Systems and methods for degassing water

Abstract

A system (1) for degassing water is provided The system comprises: a submersible pipe assembly (2), configured to be deployed into a body of water (W), the pipe assembly comprising at least one inlet (21) arranged to allow inflow of water from the body of water (W); a reservoir (3), configured to be arranged in the body of water (W) and in fluid communication with the pipe assembly (2), the reservoir (3) comprising a plurality of stirrer blades (31) arranged within the reservoir (3), configured to create turbulence and thereby release gas (G) from the water in the reservoir (3); a control unit (4), configured to determine a level of a first gas (G1) released from the water in the reservoir (3); and at least one ignition and combustion unit (5), arranged at the reservoir (3) and configured to ignite and combust the first gas (G1). In addition, a method (100) for degassing water is provided.

Description

[0001] SYSTEMS AND METHODS FOR DEGASSING WATER

[0002] FIELD OF INVENTION

[0003] The present invention relates to systems and methods for degassing water.

[0004] BACKGROUND OF THE INVENTION

[0005] Greenhouse gas emissions originate both from human activity and natural sources. Natural sources include various bodies of water from which dissolved greenhouse gases can be released into the atmosphere, such as lakes and wetlands. Dissolved gases include carbon dioxide as well as combustible gases, such as methane.

[0006] In order to reduce greenhouse gas emissions from bodies of water, various methods have been attempted. Concerning methane, solutions include extraction of the methane from the surrounding air including absorbent materials such as zeolite based structures and catalysts such as platinum or palladium. Catalytic filters generally have a very short lifetime, are technologically challenging and require high temperatures. Methane separation technologies including membrane-based technologies and degassing towers, which require large energy inputs and cannot usually process more than 50 cubic meters per second, and most importantly are very expensive and bulky. Some further solutions involve spraying iron chloride particles over oceans as catalysts to convert methane to CO2 and water by increasing OH and Cl levels. Attempts at spraying iron chloride particles to enhance natural sinks of the hydroxyl radical °OH (responsible for 90% of the natural methane sink) and the chlorine atom Cl (3-4% of the natural methane sink) claim to increase the Cl sink four-to-six-fold during the day and continuing to enhance the °OH sink at night. However, it is very difficult to control unintended parallel reactions such as the partial oxidation of methane to carbon monoxide (CO), methanol (CH3OH), or, for iron-salt aerosols, chloromethane (CH3CI) instead of CO2.

[0007] In addition, agricultural practices are being investigated to reduce emissions from rice paddies including crop diversification and the Alternate Wetting and Drying (AWD) method. Despite recording reduced methane emissions compared to continuously flooded paddies the AWD practices have been seen to increase nitrous oxide (N2O) emissions by 105% and decrease yield by 4%.

[0008] Thus, a technology that would meaningfully mitigate greenhouse gas emissions with economic feasibility is required, without altering wetland chemistry / biology and their function in the ecosystem as carbon sinks. SUMMARY OF THE INVENTION

[0009] The present invention provides systems and methods for degassing water.

[0010] The solutions disclosed herein provide versatile systems and methods for degassing water, functioning across different types of bodies of water, including lakes and wetlands, and having low deployment and implementation cost. Furthermore, systems and methods as disclosed herein mitigate harmful release of greenhouse gases.

[0011] According to a first aspect of the present invention, there is provided a system for degassing water. The system comprises a submersible pipe assembly, configured to be deployed into a body of water, the pipe assembly comprising at least one inlet arranged to allow inflow of water from the body of water. The system also comprises a reservoir arranged at the body of water and in fluid communication with the pipe assembly. The reservoir is configured to create and / or allow turbulence in a volume of water introduced therein to release a first gas from the water. The reservoir may also be referred to as a container, a receptacle, or a water chamber. The system further comprises a control unit, configured to determine a level of the first gas released from the water in the reservoir. The control unit may comprise any suitable circuitry, such as a one or more processors or a computer. According to the first aspect, the system further comprises at least one gas processing unit. The at least one gas processing unit is arranged at the reservoir and configured to process the first gas.

[0012] The gas processing unit may comprise a storage unit, and optionally a compressor, configured to store the first gas released from the water in the reservoir.

[0013] The first gas may be an ignitable first gas. In such examples, the gas processing unit advantageously comprises an ignition and combustion unit, configured to ignite and combust the ignitable first gas.

[0014] The system may further comprise a gas release mechanism configured to create the turbulence in the volume of water within the reservoir to release the first gas from the water. In some examples, the gas release mechanism may be configured to create a vacuum within the reservoir to cause turbulence in the volume of water therein. In some examples, the system may comprise water atomising nozzles. Alternatively, or additionally, the reservoir may comprise a plurality of stirrer blades. The stirrer blades are advantageously arranged within the reservoir and configured to create turbulence to thereby release gas from the water in the reservoir. Such a gas release function may be referred to as water vacuum atomization. The released gas comprises the first gas.

[0015] The first gas is advantageously a biogas, such as biomethane. In some examples, the system may comprise a biogas purification unit, the biogas purification unit being configured to purify the gas. The gas purification unit may be configured in any suitable way and may purify the gas using any suitable methods, such as any suitable gas separation technique. In some examples, cryogenic separation may be used to separate one or more components of biogas, such as methane. In such examples, one or more components of the biogas may be compressed and then cooled using any suitable cooling means. In some examples, a freezer having a capacity of - 86 degrees is used. The cooling may be allowed to continue until the mixture reaches the relevant cryogenic temperatures. The temperature may, for example, be lowered to -60°C to separate carbon dioxide (CO2) which has undergone a phase shift to liquid form from the methane (CH4) which remains in gaseous form. Lowering the temperature down to -86°C may turn the CO2 into dry ice, while the CH4 remains in the gas phase.

[0016] Example methods for purification include the use of absorbent-based catalytic filters; temperature adjustments; pressure adjustments; pressure swing adsorption (PSA); vacuum swing adsorption (VSA); temperature swing adsorption (TSA); and bioreactors.

[0017] Alternatively, or additionally, the system may comprise a biogas neutralisation unit, such as a methane neutralisation unit. Such a biogas neutralisation unit may be configured to neutralise the biogas using any suitable method. In some examples, the biogas may be neutralised through ignition and combustion. Alternatively, or additionally, some examples, the biogas may be neutralised by exposing the biogas to hydroxyl (OH) radicals, for example through spraying. In some examples, the biogas may be neutralised by exposing the biogas to iron chloride aerosols, such as FeCL aerosols, for example through spraying. Thereby, natural biogas sinks may be promoted.

[0018] The pipe assembly may be a flexible pipe assembly. The pipe assembly may be configured to be coiled. A coiled, or coilable, pipe assembly is beneficial in transportation and storage of the degassing system. The pipe assembly may be manufactured from a lightweight material, lowering the total weight of the degassing system and thus even further improving the portability of the degassing system. The pipe assembly may advantageously be resistant to an external hydrostatic pressure of at least 5 Bar, preferably over 10 Bar. In order to withstand the external hydrostatic pressure, the pipe assembly may be reinforced. Alternatively or additionally, the pipe assembly or components thereof may be manufactured from a high-resistance material. The pipe assembly or components thereof may be manufactured from a rubber material reinforced with high tensile textile cords. The pipe assembly or components thereof may comprise one or more of a flexible stainless steel interlocking carcass, a seamless polyamide core tubing and / or aramid fibre braid reinforcement.

[0019] The plurality of stirrer blades are configured to cause enough turbulence to release the ignitable first gas dissolved in the water in the reservoir. The plurality of stirrer blades may comprise any number of stirrer blades, such as two, three, four, five or six stirrer blades. The stirrer blades may be arranged along a shared axis, on parallel axes or arranged in an array. The stirrer blades may be arranged at equal intervals along a shared axis. Advantageously, the stirrer blades are configured to cover the whole length, or diameter when the reservoir is circular, of the reservoir, such that turbulence is created all through the water contained in the reservoir. Each of the plurality of stirrer blades may be rotated independently of the other stirrer blades of the plurality of stirrer blades. Alternatively, all the stirrer blades of the plurality of stirrer blades may be rotated together, or in any other synchronised manner. The arrangement of the stirrer blades is chosen based on the configuration of the reservoir, both in terms of geometry and capacity. A larger capacity reservoir, containing a larger volume of water, may need a larger number of stirrer blades. The stirrer blades may be configured to stir 500 litres of water, or more. In some examples, however, the stirrer blades need only to stir a smaller volume, such as 16 litres. A suitable rotational speed of the stirrer blades is selected based on the volume of water and the distribution and design of the stirrer blades within the reservoir. The stirrer blades may in some examples be configured to rotate with a rotational speed in excess of 10,000 RPM. The configuration of the stirrer blades and the rotational speed affect the time needed for degassing. A more effective set of stirrer blades will provide a faster degassing process.

[0020] The system may further comprise at least one gas outlet, configured to restrict or allow a flow of gas from the reservoir.

[0021] In examples where the gas processing unit comprises an ignition and combustion unit, the ignition and combustion unit may advantageously be arranged outside of the reservoir, such that ignition and combustion of the ignitable first gas occurs on exit from the reservoir. Thereby, the reservoir may be manufactured from a material that is lightweight and is not required to be flame and explosion proof, since explosions or high temperatures inside the reservoir are avoided when the ignitable first gas is not combusted within the reservoir itself. A reservoir constructed in a lightweight material, such as a robust plastic material or aluminium, improves the portability of the system by reducing the total weight of the system. A lower weight is, for example, useful in transportation of the system from one degassing site to another. Furthermore, a less durable material may be less costly than a flame and explosion proof material. The at least one outlet may be configured to be opened when the control unit has determined that the level of the ignitable first gas in the reservoir is within an ignition range. The at least one ignition and combustion unit may be configured to be activated when the at least one outlet is opened.

[0022] The ignition and combustion unit may be any suitable ignition and combustion unit, such as a spark generator. The ignition and combustion unit may either be triggered at a constant frequency or on an ad hoc basis upon detection of a gas flow. When configured as a spark generator, the frequency may be 1 Hz, 0.5 Hz, within the range of 0.2-2 Hz, or arranged to trigger as a predetermined level of the ignitable first gas is detected. The skilled person will readily understand that other frequencies are equally envisioned.

[0023] The system may further comprise a valve mechanism. The valve mechanism may be any suitable valve mechanism. The valve mechanism is suitably arranged in connection with the pipe assembly. The valve mechanism may be configured to control the inflow of water from the body of water into the pipe assembly. The valve mechanism may be arranged at the inlet of the pipe assembly. The valve mechanism may be arranged at an inlet of the reservoir. The valve mechanism may comprise a plurality of valves. In examples where the valve mechanism comprises a plurality of valves, the valves may be arranged at different positions. The valve mechanism may comprise a first valve and / or a second valve. The first valve may be arranged at the inlet of the pipe assembly. The second valve may be arranged at an inlet port of the reservoir. The inlet port may be arranged below a surface of the body of water when the reservoir is floating in the body of water. Thereby, a hydrostatic pressure on the inlet of the pipe assembly may drive a flow of water into the reservoir through the inlet port when the first valve and / or the second valve is open. The valve mechanism may be an electronically controlled valve mechanism. The valve mechanism may be controllable through the control unit.

[0024] The pipe assembly is configured to be deployed at a depth suitably for the circumstances at hand. In some examples, the pipe assembly is configured to be deployed in profound depths, such that the inlet is located at a depth of 300 meters or more. In other examples, the pipe assembly is configured to be deployed such that the inlet is located at a depth of 0.1 , 0.5, 5, 10, 25, 50, 100, 150, 200 or 250 meters, or any depths therebetween. Thereby, the hydrostatic pressure difference between the reservoir, arranged substantially at surface level, and the inlet of the pipe assembly drives a flow of water from the profound depth though the pipe assembly into the reservoir. In examples where the system comprises a valve mechanism, the opening of the valve mechanism allows the flow of water from the profound depth to enter the pipe assembly and / or the reservoir. Such a self-priming flow may be referred to as an automatic siphon, or auto siphon. The water flowing into the pipe assembly via the inlet advantageously has a high concentration of dissolved gases, preferably of the first gas. In examples where the first gas is methane, the water flowing into the pipe assembly advantageously has a high concentration of dissolved methane. As the hydrostatic pressure difference drives the flow through the pipe assembly, gas bubbles are formed in the rising water pillar, releasing at least some of the dissolved first gas, when present in the water drawn into the pipe assembly at the inlet. Thereby, an amount of gas already degassed from the water is introduced into the reservoir together with the water. The self-priming flow of water thus functions synergistically with the stirrer blades to rapidly generate a level of the ignitable first gas in the reservoir that is within the ignition range.

