Green energy sources authentication and compliance testing

Abstract

A method for authenticating a liquefied gas by exposing a sample of the liquefied gas to a specific excitation wavelength of electromagnetic radiation and detecting a resulting signal with a detector, wherein the specific excitation wavelength is a wavelength at which a marker in an authentic liquefied gas exhibits a distinguishable signal detected by the detector; authenticating said liquefied gas when the resulting signal corresponds to an expected signal provided by the authentic liquefied gas having an authentic marker concentration; and identifying the liquefied gas as suspect or counterfeit when the resulting signal deviates from the expected signal by more than an amount provided by an authentication standard.

Description

Atty Docket No: 4377-12701 GREEN ENERGY SOURCES AUTHENTICATION AND COMPLIANCE TESTING BACKGROUND

[0001] Various products are subject to adulteration and tax evasion worldwide. These illegal practices deprive governments and legitimate businesses of profits and may be hazardous to users, as well as the environment. Such deception can also cause harm, sometimes irreparable harm, including, for example, to the brand name or brand image of the producer of the original product. Significant commercial gain can also be obtained by counterfeiters through the dilution of the original products with a readily available, less expensive material.

[0002] Fuels like hydrogen can be classed as green, blue or grey (and other designations / colors) depending on the processes used to produce them. The price for these fuels generally differs depending on how carbon neutral they are, with true green fuels, which can be completely carbon neutral, demanding substantially higher prices. This classification finds a synergy with traditional gasoline and diesel grades, where premium grades with higher octane levels or bespoke additives also demand higher prices, or where governments will subsidize, or reduce taxes, on certain fuels for certain markets, for example reduced taxes on agricultural diesel or subsidizing kerosene for the neediest of the population.

[0003] With the global drive away from the use of petrochemical hydrocarbons as an energy source, and the move to more renewable energy sources, there is a need for compliance, assurance and authentication of these renewable energy sources (e.g., green fuels), as suppliers that do not pay required taxes can offer cost advantages through unfair practices, without necessarily adhering to safety and maintenance standards. BRIEF DESCRIPTION OF THE DRAWINGS

[0004] FIG.1 illustrates a schematic diagram of an embodiment of an apparatus for direct detection of one or more markers in a liquefied gas.Atty Docket No: 4377-12701

[0005] FIG. 2 illustrates a schematic diagram of an embodiment of a system for direct detection of one or more markers in a liquefied gas.

[0006] FIG. 3 is a schematic illustration of a system for direct detection of one or more markers in a liquefied gas utilized as the laboratory equipment setup for the experiments of the Examples.

[0007] FIG.4 is an image of the experimental setup utilized for the experiments of the Examples.

[0008] FIG. 5 is a plot of average fluorescent response as a function of marker concentration for Marker 1 of Example 4. DETAILED DESCRIPTION

[0009] As used herein, "green" in reference to a green fuel indicates fuels that are carbon-neutral or carbon-free alternatives to fossil fuels that are produced from renewable energy sources, such as and without limitation, hydro, solar, and / or wind power. Green fuels can also be termed synthetic or electrofuels (e-fuels), and can be liquid or gaseous fuels produced with electricity from renewables. Examples for such e-fuels are synthetic natural gas (SNG), green methanol or green ammonia. A “blue” or “grey” designation for a fuel can refer to reclamation of carbon for feed stocks and / or the source of energy used for the fuel production.

[0010] A green fuel, (also known as biofuel or renewable fuel), can include a fuel distilled from biomass (e.g., plants and / or animal materials), that may be more environmentally friendly than the widely-used fossil fuels that now power most of the world. Although the processing of products / crops into biofuels can itself create a considerable amount of pollution, such are referred to herein as green fuels. Renewable fuels include fuels produced from renewable resources, including, without limitation, biofuels (e.g., vegetable oil, ethanol, methanol from clean energy and carbon dioxide or biomass, and biodiesel), hydrogen fuel produced via renewable processes, and fully synthetic electrofuel produced from ambient carbon dioxide and water. Renewable fuelsAtty Docket No: 4377-12701 can include fuels synthesized with renewable energy sources, such as wind and solar. Renewable fuels provide sustainability, reduced concentrations to the carbon cycle, and greenhouse gases.

[0011] As used herein, "authenticate" generally refers to confirming a product or commodity as genuine or substantially unadulterated and / or to confirm an origin or intended use of a product or commodity.

[0012] As used herein, "coupled" generally refers to pieces that may be used operatively with each other, or pieces that are joined or linked together, with or without one or more intervening members. As described herein, pieces that are coupled may be removably coupled. That is, coupled pieces may be uncoupled to alter a relationship between the coupled pieces. Pieces that are physically coupled can be in direct contact.

[0013] As used herein, "direct detection" generally refers to a process in which one or more markers are detected in a liquefied gas in an apparatus that is coupled to a source of the liquefied gas and, generally, without the addition of reagents to the liquefied gas. Thus, in embodiments of this disclosure, detection of markers can be achieved at the site of the liquefied gas source.

[0014] As used herein, "detector" generally refers to an apparatus or system used to detect the presence of an object, radiation, chemical compound, or such. A detector can be, for instance, a fluorometer. A detector can have a radiation source. The radiation source can provide electromagnetic radiation of one wavelength or a range of wavelengths, including, but not limited to, visible, ultraviolet, and infrared radiation or a combination thereof. The detector can include a fluorometer, As used herein, "fluorometer" generally refers to an instrument that irradiates a sample and measures the fluorescent radiation emitted by the sample that is exposed to radiation. A fluorometer can provide the intensity of the radiation producing fluorescence. The detector can be portable or non-portable (e.g., installed within a lab or other analytical location). PortableAtty Docket No: 4377-12701 detectors include vehicle portable devices (e.g., mounted in or capable of being placed in a vehicle such as a service van or pickup truck) or man portable devices (e.g., handheld, backpack mounted, suitcase / briefcase mounted, or the like). Portable detectors may be transported to a marked fuel production (e.g., chemical plant or processing unit) and / or storage location (e.g., tank farm, blending / marking site, fuel depo, service station, dispensing station, etc.) and used to verify / authenticate the marked green fuel as described herein.

[0015] As used herein, “liquefied gas” refers to a liquid form of a fluid that is gaseous at room temperature and pressure (e.g., a temperature of about 70°F ± 10°F (e.g., from about 68 to 76°F) and a pressure of about 1 atmosphere (0.101 MPa)). In embodiments, the liquefied gas comprises a "hydrocarbon", which generally refers to an aggregate of matter consisting essentially of carbon and hydrogen in which the molecules are able to flow past each other without limit and without fracture planes forming. In embodiments, the liquefied gas comprises a hydrocarbon liquid, which can be formed by pressurizing a hydrocarbon gas. Hydrocarbon fluids include, but are not limited to, fuels, oils, lubricants, and other petroleum products. In embodiments, the liquefied gas is not a hydrocarbon. A liquefied gas source of this disclosure can be a container of any description that contains the liquefied gas or a conduit of any description that allows the passage of a liquefied gas therefrom.

[0016] As used herein, "liquefied natural gas" or "LNG" is natural gas generally known to include a high percentage of methane, but also other elements and / or compounds including, but not limited to, ethane, propane, butane, carbon dioxide, nitrogen, helium, hydrogen sulfide, or a combination thereof) that has been processed to remove one or more components (for instance, helium) or impurities (for instance, water and / or heavy hydrocarbons) and then condensed into a liquid at almost atmospheric pressure by cooling.Atty Docket No: 4377-12701

[0017] As used herein, "liquefied petroleum gas" or "LPG" generally refers to a mixture of propane, butane, and other light hydrocarbons derived from refining crude oil. At normal temperature this mixture is a gas but can be cooled or subjected to pressure to facilitate storage and transportation.

[0018] As used herein, "marker" generally refers to a material used to authenticate or identify a liquefied gas by absorbing, reflecting, emitting, or otherwise altering electromagnetic radiation incident on the marker. Light-emitting markers can exhibit phosphorescence, chemiluminescence, electroluminescence, fluorescence upconversion, Raman fluorescence, or fluorescence alone or in combination with the liquefied gas. A marker can respond to incident electromagnetic radiation so as to change in a physically measurable manner upon exposure to one or more wavelengths of light. As used herein, marker generally refers to one or more markers.

[0019] As used herein, "processor" generally refers to an electronic device (e.g., a computer or laptop) that receives, processes, and outputs data.

[0020] As used herein, "reader cell" generally refers to a vessel that permits passage of radiation of interest from an exterior of the vessel to an interior of the vessel. The vessel can be, for instance, a conduit or a container, such as a cuvette or a flow cell. The vessel can be transparent, translucent, or opaque. The apparatus and methods described herein are applicable to a wide range of liquefied gases and can be used to authenticate these fluids in a range of circumstances.

[0021] Conventional systems use digital platforms to track materials through the supply chain using information related to the material, e.g., track and trace or block-chain systems. These types of digital systems suffer from the physical material being easily swapped and, while the information related to the product may be genuine, it lacks the ability to prove that the associated product matches the stored information. To achieve this, a physical marker can be included in theAtty Docket No: 4377-12701 product, which physical marker can be utilized to verify the identity of the product to ensure that it indeed matches with any digital paper trail.

[0022] Unlike most conventional (e.g., hydrocarbon) fuels which are liquid at room temperature and pressure, some renewable energy sources are gaseous at room temperature and pressure. Such gaseous fuels can be liquefied, for example, under pressure and / or cooling, to provide a liquefied gas. This disclosure relates to a method and apparatus for direct detection of one or more markers in liquified gases (e.g., a liquified fuel). These gases can be for direct use as fuels, (green, blue or grey) or can be used in other industries, such as and without limitation refrigeration coolants or in the production of green agrochemicals (e.g. ammonia, which is the primary feedstock for fertilizer production). In embodiments, the system and method of this disclosure can be utilized to authenticate liquefied gas. In embodiments, the herein disclosed system and method can be utilized rather than simple certification to verify green credentials. In embodiments, the liquified gas can be selected from any liquefied gases which have different green credentials.

[0023] There are many types of renewable energy sources (e.g., green fuels) which can now be generated, which do not produce any greenhouse gases (e.g., carbon dioxide). Such products can be classified as truly green if formed using renewable power sources, such as and without limitation, solar / wind / tide / wave. Examples of such renewable energy sources (e.g., green fuels) include, without limitation, hydrogen, ammonia, alcohols (such as, and without limitation, biomethanol and bioethanol), fatty acid methyl esters (such as, and without limitation, used cooking oil methyl ester [UCOME]), biomethane (bio-LNG), or a combination thereof.

[0024] When considering these renewable energy sources (e.g., green fuels) there is expected to be a transition from 100% grey to 100% green over time, and the supply chain of these energy sources generally mandates that there will be mixing during transport and use. In addition, a priceAtty Docket No: 4377-12701 differential may provide a driving force for blue or grey energy sources to be passed off as green, to achieve a higher pricing afforded the green(er) fuels. Thus, there is a need for a system and method that can be utilized to track the individual “colored energy sources” through the supply chain and also protect the higher-grade green energy sources (e.g., green fuel) to be able to prove / verify their green credentials and ensure that there has been no adulteration with lesser value fuels, such as blue or grey (or other designated color) fuel(s).

