Lake lagoon cover

Abstract

A cover for a lagoon is provided. The cap includes: an expandable membrane; a plurality of stretchable members coupled to the expandable membrane and configured to compress the expandable membrane; and a plurality of restricting members coupled to the expandable membrane and configured to restrict expansion of the expandable membrane.

Description

[0001] This application is a divisional application of the invention patent application with application date of February 14, 2022, application number 202280014945.1, and invention name “Lagoon Cover”. Technical Field

[0002] The present disclosure relates generally to anaerobic digestion and related processing of gaseous materials, and in particular, to covered anaerobic digestion systems and their installation or operation, and lagoon covers. Background Art

[0003] Anaerobic digestion is a process that can be used to convert a variety of biomass materials into usable gases, such as gases containing primarily methane and carbon dioxide (CO2). Carbon dioxide can be used for a variety of purposes, such as food and industrial processing. Methane may be more valuable than carbon dioxide and can be used as a direct replacement for fossil fuels such as oil and natural gas. When methane is produced by anaerobic digestion of organic matter (i.e., biomass), it is often referred to as biomethane.

[0004] Biomethane can be used as a fuel (e.g., for internal combustion engines or fuel cells) to provide electricity and heat. When biomethane is burned, the exhaust gases typically contain only carbon dioxide and water. In principle, the amount of carbon dioxide released is equal to the amount that would be released if the biomass were naturally decomposed aerobically; therefore, methane produced in this way is actually considered a zero-carbon fuel. Therefore, the production of methane using anaerobic digestion of biomass is seen as an effective way to reduce the amount of carbon dioxide in the atmosphere and help mitigate climate change. Patent application PCT / IB2020 / 054392, entitled "Anaerobic Digester and Mobile Biogas Processing Plant," describes an anaerobic digester and certain gas processing equipment and methods.

[0005] Because anaerobic digestion systems are often located outdoors or otherwise exposed to natural elements (e.g., rain and snow), operation and monitoring of such systems can be difficult.Therefore, there is a need for improved anaerobic digestion systems and methods and related gas treatment. Summary of the invention

[0006] According to a first aspect, a cover for a lagoon is provided. The cover comprises an inflatable membrane. The cover comprises a plurality of stretchable members coupled to the inflatable membrane and configured to compress the inflatable membrane. The cover comprises a plurality of restraining members coupled to the inflatable membrane and configured to restrain expansion of the inflatable membrane.

[0007] In some embodiments, the inflatable membrane comprises a plurality of parts, and each of the plurality of stretchable members is located at a position where two or more of the plurality of parts intersect, and each of the plurality of stretchable members is located at a position where two or more of the plurality of parts intersect, and each of the plurality of limiting members is located at a position where two or more of the plurality of parts intersect. In some embodiments, the plurality of parts form a matrix. In some embodiments, the cover further comprises a skirt surrounding the outer periphery of the inflatable membrane. In some embodiments, the skirt comprises a pressurized tube. In some embodiments, the cover further comprises a gas processing unit configured to process raw biogas from a gas outlet and feed the processed biogas into a gas inlet of the inflatable membrane. In some embodiments, the plurality of stretchable members comprises an elastic material located within the inflatable membrane and connected to the top and bottom surfaces of the interior of the inflatable membrane. In some embodiments, the plurality of stretchable members comprises a spring and a pulley. In some embodiments, the spring comprises a clock spring.

[0008] In some embodiments, the top surface of the exterior of the inflatable membrane has an inclined profile. In some embodiments, the top surface of the exterior of the inflatable membrane has a concave shape. In some embodiments, the elasticity of the plurality of stretchable members is varied so as to define the top surface of the exterior of the inflatable membrane. In some embodiments, the plurality of stretchable members include an elastic material located within the inflatable membrane and connected to the top and bottom surfaces of the interior of the inflatable membrane. In some embodiments, the plurality of restraining members include ropes located within the inflatable membrane and connected to the top and bottom surfaces of the interior of the inflatable membrane. In some embodiments, the ropes of each restraining member are configured to be slack when the inflatable membrane is empty and to be taut when the inflatable membrane is full. In some embodiments, the cover further includes a water collection area and a water outlet for allowing water on the top surface of the exterior of the inflatable membrane to escape. In some embodiments, the inflatable membrane includes one or more of the following: XR-5 geomembrane, Sattler Pro-Tex Polyplan composite material, polypropylene, polyethylene, PEEK, PVC, PTFE, PPS, and ETFE. In some embodiments, the inflatable membrane is capable of expanding in a vertical direction so that the outer perimeter of the inflatable membrane resists expansion.