[0025] The control unit may comprise any suitable processor and / or circuitry. The control unit may further comprise a sensor unit. The sensor unit may be configured to detect a level of the first gas in the reservoir. The sensor unit may also be referred to as a gas meter. The first gas may be any relevant gas. Advantageously, the first gas is methane, and the control unit is configured to determine a level of methane released from the water in the reservoir as the level of the first gas.

[0026] The term ignition range, when used herein, refers to concentrations of an ignitable first gas in the reservoir that are within the flammability limits of a gas. In other words, a percentage of gas per volume of air where it is possible to ignite and combust the ignitable first gas using the ignition and combustion unit. A lowest value of the ignition range may also be expressed as a lower flammability limit (LFL). A highest value of the ignition range may also be expressed as an upper flammability limit (UFL). In examples where the ignitable first gas is methane, the at least one ignition and combustion unit of the system may be configured to be activated when the control unit has determined that the level of methane is within an ignition range. At substantially atmospheric pressure, the lowest flammability limit of methane is approximately 4.4 %vol. and the highest upper flammability limit is approximately 17 %vol. Thus, at atmospheric pressure, the ignition range for methane as the ignitable first gas may extend from 4.4 %vol. to 17 %vol., where the lowest point of the ignition range is approximately 4.4 %vol. and the highest point of the ignition range is 17 %vol. The exact volume percentage may vary depending on the circumstances at hand, for example depending on the temperature of the gas / air mixture in the reservoir.

[0027] In some examples, the control unit may continuously monitor the level of the first gas in the reservoir. In examples where the control unit comprises the sensor unit, the sensor unit may continuously monitor the level of the first gas in the reservoir. Alternatively, the control unit may be activated when a predetermined volume of water has entered the reservoir. In such examples, the sensor unit may be activated to detect the level of the first gas when the predetermined volume of water in the reservoir has been reached.

[0028] Alternatively, or additionally, a pressure sensor of any suitable kind is arranged in, at least partially in, or in direct connection with, the reservoir.

[0029] The system may further comprise an air inlet and an associated air inlet valve arranged to allow an inflow of air toward the reservoir and / or toward the ignition and combustion unit. In examples where the system comprises a return path, the inflow of air may flow in a direction toward the return path and the ignition and combustion unit. The air inlet valve may be an electronically controlled valve. The air inlet valve may be connected to the control unit. The control unit may control the air inlet valve to open when it has been determined, at the control unit, that the level of the ignitable first gas exceeds a highest value of the ignition range. As air flows toward the ignition and combustion unit, the concentration of oxygen in the gas mixture flowing toward the ignition and combustion unit increases. Thereby, the level of the ignitable first gas may be lowered to a value within the ignition range. The system may further comprise a fan or impeller, arranged in fluid connection with the air inlet, such that when the air inlet valve is open, the fan / impeller increases the flow of air from the outside.

[0030] The system may further comprise a second outlet in fluid communication with the reservoir, a compressor and at least one duct. The at least one duct may be configured to route the first gas via the second outlet from the reservoir to the compressor. The second outlet may be an electronically controlled valve. The second outlet may be connected to the control unit. The control unit may control the second outlet to open when it has been determined, at the control unit, that the level of the ignitable first gas is less than a lowest value of the ignition range. The at least one duct may be equipped with a fan / impeller, to draw the ignitable first gas from the reservoir, via the outlet to the compressor. In some examples, the compressor may be detachable. A sensor unit arranged at the compressor, may transmit an indication of the volume of the ignitable first gas within the compressor to the control unit. The reservoir may be shaped in any suitable way. The reservoir may be any suitable type of receptacle with a body defining a volume that can house at least a desired volume of water, air and / or gas mixture, as well as the stirrer blades in some examples. The reservoir advantageously comprises a bottom surface, which may be planar, sloped and / or composed of several sections. Such sections may or may not have the same shape and / or slope. The bottom surface may be intact, or it may comprise one or more apertures. In examples where the bottom surface comprises one or more apertures, one or more of these apertures may be configured to be connected to the pipe assembly. Alternatively or additionally, one or more of these apertures may be configured to be connected to other openings, outlets, inlets, etc. In some examples, the reservoir may be substantially cylindrical with a substantially circular cross section. In other examples, the reservoir may be block or box shaped. The reservoir may have a triangular or quadrilateral cross section. The reservoir may have at least one outer surface, also referred to as a sidewall. In such examples, the at least one sidewall is connected to the bottom surface in an air- and watertight manner. In examples where the reservoir is cylindrical with a circular cross-section, the reservoir may be said to contain one sidewall, which may also be referred to as an envelope surface. The reservoir may have the shape of a rectangular box, with a quadrilateral cross-section and four sidewalls. The reservoir may comprise a removable lid. The removable lid may be placed at the top of the reservoir to form an air- and watertight seal with the at least one sidewall of the reservoir. The removable lid may form an air- and watertight seal with a plurality of sidewalls of the reservoir. The removable lid may be foldable. The space enclosed by the bottom surface, the at least one outer surface and the lid may be said to define the reservoir body. The reservoir may further comprise a drain outlet, for efficiently emptying the reservoir of water contained therein. The drain outlet may be arranged at any suitable location on, or in, the reservoir. Advantageously, the drain outlet is arranged at the bottom surface or at a lower end of an outer surface, preferably adjacent the bottom surface.

[0031] The reservoir may be configured to be collapsible. Additionally or alternatively, the reservoir may be foldable. The reservoir may comprise grooves to facilitate collapsing or folding. The stirrer blades may be jointed, or otherwise arranged to be tilted, folded or collapsed, such that they are collapsible and / or foldable while remaining within the reservoir. Alternatively or additionally, the stirrer blades may be detachably arranged within the reservoir, such that they can be readily removed before collapsing and / or folding the reservoir. The system may comprise buoyancy means, attached to the reservoir. Such buoyancy means may be one or more floats, attached to the one or more outer surfaces of the reservoir, acting to keep the reservoir afloat.

[0032] The pipe assembly may comprise a plurality of flexible tubes, configured to restrict an inflow of water into at least a first flexible tube of the plurality of flexible tubes while allowing an inflow of water into at least a second flexible tube of the plurality of flexible tubes. The flexible tubes of the plurality of tubes may be arranged substantially in parallel. The plurality of tubes may include any suitable number of flexible tubes. In some examples, the pipe assembly comprises five flexible tubes: a first tube, a second tube, a third tube, a fourth tube and a fifth tube. The second, third, fourth and fifth tubes are arranged substantially parallel to, and evenly distributed around, the first flexible tube. Advantageously, the flexible tubes are made from a lightweight material. Such a configuration of the pipe assembly works to gradually increase the weight of the pipe assembly as it is deployed into the body of water, pulling the pipe assembly downward as water flows into at least the second flexible tube while the first flexible tube remains closed at the inlet. Thereby, the inlet of the first flexible tube can be opened when the pipe assembly has reached a predetermined depth, and thereby contribute to the creation of the self-priming fluid flow through the pipe assembly, described above. Such a configuration also ensures the pipe assembly remains substantially straight during deployment. At least the second flexible tube, which takes in water, acts as a weight and pulls the first flexible tube, which does not take in water, down toward the predetermined depth. Such a configuration provides the effect of a weight attached to the pipe assembly, while keeping the pipe assembly itself low-weight, which is beneficial in transport of the system, thus contributing to making the degassing system disclosed herein portable.

[0033] The pipe assembly may comprise a sinker device. The sinker device may be arranged at a first end of the pipe assembly. The first end of the pipe assembly may be the end of the pipe assembly that comprises the inlet. In such examples, the pipe assembly is suitably deployed by lowering the first end of the pipe assembly first into the body of water. The sinker device may be any suitable device that improves the ability of the pipe assembly to be deployed into the body of water. The sinker device may act to uncoil the pipe assembly and / or to ensure the pipe assembly remains substantially straight when it is deployed into the body of water. The sinker device may be a metal sink weight, commonly known as a sinker.

[0034] The pipe assembly may comprise a removable filter arranged at the inlet, preventing inflow of debris into the pipe assembly as well as protecting aquatic life. The system may be a wirelessly connected system. The control unit may be configured to communicate with at least one piece of user equipment. The user equipment may be specifically designed for use with the system, or it may be any type of user equipment, such as a smart phone or a tablet. The control unit may comprise a transceiver unit, configured to transmit signals to and receive signals from, at least, the user equipment. The transceiver unit may be configured to transmit signals and to receive signals from more than one piece of user equipment, such as from and to a plurality of smartphones, tablets, servers, cloud infrastructure, etc. A user may monitor several parameters of the degassing system through their user equipment. Such parameters may include a level of the first gas in the reservoir, the depth at which the inlet of the pipe assembly is located, and the concentration of the first gas in the water surrounding the inlet of the pipe assembly. The system may also be configured such that the user can continuously monitor a volume of the first gas that has been processed, through any suitable method, and, optionally, stored in any suitable vessel. The system may also be configured such that the user may control components of the degassing system through their user equipment, via the control unit. The user may, for example, control the opening and closing of the valve mechanism, the actuation of the gas release mechanism, comprising actuating stirrer blades and / or actuating one or more vacuum pumps, and the activation of the gas processing unit, optionally comprising the ignition and combustion unit.

[0035] According to a second aspect of the present invention, there is provided a method for degassing water. The steps of the method as disclosed herein may be taken in any suitable order. The method comprises a step of deploying a submersible pipe assembly into a body of water, such that an inlet of the pipe assembly is arranged in fluid communication with the body of water. Thereby, water may flow into the pipe assembly via the inlet, unless the inlet is closed or otherwise restricted. The method further comprises arranging a reservoir at the body of water and flowing water from the body of water into the reservoir through the pipe assembly. The reservoir may be arranged partly submerged, such that it is arranged substantially afloat, while at least a portion of the reservoir extends below the water surface. The rising level of water in the reservoir may be halted when the reservoir comprises both a volume of water and a volume of air. The relationship between the volume of air and volume of water may vary depending on the circumstances at hand.

[0036] The method further comprises actuating a gas release mechanism in the reservoir, thereby releasing a first gas from the water in the reservoir. The method further comprises determining a level of the first gas in the reservoir. If the determined level of the first gas in the reservoir is within a predetermined processing range, the method comprises processing the first gas.

[0037] The first gas may be processed in any suitable location using any suitable method. In some examples, the first gas is processed outside of the reservoir. When the first gas in the reservoir has been processed, in any suitable way, a degassing cycle may be said to be complete.

[0038] In some examples, the step of actuating the gas release mechanism may comprise actuating stirrer blades arranged in the reservoir to release the first gas from the water in the reservoir. Advantageously, the stirrer blades are actuated when a suitable volume of water has been introduced into the reservoir, leaving a suitable volume of air within the reservoir. The stirrer blades may be actuated automatically, for example by means of a control unit, such as the control unit discussed herein. Alternatively, or additionally, the stirrer blades may be actuated manually, for example by a user pressing a button.

[0039] The first gas may be an ignitable first gas. In such examples, if the determined level of the ignitable first gas in the reservoir is within an ignition range, the step of processing the first gas may comprise igniting and combusting the first gas. In some examples, the first gas is advantageously ignited and combusted after having reached an appropriate cylinder within the gas processing unit. Thus, the method may comprise the step of determining a level of an ignitable first gas in the reservoir and, if the determined level of the ignitable first gas in the reservoir is within an ignition range, the method may comprise the step of igniting and combusting the ignitable first gas. When the ignitable first gas in the reservoir has been ignited and combusted, a degassing cycle may be said to be complete.

[0040] The step of actuating the gas release mechanism may comprise actuating a vacuum pump to cause turbulence in the volume of water in the reservoir and release the first gas from the water in the reservoir.