[0025] Energy sources, such as green hydrogen and green ammonia, are not expected to suffer from high background interference, but being gases, they are not as easily marked as liquids. Normally, markers are added as concentrated liquids to other liquids. Ammonia and other fluids that are gaseous at room temperature and pressure can be liquid when under pressure, like LPG. According to this disclosure, a reader can be designed to read a fluorescent marker added to liquefied gas (e.g., a gas under pressure and / or cooling). A “reader” can refer to a fluorescence spectrometer that includes a pressurized flow cell where the compressed liquified gas and marker can be analyzed in the liquid state.

[0026] As noted above, as used herein, “marker” generally refers to a material used to authenticate or identify a liquefied gas (e.g., a liquid fuel) by absorbing, reflecting, emitting, or otherwise altering electromagnetic radiation incident on the marker. Light-emitting markers can exhibit phosphorescence, chemiluminescence, electroluminescence, fluorescence upconversion, Raman fluorescence, or fluorescence alone or in combination with the liquefied gas. A marker can respond to incident electromagnetic radiation so as to change in a physically measurable manner upon exposure to one or more wavelengths of light. As noted above, “marker” includes one or more (e.g., a plurality of) markers.Atty Docket No: 4377-12701

[0027] When selecting a marker to be added to a liquefied gas, the marker can desirably be immune to extraction from the liquefied gas by common means. That is, in embodiments, the marker cannot be substantially differentially adsorbed from the product using conventional inexpensive adsorbents; the marker cannot be removed by extraction with acids, bases, or immiscible solvents; the marker cannot be easily oxidized, reduced or reacted with common agents to effectively remove them; and / or the marker can be difficult to disguise by masking with other agents.

[0028] Markers added to liquefied gas according to this disclosure can allow qualitative and / or quantitative authentication of the liquefied gas. Desirable markers can exhibit one or more properties, such as and without limitation adequate solubility in the chosen liquefied gas, strong absorbance in the region of the radiation provided and / or minimal absorbance in other regions, strong fluorescence in a chosen wavelength range, and / or good stability under a range of environmental conditions. By way of non-limiting examples, markers that can be added to liquefied gases according to this disclosure include, but are not limited to, visible dyes, such as anthraquinone and diazo dyes, and near infrared dyes, such as squairaines, phthalocyanines, naphthalocyanines, croconic acid derivatives, and pyrazinoporphyrazine dyes. Other markers can include carbonyl compounds, such as ketones, aldehydes, esters, amides, anhydrides and carboxylic acids, for example which absorb in the infrared. Other markers, such as nonylphenol and bisphenol A, can include polyamines and / or isocyanates. In embodiments, the marker comprises a coumarin core structure, a xanthene dye core structure, or a perylene dye core structure, such as the markers detailed further hereinbelow. Markers are available, for example, from Morton International, Inc. (Chicago, IL). A wide range of compounds can be utilized as marker, and this disclosure is not intended to be limited to the aforementioned example markers.Atty Docket No: 4377-12701 According to this disclosure, specific markers can be customized for use with a specific liquefied gas.

[0029] After the marker has been selected, it can be added to the liquefied gas. The liquefied gas can be contained in a transport container or “liquefied gas source”, such as and without limitation a tanker truck, tanker ship, pipeline, or any other apparatus / process known in the art for transporting liquefied gas from one place to another. For example, and not by way of limitation, if the liquefied gas is in a pipeline, the marker can be injected into the stream through an injection valve, as the liquefied gas flows from, for instance, a processing plant to a storage container. If the liquefied gas is in a tanker truck or ship, the marker can be added by opening a port to the transport container and adding the marker directly through the port. In embodiments, the marker can be injected into the transport container below a fluid level therein. The liquefied gas can also be in a static storage container (either above ground or below ground) or a moveable cylinder. If the liquefied gas is in a static storage container, the marker can be added by opening a port to the static container and adding the marker directly through the port or the marker can be injected into the container below the fluid level therein. In embodiments, the marker can be added to a dry container before the liquefied gas is added. In embodiments, one or more markers can be dosed into a liquefied gas along with another additive. In some cases, a known amount of a marker can be combined with an additive to form a mixture with a known concentration of the marker, and the mixture can be added to the liquefied gas. The amount of marker to be added can be based on the properties of the marker and the detection limits of the detector.

[0030] In embodiments, the marker can be added in such an amount so the concentration of the marker in the liquefied gas is in a range of about 0.1 parts per billion (ppb) to about l000 parts per million (ppm). In embodiments, the concentration of the marker in the liquefied gas can be in aAtty Docket No: 4377-12701 range of about 0.1 ppb to about 100 ppm or in a range of about 1 ppb to about 100 ppb. Markers can be chosen to be soluble in the liquefied gas, such that a concentration of the marker in the liquefied gas is dispersed substantially uniformly throughout the liquefied gas. Markers and concentrations thereof can also be chosen such that valves, diaphragms, filters, or other portions of a container or equipment contacted by the liquefied gas are not adversely affected by the marker or the combination of the marker and the liquefied gas.

[0031] Direct detection can allow testing of the liquefied gas to be performed in the field. Testing in the field includes testing at any location where a liquefied gas source is found. Field determination of the presence of a marker in a liquefied gas can allow rapid qualitative and / or quantitative assessment of one or more properties of the marker. In embodiments (e.g., when a known amount of a marker is added to the liquefied gas, a quantitative assessment of the amount (or concentration) of the marker in the liquefied gas can be used as a quality control method. In embodiments (e.g., when a known amount of a marker is combined with an additive to form a mixture and the mixture is added to the liquefied gas), a quantitative assessment of the amount (or concentration) of the marker in the liquefied gas can be used as a quality control method to determine the amount (or concentration) of the additive in the liquefied gas. Thus, a liquefied gas can be authenticated according to embodiments of this disclosure without the necessity of removing a sample of the liquefied gas from the liquefied gas source, placing the sample in a container, and transporting the container to another site (for instance, a laboratory) for analysis. Furthermore, in embodiments, direct detection can also allow for the qualitative and / or quantitative assessment of at least one property of a marker without addition / incorporation of reagents to / into the liquefied gas, thereby reducing costs and increasing the efficiency of marker detection. InAtty Docket No: 4377-12701 embodiments, direct detection includes using an in-line optical fiber, for example, in an substantially opaque vessel for continuous monitoring.

[0032] A schematic diagram of an embodiment of an apparatus for direct detection of markers in a liquefied gas is depicted in FIG.1. System or apparatus 100 includes conduit 110. Conduit 110 can be formed from a material that can include, but is not limited to, stainless steel, resistant plastics, etc., or a combination thereof. Conduit 110 can include two or more conduits coupled together. Conduit 110 can be formed from portions of like or different shapes, sizes (length and / or diameter), and / or composition. In embodiments, a portion of conduit 110 can be a flexible tubing.

[0033] A connector 120 can be directly or indirectly coupled to conduit 110. Connector 120 can include, but is not limited to, a ¼ inch USP connector. Connector 120 can be one of a variety of connectors known in the art to allow apparatus 100 to be coupled a liquefied gas source. Cell or “vessel” 130 can be coupled to conduit 110, such as shown in FIG.1. Cell 130 can be transparent, translucent, or opaque. Detector 140 can be operatively coupled to vessel 130. Valves can be incorporated within system 100 to control fluid flow therethrough. For example, system 100 of FIG. 1 includes valves V1, V2, V3 coupled to conduit 110 to regulate fluid flow into and out of vessel 130.

[0034] Vessel 130, when transparent, can be designed to allow radiation from detector 140 to pass into the liquefied gas. The radiation can be any form of electromagnetic radiation including, but not limited to, visible, infrared, and / or ultraviolet radiation. Vessel 130, when transparent, can further be designed to allow radiation (emitted from one or more markers in the liquefied gas in the vessel) to pass through the vessel such that the radiation emitted from the markers can be detected by detector 140.

[0035] In single point mode embodiments, detector 140 comprises a single point wavelength deviceAtty Docket No: 4377-12701 used to detect a single fluorescent marker. Alternatively, detector 140 can comprise a white light source device with full spectrometer operable to detect multiple fluorescent markers. In embodiments, detector 140 is a flow reading device. In such embodiments, detector 140 can be attached into pipework or otherwise, and configured to continuously read the fluorescent signal of the sample of the liquefied gas in the reader cell 130. Thus, in embodiments, a detector 140 comprises a single wavelength excitation source / lamp or a white light / full spectrometer instrument.

[0036] Vessel 130 can be of any shape, size, or composition known in the art. For instance, vessel 130 can include a rectangular quartz cuvette coupled to conduit 110 with high pressure seals. In one example, vessel 130 is a 10 mm outer diameter glass tube with threaded ends. Conduit 110 can be coupled to two sides of vessel 130 with threaded caps and a-ring seals to allow entry and exit of fluid without leakage. In embodiments, vessel 130 can be positioned in a housing that secures the threaded caps. For example, a suitable high pressure seal can be able to contain liquefied gas at a pressure of up to 15 bar at a temperature of 50° C. In embodiments, vessel 130 can be designed to accept an inline optical fiber to allow continuous monitoring of liquefied gas in the vessel. In such embodiments, vessel 130 can be opaque. The liquefied gas can be maintained liquid in the system, for example by using elevated pressure.

[0037] Detector 140 can be designed to emit and / or collect radiation at one or more wavelengths or one or more ranges of wavelengths. Detector 140 can be further designed to allow data capture and transfer to a receiving device such as, for example, a personal digital assistant, a laptop, or other computer, such that qualitative and / or quantitative assessment of one or more properties of one or more markers in a liquefied gas can be analyzed, displayed, and / or recorded.

[0038] In embodiments, detector 140 includes a spectrometer capable of monitoring marked liquefied gas at wavelengths where there is low spectral response from unmarked liquefied gas.Atty Docket No: 4377-12701 Detector 140 can include a UV, visible, or infrared spectrometer, or a combination thereof. Detector 140 can include a fluorometer. For instance, detector 140 can include a handheld fluorometer available, for instance, from Turner Designs (Sunnyvale, Calif.), in embodiments. In embodiments, detector 140 can be designed to accept vessel 130 of a desired size and shape.

[0039] Optionally, detector 140 can be physically coupled to vessel 130 during use to assess one or more properties of one or more markers in a liquefied gas. For example, at least a portion of vessel 130 can fit in an opening of detector 140 during use. In embodiments, detector 140 can be operatively coupled to vessel 130 while being maintained in proximity to the vessel during use without physically contacting the vessel or conduit 110. For example, detector 140 can be a hand- held device, portions of which can be positioned as desired to substantially surround vessel 130. In other embodiments, detector 140 can include, for example, a housing designed to allow the detector to be snap-fit or otherwise removably coupled to conduit 110 such that the detector contacts the conduit and / or vessel 130 during use. In still further embodiments, detector 140 can be affixed to conduit 110 and / or vessel 130 during use.