[0009] According to a second aspect, a system is provided. The system includes a slurry lagoon. The system includes a cover for the slurry lagoon. The cover includes: an inflatable membrane; a plurality of stretchable members coupled to the inflatable membrane and configured to compress the inflatable membrane; and a plurality of restraining members coupled to the inflatable membrane and configured to restrain expansion of the inflatable membrane.

[0010] In some embodiments, the cover for the slurry lagoon is any of the embodiments of the first aspect. In some embodiments, the system further comprises a skirt surrounding the periphery of the inflatable membrane, wherein the skirt is located within the slurry lagoon and is configured to remain submerged in the slurry in the slurry lagoon. In some embodiments, the skirt is weighted so that it remains submerged in the slurry lagoon. In some embodiments, there is a gap between the edge of the slurry lagoon and the skirt, and the liquid within the gap seals the slurry lagoon to prevent gas leakage. In some embodiments, the system further comprises a water collection area and a water outlet for allowing water on the top surface of the exterior of the inflatable membrane to escape.

[0011] In some embodiments, the system further comprises a pipeline coupled to the water outlet so that the escaping water can pass through the pipeline by gravity. In some embodiments, the system further comprises a pump and a pipeline coupled to the water outlet so that the escaping water can pass through the pipeline by pumping. In some embodiments, the system further comprises a gas processing unit configured to process raw biogas from a gas outlet coupled to the slurry lagoon and feed the processed biogas into a gas inlet of the expandable membrane. In some embodiments, the system further comprises one or more of: (i) a gas processing system, (ii) a mobile processing system, (iii) a thermal management system, (iv) a water collection and reuse system, and (v) an energy recovery system, each as described herein.

[0012] According to a third aspect, a method of retrofitting an uncovered slurry lagoon with a cover is provided. The method comprises installing a cover on the uncovered slurry lagoon. The cover is any one of the embodiments of the first aspect.

[0013] Other features and characteristics of the subject matter of the present disclosure, as well as the method of operation, the functionality of the related elements and combinations of parts of the structure, and the economy of manufacture will become more apparent upon consideration of the following description and appended claims with reference to the accompanying drawings, all of which form a part hereof, wherein like reference numerals represent corresponding parts in the various figures thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The accompanying drawings, which are incorporated herein and form a part of the specification, illustrate various embodiments of the subject matter of the present disclosure. In the drawings, like reference numerals indicate identical or functionally similar elements.

[0015] Figure 1A and Figure 1B An anaerobic digestion system according to some embodiments is shown.

[0016] Figure 2A Aspects of an anaerobic digestion system according to some embodiments are shown.

[0017] Figure 2BAspects of an anaerobic digestion system according to some embodiments are shown.

[0018] Figure 3 A thermal management system according to some embodiments is shown.

[0019] Figure 4A An energy storage and recovery system according to some embodiments is shown.

[0020] Figure 4B is a flow chart of a method for energy recovery according to some embodiments.

[0021] Figure 5A A block diagram of an apparatus according to some embodiments is shown.

[0022] Figure 5B Aspects of an anaerobic digestion system according to some embodiments are shown.

[0023] Fig. 6A and Figure 6B A cover for an anaerobic digester is shown, according to some embodiments.

[0024] Figure 7 A lagoon is shown having one or more elements for mixing and / or heating the slurry.

[0025] Figure 8 is a flow chart of a method of operating and / or assembling an anaerobic digestion system according to some embodiments.

[0026] Fig. 9 An exemplary biogas separation and methane liquefier is shown in accordance with some embodiments. Fig. 9A An exemplary CO 2 removal unit (eg, cold box) is shown according to some embodiments. Fig. 9B An exemplary liquefaction cell (eg, a Joule-Thompson cell) is shown in accordance with some embodiments. Fig. 9C An exemplary combined CO2 removal and liquefaction unit is shown according to some embodiments.

[0027] Fig. 10A and Fig. 10B A slurry lagoon is shown without a cover.

[0028] Fig.11 A covered slurry lagoon system is shown according to an embodiment.

[0029] Fig.12 A covered slurry lagoon system is shown according to an embodiment.

[0030] Fig.13 A covered slurry lagoon system is shown according to an embodiment.