[0041] In some examples, the step of processing the first gas may comprise purifying the first gas. The first gas may be purified using any suitable method. Example methods for purification include the use of absorbent-based catalytic filters; temperature adjustments; pressure adjustments; pressure swing adsorption (PSA); vacuum swing adsorption (VS A); temperature swing adsorption (TSA); and bioreactors. Alternatively, or additionally, the step of processing the first gas may comprise neutralising the first gas. The first gas may be neutralised using any suitable method. The first gas, which may be a biogas, may be neutralised by exposing the biogas to hydroxyl (OH) radicals, for example through spraying. In some examples, the first gas may be neutralised by exposing the biogas to iron chloride aerosols, such as FeCF aerosols, for example through spraying. Thereby, natural biogas sinks may be promoted. In some examples, the first gas may be compressed for storage and future use.

[0042] A pressure sensor, in contact with the control unit, may be arranged at the reservoir. The pressure sensor may be arranged within the reservoir or it may be arranged outside the reservoir in contact with the reservoir.

[0043] A controller, such as the control unit of the system disclosed herein, may suitably be used for determining the level of the first gas in the reservoir. One or more gas sensors may be provided in communication with the reservoir for detecting concentrations of one or more types of gas in the reservoir. The controller may receive signals from the one or more gas sensors indicative of a concentration of one or more gasses in the reservoir (oxygen and methane, for example). The first gas may be any relevant gas, such as an ignitable first gas. In some examples, the first gas is an ignitable first gas, such as methane. The ignition range, as discussed above, refers to concentrations of the ignitable first gas in the reservoir that are within the flammability limits of that gas. In other words, the ignition range spans from the lowest flammability limit to the highest flammability limit. In examples where the ignitable first gas is methane, the ignition range may span from approximately 4.4% by volume to approximately 17% by volume (assuming that the remaining volume fraction comprises around 20% oxygen, as is the case where the remaining volume fraction is air).

[0044] The step of flowing water from the body of water to enter into the reservoir through the pipe assembly may comprise opening a valve mechanism of the pipe assembly, the pipe assembly being deployed in the body of water. In some examples, the valve mechanism may comprise a plurality of valves and, in such examples, the method may comprise selectively opening only one or a plurality of the valves. The valve mechanism may be electronically controlled by the control unit. In some examples, the control unit may be a single central electronic control unit for the entire system. The control unit may control all controllable components of the system, such as vacuum pumps, water pumps and valves, based on input from any suitable, such as gas sensors, pressure sensors, water level sensors, and any other sensors arranged within or outside of the system. In some examples, the opening or closing of the valve mechanism may be performed based on the control unit receiving an indication from a remote secondary control unit. The remote secondary control unit may be a piece of user equipment, such as a smart phone or a tablet. Alternatively or additionally, the opening and closing of the valve mechanism may be performed automatically, based on the control unit receiving an automatically generated signal. Such an automatic signal may be generated by the sensor unit detecting a level of the ignitable first gas in the ignition range. A water level sensor, such as a water meter, may also provide an automatic signal to the control until when a predetermined volume of water has flowed into the reservoir. In some examples, such a predetermined volume of water may be within the range of 10 to 20 litres, such as 12 litres or 16 litres. In some examples, a larger reservoir may be used, with a predetermined volume of water within the range of 150 to 600 litres of water, preferably between 200 and 500 litres.

[0045] If the level of the ignitable first gas is determined to exceed a highest value of the ignition range, the method may further comprise a step of opening an air inlet valve arranged at an air inlet of the reservoir. Opening the air inlet valve serves to increase a concentration of oxygen in the gas mixture flowing toward the ignition and combustion unit, thereby lowering the level of the ignitable first gas to a value within the ignition range.

[0046] If the level of the ignitable first gas is determined to be less than a lowest value of the ignition range, the method may further comprise a step of routing the ignitable first gas toward a compressor arranged in fluid communication with the reservoir.

[0047] When water has been flowed from the body of water into the reservoir through the pipe assembly, the method may further comprise a step of determining if the water in the reservoir has reached a predetermined level. When the water level is determined to be below the predetermined level, the flow of water into the reservoir may be allowed to continue. If the water level is instead determined to have reached the predetermined level, the method may comprise two options, as described below.

[0048] In some embodiments of the system disclosed herein, the flow of water into the reservoir may not be continuous during the degassing process, the method comprises discontinuing the flow of water into the reservoir when the predetermined level has been reached. The flow is suitably discontinued by closing at least one of the valve mechanism of the pipe assembly or the inlet port of the reservoir. In some examples, the predetermined volume of water is within the range of 150 to 600 litres of water, preferably between 200 and 500 litres. In some embodiments of the system, the inlet port may correspond to the valve mechanism as a whole, or to one of the first or second valves of the valve mechanism.

[0049] In other embodiments of the system disclosed herein, where the flow of water through the reservoir is continuous, the method comprises activating an ejector unit, which may also be referred to as a pump and ejector unit. The ejector unit draws water out of the reservoir through an ejector tube. In order to ensure a constant flow of water through the reservoir, the ejector tube draws water from the reservoir at the same rate as the water flows into the reservoir through the pipe assembly. Thereby, a constant water level is maintained in the reservoir. In some embodiments, an array of suitable water pumps may be used to a desired processing rate. Such an array may comprise any suitable number of pumps, such as between 2 and 20 pumps.

[0050] The method may further comprise a step of emptying the reservoir of water. Such a method step is suitably performed when a degassing cycle is completed. The reservoir may be emptied by raising it from the body of water using any suitable tool, such as a winch, and allow the water comprised therein to flow out from a drain outlet arranged in any suitable location on, or in, the reservoir.

[0051] In some examples, the pipe assembly may be a flexible pipe assembly and, in such examples, the step of deploying the pipe assembly into the body of water may comprise uncoiling the pipe assembly. The pipe assembly may be uncoiled from a reel. Additionally or alternatively, when the pipe assembly is a flexible pipe assembly, the method may further comprise a step of retracting the pipe assembly from the body of water and coiling it onto a reel.

[0052] The method may further comprise depositing, into the body of water, combustion byproducts and / or a non-flammable second gas degassed from the water in the reservoir. The nonflammable second gas may be any relevant gas. In some examples, the non-flammable second gas may be carbon dioxide.

[0053] In some examples, the method may advantageously comprise an additional step of extracting and storing the first gas, for example methane, in an appropriate vessel arranged in fluid connection with the reservoir. Such a vessel is suitably detachable from the reservoir. A sensor unit arranged in connection with the vessel may transmit a signal to the control unit of the system indicating the volume of the first gas contained in the vessel. The control unit may in turn transmit the indication to a piece of user equipment, such as a smart phone or tablet, whereby the user can monitor the volume of the first gas in the vessel in real time. The sensor unit may additionally transmit an indication to an electronically controlled connection valve arranged between the vessel and the reservoir with instructions to close the valve when a predetermined volume of the first gas within the vessel has been reached.

[0054] In some examples where the method is used at profound depths (e.g., depths greater than 20m, 50m, 100m or 200m), the method may further comprise depressurizing the water around the pipe assembly, to facilitate inflow of water containing high concentrations of dissolved gas. Such depressurization may be achieved in any suitable way, for example by injecting water at high speed around the inlet of the pipe assembly.

[0055] The water containing the combustion byproducts may be deposited at a suitable depth through a deposition conduit, where it is released into the body of water via a deposition outlet. In some examples, the pump and ejector unit may be configured as vacuum pump where water from the reservoir, via the ejector tube, and / or gas from the return path a flows through a jet nozzle into an internal ejector tube that first narrows and then expands in cross-sectional area. In the narrow region of the ejector tube, the fluid is flowing at a high velocity, resulting in the fluid having low pressure, thus generating a vacuum. The pump and ejector unit in such examples comprises an outer ejector tube, which narrows into a mixing section where the high velocity working fluid mixes with the fluid that is drawn in by the vacuum, imparting enough velocity for it to be ejected. The outer tube then expands in order to decrease the velocity of the ejected stream, allowing the pressure to smoothly increase to the external pressure.

[0056] Such a configuration of the system provides numerous benefits. For example, if the water is not degassed completely, no methane rich water is released in the shallows, i.e., the uppermost layers of the body of water. Thereby, a potentially negative environmental impact is avoided. Furthermore, such a configuration of the system allows for a continuous process, where water may flow continuously through the system, i.e., the pipe assembly, reservoir and pump and ejector unit. Thereby, an increased processing rate is achieved, compared to filling, and emptying, the reservoir after each degassing cycle.

[0057] The pump and ejector unit may, in some examples, contribute to drawing water into the reservoir from the pipe assembly, in other words sucking the water into the reservoir. In examples where a self-priming flow is achieved, such a flow may be accelerated due to the drawing force of the pump and ejector unit. The pump and ejector unit may be configured to be used in combination with any embodiment of the system described herein. For example, the pump and ejector unit may work in tandem with the one or more vacuum pumps employed in some examples of the system The pump and ejector unit may be controlled via the control unit. The actuation of the gas release mechanism, in some examples through rotation of the stirrer blades, and the consequent turbulence, may further contribute to a flow of water within the reservoir toward the ejector tube. The turbulence created by the stirrer blades contributes to drawing water in from the pipe assembly, as well as pushing water toward the ejector tube.

[0058] According to a third aspect of the present invention, there is provided a second system for degassing water. The system comprises a submersible pipe assembly, configured to be deployed into a body of water to a depth exceeding 100 meters, the pipe assembly comprising an inlet at a first end thereof, configured to be opened when the pipe assembly has reached the predetermined depth. The pipe assembly comprises a valve mechanism at the inlet, configured to be shifted from a closed state to an open state when the predetermined depth is reached. The valve mechanism is controllable by a user through a remote control unit and / or configured to automatically shift to the open state when at least one condition is met. Such a condition may include the valve mechanism having reached the predetermined depth and / or a sensor unit indicating that water surrounding the inlet has a suitable concentration of a first gas for degassing. The system further comprises a reservoir, preferably arranged substantially at surface level of the body of water and in fluid connection with the pipe assembly, such that when the valve is in the open state, water and gas from the predetermined depth flows into the reservoir. The system further comprises a gas release mechanism, such as stirrer blades and / or a vacuum pump arrangement, arranged within the reservoir. A control unit detecting a level of a first gas released in the reservoir determines if the gas release mechanism, such as the stirrer blades and / or a vacuum pump arrangement, should be activated to release more of the first gas from the water in the reservoir.

[0059] According to a fourth aspect of the present invention, there is provided a second method for degassing water. The method comprises the steps of submerging a pipe assembly, comprising a valve mechanism at a first end thereof, into a body of water. The valve mechanism is maintained in a closed state while the pipe assembly is submerged. When the pipe assembly has reached a predetermined depth, the method further comprises the step of opening the valve mechanism, allowing an inflow of water into the pipe assembly and to a subsequent reservoir, preferably arranged substantially at water surface level, in fluid communication with the pipe assembly. Thus, when the valve mechanism is shifted to the open state at the predetermined depth, a self-priming fluid flow through the pipe assembly into the reservoir is created. The method further comprises detecting, using a control unit, a level of a first gas in the reservoir. According to a fifth aspect of the present invention, there is provided a third method for degassing water. The method comprises, at a degassing site of a body of water, assembling a degassing system by expanding a reservoir, raising or installing stirrer blades within a body of the reservoir, optionally attaching a coiled pipe assembly to the reservoir, and deploying the coiled pipe assembly into the body of water. The method further comprises monitoring the descent of the pipe assembly into the body of water, such that when a predetermined depth is reached, the method further comprises flowing water into the reservoir.

[0060] The method according to the fifth aspect may optionally comprise using a sensor unit, such as a gas meter, arranged on the pipe assembly to measure if the concentration of a first gas is suitable for extraction and degassing, in the water layer where the inlet of the pipe assembly is located. The method may further comprise detecting, using a control unit, the level of the first gas in the reservoir. If the detected level is less than a predetermined level, the method may comprise actuating stirrer blades to release more of the first gas from the water in the reservoir. The method may further comprise establishing a wireless connection between a piece of user equipment, such as a smart phone, and a control unit associated with, at least, the pipe assembly and the reservoir.