[0040] Detector 140 can be used to detect one or more properties of the marked liquefied gas comprising one or more markers in a vessel 130 including, but not limited to, properties of emission and / or absorbance of radiation. For example, if detector 140 includes a fluorometer, a marker can absorb incident radiation and emit radiation of the same or longer wavelength on the order of nanoseconds. The intensity of the reemitted radiation can be substantially directly proportional to the concentration of the marker in the liquefied gas. In embodiments, a detector can be operable to detect relative concentrations of two or more markers. Therefore, in embodiments, more than one marker can be added to identify / authenticate a liquefied gas. ForAtty Docket No: 4377-12701 example, two markers that fluoresce at different wavelengths can be added to a liquefied gas, and detector 140 can be used to assess a relative concentration of the two markers.

[0041] The valves (e.g., first valve V1, second valve V2, third valve V3) can be any like or different valves known in the art for use with liquefied gases. First valve V1 can be used to regulate flow of liquefied gas from the liquefied gas source to reader cell or vessel 130. Second valve V2 can be used to vent air and gas from apparatus 100. Third valve V3 can be used to vent liquefied gas from apparatus 100. Valves V1, V2, V3, etc. can be operated manually and / or automatically.

[0042] FIG.2 depicts a schematic drawing of an embodiment of a system for detection of one or more markers in a liquefied gas. System 200 can include apparatus 100, liquefied gas source 210, processor 220, and outlets / vents 230. In embodiments, one or more of vents 230 can be coupled to a waste receptacle or a waste treatment apparatus, such as acid scrubber 350 described hereinbelow with reference to the embodiment of FIG.3.

[0043] Apparatus 100 can be coupled to liquefied gas source 210 via connector 120. Liquefied gas source 210 can include, but is not limited to, a cylinder, a storage tank, a vehicle, transport container, or a conduit. Liquefied gas 240 (or a gas from which the liquefied gas is produced) can be stored in or transported through liquefied gas source 210.

[0044] Processor 220 can automate all or a portion of direct detection of one or more markers in a liquefied gas 240. In embodiments, processor 220 includes software to operate valves (e.g., first valve V1, second valve V2, third valve V3, and so on) to allow purging, filling, venting, and refilling of vessel 130. In embodiments, processor 220 includes software to operate detector 140 together with or separately from the valves. Processor 220 can be coupled to one or more input and / or display devices to allow a user to specify parameters including, but not limited to, timingAtty Docket No: 4377-12701 of valve opening / closure, timing of detector operation, excitation and / or emission wavelength, data content and / or display format, etc.

[0045] In embodiments, direct detection of one or more markers in a liquefied gas can include purging the vessel before detection. This can be achieved, for example, by the following steps. Valves V1-V3 are initially closed. Liquefied gas source 210 is coupled to conduit 110 via connector 120. A valve on liquefied gas source 210 is opened to allow liquefied gas 240 to flow from the liquefied gas source into apparatus 100. Valve V1 is opened to allow at least partial filling of vessel 130 with liquefied gas 240. The filling level can depend on the pressure of liquefied gas 240 in liquefied gas source 210 and / or the volume of vapor (for instance, air) in cell 130. Valve V2 is opened to allow liquefied gas 240 to rise in vessel 130 while the vapor in the vessel is displaced. Valve V2 is closed when vessel 130 is substantially filled with liquefied gas 240. Valve V1 is then closed to inhibit flow of liquefied gas 240 from liquefied gas source 210. Valve V3 can be opened to allow liquefied gas 240 to escape from vessel 130 and then re-closed.

[0046] Vessel 130 can be filled, or at least partially filled, with liquefied gas 240 to allow direction detection of markers in the liquefied gas. Again, by way of example of an embodiment of this disclosure, to fill vessel 130, valve V1 can be opened to allow liquefied gas 240 to flow from liquefied gas source 210 to vessel 130. Valve V1 can be closed after vessel 130 is filled to a desired level. In embodiments, valve V1 can be closed after vessel 130 is substantially filled with liquefied gas 240. Detector 140 is operated to assess one or more properties of one or more markers in liquefied gas 240. In embodiments, operation of the detector includes irradiating liquefied gas 240 in vessel 130 to assess the fluorescence of one or more fluorescent markers in the liquefied gas. Valve V3 can then be opened to allow liquefied gas 240 (for instance, green fuel) to exit vessel 130 and then re-closed.Atty Docket No: 4377-12701

[0047] With apparatus 100 coupled to liquefied gas source 210, direct detection can be repeated as desired. In embodiments, one or more properties of one or more markers in the liquefied gas can be assessed two or more times.

[0048] Following completion of desired testing, a valve on the liquefied gas source 210 can be closed to inhibit flow of liquefied gas 240 from the liquefied gas source. Valves V1, V2, V3 can be opened to vent apparatus 100. Apparatus 100 can, in embodiments, then be uncoupled from liquefied gas source 210. In embodiments, apparatus 100 can remain coupled to liquefied gas source 210 for future use. In embodiments, detector 140 can be uncoupled from apparatus 100, and the apparatus can remain coupled to liquefied gas source 210.

[0049] A system for detection of markers in (e.g., pressurized) liquefied gas can be intended to remain fixed to (or in) a supply line of liquefied gas. A system for detection of markers in a liquefied gas that is intended to remain fixed to a supply line of liquefied gas can be referred to as an "inline" apparatus. That is, the detection system can function as a portion of the supply line, such that pressurized liquefied gas flowing through a supply line from a first location to a second location flows through the detection system. Such an inline detection system is described in U.S. Patent No.9,097,669, the disclosure of which is hereby incorporated herein for purpose not contrary to this disclosure.

[0050] As the liquefied gas (e.g. green fuel) can be corrosive to conventional materials, such as brass or copper, in embodiments, contact surfaces of the system (i.e., surfaces that will come into contact with the liquefied gas) can be made of corrosion resistant materials, such as plastic, glass, or stainless steel.

[0051] In embodiments, the marker can be selected from coumarins, xanthene dyes, perylene dyes, derivatives thereof, or combinations thereof. For example, the marker can comprise a coumarinAtty Docket No: 4377-12701 core, a xanthene core, a perylene core, that has been functionalized. In embodiments, for example, the marker comprises a coumarin core structure (Structure 1):In such coumarin core embodiments, for example, R2 can be selected from OH, NH2, N(CH2CH3)2, N(CH3)2,and R1 and R3 to R6 can be independently selected from H, alkyl, halogen, trifluoromethyl, alkoxy, or phenyl. Alkyl and or alkoxy groups can include any suitable number of carbon atoms including but not limited to C1 to C20, C1 to C12, C1 to C10, C1 to C8, C1 to C6, C1 to C5, C1 to C4, C1 to C3, C1 to C2, methyl, ethyl, propyl, butyl, propyl, or any combination thereof.

[0052] In some coumarin core embodiments, the marker can comprise 7-(diethylamino)-3-phenyl- 2H-chromen-2-one (Structure 2):

[0053] In some coumarin core embodiments, the marker can comprise 6,8-difluoro-7-hydroxy-4- methyl-2H-chromen-2-one (Structure 3):Atty Docket No: 4377-12701

[0054] In some coumarin core embodiments, the marker can comprise 7-hydroxy-4-methyl-2H- chromen-2-one (Structure 4):

[0055] In some coumarin core embodiments, the marker can comprise 7-amino-4- (trifluoromethyl)-2H-chromen-2-one (Structure 5):

[0056] In some coumarin core embodiments, the marker can comprise 7-amino-4-methyl-2H- chromen-2-one:Atty Docket No: 4377-12701

[0057] In some coumarin core embodiments, the marker has the coumarin core sub-structure (Structure 7):where R1 to R3 can, for example, be independently selected from H, alkyl, halogen, trifluoromethyl, alkoxy, or phenyl. By way of examples, in embodiments, the marker having the coumarin core sub-structure can comprise: 9-methyl-2,3,6,7-tetrahydro-1H,5H,11Hpyrano[2,3- f]pyrido[3,2,1-ij]quinolin-11-one (Structure 8) or 9-(trifluoromethyl)-2,3,6,7-tetrahydro- 1H,5H,11Hpyrano[2,3-f]pyrido[3,2,1-ij]quinolin-11-one (Structure 9):

[0058] In embodiments, the marker comprises a xanthene dye core structure (Structure 10):Atty Docket No: 4377-12701where R2 and R5 can, for example, be independently selected from OH, NH2, N(CH2CH3)2, N(CH3)2; and where R1, R3, R4, and R6 can, for example, be independently selected from H, F, Cl, Br, I.

[0059] Representative examples of markers comprising the xanthene dye core structure (Structure 10) include, without limitation, Erythrosin B (3',6'-dihydroxy-2',4',5',7'-tetraiodo-3H- spiro[isobenzofuran-1,9'-xanthen]-3-one) (Structure 11):(Structure 11), Fluorescein (3',6'-dihydroxy-3H-spiro[isobenzofuran-1,9'-xanthen]-3-one; Structure 12)):Atty Docket No: 4377-12701

[0060] and Rhodamine B (3',6'-bis(diethylamino)-3H-spiro[isobenzofuran-1,9'-xanthen]-3-one; Structure 13):

[0061] In embodiments, the marker comprises a perylene dye core structure (Structure 14):

[0062] In this perylene dye core structure (Structure 14), R1 and R2 can, for example, be selected from H, alkyl, phenyl, alkylphenyl; and R3 to R6 can be selected from H, alkyl, OH, alkoxy, phenoxy. An example of a marker having the perylene dye core structure (Structure 14) is F Red 305 (Structure 15):Atty Docket No: 4377-12701(Structure 15).

