Apparatus and method for nitrogen generation for methanol powered marine vehicles

Abstract

An apparatus for nitrogen generation in a methanol-powered marine vehicle may include a compression system for compressing air and feeding the compressed air to a separation unit for separating nitrogen and oxygen from the compressed air. Nitrogen can be output from the separation unit for storage at a pre-selected, elevated pressure suitable for feeding into a methanol engine of a marine vehicle (e.g., a ship), for purging, leak testing, inerting, or other purposes. Embodiments may be configured such that no heat exchanger or booster compressor exists between the separation unit and the nitrogen storage unit.

Description

[0001] Cross-reference to related applications This application claims priority to U.S. non-provisional application 18 / 544,710, filed December 19, 2023, which is incorporated herein by reference. Technical Field

[0002] The present invention relates to systems and apparatuses for using methanol as fuel to power at least one engine in marine vehicles such as ships or vessels, and methods of manufacturing and using such vehicles. Background Technology

[0003] Cargo ships or tankers can transport materials via waterways (e.g., oceans, seas, rivers, etc.). These containers can be powered by methanol fuel. Wärtsilä and MAN Energy Solutions have disclosed methanol-fueled engines for ships. Chinese patent application publication number CN113047994A discloses a ship capable of using methanol as fuel. Japanese patent application publication number JP2019070387A discloses a dual-fuel injection device capable of injecting methanol as fuel. Summary of the Invention

[0004] Using methanol as a fuel option for marine engines often requires the use of gaseous nitrogen for leak testing and other operations associated with methanol fuel use. New apparatus and methods for generating gaseous nitrogen from air and storing the resulting nitrogen (N2) for use in such applications can offer improved reliability and reduced footprint to support the use of methanol as fuel. Such implementations can promote the use of methanol as a green energy source, which can help reduce dependence on fossil fuels and improve the environmental impact associated with ship operation and maintenance.

[0005] Some embodiments of the apparatus and methods described herein can generate nitrogen from air without the need for any booster compressor between a separator and a nitrogen storage unit. The separator separates nitrogen and oxygen from a feed of compressed air, and the nitrogen storage unit can store the separated nitrogen output from the separator at a pre-selected pressure (e.g., pressures exceeding 13 bar or 1300 kPa, pressures between 10 and 16 bar or between 1000 and 1600 kPa, etc.). Some embodiments also avoid using a heat exchanger to heat or cool the nitrogen output from the separator before feeding it into the nitrogen storage unit.

[0006] Some embodiments can generate and store nitrogen gas as at least 95 volume percent (V%) nitrogen (N2), or 95 to 100 V% V% N2, for storage at pressures between 10 barg and 16 barg or between 1000 kPag and 1600 kPag. Such generation and storage can be provided without the use of intermediate heat exchangers and / or booster compressors between the nitrogen / oxygen separation and storage units, to provide reduced footprint and improved reliability by reducing the equipment required for nitrogen generation and storage. While such heat exchangers and / or booster compressors may not be used between the nitrogen / oxygen separation unit and the nitrogen storage unit, process elements that can utilize stored nitrogen downstream of the nitrogen storage unit may include such elements for specific applications (e.g., purging, etc.). In other applications, no such booster or heat exchanger may be needed, as the stored nitrogen may be at sufficient pressure and temperature for one or more uses or applications downstream of the nitrogen storage unit.

[0007] Reducing the footprint and quantity of equipment helps reduce maintenance operations and improves reliability by limiting the number and type of equipment that may fail or require maintenance or repair during operation, while also reducing the capital costs associated with the manufacture and installation of the unit. In some implementations, fewer units can also reduce energy costs associated with the operation of the unit.

[0008] In a first aspect, an apparatus for generating nitrogen for a methanol-powered marine vehicle may include a compression system configured to compress air to a pre-selected feed pressure and provide a compressed air stream at the pre-selected feed pressure. A nitrogen separation unit may be located downstream of the compression system. The nitrogen separation unit may be configured to separate nitrogen (N2) and oxygen (O2) from the compressed air stream fed to the nitrogen separation unit via the compression system located upstream of the nitrogen separation unit. The nitrogen separation unit may be configured to generate a nitrogen stream (e.g., an N2-rich stream) containing the nitrogen separated from the compressed air stream, at least a portion of which may be fed to a nitrogen storage unit.

[0009] In the second aspect, the pre-selected feed pressure exceeds 1300 kPa gauge pressure (kPag) and is less than 2000 kPag. The pre-selected feed pressure can be selected such that a nitrogen flow is formed and fed into the nitrogen storage unit in the absence of a booster compressor (e.g., in the absence of a booster compressor between the nitrogen storage unit and the nitrogen separation unit).

[0010] For example, the compression system may include a compressor, and the pre-selected feed pressure may exceed 1300 kPag, so that the nitrogen gas stream is fed into the nitrogen storage unit, wherein the compressor of the compression system is the only compressor used to separate nitrogen and feed the nitrogen gas stream into the nitrogen storage unit.

[0011] In a third aspect, the apparatus may include a filtration system having at least one filter element positioned between the compression system and the nitrogen separation unit to filter the compressed air stream before it is fed into the nitrogen separation unit. The filtration unit may be configured to filter particles, lubricants, oil, and / or other impurities from the compressed air. For example, in some embodiments, the filtration system may include one or more coalescing filters.

[0012] In a fourth aspect, the apparatus may include a pretreatment unit positioned between the filtration system and the nitrogen separation unit to preheat and / or dry the compressed air stream before it is fed into the nitrogen separation unit. Drying may be provided via, for example, a refrigerant dryer, a desiccant-based dryer, a membrane dryer, or other types of dryer.

[0013] In a fifth aspect, the apparatus may include a nitrogen storage unit. The nitrogen storage unit may include a tank, multiple tanks, a vessel, multiple containers, or other arrangements of storage equipment for storing nitrogen (e.g., a gas having an N2 content of 95% to 100% by volume) output from a nitrogen separation unit.