[0031] Fig.14A rigid body according to an embodiment is shown.

[0032] Fig.15 A covered slurry lagoon system is shown according to an embodiment.

[0033] Fig.16 A covered slurry lagoon system is shown according to an embodiment.

[0034] Fig.17 A covered slurry lagoon system is shown according to an embodiment.

[0035] Fig.18 A covered slurry lagoon system is shown according to an embodiment.

[0036] Fig.19 A covered slurry lagoon system is shown according to an embodiment.

[0037] Fig. 20 A cover according to an embodiment is shown.

[0038] Fig.21A and Fig.21B A clock spring with a rotating pulley system is shown according to an embodiment. DETAILED DESCRIPTION

[0039] Although various aspects of the subject matter of the present disclosure can be embodied in a variety of forms, the following description and drawings are intended only to disclose some of these forms as specific examples of the subject matter. Therefore, the subject matter of the present disclosure is not intended to be limited to the forms or embodiments described and shown in this manner.

[0040] Unless otherwise defined, all technical terms, symbols and other technical terms or expressions used herein have the same meaning as those generally understood by those of ordinary skill in the art to which the present disclosure belongs. All patents, applications, published applications and other publications mentioned herein are incorporated by reference in their entirety. If the definition set forth in this section is contrary to or inconsistent with the definition set forth in the patents, applications, published applications and other publications incorporated by reference herein, the definition set forth in this section takes precedence over the definition incorporated by reference herein.

[0041] As used herein, "a" or "an" means "at least one" or "one or more", unless stated otherwise or implicit from the context.

[0042] The present description may use relative spatial and / or orientation terms to describe the position and / or orientation of a component, device, position, feature, or portion thereof. Unless specifically stated or otherwise dictated by the context of the specification, terms including, but not limited to, top, bottom, above, below, below, top, upper, lower, left, right, front, "behind," "beside," "adjacent," "between," "horizontal," "vertical," "diagonal," "longitudinal," "lateral," "radial," "axial," and the like are used for convenience in referring to such components, devices, positions, features, or portions thereof in the accompanying drawings and are not intended to be limiting.

[0043] Furthermore, unless otherwise stated, any specific dimensions mentioned in this specification merely represent exemplary embodiments of devices embodying aspects of the present disclosure and are not intended to be limiting.

[0044] As used herein, the term "adjacent" refers to being close to or adjacent to each other. Adjacent objects may be spaced apart from each other, or may be in actual or direct contact with each other. In some cases, adjacent objects may be coupled to each other or may be integrally formed with each other.

[0045] As used herein, the terms "substantially" and "essentially" refer to a considerable degree or extent. When used in connection with, for example, an event, circumstance, characteristic, or attribute, these terms may refer to instances where the event, circumstance, characteristic, or attribute occurs precisely, as well as instances where the event, circumstance, characteristic, or attribute occurs nearly approximately, for example taking into account typical tolerance levels or variability of the embodiments described herein.

[0046] Anaerobic digestion is a process that can be used to convert a variety of biomass materials into primarily methane and carbon dioxide gases. Carbon dioxide (CO2) can be used for a variety of purposes, such as food and industrial processing. Methane is generally more valuable than carbon dioxide and can be used as a direct replacement for fossil fuels such as oil and natural gas. When methane is produced by anaerobic digestion of organic matter (i.e. biomass), it is often referred to as biomethane.

[0047] Biomethane can be used as a fuel (e.g., for internal combustion engines or fuel cells) to provide electricity and heat. When biomethane is burned, the exhaust contains only carbon dioxide and water. In principle, the amount of carbon dioxide released is equal to the amount that can be released when biomass decomposes aerobically naturally; therefore, methane produced in this way is actually considered a zero-carbon fuel. Therefore, the production of methane using anaerobic digestion of biomass is seen as an effective way to reduce the amount of carbon dioxide in the atmosphere and help mitigate climate change. The present disclosure describes an anaerobic digester based on the disclosures of patent applications US63 / 052,190 and PCT / IB2021 / 056375 entitled "Systems and Methods for Anaerobic Digestion".