[0063] In embodiments, the marker is selected from 7-(diethylamino)-3-phenyl-2H-chromen-2- one (Structure 2), 6,8-difluoro-7-hydroxy-4-methyl-2H-chromen-2-one (Structure 3), 7-hydroxy- 4-methyl-2H-chromen-2-one (Structure 4), 7-amino-4-(trifluoromethyl)-2H-chromen-2-one (Structure 5), 7-amino-4-methyl-2H-chromen-2-one (Structure 6), 9-methyl-2,3,6,7-tetrahydro- 1H,5H,11Hpyrano[2,3-f]pyrido[3,2,1-ij]quinolin-11-one (Structure 8), 9-(trifluoromethyl)- 2,3,6,7-tetrahydro-1H,5H,11Hpyrano[2,3-f]pyrido[3,2,1-ij]quinolin-11-one (Structure 9), 3',6'- dihydroxy-2',4',5',7'-tetraiodo-3H-spiro[isobenzofuran-1,9'-xanthen]-3-one (Erythrosin B; Structure 11), 3',6'-dihydroxy-3H-spiro[isobenzofuran-1,9'-xanthen]-3-one (Fluorescein; Structure 12), 3',6'-bis(diethylamino)-3H-spiro[isobenzofuran-1,9'-xanthen]-3-one (Rhodamine B; Structure 13), F Red 305 (Structure 15), or a combination thereof. In embodiments, the marker is selected from 7-(diethylamino)-3-phenyl-2H-chromen-2-one (Structure 2), 6,8-difluoro-7- hydroxy-4-methyl-2H-chromen-2-one (Structure 3), 7-hydroxy-4-methyl-2H-chromen-2-one (Structure 4), 7-amino-4-(trifluoromethyl)-2H-chromen-2-one (Structure 5), 7-amino-4-methyl- 2H-chromen-2-one (Structure 6), or combinations thereof. In embodiments, the marker is selected from 3',6'-dihydroxy-2',4',5',7'-tetraiodo-3H-spiro[isobenzofuran-1,9'-xanthen]-3-one (ErythrosinAtty Docket No: 4377-12701 B; Structure 11), 3',6'-dihydroxy-3H-spiro[isobenzofuran-1,9'-xanthen]-3-one (Fluorescein; Structure 12), 3',6'-bis(diethylamino)-3H-spiro[isobenzofuran-1,9'-xanthen]-3-one (Rhodamine B; Structure 13). In embodiments, the marker comprises (e.g., LUMOGEN®) F Red 305 (Structure 15).

[0064] A method for authenticating a liquefied gas according to this disclosure can comprise: exposing a sample of the liquefied gas 240 to a specific excitation wavelength of electromagnetic radiation and detecting a resulting signal with a detector 140, wherein the specific excitation wavelength is a wavelength at which a marker in an authentic liquefied gas exhibits a distinguishable signal detected by the detector 140; authenticating said liquefied gas when the resulting signal corresponds to an expected signal provided by the authentic liquefied gas having an authentic marker concentration (e.g., indicating that the liquefied gas originates from a known or verified source and has not been adulterated or diluted with another substance); and identifying the liquefied gas as suspect or counterfeit when the resulting signal deviates from the expected signal by more than an amount provided by an authentication standard.

[0065] As noted herein, the liquefied gas can comprise any liquid formed via liquefaction of a fluid that is a gas at room temperature and pressure. In embodiments, the liquefied gas comprises a green fuel, a refrigerant coolant, an agrochemical (e.g., ammonia for fertilizer), or a combination thereof. The liquefied gas can comprise a green fuel, such as a green fuel selected from hydrogen, ammonia, alcohols (e.g., biomethanol, bioethanol), fatty acid methyl esters (e.g., (used) cooking oil methyl ester [UCOME]), biomethane (e.g., bio-LNG), or a combination thereof. The green fuel (e.g., ammonia) can be at least 80, 90, 95, or 100% renewable and carbon free. For example green ammonia can be made using hydrogen from water electrolysis and nitrogen separated from the air if the process uses “green electricity”.Atty Docket No: 4377-12701

[0066] The method of this disclosure can further include, prior to the exposing the liquefied gas (e.g., green fuel) to the electromagnetic radiation: producing the liquefied gas (e.g., the green fuel); marking the liquefied gas (e.g., the green fuel) by adding the marker thereto to provide a marked liquefied gas (e.g., a marked green fuel); and transporting the marked liquefied gas (e.g., the marked green fuel). Producing the liquefied gas (e.g., the green fuel) can be effected via any methods known to those of skill in the art or discovered on the future. In embodiments, the liquefied gas comprises a green fuel generated with no net production of greenhouse gases (e.g., carbon dioxide) and / or using renewable power sources, such as and without limitation, solar / wind / wave. In embodiments, the authentic liquefied gas is or the sample of the liquefied gas is determined upon authentication testing to be a green fuel. In embodiments, the authentic liquefied gas is or the sample of the liquefied gas is determined upon authentication testing to be a blue fuel. In embodiments, the authentic liquefied gas is or the sample of the liquefied gas is determined upon authentication testing to be a grey fuel.

[0067] By way of example, in embodiments, the liquefied gas comprises hydrogen. Green hydrogen (GH2 or GH2) can be produced by the electrolysis of water using renewable electricity. Production of green hydrogen causes significantly lower greenhouse gas emissions than production of grey hydrogen, which is generally derived from fossil fuels without carbon capture.

[0068] By way of further example, in embodiments the liquefied gas comprises ammonia. Green ammonia can be produced through two main processes. In embodiments, the green ammonia is produced via a lithium-mediated process, which is a hybrid of lithium-ion batteries and electro- catalysis. Via this lithium-mediated process, lithium can spontaneously react with nitrogen to form lithium nitride which, if protonated, can form ammonia. Alternatively or additionally, greenAtty Docket No: 4377-12701 ammonia can be produced via electrolysis, which can utilize excess electricity from renewable energy sources, such as solar or wind power, to split hydrogen from water.

[0069] By way of further example, in embodiments, the liquefied gas comprises bioethanol (or “green ethanol”). The bioethanol can be produced via pretreatment, hydrolysis, fermentation, and / or ethanol recovery Bioethanol can be produced via microbial fermentation of fermentable sugars, such as glucose, to ethanol. Traditional (e.g., biomass) feedstocks can include cereal grains, sugar cane, and sugar beets. Bioethanol can be produced by the fermentation of starch and lignocellulosic substrates via microorganisms. The carbon dioxide released by the combustion of bioethanol can recycle in microalgae production as a carbon source.

[0070] By way of further example, in embodiments, the liquefied gas comprises biomethanol. Biomethanol is a renewable form of methanol that can be produced from various feedstocks, such as and without limitation biomass, biogas, waste streams, or carbon dioxide from flue gases. The main production process can involve converting the feedstock(s) into syngas, a mixture of carbon monoxide, hydrogen and other molecules, through gasification or reforming.

[0071] By way of further example, in embodiments, the liquefied gas comprises fatty acid methyl esters (FAME). FAME are a type of fatty acid ester that can be derived by transesterification of fats with methanol. The molecules in biodiesel comprise primarily FAME, typically produced from vegetable oils by transesterification. FAME can be produced by an alkali-catalyzed reaction between fats and methanol in the presence of a base, such as and without limitation sodium hydroxide, sodium methoxide, or potassium hydroxide. One reason for using FAME (fatty acid methyl esters) in biodiesel production, rather than free fatty acids, is to mitigate the potential corrosion they can cause to metals of engines, production facilities, and related infrastructure. While free fatty acids are only mildly acidic, over time they can lead to cumulative corrosion. InAtty Docket No: 4377-12701 contrast, their esters, such as FAME, are less corrosive and therefore can be preferred for biodiesel production. As another beneficial quality, FAMEs also typically have about 12-15 units higher cetane number than their unesterified counterparts. In embodiments, the liquefied gas comprises UCOME, made from used cooking oil, residual non-food crops, agricultural waste, or a combination thereof.

[0072] By way of further example, in embodiments the liquefied gas comprises biomethane or “bio-LNG”. Bio-LNG is a renewable fuel source that can be produced via an anaerobic digestion process to convert organic waste into biogas and then liquefying it. The production of bio-LNG can help reduce greenhouse gas emissions and contribute to a greener future by providing a clean / green fuel alternative. Anaerobic digestion involves the breakdown of organic matter in the absence of oxygen. In anaerobic digestion, specific types of bacteria transform food waste and / or animal manure into biogas in an oxygen-free tank. The resulting biogas comprises primarily methane and carbon dioxide, which can then be used as a source of renewable energy. The biogas can be liquefied to produce bio-LNG. The anaerobic digestion process can thus be utilized to transform food and / or animal waste into high-value bio-LNG that can be used as an alternative to fossil fuels.

[0073] Marking the liquefied gas can be effected as described hereinabove to incorporate one or more markers into the liquefied gas. As noted herein, the marker utilized in the herein disclosed method can include one or more markers tailored for use with the liquefied gas. In embodiments, the marker comprises an anthraquinone dye, a diazo dye, a squairaine dye, a phthalocyanine dye, a naphthalocyanine dye, a croconic acid derivative dye, a pyrazinoporphyrazine dye, a ketone, an aldehyde, an ester, an amide, an anhydride, a carboxylic acid, a polyamine, an isocyanate, or a combination thereof. In embodiments, the liquefied gas comprises ammonia.Atty Docket No: 4377-12701

[0074] The marked liquefied gas can be transported from the site of the marking to a destination, and the method of authentication disclosed herein utilized to authenticate the liquefied gas (as still “green, for example) at the destination.

[0075] As noted hereinabove with reference to FIG.1, the detector 140 can detect a distinguishable signal comprising phosphorescence, chemiluminescence, electroluminescence, fluorescence upconversion, Raman fluorescence, fluorescence, or a combination thereof. In embodiments, the liquefied gas 240 comprises ammonia and the distinguishable signal comprises fluorescence.

[0076] As noted hereinabove, in embodiments the detector 140 comprises a flow path for the sample of the liquefied gas 240, and the flow path is resistant to corrosion by the liquefied gas alone and in combination with the marker. For example, the liquefied gas (e.g., green fuel, blue fuel, etc.) can have a corrosivity, as measured by ASTM D130-19 Standard Test Method for Corrosiveness to Copper from Petroleum Products by Copper Strip Test classification 4, Corrosion.

[0077] In embodiments, a method for authenticating a liquefied gas (e.g., a green fuel) comprises: (a) selecting a fluorescent marker compound with unique fluorescence properties capable of emitting a distinguishable fluorescent signal upon exposure to a specific excitation wavelength; (b) mixing said fluorescent marker compound into the liquefied gas (e.g., green fuel) to provide a marked liquefied gas (e.g., a marked green fuel), ensuring even distribution throughout the liquefied gas (e.g., green fuel) and controlling the concentration of said marker compound during the mixing process; (c) providing an excitation source emitting light at said specific excitation wavelength to induce fluorescence in said fluorescent marker compound within said marked liquefied gas (e.g., marked green fuel); (d) employing a detector to record the emitted fluorescence from said marked liquefied gas (e.g., marked green fuel) after excitation, said detector capable ofAtty Docket No: 4377-12701 distinguishing said emitted fluorescence from background noise; (e) optionally, conducting signal processing on the recorded fluorescence emission data to enhance signal-to-noise ratios and / or eliminate unwanted artifacts; (f) accessing or establishing an authentication standard defining the expected fluorescence properties of said fluorescent marker compound and accessing or establishing an acceptable range of variability for authentic liquefied gas (e.g., authentic green fuel); (g) comparing the detected fluorescence properties of said marked liquefied gas (e.g., marked green fuel) to said authentication standard; (h) authenticating said marked liquefied gas (e.g., marked green fuel) as genuine when the detected fluorescence properties fall within said acceptable range of variability as defined by said authentication standard (e.g., indicating that the marked liquefied gas (e.g., marked green fuel) originates from a known or verified source and has not been adulterated or diluted with another substance); and (i) identifying said marked liquefied gas (e.g., marked green fuel) as suspect or counterfeit when the detected fluorescence properties deviate from said acceptable range of variability as defined by said authentication standard.