[0014] In a sixth aspect, the nitrogen separation unit may include one or more membranes, or may consist of an adsorption system. In some embodiments, the adsorption system may be a pressure swing adsorption (PSA) system. Other embodiments may utilize one or more membranes (e.g., a single membrane, multiple membranes operating in parallel, and / or multiple membranes operating in series, etc.). For example, the nitrogen separation unit may include at least one membrane for forming a nitrogen stream and an O2-rich stream, wherein the O2-rich stream output from the nitrogen separation unit is vented, and the formed nitrogen stream is an N2-rich stream, having at least 90 vol% N2 or 95 vol% to 100 vol% N2.

[0015] Seventhly, the means of transport by sea can be a vessel. For example, a means of transport by sea can be a cargo ship, barge, tanker, or other type of vessel.

[0016] In an eighth aspect, the apparatus may include a nitrogen storage unit and a methanol engine unit. The nitrogen storage unit may be positioned to output nitrogen stored in the nitrogen storage unit to the methanol engine unit via a methanol engine feed conduit positioned between the nitrogen storage unit and the methanol engine unit. In some embodiments, the nitrogen storage unit may also be connected to a supplemental nitrogen feed conduit for feeding nitrogen to one or more other components of the marine vehicle.

[0017] In the ninth aspect, the means of the first aspect may include one or more features of the second, third, fourth, fifth, sixth, seventh, and / or eighth aspects. Therefore, it should be understood that other embodiments may utilize other combinations of features. Examples of such features can be understood from the exemplary embodiments discussed herein.

[0018] For example, in some embodiments, a nitrogen generation device for a methanol-powered marine vehicle includes a compression system configured to compress air to a pre-selected feed pressure and provide a compressed air stream at the pre-selected feed pressure; and a nitrogen separation unit located downstream of the compression system, configured to separate nitrogen and oxygen from the compressed air stream fed to the nitrogen separation unit via the compression system. The nitrogen separation unit may be configured to output nitrogen separated from the compressed air stream as a nitrogen stream, at least a portion of which is fed to a nitrogen storage unit via a nitrogen storage unit feed conduit connected between the nitrogen storage unit and the nitrogen separation unit. The nitrogen storage unit may be connected to a methanol engine unit via a methanol feed conduit to feed nitrogen stored in the nitrogen storage unit to the methanol engine unit. A nitrogen venting conduit may be located between the nitrogen separation unit and the nitrogen storage unit to vent at least a portion of the nitrogen stream. The nitrogen venting conduit may have a valve. A sensor can be positioned to detect the pressure of a nitrogen storage unit, and a controller having a processor communicatively connected to a non-transitory memory can be communicatively connected to the sensor and a valve in a nitrogen discharge conduit. The controller can be configured to determine, based on data from the sensor, whether the pressure of the nitrogen storage unit is at or above a pre-selected pressure threshold, and in response to whether the pressure of the nitrogen storage unit is at or above the pre-selected pressure threshold, actuate the valve in the nitrogen discharge conduit to open the valve to discharge at least a portion of the nitrogen flow. The controller can also be communicatively connected to a compression system to actuate the deactivation of the compression system in response to whether the pressure of the nitrogen storage unit is at or above the pre-selected pressure threshold. The controller can also be configured to communicate with a sensor positioned to detect the nitrogen purity of the nitrogen flow to monitor the nitrogen content of the flow, thereby ensuring that the vapor is a sufficiently N2-rich flow (e.g., having an N2 content of at least 95% by volume or at least 97% by volume).

[0019] In some embodiments, the controller may also be configured to communicate with a nitrogen purity sensor to determine the oxygen content of the nitrogen stream, and when the oxygen content is at or above a pre-selected threshold (e.g., 3% O2 ​​by volume, 5% O2 by volume, etc.), determine that the nitrogen content in the nitrogen stream is too low, and communicate with a valve in the nitrogen discharge conduit to open the valve and also communicate with a valve in the nitrogen storage unit feed conduit to close the valve, so that low-purity nitrogen is discharged instead of being fed into the nitrogen storage unit. In response to receiving data from the nitrogen purity sensor indicating that the nitrogen content of the nitrogen stream is at or above a pre-selected nitrogen purity threshold (e.g., the oxygen content of the nitrogen stream is at or below 3% or 5% by volume, 10% by volume, or other pre-selected thresholds, etc.), the controller may communicate with a valve in the nitrogen discharge conduit to close the valve and communicate with a valve in the nitrogen storage unit feed conduit to open the valve, so that a sufficiently pure nitrogen stream is fed into the nitrogen storage unit for storage therein.

[0020] In a tenth aspect, a method for generating nitrogen for a methanol-powered marine vehicle is provided. An embodiment of the method may include compressing air to a pre-selected feed pressure to output a compressed air stream. The pre-selected feed pressure may be greater than 1300 kPag and less than 2000 kPag. The method may further include separating the compressed air stream to form a nitrogen stream having at least 90% by volume N2 and less than 100% by volume N2, and feeding the formed nitrogen stream to a nitrogen storage unit connected to a methanol engine unit.

[0021] This method can be implemented using a nitrogen generation device for methanol-powered marine vehicles. The resulting nitrogen stream can be considered as an N2-rich stream.

[0022] In the eleventh aspect, the method may further include feeding nitrogen from a nitrogen storage unit to a methanol engine unit for leak testing and / or purging.

[0023] In the twelfth aspect, the pre-selected feed pressure can be selected such that a nitrogen flow is formed and fed into the nitrogen storage unit without the need for a booster compressor.

