a second hull 206 as an inner hull. The hull 202 defines an interior space 208 extending from the inner surface of the first hull 204 to the opposing inner surface of the second hull 206. The interior space 208 is generally empty, but may include various systems and components (not shown). In some examples, it may be advantageous to provide an inert blanket 210 of carbon dioxide through the control valve 142 to reduce the possibility that flammable gases will accumulate in the interior space 208 and possibly explode. It should be noted that the inert blanket 210 is illustrated as partially filling the interior space 208. In some embodiments, because the inert blanket 210 is formed of a gas, it will expand to fill the entire interior space 208. In other examples, when carbon dioxide is used, if air is present, the inert blanket 210 may fill less than the entire interior space 208 because carbon dioxide is heavier than air.

[0027] To provide carbon dioxide to the inert blanket 210, the vessel 200 includes Figure 1 It should be noted that for the purpose of explanation and simplicity of illustration, Figure 2 No picture Figure 1 All parts shown in the figure. Figure 1As explained in , reformer 128 uses methanol 112 in tank 114 to produce hydrogen 130. Carbon dioxide concentrated gas mixture 135 is delivered to vapor region 122 of tank 114 via control valve 142 to provide an inert blanket 148. Figure 2 2, at least a portion of the carbon dioxide concentrated gas mixture 135 may be supplied to the compressor 212 via the control valve 142. The compressor 212 may compress the carbon dioxide concentrated gas mixture 135 for storage in the pressurized tank 214. The carbon dioxide concentrated gas mixture 135 stored in the pressurized tank 214 may be used for various purposes, such as, but not limited to, as a supplemental source of the inert blanket 148 if the reformer 128 is not operating or does not provide enough carbon dioxide concentrated gas mixture 135 to provide the inert blanket 148. In another example, the carbon dioxide concentrated gas mixture 135 stored in the pressurized tank 214 may be used in a system such as a fire fighting system 216. The fire fighting system 216 may use the carbon dioxide concentrated gas mixture 135 to suppress a fire on the vessel 200.

[0028] like Figure 1 and Figure 2 As described, the blanket controller 146 provides control signals to operate valves and pumps to create or maintain an inert blanket 148 in the tank 114. The blanket controller 146 receives various inputs and provides various outputs, which are described below. Figure 3 The examples in this article describe this.

[0029] Figure 3 is a flow chart illustrating a method 300 of providing an inert cover layer 148 according to an example of the presently disclosed subject matter. The method 300 may include different and / or additional steps, or the steps may be performed in a different order than described herein. Furthermore, the method 300 may be performed in whole or in part by one or more system controllers or processors, such as Figure 1 For ease of description, the various steps of method 300 are described below as being performed by overlay controller 146 unless otherwise specified.

[0030] At step 302, the blanket controller 146 initiates operation of the reformer 128. The reformer 128 may be a variety of types of reformers. The presently disclosed subject matter is not limited to any particular type of reformer. Figure 1 The reformer 128 is a methanol 112 reformer. According to reaction 1, at step 302, the reformer 128 produces carbon dioxide and hydrogen, but it should be understood that other gases such as nitrogen may be present depending on the operation of the reformer 128 and the input fluids.

[0031] At step 304, the hydrogen 130 produced by the reformer 128 is separated from the carbon dioxide concentrated gas mixture 135 by the hydrogen selective membrane 140. The hydrogen selective membrane 140 may use various metal membranes, such as but not limited to palladium (Pd), vanadium (V), niobium (Nb) and tantalum (Ta) or alloys thereof. Other hydrogen separation techniques, such as pressure swing adsorption and cryogenic distillation, may be used and are considered to be within the scope of the presently disclosed subject matter.

[0032] At step 306, the blanket controller 146 causes the carbon dioxide concentrated gas mixture 135 to be delivered to the tank 114 through the control valve 142 via the control signal 144 to generate an inert blanket 148 in the vapor region 122 of the methanol tank 114. The inert blanket 148 is formed by the carbon dioxide concentrated gas mixture 135 and is used to extinguish and / or prevent the occurrence of conditions that can support combustion in the tank 114, such as oxygen (air), methanol 112 gas in the vapor region 122, and displacement of other potential fuels for combustion. It should be noted that the inert blanket 148 may also include other gases, such as nitrogen and water vapor, depending on the operating conditions within the reformer 128.

[0033] At step 308, the pressure sensor 154 measures the pressure in the tank 114 and provides a pressure reading 156 to the blanket controller 146. The pressure reading 156 is an indication of the presence and concentration of the carbon dioxide concentrated gas mixture 135 that forms the inert blanket 148. If the pressure is too high, the carbon dioxide concentrated gas mixture 135 delivered to the tank 114 may pressurize the tank above an acceptable operating range. If the pressure is too low, there may not be enough carbon dioxide concentrated gas mixture 135 to form the inert blanket 148.