[0078] As noted herein, in embodiments, the liquefied gas can comprise a green fuel, such as and without limitation, a green fuel selected from hydrogen, ammonia, alcohols (e.g., biomethanol, bioethanol), fatty acid methyl esters (e.g., (used) cooking oil methyl ester [UCOME]), biomethane (e.g., bio-LNG), or a combination thereof. As noted herein, the marker can be selected / tailored for use with the liquefied gas being authenticated / tracked. By way of non-limiting examples, the marker can comprise an anthraquinone dye, a diazo dye, a squairaine dye, a phthalocyanine dye, a naphthalocyanine dye, a croconic acid derivative dye, a pyrazinoporphyrazine dye, a ketone, an aldehyde, an ester, an amide, an anhydride, a carboxylic acid, a polyamine, an isocyanate, or a combination thereof. Other markers will be apparent for use with specific liquefied gases and such are within the scope of this disclosure.Atty Docket No: 4377-12701

[0079] Also disclosed herein is a marked liquefied gas (e.g., a marked green fuel) comprising: a liquefied gas selected from green fuels (e.g., a green fuel selected from hydrogen, ammonia, alcohols (e.g., biomethanol, bioethanol), fatty acid methyl esters (e.g., (used) cooking oil methyl ester [UCOME]), biomethane (e.g., bio-LNG), or a combination thereof), coolants / refrigerants, agrochemicals (e.g., ammonia, fertilizer), or a combination thereof; and one or more (e.g., fluorescing) markers (e.g., a marker that, when present in the fuel, emits detectable fluoresce spectra when subjected to an excitation source). The one or more markers can be as noted hereinabove. For example, in embodiments, the marker includes an anthraquinone dye or a diazo dye. In embodiments, the marker includes a squairaine dye, a phthalocyanine dye, a naphthalocyanine dye, a croconic acid derivative dye, or a pyrazinoporphyrazine dye. In embodiments, the marker comprises a ketone, an aldehyde, an ester, an amide, an anhydride, or a carboxylic acid. In embodiments, the marker comprises a polyamine, an isocyanate, or both. In embodiments, the marker comprises one or more of Structures 1 to 15. In embodiments, the marker has coumarin core Structure 1, coumarin sub-core Structure 7, xanthene dye core Structure 10, or perylene dye core Structure 14. In embodiments, the marker is selected from 7- (diethylamino)-3-phenyl-2H-chromen-2-one (Structure 2), 6,8-difluoro-7-hydroxy-4-methyl-2H- chromen-2-one (Structure 3), 7-hydroxy-4-methyl-2H-chromen-2-one (Structure 4), 7-amino-4- (trifluoromethyl)-2H-chromen-2-one (Structure 5), 7-amino-4-methyl-2H-chromen-2-one (Structure 6), 9-methyl-2,3,6,7-tetrahydro-1H,5H,11Hpyrano[2,3-f]pyrido[3,2,1-ij]quinolin-11- one (Structure 8), 9-(trifluoromethyl)-2,3,6,7-tetrahydro-1H,5H,11Hpyrano[2,3-f]pyrido[3,2,1- ij]quinolin-11-one (Structure 9), 3',6'-dihydroxy-2',4',5',7'-tetraiodo-3H-spiro[isobenzofuran-1,9'- xanthen]-3-one (Erythrosin B; Structure 11), 3',6'-dihydroxy-3H-spiro[isobenzofuran-1,9'- xanthen]-3-one (Fluorescein; Structure 12), 3',6'-bis(diethylamino)-3H-spiro[isobenzofuran-1,9'-Atty Docket No: 4377-12701 xanthen]-3-one (Rhodamine B; Structure 13), F Red 305 (Structure 15), or a combination thereof. In embodiments, the marker is selected from 7-(diethylamino)-3-phenyl-2H-chromen-2-one (Structure 2), 6,8-difluoro-7-hydroxy-4-methyl-2H-chromen-2-one (Structure 3), 7-hydroxy-4- methyl-2H-chromen-2-one (Structure 4), 7-amino-4-(trifluoromethyl)-2H-chromen-2-one (Structure 5), 7-amino-4-methyl-2H-chromen-2-one (Structure 6), or combinations thereof. In embodiments, the marker is selected from 3',6'-dihydroxy-2',4',5',7'-tetraiodo-3H- spiro[isobenzofuran-1,9'-xanthen]-3-one (Erythrosin B; Structure 11), 3',6'-dihydroxy-3H- spiro[isobenzofuran-1,9'-xanthen]-3-one (Fluorescein; Structure 12), 3',6'-bis(diethylamino)-3H- spiro[isobenzofuran-1,9'-xanthen]-3-one (Rhodamine B; Structure 13). In embodiments, the marker comprises (e.g., LUMOGEN®) F Red 305 (Structure 15).

[0080] The method for authenticating green fuels as disclosed and claimed herein provides an accurate and reliable means of detecting the presence of a (e.g., fluorescent) marker compound within a marked liquid (e.g., a marked liquefied gas, such as a marked liquid green fuel) and verifying its authenticity (e.g., against an established authentication standard). The incorporation of unique (e.g., fluorescent) marker compounds can ensure increased security and protection against counterfeiting attempts, making it applicable in various fields where substance authentication is of paramount importance.

[0081] Bespoke / custom markers and / or readers can be provided for the specific liquefied gas (e.g., green fuel) being tracked / authenticated. In embodiments, a sleeper forensic marker can be utilized, for example if infringement is suspected.

[0082] It will be appreciated by those skilled in the art that changes could be made to the embodiments described herein without departing from the broad inventive concept thereof. It is understood, therefore, that this disclosure is not limited to the particular embodiments disclosed,Atty Docket No: 4377-12701 but it is intended to cover modifications within the spirit and scope of the present disclosure as defined by the appended claims.

[0083] To facilitate a better understanding of the present embodiments, the following examples of certain aspects of embodiments are given. In no way should the following examples be read to limit, or define, the entire scope of the embodiments. EXAMPLES

[0084] Overview. As a model chosen for this disclosure, ammonia was chosen as the prospective energy source (e.g., green fuel) since it is a liquid under pressure, or can be used as a cryogenic liquid at atmospheric pressure and therefore acts as a good example of the potential states of the renewal energy sources noted herein. Experiments were initiated to investigate the potential of using fluorescent compounds to identify and quantify the dilution of ammonia. The following objectives were set: (a) ensure equipment safe, compatible and suitable for use with ammonia; (b) determine background fluorescence of ammonia; (c) choose a potential marker compound and add to ammonia and determine if fluorescence of this marker can be observed; (d) determine the linearity of instrument response after the dilution of marked ammonia with unmarked ammonia; (e) determine if fluorescence can be read in a stream of flowing ammonia, as might be utilized in an industrial application; (f) observe if addition of water to ammonia affects results, as industrial grade ammonia can contain about 5% residual water; and (g) investigate a further range of marker compounds and determine their potential for marking ammonia.

[0085] The experimental system 300 is described in detail below and depicted schematically in FIG.3 and pictured in FIG.4. The ammonia marker system 300 comprised an ammonia cylinder (or liquefied gas source) 305 fluidly connected via an ammonia flow line 310 with a pressure hydrometer 360 and further fluidly connected via a flow line 315 to a fluorescence reader cell 330;Atty Docket No: 4377-12701 an acid scrub 350 into which ammonia liquid from flow line 315 and ammonia gas vented via gas vent tube 350 can be introduced; a marker introduction port 340 configured to introduce a marker(s) into pressure hydrometer 360; and a pressure gauge 320 configured to determine a pressure in pressure hydrometer 360. One or more valves are configured to control flow throughout the ammonia marker system 300, with six, including valves V1-V6, depicted in the embodiment of FIG.3. A first valves V1 was positioned on ammonia cylinder 305, to control the flow of liquid ammonia therefrom; a second valve V2 was positioned on inlet unmarked liquid ammonia flow line 310 to control the flow therethrough; a third valve V3 was positioned on outlet flow line V3 to control the flow therethrough; a fourth valve V4 was positioned downstream from the fluorescence reader cell 330, to control the flow of liquid out of the fluorescence reader cell 330; a fifth valve V5 was positioned on marker introduction port 340 to control the flow of fluid therethrough; and a sixth valve V6 was positioned on the gas vent tube 350, to control the venting of fluid (e.g., gas, vapor) therethrough.

[0086] Ammonia Source 305. High purity, laboratory grade ammonia was purchased for the experiments of these Examples. A cylinder 305 configured with a dip-tube capable of supplying liquid ammonia rather than gaseous ammonia was selected.

[0087] Pressure Hydrometer 360. A pressure hydrometer 360 comprising a clear poly(methyl methacrylate) (PMMA) pressure sleeve with port / valves (e.g., second valve V2 and third valve V3) at a bottom thereof for input and output of liquid ammonia 240, respectively. At a top of pressure hydrometer 360 were configured a valve (e.g., fifth valve V5 for the introduction of liquid marker solution via introduction port 340) and a gas vent port / tube 250 and associate valve (e.g., sixth valve V6) and a pressure gauge 320.Atty Docket No: 4377-12701

[0088] Fluorescence Reader. Ammonia marker system 300 comprises a modified version of a water analysis fluorometer as detector 140 with a standard cuvette replaced by optically clear pressure cell 330 and valve (e.g., fourth valve V4) to control liquid flow rate leaving this clear pressure cell 330. This detector 140 comprised a wide band UV excitation LED and broad band blue emission filter. The detector 140 was not calibrated to any specific standard and all readings are described are raw numbers output by the instrument.

[0089] Acid Scrubber 350. Ammonia marker system 300 comprised acid scrubber 350 comprising acid 355 (e.g., (4M) acetic acid). All exhaust from the equipment (e.g., gas vented via gas vent tube 350 and sixth valve V6 and fluid / liquid exiting reader cell 330) was bubbled through this acid scrubber 350 to capture the waste ammonia and safely convert it to ammonium acetate. EXAMPLE 1

[0090] Leak Detection. To ensure all equipment was safe, compatible and suitable, all work was carried out in a fume hood and full personal protective equipment (PPE) was worn in accordance with the safety assessment. The equipment was set up with all valves V1-V6 closed. As valves were opened and the system pressurized, the integrity of each pipe joint and valve (e.g., V1-V6) was checked for leaks with moistened full range pH paper for detecting the presence of ammonia. Once the pressure hydrometer liquid input valve V2 was opened, the reading on the pressure gauge 320 was observed. The equipment was left for 30 minutes and then the pressure reading was again checked. This pressure check was repeated after the hydrometer output valve V3 was open to ensure that the integrity of the pressure cuvette 330 in the fluorometer / detector 140. No leaks were detected during this leak test.Atty Docket No: 4377-12701 EXAMPLE 2

[0091] Determining Background Fluorescence of Ammonia. Initially, three readings were made on the fluorometer 140 to determine the value obtained from the empty pressure cell 330.