[0024] In the thirteenth aspect, the feed air can be compressed by a compression system including a compressor, and a pre-selected feed pressure can be selected such that the nitrogen stream is fed into the nitrogen storage unit, wherein the compressor of the compression system is the only compressor used to separate the compressed air stream and feed the nitrogen stream into the nitrogen storage unit.

[0025] In a fourteenth aspect, the method may further include filtering the compressed air stream upstream of the separation to form a nitrogen stream, pretreating the compressed air stream upstream of the separation to dry and / or preheat the compressed air stream to form a nitrogen stream, and / or removing oil vapor and / or lubricant from the compressed air stream upstream of the separation to form a nitrogen stream.

[0026] In a fifteenth aspect, the method may further include detecting the pressure of the nitrogen storage unit. In response to whether the pressure of the nitrogen storage unit is at or above a first pressure threshold, the nitrogen flow may be vented and / or the compression system may be deactivated to stop compressing the feed air. In response to whether the pressure of the nitrogen storage unit is at or below a second pressure threshold, the compression system may be activated to begin compressing the feed air and / or the venting of the nitrogen flow may be prevented.

[0027] In some implementations, nitrogen flow emission may also occur based on the detected nitrogen purity of the nitrogen flow. For example, in response to whether the oxygen content in the nitrogen flow output from the nitrogen separation unit is too high (e.g., exceeding 3 vol%, 5 vol%, 10 vol%, or other pre-selected oxygen thresholds indicating low nitrogen purity), the nitrogen flow may be emitted, preventing the nitrogen flow with insufficient purity from being fed into the storage unit for storage and subsequent use. In response to whether the oxygen content in the nitrogen flow is sufficiently low (e.g., not exceeding 3 vol%, 5 vol%, 10 vol%, or other pre-selected oxygen thresholds indicating nitrogen purity at a pre-selected concentration, such as 97 vol%, 95 vol%, 90 vol%, or other pre-selected purity thresholds), nitrogen flow emission may be stopped, and a nitrogen flow with sufficient purity may be fed into the storage unit for storage and subsequent use of the nitrogen flow (which may be considered an N2-rich flow).

[0028] In the sixteenth aspect, the method of the tenth aspect may include one or more features of the eleventh, twelfth, thirteenth, fourteenth, and / or fifteenth aspects. Therefore, it should be understood that other embodiments may utilize other combinations of features. Examples of such features can be understood from the exemplary embodiments discussed herein.

[0029] Further details, objectives, and advantages of the apparatus, method, and manufacture and use of the nitrogen generation for methanol-powered marine vehicles described herein will become apparent from the following description of certain exemplary embodiments thereof. Attached Figure Description

[0030] Exemplary embodiments of the invention are shown in the accompanying drawings, which are included herein, wherein the same reference numerals used in the drawings may identify the same parts.

[0031] Figure 1 This is a block diagram illustrating a first exemplary embodiment of an apparatus for nitrogen generation in a methanol-powered marine vehicle. Exemplary embodiments of a method for nitrogen generation in a methanol-powered marine vehicle can also be found from... Figure 1 Understanding.

[0032] Figure 2 This is a block diagram of an exemplary implementation of a controller CTRL, which can be used for Figure 1 The first exemplary embodiment of the apparatus for nitrogen generation for methanol-powered marine vehicles is shown.

[0033] Figure 3 This is a flowchart illustrating a first exemplary embodiment of a method for generating nitrogen for a methanol-powered marine vehicle. Embodiments of an apparatus for generating nitrogen for a methanol-powered marine vehicle can implement this method. Detailed Implementation

[0034] refer to Figures 1-3 An exemplary embodiment of the nitrogen generation device 1 for a methanol-powered marine vehicle includes a vessel 2. The vessel 2 is a marine vehicle that may have a methanol engine unit 13. The methanol engine unit 13 can power the propulsion of the vessel 2 and other features of the vessel, such as power generation for powering the vessel's equipment. In some embodiments, the vessel 2 may also be powered by diesel, petroleum, natural gas, or other types of fuel. The methanol engine unit 13 may be a dual-fuel type engine unit that can switch between different fuel sources, or it may be an engine adapted only for using methanol. If the vessel 2 can utilize another fuel, and the methanol engine unit 13 is configured to utilize only methanol fuel, then in such embodiments, the vessel 2 may have a separate engine for using that other fuel.

[0035] The vessel 2 may include a nitrogen generation system (NGS). The nitrogen generation system may include a feed compression system 3, which can compress the air around the vessel and feed the compressed air into a filtration system 5.

[0036] Compression system 3 may include compressor C, which compresses air to a preselected feed pressure. The preselected feed pressure may be at least 1300 kPag, between 1300 kPag and 1700 kPag, or at least 1500 kPag (e.g., between 1500 kPag and 2000 kPag). In other embodiments, the preselected feed pressure may be at least 1400 kPag or another suitable pressure within the preselected pressure range. The preselected feed pressure may be selected such that nitrogen (N2) formed via downstream nitrogen separation unit 9 can be fed to nitrogen storage unit 11 without requiring a booster compressor or heat exchanger between nitrogen separation unit 9 and nitrogen storage unit 11. In some embodiments, the feed pressure may be selected such that no additional compressor is required for the nitrogen generation system NGS (e.g., compressor C of compression system 3 is the only compressor for the nitrogen generation system NGS).

[0037] The compressor C of the compression system can be a single-stage compressor or may include a multi-stage compressor. The compression system 3 may also include at least one heat exchanger HX for cooling the feed air and / or the compressor. In some embodiments, the heat exchanger HX may utilize water or brine as the cooling medium. In some embodiments, the heat exchanger HX may be a chiller or air cooler, utilizing, for example, air, seawater, or water as the cooling medium.

[0038] The compression system 3 may also include an oil separator OS, which may be configured to remove oil or other compressor lubricants that may be used in the compressor C for the movement of the blades, screw, or other components of the compressor C. The oil separator OS may be or may include at least one cyclone separator or other type of oil separation or lubricant separation element, which may remove lubricant and / or oil from the compressed air before the compressed air is fed downstream to the filtration system 5 and / or the nitrogen separation unit 9.