[0061] BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Embodiments of the invention shall now be described in detail by way of example and with reference to the accompanying drawings in which:

[0063] Figure 1 shows a schematic view of a system for degassing water according to some embodiments / examples.

[0064] Figure 2 shows a schematic view of a system for degassing water according to some embodiments / examples.

[0065] Figure 3 shows a schematic view of a system for degassing water according to some embodiments / examples.

[0066] Figure 4 shows a schematic view of a system for degassing water according to some embodiments / examples.

[0067] Figure 5 shows a perspective view of a system for degassing water according to some embodiments / examples.

[0068] Figure 6 shows a perspective view of a pipe assembly according to some embodiments / examples.

[0069] Figure 7 shows a perspective view of a system for degassing water according to some embodiments / examples.

[0070] Figure 8 shows a schematic view of components of a system for degassing water according to some embodiments / examples. Figure 9 shows a schematic view of a method for degassing water according to some embodiments / examples.

[0071] Figure 10 shows a schematic view of a method for degassing water according to some embodiments / examples.

[0072] Figure 11 shows a schematic view of optional sub-steps of the method in Figure 10.

[0073] Figure 12 shows a schematic view of a method for degassing water according to some embodiments / examples.

[0074] Figure 13 shows a schematic view of a method for degassing water according to some embodiments / examples.

[0075] DETAILED DESCRIPTION

[0076] Figure 1 schematically illustrates a system 1 for degassing water, the system comprising: a pipe assembly 2, a reservoir 3, a control unit 4, and a gas processing unit 10.

[0077] The submersible pipe assembly 2 is configured to be deployed into a body of water W, the pipe assembly 2 comprising at least one inlet 21 arranged to allow inflow of water from the body of water W. The reservoir 3 is configured to be arranged at the body of water W and in fluid communication with the pipe assembly 2. Depending on the configuration of the system and the setting in which the system is used, the reservoir 3 may be arranged in the body of water W, such as floating therein or thereon; partially in the body of water W, such that at least a portion of the reservoir is arranged in contact with the body of water W; or arranged adjacent to a body of water, such as on the shore or on any suitable type of floating or hovering vessel or vehicle. The reservoir 3 may also be referred to as a container or water chamber. The reservoir 3 comprises a gas release mechanism 30. The gas release mechanism 30 is configured to create turbulence and thereby release gas G from the water in the reservoir 3. The gas release mechanism 30 may be arranged completely within the body of the reservoir 3, at least partially within the body of the reservoir 3, or in connection with the body of the reservoir 3.

[0078] The control unit 4 is configured to determine a level (e.g. a concentration or partial pressure) LI of a first gas G1 released from the water in the reservoir 3.

[0079] The gas processing unit 10 is arranged at the reservoir, such that it is arranged in connection with the reservoir 3 or arranged at least partially within the reservoir 3. The gas processing unit 10 is configured to process the first gas Gl . The gas processing unit 10 may be any suitable unit capable of processing the first gas Gl in any suitable way. The gas processing unit 10 may either be triggered at a constant frequency or on an ad hoc basis upon detection of a gas flow. Alternatively or additionally, the gas processing unit 10 may be activated manually, or automatically using a timer or similar control means.

[0080] Advantageously, the pipe assembly 2 may be a flexible pipe assembly. In such embodiments, the pipe assembly 2 may be configured to be coiled.

[0081] In some examples, the pipe assembly 2 is resistant to an external hydrostatic pressure of at least 5 Bar. To withstand the external hydrostatic pressure at lower depths, the pipe assembly 2 may be constructed so that it is resistant to an external hydrostatic pressure of at least 10 Bar. The pipe assembly 2 may even be constructed such that it is resistant to at least 15 Bar, 20 Bar, 25 Bar, 30 Bar or more.

[0082] In order to withstand the external hydrostatic pressure, the pipe assembly 2 may be reinforced. Alternatively or additionally, the pipe assembly 2 or components thereof may be manufactured from a high-resistance material. The pipe assembly 2 or components thereof may be manufactured from a polymeric material, such a synthetic rubber material, reinforced with high tensile textile cords. The required tensile strength of the textile cords depends on the situation at hand. The tensile strength may, on average, be 2000 MPa, and may range from 100 MPa to 10 000 MPa. The pipe assembly 2 or components thereof may comprise one or more of a flexible stainless steel interlocking carcass, a seamless polyamide core tubing and / or aramid fibre braid reinforcement.

[0083] Figure 2 schematically illustrates a system 1 for degassing water. The illustrated system comprises the pipe assembly 2, the reservoir 3, the control unit 4, the gas release mechanism 30 and the gas processing unit 10.

[0084] In the illustrated example, the gas release mechanism 30 comprises a vacuum pump arrangement 13. The vacuum pump arrangement 13 may be arranged and configured in any suitable way. The vacuum pump arrangement 13 may be comprised at least partially within the reservoir 3, or it may be separate from but connected to the reservoir 3, such that the vacuum pump arrangement 13 is able to cause turbulence within the reservoir by creating a vacuum. The vacuum pump arrangement 13 may in turn comprise one or more vacuum pumps 13a, 13b. The pump arrangement 13 is scalable and adaptable, such that it is configured to be adapted based on system parameters. In some examples, the flow rate of the first vacuum pump 13a is approximately 15 litres per minute, and the pressure range is from vacuum at - 0.53 bar to 1.2 bar. In some examples, the flow rate of the second vacuum pump 13b is approximately 150 litres per minute, the pressure range is from vacuum at -0.93 bar to 8 bar. As illustrated in Fig. 2, the system 1 may also comprise one or more cylinders 14, or other suitable vessels, for transferring the first gas from the reservoir 3 to the gas processing unit 10 and / or for storing the first gas in the gas processing unit 10. In some examples, the system 1 comprises at least a first cylinder 14a and at least a second cylinder 14b.

[0085] In some embodiments, the first cylinder 14 a may have a pressure range that provides perfect vacuum (-1.0 bar gauge pressure, 0 bar absolute) up to 150 bar, at roughly 5.5 litres. The first cylinder 14a may act as a buffer to mediate the transfer of the degassed first gas, which is advantageously a biogas, into the gas processing unit 10. In order to keep the pressure in the water chamber at -0.5, a vacuum pump, such as one or more pumps of the vacuum pump arrangement 13, may be used. A weak vacuum rate may provide insufficient positive pressure at the output end, and in such circumstances the first cylinder 14a acts together with vacuum pump arrangement 13 to degass the water and transiently hold the first gas, which is suitably a biogas. In examples where the first cylinder 14a acts together with the first vacuum pump 13a, during the normal operation stage, once the pressure reaches Ibar due to the accumulation of the first gas, the second vacuum pump 13b of the vacuum pump arrangement 13 initiates and may transfer the collected first gas to the gas processing unit 10.

[0086] The gas processing unit 10 may comprise the second cylinder 14b. In such examples, the second cylinder 14b may be referred to as a processing chamber. The gas processing unit 10 may comprise additional components, in addition to the second cylinder 14b, or it may consist of the second cylinder 14b. The second cylinder 14b may have a pressure range from perfect vacuum up to 150 bar, and a storage capacity of 5.5 litres (i.e., 45 litres at 8 bar pressure). The second cylinder 14b may also be referred to as a final processing chamber of the gas processing unit 10. In some examples, when cylinder 1 reaches 1 bar, the second vacuum pump 13b, or any other suitable pump of the pump arrangement 13, is initiated and transfers the first gas in the first cylinder 14a to the second cylinder 14b. This process may be repeated until the maximum positive pressure is reached. In some examples, the maximum pressure is 8 bar. In other examples, the maximum pressure may be higher, or it may be lower.

[0087] In some embodiments, the system 1 advantageously comprises a water pump 39, for pumping water into the reservoir 3. The water pump may be used instead of, or in combination with, a natural flow of water into the reservoir resulting from the hydrostatic pressure. Alternatively, or additionally, the system comprises a water outlet pump, which may be configured to work alongside the one or more vacuum pumps to pull water into the reservoir. The water pump 39 may suitably be located at an outlet 32 of reservoir. The water pump 39 may have any suitable flow rate, such as 150 litres per minute or more. The system 1 may comprise a plurality of water pumps 39 to increase the pumping capacity and overall processing rate of the system 1. The pumping capacity of the system may be approximately 270 cubic meters per hour, which may be achieved through fewer pumps with high capacity or a larger number of pumps with lower capacity, preferably arranged as a modular design of the system 1. The modularity of the system facilitates transportation and handling, due to efficient storage as well as the ability to distribute the modules in a rational manner.

[0088] The reservoir 3 in the illustrated example is suitably a pressure-sealed chamber, with a pressure range that creates perfect vacuum up to 10 bar. The reservoir may have any suitable size, such as 16 litres or more. During normal operation, the pressure in the reservoir 3 may around -0.5 bar. The water level is advantageously kept around a midpoint (such as 8 litres in a 16 litre reservoir. Advantageously, the water level may be kept between high (10L) and low levels (6L), which may be around 10 litres and 6 litres, respectively, for a 16 litre vessel. The reservoir is callable and the midpoint, high level and low level are suitably proportional to the reservoir 3 at hand. The water level within the reservoir 3 may be determined by digital water level sensors, such as one or more floating level switches.

[0089] In use, an operator of the system 1 , having arrived at a suitable location, assembles the system 1. Once the system 1 is started, gases are directed through an adaptable flow system and processed depending on their composition. In some examples, the use phases of the system may roughly be defined as having the following main stages:

[0090] • Stage 1 - Setup or priming phase

[0091] • Stage 2 - Water processing, degassing and gas collection phase

[0092] • Stage 3 - Biogas processing phase (i.e., processing of the first gas)

[0093] The aim of the setup and priming phase is to create ideal conditions for the final gas processing. The final gas processing may, for example, result in production of pure biomethane. Hence, in the setup stage, any residual air in the one or more cylinders 13 is removed. Any suitable valve arrangement 60 may be used in the system. Any suitable type of valve may be used in the valve arrangement 60, such as solenoid valves.

[0094] To remove residual air from the second cylinder 14b, the second vacuum pump 13b may be turned on and one or more valves, such as a fourth vacuum valve 64 and a sixth vacuum valve 66, are opened so that the residual air in the second cylinder 14b is transferred to an exhaust port. The fourth and sixth vacuum valves 64, 66, may be any suitable valves, such as solenoid valves. Any valves that do not serve to remove residual air from the second cylinder 13b are suitably closed, such as a first vacuum valve 61 , a second vacuum valve 62, a third vacuum valve 63 and a fifth vacuum valve 65. Once the desired vacuum rate is reached (which may be about -0.8 kPa in some examples), the fourth vacuum valve 64 is closed to keep the vacuum in the second cylinder 14b. At this point, the third vacuum valve 63 is opened to remove residual air in the first cylinder 14a to the exhaust port. Once the first cylinder 14a reaches a predetermined suitable pressure level, such as-0.5 bar, the third vacuum valve 63 is closed to maintain the vacuum in the first cylinder 14a, and the second vacuum pump 13b is turned off, while the first vacuum 13a is turned on to remove any air in the reservoir 3 and release it to the exhaust port of vacuum pump 1 by opening the second vacuum valve 62. At the same time, any suitable inlet port valve may be opened so that the reservoir and pipe assembly are primed (i.e. filled with water) to a desired level. Due to the vacuum created in the water chamber, hydrostatic pressure pushes water into the chamber without the need of any external power. If the water level reaches the high level previously defined (such as 10 litres), before the vacuum level reaches -0.5 bar, the inlet port is temporarily closed. Once the water level is at the high level, and the reservoir 3 is at -0.5 bar, the setup or priming phase (stage 1) may be said to be complete.