[0092] With the hydrometer output valve V3 closed, the gas vent valve V6 was partially opened to allow the trapped air to escape the hydrometer 360. This permitted the level of liquid ammonia to rise in the hydrometer 360. When a sufficient quantity of liquid ammonia 240 had been loaded into the hydrometer 360, the gas vent valve (sixth valve) V6 and input valve (second valve) V2 were closed. Throughout the experimental work, when not filling the hydrometer 360, the ammonia cylinder valve (first valve) V1 remained closed.

[0093] The hydrometer liquid output valve (third valve) V3 and fluorometer liquid flow rate control valve (fourth valve) V4 were opened so that ammonia 240 passed through the cuvette 330 of the fluorometer 140. The flow valve (fourth valve) V4 was then closed and readings were taken. This process was repeated a total of five times.

[0094] The hydrometer 360 was then refilled and readings were obtained for a fresh charge of ammonia 240. The remaining ammonia 240 in the pressure hydrometer 360 was evaporated by opening the gas vent valve (sixth valve) V6 to return the system 300 to atmospheric pressure before the next stage of testing. The results are tabulated in Table 1. Table 1: Fluorescence Readings from Example 2Atty Docket No: 4377-12701 1152 17

[0095] Marking Ammonia and Determining if Fluorescence Can Be Observed. With the pressure hydrometer 360 empty of ammonia 240 and at atmospheric pressure, the marker introduction port 340 was opened and sufficient Marker 1 concentrate was pipetted inside the pressure hydrometer 360 to provide a final marker concentration of 250 ppb / mL if diluted by 100 mL of ammonia 240. Marker 1 of this disclosure comprised 7-(diethylamino)-3-phenyl-2H- chromen-2-one.

[0096] With the pressure hydrometer output valve (third valve) V3 and marker introduction port 340 valve (fifth valve) V5 closed, the gas vent valve (sixth valve) V6 was partially opened to allow the trapped air to escape the pressure hydrometer 360. This allowed the level of liquid ammonia 240 to rise within the pressure hydrometer 360.

[0097] When about 100 mL of liquid ammonia 240 had been loaded into the pressure hydrometer 360, the gas vent valve (sixth valve) V6 and pressure hydrometer input valve (second valve) V2 were closed. Control over the flow of ammonia 240 into the pressure hydrometer 360 via second valve V2 was coarse, so it was not possible to fill with an exact volume via the flow line 310 and valves (e.g., second valve V2). Thus, the concentration was calculated based on the volume of ammonia actually added, as determined with the pressure hydrometer 360. That is, the marker concentration was back-calculated from the weight of marker added and the subsequent volume of ammonia introduced into the hydrometer.

[0098] The hydrometer liquid output valve (third valve) V3 and fluorometer liquid flow rate control valve (fourth valve) V4 were opened so that ammonia 240 passed through the cuvette 330Atty Docket No: 4377-12701 of the fluorometer 140. The fluorometer flow valve (fourth valve) V4 was then closed and a reading taken with detector 140. This process was carried out a total of five times.

[0099] The pressure hydrometer 360 was next refilled and readings were obtained for a fresh charge of ammonia 240. The remaining ammonia 240 in the pressure hydrometer 360 was evaporated by opening the gas vent valve (sixth valve) V6 to return the ammonia marker system 300 to atmospheric pressure before the next stage of testing.

[0100] Fluorescence readings of over 600 units were observed, thus showing that fluorescence from the marker (e.g., Marker 1) could be seen in ammonia marked therewith. Readings from this Example 3 are reported in Table 2 below. EXAMPLE 4

[0101] Determining Linearity of Instrument Response with Dilution of Marked Ammonia. Once the initial readings had been taken for Example 3, more ammonia was added to bring the volume in the pressure hydrometer 360 back up to about 100 mL. A dilution ratio, and therefore the new concentration, were calculated. The sampling and reading process was repeated and a minimum of five readings were taken.

[0102] The dilution process was again repeated using the remaining marked ammonia.

[0103] The marking and dilution process was then repeated twice more to obtain more dilution points. The pressure hydrometer 360 was flushed with unmarked ammonia 240 and then a blank reading taken.

[0104] This process was repeated to observe a second marking operation and subsequent dilution of this newly marked sample.Atty Docket No: 4377-12701

[0105] The remaining ammonia in the pressure hydrometer 360 was purged through the fluorometer detector 140 and the gas vent valve (sixth valve) V6 opened to return the ammonia marker system 300 to atmospheric pressure before the next stage of testing.

[0106] The results of this Example 4 are tabulated in Table 2, Table 3, and Table 4. Table 2: Fluorescence Readings with Marking Operation 1 from Examples 3 and 4Atty Docket No: 4377-12701 Table 3: Fluorescence Readings with Marking Operation 2 from Example 4 Marking Operation Unmarked Marked Dilution 1 Dilution 1(further readings)Table 4: Fluorescence Readings with Marking Operation 3 from Example 4

[0107] Results from the serial dilution steps showed good linearity of the marker, as can be seen in FIG. 5, which is a plot of average fluorescent response as a function of marker concentration for Marker 1 of this Example 4.Atty Docket No: 4377-12701 EXAMPLE 5

[0108] Determining if Fluorescence Can be Read in Stream of Flowing Marked Ammonia. Using the final dilution of the third marking operation from Example 4, the liquid flow control valve (fourth valve) V4 was edged open until a steady flow of ammonia was observed flowing into the container of acid scrubber 350.

[0109] Repeated readings were taken until the marked ammonia in the pressure hydrometer 360 was exhausted. The results are presented in Table 5, which illustrate the ability to take fluorescence readings in the stream of flowing ammonia. Table 5: Fluorescence Readings from Example 5EXAMPLE 6

[0110] Observing Effect on Fluorescence Reading in Water Contaminated Ammonia. After purging, flushing and checking the reading for unmarked ammonia, a further portion of ammonia was marked as described above. With the pressure hydrometer 360 empty of ammonia and at atmospheric pressure, the marker introduction port 340 was opened and sufficient Marker 1 concentrate was pipetted inside the pressure hydrometer 360 to provide a final marker concentration of 250 ppb / mL when diluted by 100 mL of ammonia. Five (5) milliliters (mL) ofAtty Docket No: 4377-12701 distilled water was also added to the pressure hydrometer 360 through the marker addition port 340. With the pressure hydrometer 360 output valve (third valve) V3 closed, the gas vent valve (sixth valve) V6 was partially opened to allow the trapped air to escape the pressure hydrometer 360. This allowed the level of liquid ammonia to rise in the pressure hydrometer 360. When about 100 mL of liquid ammonia had been loaded into the pressure hydrometer 360, the gas vent valve (sixth valve) V6 and input valve (second valve) V2 were closed.

[0111] The pressure hydrometer liquid output valve (third valve) V3 and fluorometer liquid flow rate control valve (fourth valve) V4 were opened so that ammonia passed through the cuvette 330 of the fluorometer 140. The fluorometer flow valve (fourth valve) V4 was then closed and a reading taken with the detector 140. This process was repeated a further six times to give a total of seven readings. The remaining ammonia in the pressure hydrometer 360 was then removed / evaporated by opening the liquid output valve (third valve) V3. The ammonia marker system 300 was then returned to atmospheric pressure by opening the gas vent valve (sixth valve) V6 before the next stage of testing. Table 6 Fluorescence Readings from Example 6Atty Docket No: 4377-12701 EXAMPLE 7

[0112] Investigating Additional Marker Compounds. Four more markers were added to ammonia 240 using the same process as outlined hereinabove. These were labeled Marker 2 (7- diethylamino-4-methyl coumarin): , Marker 3 (3-(2-benzimidazolyl)-,Marker 4 (3',6'-dihydroxy- -3-one; Structure 12): ,Atty Docket No: 4377-12701 and Marker 5 (9-(2-carboxyphenyl)-6-(diethylamino)-N,N-diethyl-3H-xanthen-3-iminium chloride): . Wherewas followed to determine if the marker could be detected under flow conditions.

[0113] The results for Marker 2 are depicted in Table 7. Table 7: Fluorescence Readings from Marker 2 of Example 7Atty Docket No: 4377-12701

[0114] As seen in the results of Table 7, the fluorescence for Marker 2 appeared to be lower than that for Marker 1.

[0115] For Marker 3, no signal higher than the usual background ammonia reading was observed. This is not surprising as this marker has a blue excitation wavelength and a green emission wavelength. This marker may be utilized with modified fluorescent conditions.

[0116] As for Marker 3, Marker 4 did not excite / emit with UV / blue wavelength and no signal was seen above the typical ammonia background.

[0117] Again, with Marker 5, the fluorescent parameter available with the fluorometer 140 used did not match this marker, and thus no signal was observed. It was noted that, when marked, the ammonia was not colored. This Marker 5 is known to give a vivid pink coloration to polar liquids such as water or isopropyl alcohol (IPA).

[0118] Summary. The Examples illustrate the effectiveness of the systems of this disclosure for authenticating liquefied gas. It is possible to safely and repeatedly mark ammonia and measure the concentration using the systems and methods of this disclosure. Ammonia liquid, both anhydrous and containing 5% moisture, had a clean stable detector background, averaging approximately 30 counts on the detector 140. Several other markers can be suitable if different fluorescence parameters are utilized. All markers tested showed a linear detector response with dilution over the concentration range of interest. All markers tested worked well with both anhydrous and ammonia containing 5% moisture. All markers tested worked whilst paused in the fluorimeter cell 130 / 330 and also whilst flowing through that cell, illustrating that both single point and (e.g., continuous) flow readings are possible.

[0119] In this patent, certain U.S. patents, U.S. patent applications, and other materials (e.g., articles) have been incorporated by reference. The text of such U.S. patents, U.S. patentAtty Docket No: 4377-12701 applications, and other materials is, however, only incorporated by reference to the extent that no conflict exists between such text and the other statements and drawings set forth herein. In the event of such conflict, then any such conflicting text in such incorporated by reference U.S. patents, U.S. patent applications, and other materials is specifically not incorporated by reference in this patent.

[0120] Further modifications and alternative embodiments of various aspects of this disclosure will be apparent to those skilled in the art in view of this description. Accordingly, this description is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the general manner of carrying out the methods of this disclosure. It is to be understood that the forms of the system and method of this disclosure shown and described herein are to be taken as examples of embodiments. Elements and materials may be substituted for those illustrated and described herein, parts and processes may be reversed, and certain features of the disclosure may be utilized independently, all as would be apparent to one skilled in the art after having the benefit of this disclosure. Changes may be made in the elements described herein without departing from the spirit and scope of this disclosure as described in the following claims. ADDITIONAL DISCLOSURE

[0121] The following are non-limiting, specific embodiments in accordance with the present disclosure:

[0122] In a first embodiment, a method for authenticating a liquefied gas comprises: exposing a sample of the liquefied gas to a specific excitation wavelength of electromagnetic radiation and detecting a resulting signal with a detector, wherein the specific excitation wavelength is a wavelength at which a marker in an authentic liquefied gas exhibits a distinguishable signal detected by the detector; authenticating said liquefied gas when the resulting signal corresponds toAtty Docket No: 4377-12701 an expected signal provided by the authentic liquefied gas having an authentic marker concentration (e.g., indicating that the liquefied gas originates from a known or verified source and has not been adulterated or diluted with another substance); and identifying the liquefied gas as suspect or counterfeit when the resulting signal deviates from the expected signal by more than an amount provided by an authentication standard.