[0039] The filtration system 5 is located downstream of the compression system 3 and can receive compressed air from the compression system 3. In some embodiments, the compressed air can be fed into the filtration system 5 via a compressed air feed duct 4 connected between the filtration system 5 and the compression system 3.

[0040] The filtration system 5 can be configured to filter particles, oil, lubricants, or other elements from the air and output the filtered compressed air stream to the pretreatment unit 7 and / or the nitrogen separation unit. For example, the filtration system 5 may include at least one filter element FE. Each filter element FE may be a coalescing filter, an activated carbon filter, or other type of filter, configured to remove particles, oil, liquid water, and / or other impurities from the compressed air output from the compression system 3.

[0041] Filtered compressed air can be output from the filtration system 5 and fed into the pretreatment unit 7 via the pretreatment unit feed duct 6 located between the filtration system 5 and the pretreatment unit 7.

[0042] The pretreatment unit 7 can be configured to preheat and / or dry the compressed and filtered air before it is fed into the nitrogen separation unit 9. For example, the pretreatment unit 7 may include a preheater (HR) and / or a dryer unit (DU). The preheater HR can preheat the compressed air to a preselected separation feed temperature. For example, the preheater may be an electric heater, an electric temperature-controlled heater, or other type of preheater for preheating the air before it is fed into the nitrogen separation unit 9. The preselected separation feed temperature may be between 10°C and 75°C or between 30°C and 60°C. Other suitable temperature ranges that can heat the compressed air to a desired temperature to facilitate the separation of oxygen and nitrogen in the compressed air may also be utilized.

[0043] A dryer unit (DU) may include at least one desiccant for removing moisture from the air (e.g., silica and / or other desiccants for removing water vapor from the air). For example, a dryer unit (DU) includes a container containing a desiccant that can contact compressed and filtered air to remove water vapor from the air. In other embodiments, the dryer unit (DU) may be a membrane dryer or a refrigerant-type dryer.

[0044] In some implementations, the dryer unit (DU) may be located at different locations between the compressor C of the compression system 3 and the nitrogen separation unit 9. For example, in some alternative arrangements, the dryer unit (DU) may be located between the filtration system 5 and the compression system 3.

[0045] The pretreatment unit 7 may also include an adsorber, a container with an activated carbon bed and / or an activated carbon filter, which may be positioned and configured to remove oil vapor and / or other impurities from the compressed air before the compressed air is fed into the nitrogen separation unit 9.

[0046] Compressed air can be output from the pretreatment unit 7 and fed into the nitrogen separation unit 9 via the nitrogen separation unit feed duct 8 located between the pretreatment unit 7 and the nitrogen separation unit 9.

[0047] In other embodiments, the pretreatment unit 7 may be omitted. In such embodiments, filtered compressed air output from the filtration unit 5 may be fed from the filtration system 5 to the nitrogen separation unit 9 via a nitrogen separation unit feed conduit 8 positioned between the nitrogen separation unit 9 and the filtration system 5. In embodiments where the filtration system 5 may also be omitted, compressed air output from the compression system 3 may be fed to the nitrogen separation unit 9 via a nitrogen separation unit feed conduit 8 positioned between the nitrogen separation unit 9 and the compression system 3.

[0048] The nitrogen separation unit 9 may include at least one membrane or adsorption system for separating oxygen (O2) from nitrogen (N2) in compressed air to form an O2-rich stream and an N2-rich stream. The O2-rich stream may be discharged, and the N2-rich stream may be fed into the nitrogen storage unit 11.

[0049] In embodiments utilizing the adsorption system, in some implementations, the adsorption system may be a pressure swing adsorption (PSA) system. In such embodiments, the adsorbent material within one or more adsorbers of the adsorption system can adsorb oxygen to separate oxygen from nitrogen, forming an N2-rich stream. The N2-rich stream can be output via a nitrogen output conduit 10, which is connected to and positioned between a nitrogen storage unit 11 and the nitrogen separation unit 9, for feeding nitrogen into the nitrogen storage unit 11 and / or for discharging excess nitrogen that may not be stored in the nitrogen storage unit 11. Regeneration of one or more adsorbers of the adsorption system can result in the formation of an O2-rich stream, which, in embodiments utilizing the adsorption system for the nitrogen separation unit 9, can be discharged via an oxygen discharge conduit 12.

[0050] In embodiments utilizing at least one membrane, the at least one membrane may be a membrane unit having at least one membrane (e.g., a single membrane or multiple membranes arranged in series or parallel), the membrane unit being configured to permeate oxygen from compressed air to form an O2-rich stream and a high-purity N2-rich stream (e.g., a stream having at least 95% by volume N2). The O2-rich stream formed by the membrane can be output via oxygen discharge conduit 12. The high-purity nitrogen stream can be fed into a nitrogen storage unit 11 and / or discharged via a nitrogen output conduit 10 positioned between a nitrogen separation unit 9 and a nitrogen storage unit 11.

[0051] The nitrogen separation unit 9 can output an N2-rich stream containing 95% to less than 100% N2 via the nitrogen output conduit 10. In other embodiments, the N2-rich stream may have a different nitrogen composition (e.g., more than 90% N2, 85% to 100% N2, etc.).

[0052] The O2-rich stream can contain a significant amount of oxygen. For example, the formed O2-rich stream can contain more than 0 and less than or equal to 50% by volume of O2, can be 10% to 40% by volume of O2, or can be 25% to 40% by volume of O2. The O2-rich stream can be discharged into the atmosphere near the ship 2 via oxygen discharge duct 12.