[0048] Many types of biomass can be digested anaerobically. To achieve the most beneficial impact on climate change, it may be most effective to use anaerobic digestion to limit or eliminate "fugitive" emissions of methane (e.g., methane currently produced due to poor management of animal waste such as cattle and pig manure in open lagoons). The use of open slurry lagoons in the agricultural sector can result in very high levels of fugitive methane emissions. By sealing the slurry lagoons to prevent aerobic digestion, methane can be controlled. This practice can be advantageous for the purpose of limiting or eliminating "fugitive" emissions of methane, and in the embodiments disclosed herein can also provide considerable operational benefits.

[0049] Such benefits can include, for example, reduced nitrogen losses, because nitrogen is contained in the digestate (i.e., the material remaining after anaerobic digestion of biomass), which in turn can reduce the need for fertilizer when the digestate is spread back on the land. Benefits also include, for example, reduced handling and management of slurry, because rainwater can be prevented from entering the covered lagoon, which means that the digestate is more concentrated and less diffuse. For example, benefits also include reduced risk of overflow, because rainwater can be prevented from entering the covered lagoon, thereby minimizing the possibility of raw slurry leaking into waterways (which may be illegal in many countries). Benefits also include, for example, reduced greenhouse gases, because biomass (such as waste or spoiled animal feed) is typically managed through aerobic composting, and the energy saved therein is lost as heat in the process, and large amounts of methane and nitrous oxide may be produced, both of which are powerful greenhouse gases. However, such greenhouse gases can be reduced by using sealed slurry lagoons, such as provided by the embodiments disclosed herein. Benefits also include, for example, reduced energy requirements, as the methane produced by anaerobism can be used as fuel for generators, for example, to produce electricity and heat that can be used on the farm, thereby offsetting its electricity and energy use.

[0050] While the installation costs of covered slurry lagoons remain low, the above benefits can provide a reasonable return on investment for small and medium-sized farms compared to open slurry lagoons.

[0051] However, because anaerobic digestion systems are often located outdoors or otherwise exposed to the natural elements (e.g., rain and snow), operation and monitoring of such systems can be difficult. Thus, there remains a need for improved anaerobic digestion systems and methods.

[0052] According to embodiments, covers for lagoons and systems having slurry lagoons and covers for slurry lagoons are provided. These can have a variety of benefits. Embodiments can advantageously control the amount of rainwater entering the lagoon, thereby minimizing the size of the lagoon required for application. Embodiments can advantageously include an edge sealing system that allows monitoring and / or detection of leaks in one or more seals when filling with water. Embodiments can advantageously include an edge sealing system that directs rainwater into a storage system so that the collected rainwater can be used for various farm tasks. Embodiments can advantageously include an edge sealing system that minimizes contact between metal parts of a covered lagoon and biogas produced or stored therein, thereby reducing the possibility of corrosion.

[0053] Other benefits include that in some embodiments, the cover can capture 80-95% of fugitive methane, depending on lagoon shape and final conditions. Embodiments can also reduce stormwater loads, retrofit any open slurry lagoon or pond (even a haystack), are inexpensive, stable in high winds, can store large amounts of clean biogas, can reduce slurry volume for unloading and spreading, and utilize existing slurry disposal. Embodiments can be long-lasting (e.g., 20-year expected life for XR5 geomembrane or similar materials), can be recycled as a capital project, making financing easier to obtain, and can allow farmers to make a living from fugitive methane, allowing farmers to invest in complete equipment or slurry storage improvements.

[0054] According to embodiments, many types of materials can be digested, including anaerobic digestion of biomass. In order to achieve the most beneficial impact in terms of climate change, it may be most effective to use anaerobic digestion to limit or eliminate "fugitive" emissions of methane (such as methane currently produced due to poor management of animal waste such as cattle and pig manure in open lagoons). Specifically, the use of open slurry lagoons in the agricultural sector may result in very high levels of fugitive methane emissions. By sealing the slurry lagoons to prevent aerobic digestion, methane can be controlled. This practice can be beneficial for the purpose of limiting or eliminating "fugitive" emissions of methane, and in the embodiments disclosed herein can also provide considerable operational benefits. These benefits may include reduced nitrogen losses, where nitrogen is contained in the digestion residue (i.e., the material remaining after anaerobic digestion of biomass), which in turn can reduce the need for fertilizer when the digestion residue is spread back on the land. Another benefit may include reduced disposal and management of slurry. This is because rainwater is prevented from entering the covered lagoons, which means that the digestion residue is more concentrated and less diffuse. Another benefit is that the risk of overflow can be reduced because rainwater can be prevented from entering the covered lagoon, thereby minimizing the possibility of raw slurry leaking into waterways. Another benefit may include reduced greenhouse gas emissions. When biomass (such as waste or spoiled animal feed) is aerobically composted and managed in an uncontrolled manner, the energy saved therein is lost in the form of heat in the process, and large amounts of methane and nitrous oxide may be produced, both of which are powerful greenhouse gases. However, by using sealed slurry lagoons, such as provided by the embodiments disclosed herein, such greenhouse gases can be reduced. Another benefit may be reduced energy demand. This is because the methane produced by anaerobically can be used as fuel for generators, such as to produce electricity and heat that can be used on the farm, thereby offsetting its use of electricity and energy. For example, while the installation cost of a covered slurry lagoon remains low, the above advantages can provide a reasonable return on investment for small and medium-sized farms compared to open slurry lagoons.