[0123] A second embodiment can include the method of the first embodiment, wherein the liquefied gas comprises a green fuel, a refrigerant coolant, an agrochemical (e.g., ammonia for fertilizer), or a combination thereof.

[0124] A third embodiment can include the method of the second embodiment, wherein the green fuel or the liquefied gas comprises hydrogen, ammonia, alcohols (e.g., biomethanol, bioethanol), fatty acid methyl esters (e.g., (used) cooking oil methyl ester [UCOME]), biomethane (e.g., bio- LNG), or a combination thereof.

[0125] A fourth embodiment can include the method of the second or third embodiment, wherein the authentic green fuel is 100% renewable and carbon free.

[0126] A fifth embodiment can include the method of any one of the second to fourth embodiments further comprising, prior to the exposing of the green fuel to the electromagnetic radiation: producing the green fuel; marking the green fuel by adding the marker thereto to provide a marked green fuel; and transporting the marked green fuel.

[0127] A sixth embodiment can include the method of the fifth embodiment, wherein producing the green fuel comprises producing the green fuel using renewable energy.

[0128] A seventh embodiment can include the method of any one of the first to sixth embodiments, wherein the liquefied gas comprises ammonia.Atty Docket No: 4377-12701

[0129] An eighth embodiment can include the method of any one of the first to seventh embodiments, wherein the marker comprises a coumarin core structure, a xanthene core structure, or a perylene dye core structure.

[0130] A ninth embodiment can include the method of the eighth embodiment, wherein the liquefied gas comprises ammonia.

[0131] A tenth embodiment can include the method of any one of the first to ninth embodiments, wherein the marker is selected from 7-(diethylamino)-3-phenyl-2H-chromen-2-one, 6,8-difluoro- 7-hydroxy-4-methyl-2H-chromen-2-one, 7-hydroxy-4-methyl-2H-chromen-2-one, 7-amino-4- (trifluoromethyl)-2H-chromen-2-one, 7-amino-4-methyl-2H-chromen-2-one, 9-methyl-2,3,6,7- tetrahydro-1H,5H,11Hpyrano[2,3-f]pyrido[3,2,1-ij]quinolin-11-one, 9-(trifluoromethyl)-2,3,6,7- tetrahydro-1H,5H,11Hpyrano[2,3-f]pyrido[3,2,1-ij]quinolin-11-one, 3',6'-dihydroxy-2',4',5',7'- tetraiodo-3H-spiro[isobenzofuran-1,9'-xanthen]-3-one, 3',6'-dihydroxy-3H-spiro[isobenzofuran- 1,9'-xanthen]-3-one, 3',6'-bis(diethylamino)-3H-spiro[isobenzofuran-1,9'-xanthen]-3-one, F Red 305, a squairaine dye, a phthalocyanine dye, a naphthalocyanine dye, a croconic acid derivative dye, a pyrazinoporphyrazine dye, a ketone, an aldehyde, an ester, an amide, an anhydride, a carboxylic acid, a polyamine, an isocyanate, or a combination thereof.

[0132] An eleventh embodiment can include the method of the tenth embodiment, wherein the liquefied gas comprises ammonia.

[0133] A twelfth embodiment can include the method of any one of the first to eleventh embodiments, wherein the liquefied gas comprises ammonia.

[0134] A thirteenth embodiment can include the method of any one of the first to twelfth embodiments, wherein the distinguishable signal comprises phosphorescence,Atty Docket No: 4377-12701 chemiluminescence, electroluminescence, fluorescence upconversion, Raman fluorescence, fluorescence, or a combination thereof.

[0135] A fourteenth embodiment can include the method of any one of the first to thirteenth embodiments, wherein the liquefied gas comprises ammonia and wherein the distinguishable signal comprises fluorescence.

[0136] A fifteenth embodiment can include the method of any one of the first to fourteenth embodiments, wherein the detector comprises a flow path for the sample of the liquefied gas, and wherein the flow path is resistant to corrosion by the liquefied gas (e.g., wherein the green fuel has a classification 4 corrosivity, as measured by ASTM D130-19).

[0137] In a sixteenth embodiment, a method for authenticating a green fuel comprises: a. selecting a fluorescent marker compound with unique fluorescence properties capable of emitting a distinguishable fluorescent signal upon exposure to a specific excitation wavelength; b. mixing said fluorescent marker compound into the green fuel to provide a marked green fuel, ensuring even distribution throughout the green fuel and controlling the concentration of said marker compound during the mixing process; c. providing an excitation source emitting light at said specific excitation wavelength to induce fluorescence in said fluorescent marker compound within said marked green fuel; d. employing a detector to record the emitted fluorescence from said marked green fuel after excitation, said detector capable of distinguishing said emitted fluorescence from background noise; e. optionally, conducting signal processing on the recorded fluorescence emission data to enhance signal-to-noise ratios and / or eliminate unwanted artifacts; f. accessing or establishing an authentication standard defining the expected fluorescence properties of said fluorescent marker compound and accessing or establishing an acceptable range of variability for authentic green fuels; g. comparing the detected fluorescence properties of saidAtty Docket No: 4377-12701 marked green fuel to said authentication standard; h. authenticating said marked green fuel as genuine when the detected fluorescence properties fall within said acceptable range of variability as defined by said authentication standard (e.g., indicating that the marked green fuel originates from a known or verified source and has not been adulterated or diluted with another substance); and i. identifying said marked green fuel as suspect or counterfeit when the detected fluorescence properties deviate from said acceptable range of variability as defined by said authentication standard. The method may also comprise transporting a portable detector to a location of the marked green fuel, sampling the green fuel at the location, and testing the sample of the green fuel at the location to authenticate the green fuel according to an applicable authentication standard.

[0138] A seventeenth embodiment can include the method of the sixteenth embodiment, wherein the green fuel comprises hydrogen, ammonia, alcohols (e.g., biomethanol, bioethanol), fatty acid methyl esters (e.g., (used) cooking oil methyl ester [UCOME]), biomethane (e.g., bio-LNG), or a combination thereof.

[0139] An eighteenth embodiment can include the method of the sixteenth or seventeenth embodiment, wherein the marker comprises a coumarin core structure, a xanthene core structure, or a perylene dye core structure.

[0140] A nineteenth embodiment can include the method of any one of the sixteenth to eighteenth embodiments, wherein the marker is selected from 7-(diethylamino)-3-phenyl-2H-chromen-2-one, 6,8-difluoro-7-hydroxy-4-methyl-2H-chromen-2-one, 7-hydroxy-4-methyl-2H-chromen-2-one, 7-amino-4-(trifluoromethyl)-2H-chromen-2-one, 7-amino-4-methyl-2H-chromen-2-one, 9- methyl-2,3,6,7-tetrahydro-1H,5H,11Hpyrano[2,3-f]pyrido[3,2,1-ij]quinolin-11-one, 9- (trifluoromethyl)-2,3,6,7-tetrahydro-1H,5H,11Hpyrano[2,3-f]pyrido[3,2,1-ij]quinolin-11-one, 3',6'-dihydroxy-2',4',5',7'-tetraiodo-3H-spiro[isobenzofuran-1,9'-xanthen]-3-one, 3',6'-dihydroxy-Atty Docket No: 4377-12701 3H-spiro[isobenzofuran-1,9'-xanthen]-3-one, 3',6'-bis(diethylamino)-3H-spiro[isobenzofuran- 1,9'-xanthen]-3-one, F Red 305, a squairaine dye, a phthalocyanine dye, a naphthalocyanine dye, a croconic acid derivative dye, a pyrazinoporphyrazine dye, a ketone, an aldehyde, an ester, an amide, an anhydride, a carboxylic acid, a polyamine, an isocyanate, or a combination thereof.

[0141] In a twentieth embodiment, a marked green fuel comprises: a fuel selected from hydrogen, ammonia, alcohols (e.g., biomethanol, bioethanol), fatty acid methyl esters (e.g., (used) cooking oil methyl ester [UCOME]), biomethane (e.g., bio-LNG), or a combination thereof; and a fluorescing marker (e.g., a marker that, when present in the fuel, emits detectable fluoresce spectra when subjected to an excitation source).

[0142] A twenty first embodiment can include the marked green fuel of the twentieth embodiment, wherein the marker comprises a coumarin core structure, a xanthene core structure, or a perylene dye core structure.

[0143] A twenty second embodiment can include the marked green fuel of the twentieth or twenty first embodiment, wherein the marker is selected from 7-(diethylamino)-3-phenyl-2H-chromen-2- one, 6,8-difluoro-7-hydroxy-4-methyl-2H-chromen-2-one, 7-hydroxy-4-methyl-2H-chromen-2- one, 7-amino-4-(trifluoromethyl)-2H-chromen-2-one, 7-amino-4-methyl-2H-chromen-2-one, 9- methyl-2,3,6,7-tetrahydro-1H,5H,11Hpyrano[2,3-f]pyrido[3,2,1-ij]quinolin-11-one, 9- (trifluoromethyl)-2,3,6,7-tetrahydro-1H,5H,11Hpyrano[2,3-f]pyrido[3,2,1-ij]quinolin-11-one, 3',6'-dihydroxy-2',4',5',7'-tetraiodo-3H-spiro[isobenzofuran-1,9'-xanthen]-3-one, 3',6'-dihydroxy- 3H-spiro[isobenzofuran-1,9'-xanthen]-3-one, 3',6'-bis(diethylamino)-3H-spiro[isobenzofuran- 1,9'-xanthen]-3-one, F Red 305, a squairaine dye, a phthalocyanine dye, a naphthalocyanine dye, a croconic acid derivative dye, a pyrazinoporphyrazine dye, a ketone, an aldehyde, an ester, an amide, an anhydride, a carboxylic acid, a polyamine, an isocyanate, or a combination thereof.Atty Docket No: 4377-12701

[0144] While embodiments have been shown and described, modifications thereof can be made by one skilled in the art without departing from the spirit and teachings of this disclosure. The embodiments described herein are exemplary only, and are not intended to be limiting. Many variations and modifications of the embodiments disclosed herein are possible and are within the scope of this disclosure. Where numerical ranges or limitations are expressly stated, such express ranges or limitations should be understood to include iterative ranges or limitations of like magnitude falling within the expressly stated ranges or limitations (e.g., from about 1 to about 10 includes, 2, 3, 4, etc.; greater than 0.10 includes 0.11, 0.12, 0.13, etc.). For example, whenever a numerical range with a lower limit, Rl, and an upper limit, Ru, is disclosed, any number falling within the range is specifically disclosed. In particular, the following numbers within the range are specifically disclosed: R=Rl +k* (Ru-Rl), wherein k is a variable ranging from 1 percent to 100 percent with a 1 percent increment, i.e., k is 1 percent, 2 percent, 3 percent, 4 percent, 5 percent, …..50 percent, 51 percent, 52 percent, ….., 95 percent, 96 percent, 97 percent, 98 percent, 99 percent, or 100 percent. Moreover, any numerical range defined by two R numbers as defined in the above is also specifically disclosed. Use of broader terms such as comprises, includes, having, etc. should be understood to provide support for narrower terms such as consisting of, consisting essentially of, comprised substantially of, etc. When a feature is described as “optional,” both embodiments with this feature and embodiments without this feature are disclosed. Similarly, the present disclosure contemplates embodiments where this “optional” feature is required and embodiments where this feature is specifically excluded.