[0053] Nitrogen outlet conduit 10 can be connected to nitrogen storage unit feed conduit 14. Nitrogen storage unit feed conduit 14 may include a valve V adjustable between an open and closed position to feed nitrogen into nitrogen storage unit 11. If valve V of nitrogen storage unit feed conduit 14 is closed, the closed valve can discharge the entire N2-rich flow via nitrogen discharge conduit 16. For example, valve V of nitrogen storage unit feed conduit 14 can be closed when sensor S detects that nitrogen storage unit 11 is full or at a pre-selected pressurization level (at or above a first pre-selected nitrogen storage unit pressure threshold) and cannot receive additional nitrogen.

[0054] The valves V of the nitrogen storage unit feed conduit 14 and nitrogen discharge conduit 16 can have multiple different open positions, and can be opened at different open positions, so that a portion of the resulting N2-rich flow can be discharged, while another portion is fed into the nitrogen storage unit for storage. Such partial discharge can be performed when the nitrogen storage unit 11 is detected as being mostly full or having a limited capacity that cannot receive the entire N2-rich flow, based on data obtained via at least one sensor S, which is positioned to detect the degree of fullness of the nitrogen storage container 11 and / or the pressure of the nitrogen storage unit 11.

[0055] For example, the controller CTRL can communicatively connect to valves V of the nitrogen discharge conduit 16 and the nitrogen storage unit feed conduit 14, and (i) a sensor S that can detect the pressure of the nitrogen storage unit 11 and / or (ii) a sensor S positioned to detect the nitrogen purity level of the N2-rich stream fed into the nitrogen output conduit 10 to receive data from the sensor S and, based on the purity of the N2-rich stream output from the nitrogen separation unit 9 and / or the pressure of the nitrogen storage unit 11 detected by the sensor 11, to provide communication with one or both valves V for adjusting their positions to facilitate nitrogen discharge or nitrogen feeding into the nitrogen storage unit 11. The controller CTRL can also communicatively connect to the compression system 3 to regulate the operation of the compression system 3 between an on and off state.

[0056] For example, when the nitrogen storage unit 11 is at or above a pre-selected pressure threshold (e.g., a pre-selected full-capacity threshold or a first pre-selected pressure threshold), the controller CTRL can communicate with the compression system 3 via a communication connection between the controller CTRL and the motor or control element of the compressor C to actuate the compression system to stop further nitrogen generation or further generation and storage of nitrogen from the air. Examples of the pre-selected pressure threshold could be 1600 kPag, 1000 kPag, or other suitable pressures. For example, the pre-selected pressure threshold could be a pressure value between 10 barg (1000 kPag) and 16 barg (1600 kPag), or between 10 barg (1000 kPag) and 13.5 barg (1350 kPag).

[0057] When the nitrogen storage unit 11 is at or below a pre-selected nitrogen capacity threshold (e.g., below a first pre-selected pressure threshold or a second pre-selected pressure threshold below a pre-selected full capacity threshold), the controller CTRL can communicate with the compression system 3 to activate the compression system, causing the compression system 3 to compress the air to be fed into the nitrogen separation unit 9 for further generation and storage of nitrogen or for further generation and storage of nitrogen from the air. Examples of pre-selected nitrogen capacity thresholds include nitrogen storage unit 11 pressures below 10 barg (e.g., 800 kPa, 900 kPag, between 900 kPag and 1000 kPag, etc.), below 13 barg (1300 kPag), or between 10 barg and 14 barg (e.g., between 1000 kPag and 1400 kPag).

[0058] The controller CTRL can also be configured to control the valve position based on the detected nitrogen purity level. For example, nitrogen outlet conduit 10 can be connected to nitrogen discharge conduit 16, which has a valve V adjustable between an open and closed position to discharge an N2-rich stream or a portion of the N2-rich stream output from nitrogen separation unit 9. Sensor S can be positioned to detect the nitrogen purity of the N2-rich stream. In some configurations, sensor S can provide data to the controller CTRL to monitor the oxygen concentration of the N2-rich stream, for example, to assess the nitrogen purity of the stream. When the nitrogen purity is below a pre-selected nitrogen purity threshold (e.g., oxygen content exceeding 10% by volume, exceeding 5% by volume, exceeding 3% by volume, or exceeding another pre-selected oxygen content threshold corresponding to the pre-selected nitrogen purity threshold, etc.), the controller can communicate with valve V such that the valve of nitrogen discharge conduit 16 can be opened and valve V of nitrogen storage unit feed conduit 14 can be closed, so that the low-nitrogen-purity N2-rich stream is discharged and not stored. When the controller CTRL determines, based on nitrogen purity sensor data, that the nitrogen purity is at or above a pre-selected nitrogen purity threshold (e.g., oxygen content less than or equal to 10% by volume, less than or equal to 5% by volume, less than or equal to 3% by volume, etc.), the controller CTRL can communicate with the valves to close the valve V of the nitrogen discharge conduit 16 and open the valve V of the nitrogen storage unit feed conduit 14, so that an N2-rich stream with an acceptable nitrogen concentration can be fed into the nitrogen storage unit 11 for storage therein.

[0059] Nitrogen stored in nitrogen storage unit 11 can be fed into methanol engine unit 13 of vessel 2. For example, nitrogen from nitrogen storage unit 11 can be stored at a pre-selected nitrogen storage pressure. In some embodiments, the pre-selected nitrogen storage pressure can be between 10 barg and 16 barg (1000 kPag to 1600 kPag). Nitrogen can be discharged from nitrogen storage unit 11 by opening valve V of methanol engine feed duct 17 to feed nitrogen from nitrogen storage unit 11 into methanol engine unit 13. Nitrogen can be fed into methanol engine unit 13 for, for example, leak testing, purging, and / or inerting operations.