[0095] Stage 2 involves processing the water in the reservoir, including degassing, and collecting the first gas released from the water in the reservoir 3. In a standard operating stage of some examples, the first vacuum pump 13a is on at all times. On or more water pumps 39 are turned on and any inlet and outlet water valves are also open as the water is in equilibrium (i.e, the rate of inlet equals the rate of outlet) and the water level stays constant in the reservoir 3. Any suitable valve, preferably the first vacuum valve 61 , is open, so that the first gas released from the water, which may be referred to as degassed biogas, is transferred into the first cylinder 14a. Once a pressure of 1 bar is reached in the first cylinder 14a, the third and fifth vacuum valves 63, 65, are opened so that the second vacuum pump 13b transfers the collected first gas to the gas processing unitlO, which may correspond to the second cylinder 14b, which may in such examples also be referred to as the final processing cylinder. This process is very quick. The first vacuum valve 61 is only transiently closed so that the vacuum rate inside the reservoir 3 is not affected by the second vacuum pump 13b, which is stronger than the first vacuum pump 13a.

[0096] Stage 2 is repeated until a maximum pressure is reached in the gas processing unit 10, or any other criteria is met which indicates that the gas processing unit 10 is ready for processing the biogas. In some examples, stage 2 is repeated until the second cylinder 13b reaches the maximum pressure, which is 8 bar in some examples. When the maximum pressure eis reached, or any other relevant criteria is met, a first cycle (cycle 1) may be said to have reached its end.

[0097] In the stage 3, the first gas is processed. The first gas is suitably a biogas, such as methane. Depending on the composition of the first gas, different options are available for processing. In some examples the first gas is methane, which may also be referred to as biomethane. In such examples, if the methane concentration is above an ignition range, the biomethane is pure enough, and can be either neutralised / oxidised or compressed into cartridges for future use as fuel. Neuralisation may be done automatically or manually by igniting the biomethane through a release valve. Compression of the biomethane may require the compressor 12 and an additional gas cylinder, such as a third cylinder 14c.

[0098] If the methane concentration is low in the biogas composition, such as below 15% (which may, for example, be 85% CO2 and 15% CH4), the biogas is advantageously purified or processed further. Such processing may be performed in any suitable way. In some examples, separation techniques may be used, such as cooling the second cylinder 14b using a strong freezer 15, such as a -86°C freezer 15. Since the second cylinder 14b is already at a high pressure, such as 8 bar, lowering its temperature to -60°C causes a phase change to liquid. Thereby, the CO2 and CH4 are efficiently separated. Lowering the temperature down to -86°C may turn the CO2 into dry ice. At such temperatures and pressures, CH4 remains in the gas phase.

[0099] Any CO2 byproducts may also be compressed for future industrial use using the compressor 12 and an additional gas cylinder, such as a fourth cylinder 14d.

[0100] In some embodiments, the system may comprise one or more gas storage cartridge compressors. Such compressors may have any suitable technical specifications, such as a 30 bar compressor for an 18 litre cartridge. The compressor advantageously requires as little energy as possible, may be designed to be lightweight, and may have as a high a compressing capacity as possible.

[0101] In some examples, in the biogas purification stage, a vacuum / air pump with a capacity of 150 litres per minute may provide 9 m3of biogas per hour, filling 45 litres of biogas in three minutes (assuming 50 % CO2 and 50 % CH4). 45 litres of biogas may be cooled in roughly 10 seconds, using a conventional freezer 15. Using such a system could provide 22.5 litres of dry ice within one minute, with only roughly two to three minutes of filling time. All processes may be controlled electronically using any suitable electronic valves, digital pressure sensors, as well as water level sensors. Programmable multi-channel digital controllers and / or relays may be used to control the processes described herein.

[0102] The system 1 herein may be powered using a portable generator 86 and / or a portable power station 87 and / or a power bank 88. In some examples, the system 1 comprises an integrated engine, which may be powered fully or at least partly by the biogas resulting from the degassing process. In examples where the biogas is methane, the integrated engine is advantageously a combustion engine running on methane gas as its fuel source. Alternatively, or additionally, an electric engine may be incorporated in the system 1.

[0103] Renewable energy sources such as solar power, wind power and geothermal power may also be used in any suitable way by one or more components of the portable power station 87. The portable power station 87 may, in certain circumstances, comprise a small modular nuclear reactor (SMR) and / or any other type of miniature nuclear power station. Any component of the system 1 requiring power may be connected to a separate power source 85, and / or a plurality of components may be connected to the same power source 85. An internal combustion engine may alternatively or additionally be incorporated in the system 1. The system 1 may use some or all of the extracted biomethane as fuel for running the system 1 itself.

[0104] As mentioned above, the system is suitably arranged in modular units, thereby providing a modular biogas processing kit. In some examples, the components of the system 1 are divided into five modular units. The modules are advantageously detachable from each other to facilitate the distribution of weight and space during transportation, storage and handling.

[0105] As discussed above, the system 1 is scalable to fit the circumstances at hand. Materials for the various components may be selected to decrease the weight of the system, while still maintaining functionality. The capacity of the water pump(s) and vacuum pumps may be adjusted depending on the requirements at hand, by increasing the processing rate, for example. Energy efficient components are suitably selected, such that the energy requirements for the system are minimized.

[0106] Figure 3 schematically illustrates a system 1 for degassing water, the system comprising: pipe assembly 2, reservoir 3, control unit 4, and the gas processing unit 10 comprising the ignition and combustion unit 5. The submersible pipe assembly 2 is configured to be deployed into a body of water W, the pipe assembly 2 comprising at least one inlet 21 arranged to allow inflow of water from the body of water W. The reservoir 3, is configured to be arranged in the body of water W and in fluid communication with the pipe assembly 2. The reservoir 3 may also be referred to as a container. The reservoir 3 comprises a plurality of stirrer blades 31 arranged within the reservoir 3. The stirrer blades 31 are configured to create turbulence and thereby release gas G from the water in the reservoir 3.

[0107] In the illustrated example of Fig. 3, the first gas G1 is an ignitable first gas Gl. The control unit 4 is configured to determine a level (e.g. a concentration or partial pressure) LI of an ignitable first gas Gl released from the water in the reservoir 3.

[0108] The at least one ignition and combustion unit 5 is arranged at the reservoir. The ignition and combustion unit 5 is configured to ignite and combust the ignitable first gas Gl. The ignition and combustion unit 5 may be any suitable unit capable of igniting the and combusting the ignitable first gas Gl , such an electrical spark generator. The ignition and combustion unit 5 may either be triggered at a constant frequency or on an ad hoc basis upon detection of a gas flow. When configured as a spark generator, the frequency may be 1 Hz, 0.5 Hz, within the range of 0.2-2 Hz, or arranged to trigger as a predetermined level of the ignitable first gas Gl is detected. The skilled person will readily understand that other frequencies are equally envisioned.

[0109] Figure 4 shows a schematic view of a further example system 1 for degassing water according to some embodiments. The system 1 of Figure 1 again comprises: pipe assembly 2, reservoir 3, control unit 4, and ignition and combustion unit 5.

[0110] As shown in Fig. 4, the reservoir 3 comprises at least one outlet 32. The outlet 32 is configured to restrict or allow a flow of gas G from the reservoir 3. The at least one outlet 32 may be electronically controlled, for example wirelessly via the control unit 4, or manually controlled by a user pressing a button.

[0111] In the illustrated example of Fig. 4, the pipe assembly 2 comprises a sinker device 26, in order to facilitate the deployment of the pipe assembly 2 into the body of water W. The sinker device 26 may be any suitable device that improves the ability of the pipe assembly 2 to be deployed into the body of water W. The sinker device 26 may act to uncoil the pipe assembly 2 and / or to ensure the pipe assembly 2 remains substantially straight when it is deployed into the body of water W. The sinker device 26 may be a metal sink weight, commonly known as a sinker. The weight of the sinker depends on the pipe assembly with which it is used, and is selected to ensure a negative buoyancy of the pipe assembly when deployed into the body of water. Advantageously, the sinker device 26 may be arranged at a first end 21 of the pipe assembly 2. In such an example, the pipe assembly 2 is deployed by lowering the first end 21 of the pipe assembly 2 first into the body of water W.

[0112] In some examples, the pipe assembly 2 comprises a removable filter (not shown) arranged at the inlet 21, to prevent inflow of debris into the pipe assembly 2, as well as for protecting aquatic life.

[0113] The pipe assembly 2 may comprise a sensor arrangement (not shown) arrange at the inlet 21 and configured to sense the depth to which the inlet 21 is deployed. The sensor arrangement may also be configured to detect a concentration of the ignitable first gas in the water around the inlet 21. Such a sensor arrangement is connectable to the control unit, wither through a cable arrangement (not shown) along the pipe assembly 2 or wirelessly.

[0114] In the example of Fig. 4, the system 1 comprises a valve mechanism 6. The valve mechanism 6 may be any suitable valve mechanism. The valve mechanism 6 may be electronically controllable, for example by means of the control unit 4. The valve mechanism may comprise at least one solenoid valve. The valve mechanism 6 is suitably arranged in connection with the pipe assembly 2. Advantageously, the valve mechanism 6 is configured to control the inflow of water from the body of water W into the pipe assembly 2. In Fig. 4, the valve mechanism 6 comprises a first valve 61 and a second valve 62. In other embodiments, the valve mechanism may comprise only one of the first or second valve 61 , 62, arranged in any suitable location. In the example of Fig. 4, the first valve 61 is arranged at the inlet 21 of the pipe assembly 2 and the second valve 62 is arranged at an inlet port 33 of the reservoir 3. The inlet port 33 may be any suitably configured inlet, arranged below a surface of the body of water W when the reservoir is floating in the body of water W. The inlet port 33 may comprise the second valve 62. A hydrostatic pressure on the inlet 21 of the pipe assembly 2 drives a flow of water into the reservoir 3 through the inlet port 33 when the first valve 61 and / or the second valve 62 is open.

[0115] In the illustrated example, the control unit 4 comprises a sensor unit 41 configured to detect the level LI of the ignitable first gas G1 in the reservoir 3. The sensor unit 41 may also be referred to as a gas meter. The ignitable first gas G1 may be any relevant ignitable gas. Advantageously, the ignitable first gas G1 is methane, and the control unit 4 is configured to determine a level of methane released from the water in the reservoir 3 as the level LI of the ignitable first gas Gl.

[0116] The control unit 4 may be configured to continuously monitor the level LI of the ignitable first gas Gl in the reservoir 3. The control unit may use any suitable periodicity or update rate, for example updating every 0.1 , 1 , 5, 10, 15, 30, 45 or 60 seconds. In the example of Fig. 4, the sensor unit 41 may be configured to continuously monitor the level LI of the ignitable first gas Gl in the reservoir 3. Alternatively, the control unit 4 may be activated when a predetermined volume of water has entered the reservoir 3. In such examples, the sensor unit 41 may be activated to detect the level of the ignitable first gas Gl when the predetermined volume of water in the reservoir 3 has been reached.

[0117] The at least one outlet 32 of the reservoir 3 can be configured to be opened in response to the control unit 4 determining the level of the ignitable first gas Gl being within an ignition range L;. The at least one outlet 32 may comprise an electronically controllable valve of any suitable type, configured to be opened in response to a signal from the control unit. The term ignition range, when used herein, refers to concentrations of the ignitable first gas Gl in the reservoir 3 that are within the flammability limits of that gas. In other words, a percentage of gas per volume of air where it is possible to ignite and combust the ignitable first gas using the ignition and combustion unit 5. A lowest value of the ignition range, Lmin, may also be expressed as a lower flammability limit (LFL). A highest value of the ignition range, Lmax, may also be expressed as an upper flammability limit (UFL). In examples where the ignitable first gas Gl is methane, the at least one outlet 32 of the system 1 may be configured to be opened when the control unit 4 has determined that the level LI of methane is within an ignition range L;. At substantially atmospheric pressure, the lowest flammability limit of methane (in air) is approximately 4.4 %vol. and the highest upper flammability limit is approximately 17 %vol. Thus, at atmospheric pressure, the ignition range L; for methane as the ignitable first gas Gl (in air) may extend from 4.4 % to 17 %, where Lminis 4.4 %vol. and Lmaxis 17 %vol. The exact volume percentage may vary depending on the circumstances at hand, for example depending on the temperature of the gas / air mixture in the reservoir 3.