[0034] At step 310, the blanket controller 146 receives the pressure reading 156. As described above, the blanket controller 146 is configured to provide and maintain the inert blanket 148 and uses the pressure reading from the tank 114 to maintain the inert blanket 148. At step 310, when it is determined that the pressure reading 156 is above the high set point (step 310-yes), at step 312, the blanket controller will reduce the amount of the carbon dioxide concentrated gas mixture 135 delivered to the tank 114. The blanket controller 146 operates the control valve 142 to direct the carbon dioxide concentrated gas mixture 135 to the overflow system 150. In another example, the blanket controller 146 can reduce the speed or stop the hydrogen production pump 158, thereby reducing the amount of hydrogen 130 produced by the reformer 128, and subsequently reducing the amount of the carbon dioxide concentrated gas mixture 135.

[0035] At step 310, when it is determined that the pressure reading 156 is equal to or below the high set point and equal to or above the low set point, at step 314, the blanket controller 146 maintains the production of the carbon dioxide concentrated gas mixture 135. At step 310, when it is detected that the pressure reading 156 is below the low set point, at step 316, the blanket controller will increase the amount of carbon dioxide concentrated gas mixture 135 delivered to the tank 114. The blanket controller 146 operates the control valve 142 to direct less carbon dioxide concentrated gas mixture 135 to the overflow system 150 and more carbon dioxide concentrated gas mixture 135 to the tank 114. In another example, the blanket controller 146 may increase the speed of the hydrogen production pump 158 or start the hydrogen production pump 158 to increase the amount of hydrogen 130 and subsequently the carbon dioxide concentrated gas mixture 135 produced by the reformer 128. The method 300 continues to step 308, where the tank pressure is measured.

[0036] Figure 4 A component level view of an overlay controller 146 for use with the systems and methods described herein is depicted according to an example of the presently disclosed subject matter. The overlay controller 146 may include several components to perform the functions described above and provide various control signals, such as the control signal 144 and the pump control signal 160. As described below, the overlay controller 146 may include a memory 402 including an operating system (OS) 404 and one or more standard applications 406. The standard applications 406 may also include a valve signal generator to control various valves, including the control valve 142, etc.

[0037] The overlay controller 146 may also include one or more processors 410 having one or more cores and one or more of a removable memory 412, a non-removable memory 414, a transceiver 416, an output device 418, and an input device 420. In various implementations, the memory 402 may be volatile (such as random access memory (RAM)), non-volatile (such as read-only memory (ROM), flash memory, etc.), or some combination of the two. The OS 404 contains modules and software that support the basic functions of the overlay controller 146, including generating signals to open and close valves and operate pumps.

[0038] In some implementations, processor 410 may be one or more central processing units (CPUs), graphics processing units (GPUs), both CPUs and GPUs, or any other processing unit. Overlay controller 146 may also include additional data storage devices (removable and / or non-removable), such as magnetic disks, optical disks, or tapes. Such additional storage Figure 4 4 is illustrated by removable memory 412 and non-removable memory 414.

[0039] Non-transitory computer-readable media may include volatile and non-volatile, removable and non-removable tangible, physical media implemented with technology for storing information such as computer-readable instructions, data structures, program modules or other data. Memory 402, removable memory 412, and non-removable memory 414 are all examples of non-transitory computer-readable media. Non-transitory computer-readable media include, but are not limited to, RAM, ROM, electrically erasable programmable ROM (EEPROM), flash memory or other memory technology, compact disc ROM (CD-ROM), digital versatile disc (DVD) or other optical storage device, magnetic cassette, magnetic tape, magnetic disk storage device or other magnetic storage device, or any other tangible physical medium that can be used to store desired information that can be accessed by overlay controller 146. Any such non-transitory computer-readable media may be part of overlay controller 146, or may be a separate database, repository, remote server, or cloud-based server. In some implementations, transceiver 416 includes any transceiver known in the art. In some examples, transceiver 416 is used to send signals to open or close a valve, start or stop a pump, or receive pressure readings in various examples disclosed herein.

[0040] The transceiver 416 may also include one or more radio transceivers that perform communication via an antenna (e.g., Wi-Fi or Bluetooth )The ability to send and receive RF communications.

[0041] In some implementations, the output device 418 includes any output device known in the art, such as a display (e.g., a liquid crystal or thin film transistor (TFT) display), a touch screen, a speaker, a vibration mechanism, or a tactile feedback mechanism. Thus, the output device can include a screen or a display. In various implementations, the input device 420 includes any input device known in the art. For example, the input device 420 can include a camera, a microphone, or a keyboard / keypad.

[0042] Industrial Applicability

[0043] The present invention describes a system and method for inert blanketing using a carbon dioxide concentrated gas mixture 135 produced by a reformer 128 (or other carbon dioxide generating machine). Various examples of the subject matter currently disclosed utilize waste carbon dioxide produced in the hydrogen production process to reduce the flammability of a space (or atmosphere). If used as an inert blanket in a fuel tank, carbon dioxide can replace oxygen above the methanol liquid line. Carbon dioxide can also be used to disperse oxygen in a void area, such as in the space between the two hulls of a catamaran. In addition, since carbon dioxide is not discharged into the atmosphere, carbon dioxide can be isolated as an inert blanket to reduce the carbon footprint of the ship. Using the output of the reformer can provide various advantages over conventional systems. In some examples, there is no need to install additional systems or components to provide an inert blanket, such as a bottle or nitrogen generation system for storing nitrogen. In another example, the waste carbon dioxide formed by hydrogen production can be isolated as an inert blanket in a tank, thereby possibly reducing the carbon footprint of a sea vessel.