[0060] In some applications, the nitrogen storage unit 11 can be used for leak testing operations. In such applications, the pressure threshold for initiating operation of the compression system 3 can be below 13 barg, and the pressure threshold for stopping the compression system can be greater than 13 barg. In some configurations, the device can be configured to operate continuously during leak testing to supply a high-pressure nitrogen stream to the methanol engine 13 for leak testing, such that the high-pressure nitrogen stream is fed into the methanol engine unit 13 at the maximum pressure of the device.

[0061] In some embodiments, nitrogen can also be supplied from nitrogen storage unit 11 via auxiliary nitrogen output conduit 18 (shown in dashed lines) to feed nitrogen to other marine components. Nitrogen can be fed to other components by opening valve V of auxiliary nitrogen output conduit 18.

[0062] The nitrogen storage unit 11 may also include a pressure reducing valve and / or a venting valve, which can be actuated to release nitrogen to alleviate overpressure conditions. Such venting may be separate from the methanol engine feed duct 17 and the auxiliary nitrogen output duct 18.

[0063] In some configurations, at least one sensor S may also include a nitrogen purity sensor that communicates with the controller CTRL and can detect the nitrogen content of nitrogen stored in the nitrogen storage unit 11. The nitrogen purity sensor can detect nitrogen purity by detecting the oxygen content in the nitrogen or by detecting another parameter indicating nitrogen purity. In some configurations, the detected nitrogen purity can be used to actuate the emission from the nitrogen storage unit 11 and / or to feed nitrogen from the nitrogen storage unit 11 to at least one downstream element (e.g., methanol engine unit 13, other downstream applications via auxiliary conduit 18, etc.).

[0064] Furthermore (as described above), if the purity of the nitrogen output from the nitrogen separation unit 9 is detected to be below a pre-selected threshold after actuation of the compression system 3, nitrogen can be discharged until nitrogen of a higher purity that meets the nitrogen purity threshold is formed. In response to detecting that the nitrogen flow output from the nitrogen separation unit has sufficient nitrogen purity, the controller CTRL can communicate with at least one valve V to adjust the valve position and feed nitrogen from the nitrogen separation unit 9 into the nitrogen storage unit 11.

[0065] The controller CTRL can also communicate with valve V of the methanol engine feed duct 17 and valve V of the auxiliary nitrogen feed duct 18 (when utilized). The controller CTRL can communicate with one or more of these valves V to adjust their positions between at least one open and closed position based on user input transmitted to the controller or other criteria of a predefined control scheme stored in the controller CTRL's memory. For example, valve V can be adjusted from its closed position to an open position, from one open position to another open position, or from an open position to a closed position based on predefined control criteria stored in the controller CTRL's memory.

[0066] As from Figure 2As can be best viewed, the controller CTRL can be a computer device CD. The controller may include a processor 11a communicating with a non-transitory memory 11b (memory), which has one or more applications (Apps) and multiple data stores (DSs) stored thereon. The controller may also include one or more interfaces 11c (interfaces) communicating with the processor 11a. Each interface 11c may include a transceiver for communicating with one or more input devices 11id, one or more output devices 110d, one or more sensors S (e.g., nitrogen storage unit pressure sensor S, nitrogen purity sensor S, etc.), one or more other computer devices CD, and / or one or more valves V. The transceiver of interface 11c may include at least one local area network (LAN) connected transceiver, at least one wide area network (WAN) connected transceiver, and / or at least one near-field communication (NFC) transceiver. The transceiver may be configured to communicate via wireless and / or hardwired connections.

[0067] It should be understood that at least some connection CCs can utilize other components to facilitate communication. For example, some wireless connections may involve the use of access points, routers, or intermediate nodes.

[0068] Examples of input devices 11id that can be connected to the controller may include buttons, keypads, keyboards, styluses, microphones, or touchscreens. Examples of output devices 11od that can be connected to the controller's CTRL may include displays, printers, and / or speakers. For example, the controller may be configured to display a graphical user interface (GUI) on a display, allowing users to provide input to the controller by interacting with the GUI via a touchscreen display, pointing devices, and / or a keyboard.

[0069] In some implementations, the controller can communicate with operator equipment 21, which may be a computer device CD configured to run an automated process control system or other type of process control scheme, including a controller and various components of the vessel 2 and / or the nitrogen generation device 1 connected to the controller. The automated process control system of operator equipment 21 can supervise and / or assist in monitoring, for example, the operation and / or related operations of the vessel 2, the methanol engine unit 13.

[0070] An embodiment of the nitrogen generation device 1 and / or controller CTRL for a methanol-powered marine vehicle can be configured to implement an embodiment of a method for nitrogen generation for a methanol-powered marine vehicle. Figure 3 An exemplary implementation of such a method is shown in the figure.

[0071] In the first step S1, the feed air can be compressed. Such compression can occur via the compression system 3 discussed above, so that the air is compressed to a pre-selected feed pressure, which avoids any need for further air compression, for example, between the compression system 3 and the nitrogen storage unit 11.

[0072] In the second step S2, compressed air may be filtered. For example, compressed air may pass through one or more filter elements FE of the filtration system 5 and / or through the oil separator OS, as discussed above.

[0073] In the third step S3, compressed air can pass through the nitrogen separation unit 9, allowing nitrogen from the compressed air to be separated from oxygen in the compressed air. The oxygen separated from the nitrogen can be discharged (e.g., as the O2-rich gas formed as discussed above). The nitrogen separated from the oxygen can be fed into and / or discharged into the nitrogen storage unit 11 based on (i) the determined purity of the generated nitrogen, (ii) the determined pressure of the nitrogen storage unit 11, and / or (iii) the detected fullness of the nitrogen storage unit 11 (e.g., as the N2-rich stream discussed above). Examples of such discharges and / or feeds of nitrogen into the nitrogen storage unit 11 can be understood from the above.