[0118] The ignition and combustion unit 5 is arranged outside of the reservoir 3, such that ignition and combustion of the ignitable first gas Gl occurs on exit from the reservoir 3. The at least one outlet 32 is configured to be opened when the control unit 4 has determined that the level of the ignitable first gas Gl is within an ignition range When the control unit 4 has determined that the level of the ignitable first gas Gl is within an ignition range, a signal may be sent from the control unit to the electronically controlled outlet, triggering an opening of the outlet 32. Alternatively, a user may receive a signal from the control unit indicating the level of the ignitable first gas G1 is within an ignition range, at which point the user may activate an opening of the outlet 32, either by transmitting a wireless signal triggering an opening of the outlet, or manually pressing a button or another type of actuator. The outlet is further configured to be shut after releasing a suitably volume of gas, to prevent a flame from propagating into the reservoir. A fan or impeller 77 together with electronically controlled vents may be arranged to direct the gas mixture from the reservoir 3 for combustion. The pressure drop created by fan / impeller 77 prevents a back-flow of any reaction byproducts, so that such byproducts do not return to the reservoir 3. Optionally, a one-way non-return valve (not shown) may be arranged downstream of the fan / impeller, 77. In some examples, the system 1 comprises an external combustion chamber (not shown), arranged in fluid communication with the outlet 32. In such examples, the ignition and combustion unit 5 is arranged to ignite and combust the ignitable first gas G1 inside the combustion chamber.

[0119] Advantageously, the at least one ignition and combustion unit 5 can be configured to be activated when the at least one outlet 32 is opened. Thereby, the ignitable first gas G1 may be ignited on exit from the reservoir 3. In other examples, the outlet 32 may remain in an open state and the ignition and combustion unit 5 is activated based on the level of the ignitable gas in the gas mixture reaching the outlet 32.

[0120] As schematically illustrated in Fig. 4, the system 1 can be configured to be a wirelessly connected system. In such a wireless system, the control unit 4 is configured to communicate with at least one piece of user equipment 84. The user equipment 84 can be specifically designed for use with the system 1, or any type of user equipment, such as a smart phone or a tablet. In addition to the sensor unit 41, the control unit comprises a processor, 43. The control unit 4 also comprises a transceiver unit 42, configured to transmit signals to and receive signals from, at least, the user equipment 84. The transceiver unit 42 can be configured to transmit signals and to receive signals from more than one piece of user equipment 84, such as from and to a plurality of smartphones, tablets, servers, cloud infrastructure, etc. The system may be controlled and / or monitored through an application installed on the user equipment. A user may monitor several parameters of the degassing system 1 through their user equipment 84. Such parameters may include a level LI of the (ignitable) first gas G1 in the reservoir, the depth at which the inlet 21 of the pipe assembly 2 is located, and the concentration of the ignitable first gas G in the water surrounding the inlet 23 of the pipe assembly 2. The system 1 may also be configured such that the user can continuously monitor a volume of the ignitable first gas G1 that has been combusted. The system 1 may also be configured such that the user may control components of the degassing system 1 through their user equipment 84, via the control unit 4. The user may, for example, control the opening and closing of the valve mechanism 6, the actuation of the stirrer blades 31 and the activation of the ignition and combustion unit 5.

[0121] In some examples, an operator of the system 1 as described in any example herein (and not limited to the system as described in relation to Fig. 4) may use a purpose-created mobile application to identify suitable sites for degassing, such as suitable wetland sites. Upon identification of a site for degassing, and optionally of a proposed assignment for performing degassing at a specified site, the operator may register for or accept the assignment. When the operator arrives at the site with the portable system 1 , in any embodiment described herein, they assemble and use the system 1 at the specified site, and syncs their system with their UE, using NFC or Bluetooth modules, for example. The operator may log in to an account on a platform associated with, or incorporated in, the mobile application. The operator may then perform the degassing at the site, and the results of the degassing is registered in / by the mobile application. The operator may then receive a remuneration in relation to the result of the degassing. The level of remuneration may take various factors into account, such as the volume of first gas removed from the site; the type of gas removed (such as methane); the manner of disposal of the first gas (such as combustion or storing); the accessibility of the site; and the time spent on the degassing process.

[0122] In some examples, the system 1 may comprise buoyancy means (not shown), attached to the reservoir 3. Such buoyancy means may, for example, be floats, attached to one or more outer sides of the reservoir 3, acting to keep the reservoir 3 afloat.

[0123] Figure 5 shows a perspective view of a system 1 for degassing water according to some embodiments / examples. The system 1 comprises: pipe assembly 2, reservoir 3, control unit 4, air inlet 71 , air inlet valve 72, compressor 73, second outlet 74, duct 75, second valve 76 and fan / impeller 77. In Fig. 5, the gas processing unit 10 may comprise the ignition and combustion unit 5. The first gas G1 may be an ignitable first gas Gl .

[0124] The reservoir 3 of the system 1 may be shaped in any suitable way. The reservoir 3 may be any suitable type of receptacle with a body 3a defining a volume that can house at least a predetermined volume of water, air and / or gas, as well as the stirrer blades. The reservoir 3 comprises a bottom surface 37, which may be planar, sloped and / or composed of several sections, which may or may not have the same shape and / or slope. The bottom surface 37 may comprise an aperture comprising the inlet port 22 and configured to be connected to the pipe assembly 2. In some examples, the reservoir 3 may be substantially cylindrical with a substantially circular cross section. In other examples, the reservoir 3 may be block or box shaped. The reservoir 3 comprises sidewalls 36 connected to the bottom surface 37 in an air- and watertight manner. In examples where the reservoir 3 is cylindrical with a circular crosssection, the reservoir 3 may be said to contain one sidewall 36. In the example illustrated in Fig. 5, the reservoir 3 has the shape of a rectangular box, with a quadrilateral cross-section and four sidewalls 36a-d. As shown in Fig. 5, the reservoir 3 comprises a removable lid 35. The removable lid 35 may be placed at the top of the reservoir 3 to form an air- and watertight seal with the at least one sidewall 36 of the reservoir 3. In the example of Fig. 5, the removable lid 35 forms an air- and watertight seal with the sidewalls 36a-d. The removable lid 35 may be foldable. The space enclosed by the bottom surface 37, the at least one outer surface 36 and the lid 35 define the reservoir body 3a.

[0125] In some examples, the reservoir 3 may be collapsible. Additionally or alternatively, the reservoir 3 may be foldable. The reservoir 3 may comprise grooves to facilitate collapsing or folding. The stirrer blades 31 may be jointed, or otherwise arranged to be tilted, folded or collapsed, such that they are collapsible and / or foldable while remaining within the reservoir 3. Alternatively or additionally, the stirrer blades 31 may be detachably arranged within the reservoir 3, such that they can be readily removed before collapsing and / or folding the reservoir 3.

[0126] In the example of Fig. 5, the system 1 comprises an air inlet 71 and an air inlet valve 72, arranged to allow an inflow of air A toward the reservoir 3 and / or to the ignition and combustion unit 5. In examples where the system 1 comprises a return path (such as the return path 92 described below and shown in Fig. 5), the inflow of air may flow in a direction toward the return path and the ignition and combustion unit 5. The air inlet valve 72 may be an electronically controlled valve, optionally connected to the control unit 4. The control unit 4 may control the air inlet valve 72 to open when it has been determined, at the control unit 4, that the level LI of the ignitable first gas G1 exceeds a highest value Lmaxof the ignition range L;. As air A flows toward the ignition and combustion unit, the concentration of oxygen in the gas mixture flowing toward the ignition and combustion unit increases. Thereby, the level LI of the ignitable first gas G1 may be lowered to a value within the ignition range L;. The system 1 exemplified in Fig. 5 also comprises the fan / impeller 77, arranged in fluid connection with the air inlet 71 , such that when the air inlet valve 72 is open, the fan / impeller 77 is arranged to increase the flow of air A from the outside. The system 1 as illustrated in Fig. 5 comprises a second outlet 74 arranged in fluid communication with the reservoir 3. The system 1 also comprises a compressor 73 and at least one duct 75 configured to route the ignitable first gas G1 via the second outlet 74 from the reservoir 3 to the compressor 73. In examples where the ignitable first gas G1 is methane, the at least one duct 75 is configured to route the methane gas via the second outlet 74 from the reservoir 3 to the compressor 73. The second outlet 74 comprises an electronically controlled second valve 76. The system 1 may optionally comprise a second fan / impeller (not shown), arranged in fluid communication with the at least one duct 75. The second valve 76 can be connected to the control unit 4, such that when the control unit 4 has determined that the level LI of the ignitable first gas G1 is less than a lowest value Lminof the ignition range L;, the second valve 76 is opened, thereby allowing the ignitable first gas G1 to be routed through the at least one duct to the compressor 73. In examples where the system also comprises the second fan / impeller, the second fan / impeller can also be connected to the control unit 4, such that when the control unit 4 has determined the level LI of the ignitable first gas G1 being less than a lowest value Lminof the ignition range L;, the second valve 76 is opened and the fan / impeller 77 is activated, thereby increasing the flow of the ignitable first gas G1 through the at least one duct 75 to the compressor 73.

[0127] Figure 6 shows a perspective schematic view of a pipe assembly 2 according to some embodiments / examples.

[0128] The pipe assembly 2 of the system 1 as illustrated in Fig. 6 comprises a plurality of flexible tubes 24. Such a configuration of the pipe assembly may be used instead of or combined with the sinker device 26 (see Fig. 4). The plurality of flexible tubes 24 is configured to restrict an inflow of water into at least a first flexible tube 24a of the plurality of flexible tubes 24 while allowing an inflow of water into at least a second flexible tube 24b of the plurality of flexible tubes 24. In the example of Fig. 6, the flexible tubes 24a-e of the plurality of tubes 24 are arranged substantially in parallel. Although the plurality of tubes 24 may include any suitable number of flexible tubes 24a-e, Fig. 6 shows an example pipe assembly 2 comprising five flexible tubes: a first tube 24a, a second tube 24b, a third tube 24c, a fourth tube 24d and a fifth tube 24e. The second, third, fourth and fifth tubes 24b-e are arranged substantially parallel to, and evenly distributed around, the first flexible tube 24a. Advantageously, the flexible tubes 24a-e are made from a lightweight material.

[0129] Such a configuration of the pipe assembly works to gradually increase a negative buoyancy force on the pipe assembly as it is deployed into the body of water, pulling the pipe assembly downward as water flows into at least one of the flexible tubes while one flexible tube remains closed at the inlet. Thereby, the inlet of the first flexible tube can be opened when the pipe assembly has reached predetermined depth, thereby contributing to the creation of the self-priming fluid flow through the pipe assembly, described above. Such a configuration also ensures the pipe assembly remains substantially straight during deployment. At least the second flexible tube, which takes in water, acts as a weight and pulls the first flexible tube, which does not take in water, down toward the predetermined depth. Thereby, such a configuration provides the effect of a weight attached to the pipe assembly, while keeping the pipe assembly low weight, which is beneficial in transport of the system, thus contributing to making the degassing system disclosed herein portable.

[0130] Figure 7 shows a perspective view of a system 1 for degassing water according to some embodiments / examples.

[0131] In Fig. 7, the system 1 comprises a pump and ejector unit 91 and a conduit serving as a return path 92. The pump and ejector unit 91 may also be referred to as an ejector, a jet pump, a jetejector or a vacuum pump. The system 1 also comprises an ejector tube 93, arranged between the pump and ejector unit 91 and the reservoir 3. The ejector tube 93 enables fluid communication between the pump and ejector unit 91 and the reservoir 3. Combustion byproducts G3 and / or one or more gasses G can be returned to the body of water W through the return path 92 and / or the ejector tube 93, by means of the pump and ejector unit 91. The gas being returned to the body of water W may, for example, include a non-flammable second gas G2. Such a non-flammable second gas G2 may be carbon dioxide. Combustion byproducts G3 may include carbon dioxide and water.

[0132] The water containing the combustion byproducts is deposited (and dissolved) at a suitable depth through the deposition conduit 94, where it is released into the body of water W via a deposition outlet (not shown).