[0145] Accordingly, the scope of protection is not limited by the description set out above but is only limited by the claims which follow, that scope including all equivalents of the subject matter of the claims. Each and every claim is incorporated into the specification as embodiments of the presentAtty Docket No: 4377-12701 disclosure. Thus, the claims are a further description and are an addition to the embodiments of the present disclosure. The discussion of a reference herein is not an admission that it is prior art, especially any reference that can have a publication date after the priority date of this application. The disclosures of all patents, patent applications, and publications cited herein are hereby incorporated by reference, to the extent that they provide exemplary, procedural, or other details supplementary to those set forth herein.

[0146] While several embodiments have been provided in the present disclosure, it should be understood that the disclosed systems and methods may be embodied in many other specific forms without departing from the spirit or scope of the present disclosure. The present examples are to be considered as illustrative and not restrictive, and the intention is not to be limited to the details given herein. For example, the various elements or components may be combined or integrated in another system or certain features may be omitted or not implemented.

[0147] Also, techniques, systems, subsystems, and methods described and illustrated in the various embodiments as discrete or separate may be combined or integrated with other systems, modules, techniques, or methods without departing from the scope of the present disclosure. Other items shown or discussed as directly coupled or communicating with each other may be indirectly coupled or communicating through some interface, device, or intermediate component, whether electrically, mechanically, or otherwise. Other examples of changes, substitutions, and alterations are ascertainable by one skilled in the art and could be made without departing from the spirit and scope disclosed herein.

Claims

Atty Docket No: 4377-12701 CLAIMS What is claimed is:

1. A method for authenticating a liquefied gas, the method comprising: exposing a sample of the liquefied gas to a specific excitation wavelength of electromagnetic radiation and detecting a resulting signal with a detector, wherein the specific excitation wavelength is a wavelength at which a marker in an authentic liquefied gas exhibits a distinguishable signal detected by the detector; and authenticating said liquefied gas when the resulting signal corresponds to an expected signal provided by the authentic liquefied gas having an authentic marker concentration; and identifying the liquefied gas as suspect or counterfeit when the resulting signal deviates from the expected signal by more than an amount provided by an authentication standard.

2. The method of claim 1, wherein the liquefied gas comprises a green fuel, a refrigerant coolant, an agrochemical, or a combination thereof.

3. The method of claim 2, wherein the green fuel or the liquefied gas comprises hydrogen, ammonia, alcohols, fatty acid methyl esters, or a combination thereof.

4. The method of claim 2, wherein the authentic green fuel is 100% renewable and carbon free.

5. The method of claim 2 further comprising, prior to the exposing of the green fuel to the electromagnetic radiation:Atty Docket No: 4377-12701 producing the green fuel; marking the green fuel by adding the marker thereto to provide a marked green fuel; and transporting the marked green fuel.

6. The method of claim 5, wherein producing the green fuel comprises producing the green fuel using renewable energy.

7. The method of claim 1, wherein the liquefied gas comprises ammonia.

8. The method of claim 1, wherein the marker comprises a coumarin core structure, a xanthene core structure, or a perylene dye core structure.

9. The method of claim 8, wherein the liquefied gas comprises ammonia.

10. The method of claim 1, wherein the marker is selected from 7-(diethylamino)-3-phenyl- 2H-chromen-2-one, 6,8-difluoro-7-hydroxy-4-methyl-2H-chromen-2-one, 7-hydroxy-4-methyl- 2H-chromen-2-one, 7-amino-4-(trifluoromethyl)-2H-chromen-2-one, 7-amino-4-methyl-2H- chromen-2-one, 9-methyl-2,3,6,7-tetrahydro-1H,5H,11Hpyrano[2,3-f]pyrido[3,2,1-ij]quinolin- 11-one, 9-(trifluoromethyl)-2,3,6,7-tetrahydro-1H,5H,11Hpyrano[2,3-f]pyrido[3,2,1-ij]quinolin- 11-one, 3',6'-dihydroxy-2',4',5',7'-tetraiodo-3H-spiro[isobenzofuran-1,9'-xanthen]-3-one, 3',6'- dihydroxy-3H-spiro[isobenzofuran-1,9'-xanthen]-3-one, 3',6'-bis(diethylamino)-3H- spiro[isobenzofuran-1,9'-xanthen]-3-one, F Red 305, a squairaine dye, a phthalocyanine dye, a naphthalocyanine dye, a croconic acid derivative dye, a pyrazinoporphyrazine dye, a ketone, anAtty Docket No: 4377-12701 aldehyde, an ester, an amide, an anhydride, a carboxylic acid, a polyamine, an isocyanate, or a combination thereof.

11. The method of claim 10, wherein the liquefied gas comprises ammonia.

12. The method of claim 1, wherein the distinguishable signal comprises phosphorescence, chemiluminescence, electroluminescence, fluorescence upconversion, Raman fluorescence, fluorescence, or a combination thereof.

13. The method of claim 1, wherein the liquefied gas comprises ammonia and wherein the distinguishable signal comprises fluorescence.

14. The method of claim 1, wherein the detector comprises a flow path for the sample of the liquefied gas, and wherein the flow path is resistant to corrosion by the liquefied gas.

15. A method for authenticating a green fuel, the method comprising: a. selecting a fluorescent marker compound with unique fluorescence properties capable of emitting a distinguishable fluorescent signal upon exposure to a specific excitation wavelength; b. mixing said fluorescent marker compound into the green fuel to provide a marked green fuel, ensuring even distribution throughout the green fuel and controlling the concentration of said marker compound during the mixing process; c. providing an excitation source emitting light at said specific excitation wavelength to induce fluorescence in said fluorescent marker compound within said marked green fuel;Atty Docket No: 4377-12701 d. employing a detector to record the emitted fluorescence from said marked green fuel after excitation, said detector capable of distinguishing said emitted fluorescence from background noise; e. optionally, conducting signal processing on the recorded fluorescence emission data to enhance signal-to-noise ratios and / or eliminate unwanted artifacts; f. accessing or establishing an authentication standard defining the expected fluorescence properties of said fluorescent marker compound and accessing or establishing an acceptable range of variability for authentic green fuels; g. comparing the detected fluorescence properties of said marked green fuel to said authentication standard; h. authenticating said marked green fuel as genuine when the detected fluorescence properties fall within said acceptable range of variability as defined by said authentication standard; and i. identifying said marked green fuel as suspect or counterfeit when the detected fluorescence properties deviate from said acceptable range of variability as defined by said authentication standard.

16. The method of claim 15, wherein the green fuel comprises hydrogen, ammonia, alcohols, fatty acid methyl esters, or a combination thereof.

17. The method of claim 15, wherein the marker comprises a coumarin core structure, a xanthene core structure, or a perylene dye core structure.Atty Docket No: 4377-12701 18. The method of claim 15, wherein the marker is selected from 7-(diethylamino)-3-phenyl- 2H-chromen-2-one, 6,8-difluoro-7-hydroxy-4-methyl-2H-chromen-2-one, 7-hydroxy-4-methyl- 2H-chromen-2-one, 7-amino-4-(trifluoromethyl)-2H-chromen-2-one, 7-amino-4-methyl-2H- chromen-2-one, 9-methyl-2,3,6,7-tetrahydro-1H,5H,11Hpyrano[2,3-f]pyrido[3,2,1-ij]quinolin- 11-one, 9-(trifluoromethyl)-2,3,6,7-tetrahydro-1H,5H,11Hpyrano[2,3-f]pyrido[3,2,1-ij]quinolin- 11-one, 3',6'-dihydroxy-2',4',5',7'-tetraiodo-3H-spiro[isobenzofuran-1,9'-xanthen]-3-one, 3',6'- dihydroxy-3H-spiro[isobenzofuran-1,9'-xanthen]-3-one, 3',6'-bis(diethylamino)-3H- spiro[isobenzofuran-1,9'-xanthen]-3-one, F Red 305, a squairaine dye, a phthalocyanine dye, a naphthalocyanine dye, a croconic acid derivative dye, a pyrazinoporphyrazine dye, a ketone, an aldehyde, an ester, an amide, an anhydride, a carboxylic acid, a polyamine, an isocyanate, or a combination thereof.

19. A marked green fuel, comprising: a fuel selected from hydrogen, ammonia, alcohols, fatty acid methyl esters, or a combination thereof; and a fluorescing marker.

20. The marked green fuel of claim 19, wherein the marker comprises a coumarin core structure, a xanthene core structure, or a perylene dye core structure.

21. The marked green fuel of claim 19, wherein the marker is selected from 7-(diethylamino)- 3-phenyl-2H-chromen-2-one, 6,8-difluoro-7-hydroxy-4-methyl-2H-chromen-2-one, 7-hydroxy- 4-methyl-2H-chromen-2-one, 7-amino-4-(trifluoromethyl)-2H-chromen-2-one, 7-amino-4-Atty Docket No: 4377-12701 methyl-2H-chromen-2-one, 9-methyl-2,3,6,7-tetrahydro-1H,5H,11Hpyrano[2,3-f]pyrido[3,2,1- ij]quinolin-11-one, 9-(trifluoromethyl)-2,3,6,7-tetrahydro-1H,5H,11Hpyrano[2,3-f]pyrido[3,2,1- ij]quinolin-11-one, 3',6'-dihydroxy-2',4',5',7'-tetraiodo-3H-spiro[isobenzofuran-1,9'-xanthen]-3- one, 3',6'-dihydroxy-3H-spiro[isobenzofuran-1,9'-xanthen]-3-one, 3',6'-bis(diethylamino)-3H- spiro[isobenzofuran-1,9'-xanthen]-3-one, F Red 305, a squairaine dye, a phthalocyanine dye, a naphthalocyanine dye, a croconic acid derivative dye, a pyrazinoporphyrazine dye, a ketone, an aldehyde, an ester, an amide, an anhydride, a carboxylic acid, a polyamine, an isocyanate, or a combination thereof.

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