[0074] In the fourth step S4, a portion of the nitrogen can be fed into the nitrogen separation unit 11 for storage and subsequently used to feed nitrogen into the methanol engine unit 13 via the nitrogen-methanol feed duct 17, and / or into other marine components via the auxiliary nitrogen feed duct 18. The nitrogen fed into the nitrogen-methanol engine unit 13 can be used for leak testing, purging, and / or other purposes.

[0075] Implementations of this method may also include other steps. For example, based on the detected pressure of the nitrogen storage unit 11, the valve of the nitrogen storage unit feed conduit may be closed, and the discharge conduit valve V may be opened. As another example, as discussed above, based on the detected purity of the nitrogen output from the nitrogen separation unit 9, one or more valves may be adjusted between their open and closed positions. As another example, as discussed above, the compression system 3 may be started or stopped based on the detected pressure of the nitrogen storage unit 11 (and the valve positions may be adjusted to accommodate the nitrogen purity that occurs after the compression system is started, as discussed above). As yet another example, compressed air can be purified via pretreatment unit 7 to remove one or more impurities (e.g., oil vapor, water, etc.) and / or preheated before being fed to nitrogen separation unit 9 to form a high-purity nitrogen stream (e.g., a nitrogen stream with a nitrogen content of at least 95% to 100% by volume, at least 97% by volume, and having an oxygen content of less than or equal to 3% by volume or less than or equal to 5% by volume) for feeding into nitrogen storage unit 11 as discussed above.

[0076] Embodiments of the method and apparatus for nitrogen generation and storage of the present invention can provide improved operational efficiency, reducing the footprint of the nitrogen generation system (NGS) and allowing for a more reliable system with fewer devices and fewer moving parts that may be susceptible to mechanical failures or other maintenance problems. The embodiments can provide improved operational flexibility, improved operational performance, and improved reliability. Furthermore, embodiments of the present invention can promote the use of methanol as a fuel source, enabling more ships and other maritime vehicles to be designed or converted to use methanol as a fuel source. This provides an alternative to fossil fuel-based fuel sources and offers a better environmental impact for the operation of ships 2 or other maritime vehicles.

[0077] It should be understood that different modifications can be made to different components to meet a pre-selected set of design criteria. For example, the type of nitrogen separation unit utilized (e.g., membrane, adsorption system, etc.) can be any suitable system. Some embodiments may utilize membrane units including hollow fiber membranes, spiral wound membranes, or other suitable membranes. Other embodiments may utilize pressure swing adsorption systems with two or more adsorbers, or other types of adsorption systems (e.g., vacuum pressure adsorption systems, temperature swing adsorption systems, etc.).

[0078] As another example, nitrogen storage unit 11 may include a tank or other container for storing nitrogen, or multiple storage containers for storing nitrogen. For example, nitrogen storage unit 11 may include a single storage tank, multiple storage tanks or storage containers and / or other components of the tank.

[0079] As yet another example, the filtration system 5 may include one or more filter elements FE (e.g., including a single filter element, including multiple filter elements operating in series, including multiple filter elements operating in parallel, etc.).

[0080] As yet another example, the compression system 3 can be configured as any suitable type of compression system (e.g., single-stage compression, multi-stage compression, etc.) to provide a feed of compressed air at a pre-selected feed pressure and / or a pre-selected feed temperature. In embodiments of the compression system 3 that may not include the oil separator OS, the oil separator mechanism can be positioned between the compression system 3 and the nitrogen separation unit 9 (e.g., as discussed above, an activated carbon adsorber or filter element may be utilized).

[0081] Different conduits and conduit arrangements can also be adjusted to meet a set of pre-selected design criteria. Conduits may include, for example, different types of pipes or piping systems. Conduits may also include additional valves or other types of conduit arrangements.

[0082] As yet another example, while implementations may be provided such that no booster and / or heat exchanger exists between the nitrogen separation unit 9 and the nitrogen storage unit 11, a booster and / or heat exchanger may be present downstream of the nitrogen storage unit 11 to regulate the temperature and / or pressure of the nitrogen output from the nitrogen storage unit 11 for a specific downstream application of the nitrogen stored in the nitrogen storage unit 11. For example, the methanol engine unit 13 may include a heat exchanger and / or compressor to increase the temperature or pressure of the nitrogen for a particular application. As another example, an auxiliary nitrogen output conduit 18 may be connected to a booster and / or heat exchanger located downstream of the nitrogen storage unit 11 to regulate the temperature or pressure of the nitrogen for a downstream application.

[0083] In addition, the conduits and other components of the nitrogen generation system (NGS) may include different types of sensors (e.g., flow sensors, pressure sensors, temperature sensors, purity / composition sensors, etc.) to monitor the operation of the system and / or the apparatus. For example, such components may communicate with the controller CTRL and / or operator equipment 21.

[0084] Therefore, it should be understood that modifications can be made to the embodiments explicitly shown and discussed herein to meet a specific set of design objectives or a specific set of design criteria. For example, it is contemplated that specific features described separately or as part of an embodiment can be combined with other separately described features or as part of other embodiments. Thus, elements and actions of the various embodiments described herein can be combined to provide additional embodiments. Therefore, while certain exemplary embodiments of apparatuses for nitrogen generation for methanol-powered marine vehicles, methods for nitrogen generation for methanol-powered marine vehicles, and methods of manufacturing and using the same have been shown and described above, it should be clearly understood that the invention is not limited thereto, but can be implemented and practiced differently in other ways within the scope of the appended claims.

Claims

1. An apparatus for generating nitrogen for a methanol-powered marine vehicle, the apparatus comprising: A compression system configured to compress air to a preselected feed pressure and output a compressed air stream at the preselected feed pressure; and A nitrogen separation unit is located downstream of the compression system and configured to separate nitrogen and oxygen from the compressed air stream fed into the nitrogen separation unit via the compression system. The nitrogen separation unit is also configured to output the nitrogen separated from the compressed air stream as a nitrogen stream for feeding at least a portion of the nitrogen stream into a nitrogen storage unit.