[0044] Unless expressly excluded, the use of the singular to describe a component, structure, or operation does not exclude the use of the plural such components, structures, or operations or their equivalents. As used herein, the word "or" refers to any possible permutation of a group of items. For example, the phrase "A, B, or C" refers to at least one of A, B, C, or any combination thereof, such as A; B; C; A and B; A and C; B and C; A, B, and C; or multiples of any item, such as A and A; B, B, and C; A, A, B, C, and C; etc.

[0045] Although various aspects of the present invention have been specifically shown and described with reference to the above embodiments, it will be understood by those skilled in the art that various additional embodiments may be contemplated by modifications to the disclosed machines, systems, and methods without departing from the spirit and scope of the disclosure. These embodiments should be understood to fall within the scope of the present invention as determined based on the claims and any equivalents thereof.

Claims

1. A method (300), comprising: reacting methanol (112) with water vapor (132) using a reformer (128) to produce a mixture of hydrogen (130) and carbon dioxide (135); directing the mixture (130, 135) from the reformer (128) to a hydrogen selective membrane (140); separating the hydrogen (130) contained in the mixture from the carbon dioxide (135) contained in the mixture using the hydrogen selective membrane (140) to produce a carbon dioxide / water mixture (134); cooling the carbon dioxide / water mixture (134) in a condenser / cooler (141) to condense the water (132) and cool the carbon dioxide (135), thereby separating the water (132) from the carbon dioxide / water mixture (134) to form a carbon dioxide-enriched gas mixture (135); and The carbon dioxide-rich gas mixture (135) is directed from the condenser / cooler (141) to a vapor region (122) of a tank (114), the vapor region (122) comprising an area within the tank (114) above a liquid level (124) of methanol (112) within the tank (114), the carbon dioxide (135) forming an inert blanket in the vapor region (122).

2. The method (300) of claim 1, further comprising: measuring the pressure in the tank (114); as well as Determine if the pressure is: Above high set point, is equal to or below the high set point and equal to or above the low set point; or Below low set point.

3. The method (300) of claim 2, wherein if the pressure is above the high set point, the production of the carbon dioxide rich gas mixture (135) is reduced.

4. The method (300) of claim 3, wherein reducing the generation of the carbon dioxide-rich gas mixture (135) comprises: increasing a first amount of the carbon dioxide rich gas mixture (135) produced by the reformer (128) and delivered to an overflow system (150), and decreasing a second amount of the carbon dioxide rich gas mixture (135) produced by the reformer (128) and delivered to the tank (114); or Reduce the speed of the hydrogen production pump (158).

5. The method (300) of claim 2, wherein if the pressure is equal to or below the high set point and equal to or above the low set point, the production of the carbon dioxide rich gas mixture is maintained (135).

6. The method (300) of claim 2, wherein if the pressure is below the low set point, the production of the carbon dioxide enriched gas mixture (135) is increased.

7. The method (300) of claim 6, wherein increasing the production of the carbon dioxide (135) comprises: reducing a first amount of the carbon dioxide rich gas mixture (135) produced by the reformer (128) and delivered to an overflow system (150), and increasing a second amount of the carbon dioxide rich gas mixture (135) produced by the reformer (128) and delivered to the tank (114); or Increase the speed of the hydrogen production pump (158) or start the hydrogen production pump (158).

8. The method (300) of claim 1, further comprising: sensing a concentration of the hydrogen gas (130) in the carbon dioxide / water mixture (134); as well as When the concentration of the hydrogen gas (130) is detected to be above a set point, the carbon dioxide-enriched gas mixture (135) is diverted to the exhaust.

9. A system comprising: an internal combustion engine (104) mechanically coupled to a generator (106) via a shaft (108), wherein the engine (104) rotates the shaft (108) to rotate windings of the generator (106) to produce an electrical output (110); a methanol tank (114) for providing methanol (112) to the engine (1094) and a reformer (128), wherein the reformer (128) produces hydrogen (130) and carbon dioxide (135) by reacting the methanol (112) with water vapor (132); a hydrogen selective membrane (140) that separates the hydrogen (130) from the carbon dioxide (135) to produce a carbon dioxide / water mixture (134); a condenser / cooler (141) for cooling the carbon dioxide / water mixture (134) to condense the water and cool the carbon dioxide (135) to separate the water from the carbon dioxide / water mixture (134) to form a carbon dioxide-enriched gas mixture (135); and A blanket controller configured to manipulate a control valve (142) to direct the carbon dioxide-rich gas mixture (135) produced by the reformer (128) into a vapor region (122) of a tank (114), thereby producing an inert blanket in the vapor region (122) of the tank (114) to reduce the flammability of the gas in the vapor region (122).

10. The system (100) according to claim 9, wherein: The blanket controller is also configured to manipulate the control valve (142) to send a portion of the carbon dioxide rich gas mixture (135) produced by the reformer (128) to an overflow system (150).

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