[0133] In some examples, the pump and ejector unit 91 may be configured as vacuum pump (not shown in the figures), where water from the reservoir 3, via the ejector tube 93, and / or gas from the return path 92 flows through a jet nozzle into an internal ejector tube (not shown) that first narrows and then expands in cross-sectional area. The fluid in the region of narrow cross section is flowing at a high velocity, resulting in it having low pressure, thus generating a vacuum. The pump and ejector unit 91 in such examples comprises an outer ejector tube, which narrows into a mixing section where the high velocity working fluid mixes with the fluid that is drawn in by the vacuum, imparting enough velocity for it to be ejected. The outer tube then expands in order to decrease the velocity of the ejected stream, allowing the pressure to smoothly increase to the external pressure.

[0134] Such a configuration of the system provides numerous benefits, in some examples, water may not be degassed completely, and less or no methane rich water is released in the shallows,

[0135] 1.e. the uppermost layers of the body of water W. Thereby, a potentially negative environmental impact is avoided. Furthermore, such a configuration of the system 1 allows for a continuous process, where water may flow continuously through the system 1. Thereby, an increased processing rate is achieved, compared to filling and emptying the reservoir 3 after each degassing cycle. In some examples, gases such as methane and / or carbon dioxide may be intentionally released in the shallows, for environmentally beneficial purposes. For example, release of gases may improve water aeration and prevent toxic algae bloom. In some examples, gases such as carbon dioxide may instead / also be released into the air, instead of deposited into the body of water W.

[0136] The pump and ejector unit 91 may, in some examples, contribute to drawing water into the reservoir 3 from the pipe assembly 2, in other words sucking the water into the reservoir 3. In examples where a self-priming flow is achieved, such a flow may be accelerated due to the drawing force of the pump and ejector unit 91. The pump and ejector unit 91 may be configured to be controlled via the control unit 4.

[0137] The rotation of the stirrer blades 31 , and the consequent turbulence, further contribute to a flow of water within the reservoir 3 toward the ejector tube 35. The turbulence created by the stirrer blades 31 may contribute to drawing water in from the pipe assembly 2, as well as pushing water toward the ejector tube 93.

[0138] Figure 8 shows a schematic view of auxiliary components 8 of the system 1 for degassing water according to some embodiments / examples.

[0139] The auxiliary devices 8 are comprised in, or used in conjunction with, the system 1 disclosed herein. A winch 81, of any suitable design, may advantageously be used for raising the reservoir 3 up from the body of water W and thereby emptying it of the water contained therein. Advantageously, a reel 82 of any suitable type may be used to coil the pipe assembly

[0140] 2, and to release the pipe assembly 2 for deployment or winding it up during retraction from the body of water W. Using the reel 82 for the pipe assembly 2 not only improves deployment and retraction of the pipe assembly, it also provides a compact storage, which also facilitates transportation of the system 1. In order to further improve the ease of transportation of the system 1 , a trolley 83 of any suitable type may be used for transporting some or all of the components of the system 1. The trolley 83 may have connector 83a for connecting and attaching the trolley 83 to a bicycle or a motor vehicle, such as a car.

[0141] A vessel 84, of any appropriate type, is suitably used for storing the first gas Gl, which may be methane. Such a vessel is advantageously configured to be attachable to and readily detachable from the reservoir 3 or compressor 73 (see Fig. 5).

[0142] Figure 9 shows a schematic view of a method 100 for degassing water according to some embodiments / examples. The method 100 is compatible with the system 1 as disclosed in any suitable embodiment herein. Steps may be taken in any suitable order.

[0143] The method 100 comprises the step of deploying slOl a submersible pipe assembly 2 into a body of water W. When deployed, the inlet 21 of the pipe assembly 2 is arranged in fluid communication with the body of water W. Thereby, water may flow into the pipe assembly

[0144] 2 via the inlet 21 , unless the inlet 21 is closed or otherwise restricted.

[0145] The method also comprises the step of arranging si 02 a reservoir 3 at the body of water W. The reservoir 3 may be arranged in the body of water W, such as floating therein or thereon; partially in the body of water W, such that at least a portion of the reservoir is arranged in contact with the body of water W; or arranged adjacent to a body of water, such as on the shore or on any suitable type of floating or hovering vessel or vehicle. Unless already connected to the reservoir 3, the method 100 also comprises a step of connecting sl03 the pipe assembly 2 in fluid communication with the reservoir 3.

[0146] The method further comprises the step of flowing si 04 water from the body of water W into the reservoir 3 through the pipe assembly 2. The flow of water into the reservoir 3 may be discontinued when the reservoir 3 comprises both a volume of water and a volume of air. Alternatively, a constant flow of water through the system can be initiated when the reservoir

[0147] 3 comprises both a suitable volume of water and a suitable volume of air. The relationship between the volume of air and volume of water may vary depending on the circumstances at hand. Optional method steps comprised in the step of flowing si 04 water from the body of water W into the reservoir 3 through the pipe assembly 2 are discussed in more detail below, with reference to Fig. 11. When a suitable volume of water has been introduced into the reservoir 3, leaving a suitable volume of air within the reservoir 3, the step of actuating sl06 the gas release mechanism in the reservoir 3 is performed. Through the actuation of the gas release mechanism, gas G is released from the water in the reservoir 3 into the air contained in the reservoir 3.

[0148] The step of actuating si 06 the gas release mechanism may comprise actuating any suitable gas release mechanism, such as actuating sl061 stirrer blades and / or actuating sl062 a vacuum pump arrangement.

[0149] Thereafter, the method step of determining sl07 a level LI of the first gas G1 in the reservoir 3 is performed. A controller, such as the control unit 4, may suitably be used for determining the level LI of the first gas G1 in the reservoir 3. If the determined level of the first gas in the reservoir is within a predetermined processing range, the method 100 comprises processing si 10 the first gas. Processing the gas may be performed using any suitable processing method, such as purification and / or neutralisation, for example by routing si 101 the first gas G1 to a compressor and / or igniting and combusting the first gas Gl .

[0150] The method 100 may optionally comprise emptying si l l the reservoir 3 and / or retracting si 12 the pipe assembly 2.

[0151] In some examples, the first gas Gl is methane.

[0152] Figure 10 shows a schematic view of a variant of the method 100 for degassing water according to some embodiments / examples. The method 100 is compatible with the system 1 as disclosed in any suitable embodiment herein. Steps may be taken in any suitable order.

[0153] As illustrated in Fig. 10, the method comprises the step of deploying slOl the submersible pipe assembly 2 into the body of water W, as described above.

[0154] The method also comprises the step of arranging si 02 the reservoir 3 at the body of water W, as described above. Unless already connected to the reservoir 3, the method 100 also comprises the step of connecting sl03 the pipe assembly 2 in fluid communication with the reservoir 3.

[0155] The method further comprises the step of flowing si 04 water from the body of water W into the reservoir 3 through the pipe assembly 2, as described above. When a suitable volume of water has been introduced into the reservoir 3, leaving a suitable volume of air within the reservoir 3, the step of actuating sl061 stirrer blades 31 in the reservoir 3 is performed. Through the actuation of the stirrer blades 31 , gas G is released from the water in the reservoir 3 into the air contained in the reservoir 3.

[0156] When the stirrer blades 31 have been actuated, the method step of determining si 07 a level LI of the first gas Gl , which is suitably ignitable, in the reservoir 3 is performed. A controller, such as the control unit 4, may suitably be used for determining the level LI of the ignitable first gas Gl in the reservoir 3. If the determined level LI of the ignitable first gas Gl in the reservoir 3 is within an ignition range L;, the method comprises the step of igniting and combusting si 10 the ignitable first gas GL

[0157] In an example where the level LI of the ignitable first gas Gl is determined to exceed a highest value Lmaxof the ignition range L;, the method 100 may further comprise a step of opening sl08 an air inlet valve 72 arranged at an air inlet 71 of the reservoir to increase a concentration of oxygen O in the gas mixture flowing toward the ignition and combustion unit 5. As the concentration of oxygen increases, the level LI of the ignitable first gas Gl may be lowered to a value within the ignition range L;.

[0158] Alternatively or additionally, in an example where the level LI of the ignitable first gas Gl is determined to be less than a lowest value Lminof the ignition range L;, the method may further comprise a step of routing sl09 the ignitable first gas Gl toward a compressor 73 arranged in fluid communication with the reservoir 3.

[0159] In some examples, the ignitable first gas Gl is methane.

[0160] In some examples, the method 100 may further comprise a step of emptying si l l the reservoir 3 of water.

[0161] In some examples, where the pipe assembly 2 is a flexible pipe assembly 2, the step of deploying slOl the pipe assembly 2 into the body of water W may comprise uncoiling slOl l the pipe assembly 2. The pipe assembly 2 may be uncoiled from a reel, such as the reel 82 described above. Alternatively or additionally, where the pipe assembly 2 is a flexible pipe assembly 2, the method may further comprise a step of retracting si 12 the pipe assembly 2 from the body of water W and optionally coiling it onto the reel 82. In some examples, the method 100 may advantageously comprise an additional step of depositing si 13 combustion byproducts G3 and / or a non-flammable second gas G2 degassed from the water in the reservoir 3 into the body of water W. The non-flammable second gas G2 may be any relevant gas. In some examples, the non-flammable second gas G2 may be carbon dioxide.

[0162] In some examples, the method 100 may advantageously comprise an additional step of extracting and storing si 14 the ignitable first gas Gl , for example methane, in an appropriate vessel, such as the vessel 84 described above and shown in Fig. 6, arranged in fluid connection with the reservoir 3. Such a vessel is suitably detachable from the reservoir 3.

[0163] Figure 11 shows a schematic view of method steps that may be comprised in the step of flowing si 04 water from the body of water W into the reservoir 3 through the pipe assembly 2.

[0164] As illustrated in Fig. 11 , the step of flowing si 04 water from the body of water W into the reservoir 3 through the pipe assembly 2 may comprise opening sl041 at least one of a valve mechanism 6 of the pipe assembly 2 deployed in the body of water W or an inlet port 33 of the reservoir 3.

[0165] In some examples where the system 1 is used at profound depths, the method may further comprise a step of depressurizing si 040 the water around the pipe assembly 2, to facilitate inflow of water containing high concentrations of dissolved gas. Such depressurization may be achieved in any suitable way, for example by injecting water at high speed around the inlet 21 of the pipe assembly 2. The step of depressurizing sl040 the water around the pipe assembly 2 may be initiated prior to the step of opening si 041 the valve mechanism. Alternatively it may be initiated after the step of opening sl041 the valve mechanism. The depressurization may be terminated at any suitable time, when a satisfactory flow of water into the pipe assembly has been reached. Alternatively, the depressurization may be maintained throughout the process of degassing the water.

[0166] The step of flowing water si 04 from the body of water into the reservoir through the pipe assembly optionally comprises determining si 042 if the water in the reservoir has reached a predetermined level LW. In such an example, when the water level LW is determined to be below the predetermined level LW, the flow of water into the reservoir 3 may be allowed to continue. If the water level is instead determined to have reached the predetermined level LW, the method comprises two options, as described below. In embodiments of the system 1 disclosed herein, where the flow into the reservoir 3 is not continuous during the degassing process, the method comprises discontinuing the flow of water into the reservoir when the predetermined level LW has been reached. The flow is suitably discontinued by closing si 043 at least one of the valve mechanism 6 of the pipe assembly or the inlet port 33 of the reservoir 3. In some examples, the predetermined volume of water is within the range of 150 to 600 litres of water, preferably between 200 and 500 litres. In some embodiments of the system 1, the inlet port 33 may correspond to the valve mechanism 6 as a whole, or to one of the valves 61 , 62 of the valve mechanism 6.

[0167] In other embodiments of the system 1 disclosed herein, where the flow of water through the reservoir 3 is continuous, the method comprises activating sl044 an ejector unit, such as the pump and ejector unit 91 discussed above and shown in Fig. 5. The ejector unit draws water out of the reservoir 3 through an ejector tube, such as the ejector tube 93 discussed above and shown in Fig. 5. In order to ensure a constant flow of water through the reservoir 3, the ejector tube draws water from the reservoir 3 at the same rate as the water flows into the reservoir 3 through the pipe assembly 2. Thereby, a constant water level is maintained in the reservoir 3.

[0168] Figure 12 shows a schematic view of a second method 200 for degassing water according to some embodiments / examples. The method 200 is compatible with the system 1 as disclosed in any suitable embodiment herein. Steps may be taken in any suitable order.