[0055] Excess methane from one or more embodiments may be used to generate electricity which may then be injected into the grid, or may alternatively be processed and upgraded for injection into the mains gas grid.

[0056] An abundant source of biomass is grass clippings, such as on managed land including gardens, sports fields, roadsides and golf courses. Currently, grass clippings are either left where they fall or collected and composted. Either way, this is done aerobically, with the resultant methane production potential being lost in the form of waste heat. In addition, much of the Northern Hemisphere is covered with large tracts of unmanaged or underutilized grassland that could be used to produce biomethane. However, as is the case with small, remote farms, it is difficult to realize the true value of the methane produced by this process, for example due to the remote location of managed or unmanaged grasslands, or the lack of electricity or gas grid infrastructure. The financial and environmental value of this abundant form of renewable and zero-carbon energy cannot be realized economically, rendering it practically land-constrained. Embodiments may address one or more of these issues.

[0057] Reference now Figure 1A, shows an anaerobic digestion system 100 according to some embodiments. The system 100 can use, for example, a biomass storage container 101. This can be, for example, a covered lagoon device with a lagoon, with a biomass storage device 102 in the container. A gas cover 104 is also used, which can be a membrane. The lagoon can be built in the ground 112a, with an original ground level 112b. Although the underground lagoon is used as an example, other containers can also be used to store biomass for digestion, including above-ground lagoons or other containment structures. The digestion of biomass in the container produces gas, which is captured by the cover 104. In addition, according to some embodiments, a slurry membrane (or separation liner) 106 can be used to separate the slurry area from the gas area and the cover 104, thereby forming a buffer zone 116 between the cover 104 and the biomass storage device 102. In some embodiments, the gas cover 104 and the slurry separation liner 106 are impermeable to both the slurry and the generated gas. In this regard, the gas buffer 116 can be utilized by other system elements, such as the energy storage and recovery system 126. In some embodiments, the slurry separation liner or one or more additional membranes 138 can be semi-permeable for selective passage of one or more materials (e.g., selective passage of methane or CO2). In an embodiment, the region 116 can be above, below, or on both sides of the membrane 138, for example, depending on the permeability of the membrane 138. The membrane 138 can be optional in an embodiment. In some aspects, the container 101 (e.g., a lagoon) may also include a liner 114 that separates the biomass from the ground in which the lagoon is installed. According to some embodiments, one or more weights 108, 110 can be used on the surface of one or more membranes (e.g., a cover 104 or a separation liner 106). Such a weight not only fixes the membrane in place, thereby reducing fatigue and unnecessary movement, but can also be configured to perform one or more additional functions, such as thermal management or liquid level sensing. According to an embodiment, thermal insulation can be utilized. For example, the cover 104 can provide thermal insulation.

[0058] In some aspects, the digester is a biogas storage container with a semipermeable membrane, which divides the biogas storage area into a first space and a second space, so that the first space is configured to be rich in methane and the second space is configured to be rich in CO2. In some embodiments, the first space and the second space can be, for example, located on either side of the membrane 138. In some embodiments, the semipermeable membrane comprises a stretched polytetrafluoroethylene-based material or silicone. In some embodiments, the cover positioned above the container is transparent and is configured to provide passive solar heating (for example, to the slurry). The cover can be made of a variety of materials. In the example, the material is strong, chemically inert and not damaged by ultraviolet rays, such as ethylene tetrafluoroethylene (ETFE), but other materials may also be suitable. Although a single semipermeable membrane 138 is shown, multiple membranes (for example, 2, 3, 4, 5, etc.) can be used in some embodiments to produce more than two gas spaces. For example, there can be additional membranes, and the first and second membranes divide the container into three spaces-the first space, the second space and the third space, and the third space will contain purer methane than the first space. One or more spaces formed by a membrane (e.g., membrane 138) in digester 100 can be used as a receiving or extraction space, for example when used as a buffer for an energy recovery and storage system. In some embodiments, it is the uppermost space (or any space containing the cleanest biogas). In some embodiments, a gas processing (e.g., cleaning) system can draw from one or more spaces.