2. The apparatus of claim 1, wherein the preselected feed pressure is between 1300 kPa and 2000 kPa, and wherein the preselected feed pressure is selected such that the nitrogen flow is formed and fed into the nitrogen storage unit without a booster compressor.

3. The apparatus of claim 1, wherein the compression system includes a compressor, and the preselected feed pressure is greater than 1300 kPag, and wherein the preselected feed pressure is selected such that the compressor of the compression system is the only compressor for separating the nitrogen from the compressed air stream and feeding the nitrogen stream into the nitrogen storage unit.

4. The apparatus according to claim 1, comprising: A filtration system having at least one filter element positioned between the compression system and the nitrogen separation unit to filter the compressed air stream before it is fed into the nitrogen separation unit.

5. The apparatus of claim 4, further comprising a pretreatment unit positioned between the filtration system and the nitrogen separation unit to preheat and / or dry the compressed air stream before it is fed into the nitrogen separation unit.

6. The apparatus according to claim 5, comprising the nitrogen storage unit.

7. The apparatus of claim 1, wherein the nitrogen separation unit comprises at least one membrane or comprises an adsorption system.

8. The apparatus of claim 7, wherein the nitrogen separation unit comprises an adsorption system, wherein the adsorption system is a pressure swing adsorption (PSA) system.

9. The apparatus of claim 7, wherein the nitrogen separation unit includes at least one membrane for forming the nitrogen flow and forming an O2-rich flow, wherein the O2-rich flow is output from and discharged from the nitrogen separation unit.

10. The apparatus of claim 1, wherein the nitrogen gas stream comprises 95% or more by volume of N2 and less than 100% by volume of N2; and The maritime transport vehicle mentioned above is a ship.

11. The apparatus according to claim 1, comprising: The nitrogen storage unit and the methanol engine unit are configured to output nitrogen stored in the nitrogen storage unit to the methanol engine unit via a methanol engine feed pipe, the methanol engine feed pipe being positioned between the nitrogen storage unit and the methanol engine unit.

12. The apparatus of claim 11, wherein the nitrogen storage unit is connected to an auxiliary nitrogen feed duct to feed nitrogen to one or more other components of the marine vehicle.

13. A method for generating nitrogen for a methanol-powered marine vehicle, the method comprising: Air is compressed to a pre-selected feed pressure to output a compressed air stream, the pre-selected feed pressure being between 1300 kPag and 2000 kPag; and The compressed air stream is separated to form a nitrogen stream with 90% to 100% N2 by volume; and The nitrogen stream is fed into the nitrogen storage unit of the methanol engine unit connected to the methanol-powered marine vehicle.

14. The method of claim 13, comprising: Nitrogen gas is fed from the nitrogen storage unit to the methanol engine unit for leak testing and / or purging.

15. The method of claim 13, wherein the pre-selected feed pressure is selected such that the nitrogen gas flow is formed and fed into the nitrogen storage unit without a booster compressor.

16. The method of claim 13, wherein the feed air is compressed by a compression system including a compressor, and wherein the pre-selected feed pressure is selected such that the compressor of the compression system is the only compressor for separating the nitrogen from the compressed air stream and feeding the nitrogen stream into the nitrogen storage unit.

17. The method of claim 13, comprising: At least one of the following: The compressed air stream is filtered upstream of the separated compressed air stream to form the nitrogen stream; The compressed air stream is pretreated upstream of the separation process to dry and / or preheat the compressed air stream to form the nitrogen stream; And / or Oil vapor and / or lubricant are removed from the compressed air stream upstream of the separation to form the nitrogen stream.

18. The method of claim 13, comprising: Detect the pressure of the nitrogen storage unit; If the pressure in the nitrogen storage unit is at or above a first pressure threshold, the nitrogen flow is released and / or the compression system is deactivated to stop compressing the feed air; or If the pressure in the nitrogen storage unit is at or below the second pressure threshold, the compression system is activated to begin compressing the feed air.

19. An apparatus for generating nitrogen for a methanol-powered marine vehicle, the apparatus comprising: A compression system configured to compress air to a preselected feed pressure and output a compressed air stream at the preselected feed pressure; A nitrogen separation unit is located downstream of the compression system and configured to separate nitrogen and oxygen from the compressed air stream fed into the nitrogen separation unit via the compression system. The nitrogen separation unit is configured to output the nitrogen separated from the compressed air stream as a nitrogen stream and to feed at least a portion of the nitrogen stream into the nitrogen storage unit via a nitrogen storage unit feed conduit connected between the nitrogen storage unit and the nitrogen separation unit. The nitrogen storage unit is connected to the methanol engine unit of the marine vehicle via a methanol feed pipe to feed the nitrogen stored in the nitrogen storage unit to the methanol engine unit. A nitrogen discharge conduit, positioned between the nitrogen separation unit and the nitrogen storage unit, for discharging at least a portion of the nitrogen flow, the nitrogen discharge conduit having a valve; A sensor configured to detect the pressure of the nitrogen storage unit; and A controller having a processor communicating with a non-transitory memory, the controller communicating with the sensor and the valve of the nitrogen discharge conduit, the controller being configured to determine, based on data from the sensor, whether the pressure of the nitrogen storage unit is at or above a pre-selected pressure threshold, and if the pressure of the nitrogen storage unit is at or above the pre-selected pressure threshold, to actuate the valve of the nitrogen discharge conduit to adjust the valve of the nitrogen discharge conduit to an open position to discharge at least a portion of the nitrogen flow and / or to communicate with the compression system to regulate the operation of the compression system.

20. The apparatus of claim 19, wherein the controller communicates with the compression system and is configured to deactivate the compression system if the pressure of the nitrogen storage unit is at or above the pre-selected pressure threshold; and The maritime transport vehicle mentioned above is a ship.

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