[0169] The method 200 comprises the steps of submerging s201 a pipe assembly 2, comprising a valve mechanism 6 at a first end thereof, into a body of water. The valve mechanism 6 is maintained in a closed state while the pipe assembly 2 is submerged. When the pipe assembly has reached a predetermined depth, the method 200 further comprises the step of opening s202 the valve mechanism 6, allowing water to flow into the pipe assembly 2 and to a subsequent reservoir 3, preferably arranged substantially at water surface level, in fluid communication with the pipe assembly 2. Thus, when the valve mechanism 6 is shifted to the open state at the predetermined depth, a self-priming fluid flow through the pipe assembly 2 into the reservoir 3 is created. The method 200 further comprises detecting s203, using a control unit 4, a level of a first gas G1 in the reservoir 3. The first gas G1 may be an ignitable first gas Gl , such as methane. Figure 13 shows a schematic view of a method 300 for assembling the degassing system 1 according to some embodiments / examples. The method 300 is compatible with the system 1 as disclosed in any suitable embodiment herein. Steps may be taken in any suitable order.

[0170] The method illustrated in Fig. 13 comprises, at a degassing site of a body of water W, assembling the degassing system 1 by expanding s301 the reservoir 3. The method may further comprise arranging s302 the stirrer blades 31 within the body 3a of the reservoir 3, for example by raising folded stirrer blades 31 already present within the reservoir body 3a or installing stirrer blades 31 within the reservoir body 3a. In examples where the pipe assembly 2 is not already attached to the reservoir 3, the method 300 comprises the step of attaching s303 the pipe assembly 2 to the reservoir 3.

[0171] The method 300 may further comprise establishing s304 a wireless connection between the user equipment 84, such as a smart phone, and the control unit 4.

[0172] The method 300 further comprises deploying s305 the pipe assembly 2 from a coiled state, for example on a reel 82, into the body of water W and monitoring s306 the descent of the pipe assembly 2 into the body of water W, such that when a predetermined depth is reached, the method comprises flowing s307 water into the reservoir 3. The method 300 may optionally comprise using the sensor unit 41 , which may be a gas meter, arranged on the pipe assembly 2 for measuring s3061 if the concentration of the ignitable first gas in the water layer surrounding the inlet 21 is sufficient.

[0173] The method 300 further comprises detecting s308, using the control unit 4, the level of a first gas G1 in the reservoir 3. If the level is less than a predetermined level, the method 300 comprises degassing s309 the water in the reservoir 3, preferably by actuating the stirrer blades 31 arranged in the reservoir 3, to release more of the first gas G1 from the water in the reservoir 3 into the atmosphere in the reservoir 3. The first gas G1 may be an ignitable first gas Gl , such as methane.

[0174] From reading the present disclosure, other variations and modifications will be apparent to the skilled person. Such variations and modifications may involve equivalent and other features which are already known in the art of systems for degassing water and which may be used instead of, or in addition to, features already described herein.

[0175] Although the appended claims are directed to particular combinations of features, it should be understood that the scope of the disclosure of the present invention also includes any novel feature or any novel combination of features disclosed herein either explicitly or implicitly or any generalisation thereof, whether or not it relates to the same invention as presently claimed in any claim and whether or not it mitigates any or all of the same technical problems as does the present invention.

[0176] Reference may be made herein to the spatial relationships between various components and to the spatial orientation of various aspects of components as the devices are depicted in the attached drawings. However, as will be recognized by those skilled in the art after a complete reading of the present disclosure, the devices, members, apparatuses, etc. described herein may be positioned in any desired orientation. Thus, the use of terms such as “above,” “below,” “upper,” “lower,” or other like terms to describe a spatial relationship between various components or to describe the spatial orientation of aspects of such components should be understood to describe a relative relationship between the components or a spatial orientation of aspects of such components, respectively, as the device described herein may be oriented in any desired direction.

[0177] Features which are described in the context of separate embodiments may also be provided in combination in a single embodiment. Conversely, various features which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination. The applicant hereby gives notice that new claims may be formulated to such features and / or combinations of such features during the prosecution of the present application or of any further application derived therefrom. For the sake of completeness it is also stated that the term "comprising" does not exclude other elements or steps, the term "a" or "an" does not exclude a plurality, a single processor or other unit may fulfil the functions of several means recited in the claims and reference signs in the claims shall not be construed as limiting the scope of the claims.

Claims

CLAIMS1. A system for degassing water comprising: a submersible pipe assembly, configured to be deployed into a body of water, the pipe assembly comprising at least one inlet arranged to allow inflow of water from the body of water; a reservoir in fluid communication with the pipe assembly, the reservoir configured to be arranged at the body of water and arranged to create and / or allow turbulence in a volume of water introduced therein to release a first gas from the water; a control unit, configured to determine a level of the first gas released from the water in the reservoir; and at least one gas processing unit, arranged in connection with the reservoir and configured to process the first gas.

2. The system according to claim 1 , wherein the gas processing unit comprises a storage unit, and optionally a compressor, configured to store the first gas released from the water in the reservoir.

3. The system according to claim 1 or 2, wherein the first gas is an ignitable first gas.

4. The system according to claim 3, wherein the gas processing unit comprises an ignition and combustion unit, configured to ignite and combust the ignitable first gas.

5. The system according to any preceding claim, further comprising a gas release mechanism configured to create the turbulence in the volume of water within the reservoir to release the first gas from the water.

6. The system according to claim 5, wherein the gas release mechanism is configured to create a vacuum within the reservoir to cause turbulence in the volume of water therein.

7. The system according to any preceding claim, wherein the first gas is a biogas, preferably comprising methane.

8. The system according to claim 7, further comprising a biogas purification unit, the biogas purification unit being configured to purify the gas through the use of one or more of: cryogenic separation; absorbent-based catalytic filters; temperature adjustments; pressure adjustments; pressure swing adsorption (PSA) vacuum swing adsorption (VS A); temperature swing adsorption (TSA); and bioreactors.

9. The system according to claim 7 or 8, further comprising a biogas neutralisation unit, preferably a methane neutralisation unit, configured to neutralise the biogas.

10. The system according to claim 9, wherein the neutralisation unit is configured to neutralise the biogas through the use of one or more of: combustion; hydroxyl (OH) radicals exposure; and iron chloride aerosols exposure, preferably iron(III)chloride (FeCH) aerosols exposure.

11. The system according to any preceding claim, wherein the reservoir comprises a plurality of stirrer blades configured to create turbulence and thereby release gas from the water in the reservoir12. The system according to any preceding claim, wherein the pipe assembly is a flexible pipe assembly.

13. The system according to any preceding claim, further comprising at least one outlet, configured to restrict or allow a flow of gas from the reservoir.

14. The system according to claim 4 and any of claims 5 to 13, wherein the ignition and combustion unit is arranged outside of the reservoir, such that ignition and combustion of the ignitable first gas occurs on exit from the reservoir.

15. The system according to claims 13 and 14, wherein the at least one outlet is configured to be opened when the control unit has determined that the level of the ignitable first gas is within an ignition range.

16. The system according to any preceding claim, further comprising a valve mechanism arranged in connection with the pipe assembly, the valve mechanism being configured to control the inflow of water from the body of water into the pipe assembly.

17. The system according to claim 16, wherein the valve mechanism comprises a first valve and / or a second valve, the first valve arranged at the inlet of the pipe assembly and the second valve arranged at an inlet port of the reservoir, the inlet port arranged below a surface of the body of water when the reservoir is floating in the body of water, such that a hydrostatic pressure on the inlet of the pipe assembly drives a flow of water into the reservoir through the inlet port when the first valve and / or the second valve is open.

18. The system according to any preceding claim, wherein the control unit comprises a sensor unit configured to detect the level of the first gas in the reservoir.

19. The system according to any preceding claim, wherein the control unit is configured to determine a level of methane released from the water in the reservoir as the level of the first gas.

20. The system according to any preceding claim, wherein the pipe assembly is resistant to an external hydrostatic pressure of at least 5 Bar, preferably over 10 Bar.

21. The system according to any preceding claim, further comprising an air inlet and an air inlet valve arranged to allow an inflow of air toward the ignition and combustion unit.

22. The system according to any preceding claim, further comprising a second outlet in fluid communication with the reservoir, a compressor and at least one duct configured to route the first gas via the second outlet from the reservoir to the compressor.

23. The system according to any preceding claim, wherein the reservoir is configured to be collapsible.

24. The system according to any preceding claim, wherein the pipe assembly comprises a plurality of flexible tubes, configured to restrict an inflow of water into at least a first flexible tube of the plurality of flexible tubes while allowing an inflow of water into at least a second flexible tube of the plurality of flexible tubes.

25. The system according to any preceding claim, wherein the control unit comprises a transceiver unit, configured to wirelessly transmit signals to, and receive signals from, at least one piece of the user equipment.

26. A method for degassing water, comprising the steps of deploying a submersible pipe assembly into a body of water, such that an inlet of the pipe assembly is arranged in fluid communication with the body of water; arranging a reservoir at the body of water; flowing water from the body of water into the reservoir through the pipe assembly; actuating a gas release mechanism in the reservoir, thereby releasing a first gas from the water in the reservoir; determining a level of the first gas in the reservoir, and if the determined level of the first gas in the reservoir is within a predetermined processing range, processing the first gas.

27. The method according to claim 26, wherein the first gas is processed outside of the reservoir.

28. The method according to claim 26 or 27, wherein the step of actuating the gas release mechanism comprises actuating stirrer blades in the reservoir to release the first gas from the water in the reservoir.

29. The method according to any of claims 26 to 28, wherein the first gas is an ignitable first gas, and if the determined level of the ignitable first gas in the reservoir is within an ignition range, the step of processing the first gas comprises igniting and combusting the first gas.

30. The method according to any of claims 26 to 29, wherein the step of actuating the gas release mechanism comprises actuating a vacuum pump to cause turbulence in thevolume of water in the reservoir and release the first gas from the water in the reservoir.

31. The method according to any of claims 26 to 30, wherein the step of processing the first gas comprises purifying and / or neutralising the first gas.

32. The method according to any of claims 26 to 31 , wherein the first gas is methane.

33. The method according to any of claims 26 to 30, wherein the step of flowing water from the body of water to enter into the reservoir through the pipe assembly comprises opening a valve mechanism of the pipe assembly deployed in the body of water.

34. The method according to claim 29 and any of claims 30 to 33, wherein, if the level of the ignitable first gas is determined to exceed a highest value of the ignition range, the method further comprises a step of opening an air inlet valve arranged at an air inlet of the reservoir to increase a concentration of oxygen in the reservoir, thereby lowering the level of the ignitable first gas to a value within the ignition range.

35. The method according to claim 29 and any of claims 30 to 34, wherein, if the level of the ignitable first gas is determined to be less than a lowest value of the ignition range, the method further comprises a step of routing the ignitable first gas toward a compressor arranged in fluid communication with the reservoir.

36. The method according to any of claims 26 to 35, wherein the step of flowing water from the body of water into the reservoir through the pipe assembly comprises determining if the water in the reservoir has reached a predetermined level, wherein, if the water level is determined to be below the predetermined level, the flow of water into the reservoir is allowed to continue, and if the water level is determined to have reached the predetermined level, either:(i) discontinuing the flow of water into the reservoir, preferably by restricting the flow of water though an inlet port of the reservoir; or(ii) activating an ejector unit, drawing water out of the reservoir through an ejector tube at the same rate as water flows into the reservoir through the pipe assembly, such that a constant water level is maintained in the reservoir.

37. The method according to any of claims 26 to 36, wherein the pipe assembly is a flexible pipe assembly and the step of deploying the pipe assembly into the body of water comprises uncoiling the pipe assembly.

38. The method according to any of claims 26 to 37, wherein the pipe assembly is a flexible pipe assembly and the method further comprises the step of retracting the pipe assembly from the body of water and coiling it onto a reel.

39. The method according to any of claims 26 to 38, the method further comprising depositing, into the body of water, combustion byproducts and / or a non-flammable second gas degassed from the water in the reservoir.

40. The method according to any of claims 26 to 39, the method further comprising depressurizing water at the inlet of the pipe assembly.

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