[0059] In some aspects, digestion system 100 may also include an input end for receiving biomass (e.g., slurry) into a biomass storage container. In addition, anaerobic digester 100 may include an output valve that is connected to the second space and the first space respectively. That is, the biogas in the biogas storage area (e.g., in buffer 116) of digester 100 may be connected to one or more output valves without removing the pipeline or hose. Such pipeline and hose may be connected to one or more other systems described herein, including systems for gas treatment, energy storage, and energy recovery. In an embodiment, the rest of the second space and biomass storage container may be coextensive. That is, in some embodiments, there may be no physical separation between biomass storage and each gas zone.

[0060] According to some embodiments, one or more of the gas cover 104, the separator liner 106, any membrane 138, and the lagoon liner 114 are held in place by a support element 118. The support 118 can be mounted to, for example, a mounting post 120 in the ground 112b. The support 118 can be a portion of a beam. In some aspects, the support 118 shown in Figures 1 and 2 is a cross-section of a beam. The use of the support 118 or beam (e.g., similar to steel Z-shaped purlins used in construction) can be used to form a water collection area 122, where water (e.g., rain or snow) from the cover 104 is collected. According to an embodiment, the support 118 (e.g., a beam portion) has at least one 90-degree angle or approximately 90-degree angle surface, so that it provides a mounting surface for one or more L-shaped clamps. The support 118 (e.g., a beam portion) can be L-shaped. In some aspects, the angled beam can form a gutter along the outer ring of the lagoon. That is, it can be a gutter ring beam. The collected water can then be reused by one or more systems, such as a combination of Figure 2A as described. In addition, by preventing water from reaching the biomass storage device, the necessary size of the lagoon can be minimized by eliminating dilution of the slurry (e.g., storage device 102). This also helps prevent excessive rainwater from causing unnecessary overflow of the slurry. The collection of water in area 122 may have the additional benefit of covering one or more gas seals, such as seals at the connection of cover 104, slurry membrane 106, and / or liner 114. When filled with water, collection area 122 allows monitoring and detection of leaks in the seal. For example, if gas escapes the seal, it will form bubbles in water collection area 122, which can be detected visually or audibly.

[0061] In some respects, the lagoon cover 104 eliminates the need for additional capacity to handle and store rainfall over the lagoon. Rainfall over an open lagoon dilutes its contents - the additional volume must be accommodated in a lagoon of larger size.

[0062] Depending on the embodiment, the system 100 may include one or more additional subsystems. This may include, for example, thermal management 124, energy storage and recovery 126, gas processing 128, and slurry mixing 130. The gas processing 128 may include, for example, extracting gas from the biomass storage area 102 to a gas buffer 116 below the cover 104. This may be, for example, Figure 2A and Figure 2B, where acid gas is extracted from the slurry storage area 102 via a pipeline (e.g., 231), processed, and moved to the buffer 116 as refined biogas (e.g., 232). For example, the pipeline (or other extraction device) may be located between the lagoon liner 114 and the slurry cover 106. In some embodiments, the gas processing may also include cleaning or compressing the extracted gas. This may include, for example, removing hydrogen sulfide (e.g., hydrogen sulfide produced in small amounts as part of an anaerobic digestion process) by filtering, cooling or heating the gas, and extracting CO2 in liquid or solid form. Depending on the embodiment, thermal management 124, energy storage and recovery 126, and gas processing 128 may be part of the same unit or subsystem, or provided separately. With respect to thermal management 124, in some embodiments, water-filled weighted tubes on the membrane (e.g., cover 104 or slurry liner 106) can be connected as a water circulation system and used to direct solar hot water downward into the slurry area (e.g., a slurry membrane bean gravel thermal reservoir) to increase the temperature (and thereby increase the rate) of the anaerobic digestion process, or to be filled with hot water to prevent ice and snow from accumulating in the membrane folds (e.g., cover 104).

[0063] For the slurry mixing set 130, an embodiment may include an input / output conduit 132a; one or more mixing conduits 132b and 132c; and one or more angled mixing elements 134. According to an embodiment, the mixing element 134 is angled relative to the bottom of the lagoon and may have an angle that matches the angle of the side of the lagoon in the slurry area 102. In some aspects, the mixing set 130 may implement a thermal management system or be part of a thermal management system. In some embodiments, the mixing set 130 includes one or more sensors for monitoring the temperature or pH of the slurry. For example, the slurry may flow through one or more such sensors, such as sensors mounted within the housing of the set 130 or within a mixing conduit. Such information can be used to control the entire system 100.

[0064] Reference now Figure 1B, according to some embodiments, an alternative illustration of an anaerobic digestion system 100 is provided that includes a resource-neutral cofferdam lagoon 166 extending above and below the original ground level. For example, the lagoon is dug into the natural soil, and the material inside is piled up so that the sides are tapered. An advantage of this arrangement is that there is no need to remove soil from the site. In this regard, the biomass container (e.g., container 101) can be partially or completely formed of dirt (including natural soil). In some aspects, the inclined slide can be insulated to improve the performance of the slurry lagoon, and in addition, the lagoon itself can be lined with an impermeable membrane. This insulation can be provided by a coating (e.g., on a mounting column or lagoon sidewall), a lagoon liner, or both. In addition to potential thermal management, additional layers (e.g., adjacent to the lagoon liner) can further protect the lagoon liner from the impact of materials in the soil. In some embodiments, the slurry 162 in the pit is covered by a slurry separation liner 106, which keeps it separated from the gas area 116 on the top of the pit. In this example, the gas membrane or cover 104 and the slurry separation liner form a gas buffer 116. In addition, the gas membrane and the slurry separation liner can be provided with water or gravel filled tubes, which serve as counterweights (e.g., 108, 110). One or more gas and / or heat treatment elements are shown to be located on both sides of the lagoon. In some embodiments, the equipment room (e.g., equipment 130) houses one or more systems for stirring the slurry in the lagoon below the separation liner, such as using input / output pipes 132a and one or more stirring elements 134. In an embodiment, the stirring element 134 includes a pressurized nozzle.

[0065] Reference now Figure 2A , various aspects of a water and gas management subsystem 200 of an anaerobic digestion system (e.g., system 100) are shown according to some embodiments. For example, certain water management aspects of system 100 are shown, as well as one or more connections for components and / or gas handling. Figure 2A As shown, water (e.g., rain or snow) can be collected in a water collection area (e.g., Figure 1A In some aspects, the water in the collection area 122 covers one or more gas seals used to assemble the lagoon. This can include, for example, seals of the cover 104, the slurry cover membrane 106, and the lagoon liner 114. In some embodiments, all gas seals are covered by the collection area 122. In this regard, the water itself can be used as a monitoring device. For example, if there are any leaks in the gas seals, bubbles may be seen or heard. For example, one or more microphones mounted in the water collection area can be used to detect bubbles.

[0066] like Figure 2AAs shown, in some embodiments, mounting posts 120 are used. For example, posts 120 may be sunk into an embankment adjacent to the lagoon to provide support for components above the lagoon, including one or more mounting surfaces. Posts 120 may be formed, for example, from galvanized steel. In some embodiments, posts 120 may include a cladding 206, for example, for thermal management. With respect to installation, a hole may be dug for each post 120. In this example, the hole is cleaned out and the base is compacted. Each hole then has a reference pin driven into the center of the bottom of the pit to a set level. Concrete is poured and flattened to "flush" with the tops of the pins, forming a concrete pit base on which the posts stand while the ring beams are erected and aligned to ensure alignment. When the ring beams are properly positioned, a small amount of concrete is poured around the base of each post to secure it in place (e.g., as Figure 2B As the concrete perimeter path is poured, the remainder of the column pocket is filled and the concrete then encases the column and tie rods within the bottom lip of the trench ring beam.

[0067] like Figure 2A As further shown, and in accordance with some embodiments, the water management aspects of the system 100 may also include a secondary water system 212. Water collected in the collection area 122 may be transferred to the secondary system, which may include a storage tank, a wash station, a livestock watering system, an irrigation system, etc. The transferred water from the covered lagoon stormwater disposal system should be clean and therefore may be stored and used for a variety of purposes, such as parlor flushing, livestock drinking water, irrigation, etc. The water may be provided to the secondary system / storage device 212 using one or more pipes, hoses, and pumps. Additionally, gravity may be used to move water from the lagoon area to the secondary system 212. In accordance with some embodiments, the material used for the cover 104 is safe for use with potable water.

[0068] According to an embodiment, a membrane clamp strip 210 may be used to connect an edge portion of the liner 114 (or any other membrane) to an upper edge of the bracket 118. Additionally, an outer membrane clamp 202 and an inner membrane clamp 204 may be used to secure one or more of the gas cap 104, the separator liner 106, and the lagoon liner 104 to the mounting post 120. The clamp may have, for example, an "L" shape. In some embodiments, the shape of the clamp (alone or in combination) matches the shape of the water collection area. In some embodiments, one or more gaskets 208 (e.g., PVC closed cell foam gaskets) may be used to improve the seal. Figure 2A The arrangement 200 can advantageously: (1) cover all gas seals with water; and (2) prevent biogas from contacting one or more vulnerable parts, such as steel components of the anaerobic digestion system 100. For example, exposure to biogas may corrode steel components. According to an embodiment, the mounting post 120 may include one or more nuts (e.g., captive m10 rivet nuts) as mounting points for the trench ring beam.

[0069] According to an embodiment, acid gas may be extracted 231 (eg, from a slurry area), processed by system 128 , and returned to a gas storage area as refined gas 232 .

[0070] Reference now Figure 2B , an alternative illustration 250 of various aspects of an anaerobic digestion system 100 is provided according to some embodiments, including one or more of the connection of components, water management, and gas handling. According to some embodiments, the sealing of the top cover keeps all metal parts away from biogas. For example, sealing the top cover within the artificial trench around the lagoon can keep corrosive gases in the slurry pit away from metal parts, thereby potentially extending the service life of the lagoon and reducing necessary maintenance. Although the acid situation is shown as being extracted from the area below the separation liner 106, in some embodiments, it can be extracted from other areas, such as the area below one or more membranes 138. The location of the extraction pipeline (or other equipment, including one or more valves) can be arranged to accommodate extraction from any gas area. In some embodiments, the gas can be extracted, filtered or otherwise purified and returned to another gas area of ​​the digester. In some embodiments, the gas (e.g., refined gas) can be extracted and supplied to a processing system for liquefaction, storage, etc.

[0071] Reference now Figure 3 , aspects of a thermal management system (e.g., system 124 of anaerobic digestion system 100) are shown according to some embodiments. In some embodiments, the system can be used to melt snow / ice on the surface of a lagoon cover by circulating hot water or water in heat exchange with the lagoon. In some embodiments, such as on hot or sunny days, water can be circulated on the cover and then used to heat the lagoon, thereby increasing biogas production.

[0072] In an embodiment, the system 124 can be used as a heating system (e.g., a closed loop heating system) in which solar-heated water from the gas cap 104 (e.g., through a weighted tube, such as weight 108) can be circulated to the slurry or through the slurry, such as the slurry membrane 106 (e.g., through a weighted tube, such as weight 110) to heat the biomass storage device 102 of the lagoon. Similarly, hot water from the system process (e.g., anaerobic digestion in the lagoon) can be circulated to / or through the gas cap (e.g., through a weighted tube) to prevent the accumulation of snow or ice, which may damage the system 100. In this regard, the system 124 can include one or more ice / snow defrost loops 302 and slurry heating loops 304. These loops can be internal or external to the housing of the system 124, such as integrated into one or more pipes / pipes or not integrated into one or more pipes / pipes, and can be co-located or located separately from each other. According to an embodiment, the one or more loops include a pipe loop as well as a pump and a heating element. For example, the heating element can be fed directly or indirectly through a heat exchanger with waste electricity or waste heat from another process. In this example, hot water can be circulated (e.g., using a pump) to or from the cover 104 via a pipe or pipe / pipe 306a, while a pipe or pipe 306b is used for cold water. Similarly, hot water can be circulated to or from the slurry membrane 106 via a pipe or pipe 308a, while a pipe or pipe 308b is used for cold water. Although different pipes / pipes are shown, a single pipe / pipe can be used in some embodiments. In addition, in the case of using different pipes / pipes, such a pipeline can be dedicated based on direction rather than temperature. For both 306 and 308, water can be moved through a weighted tube, as described elsewhere in this disclosure. That is, the weighted tube can be used for a variety of purposes, including stabilizing the cover (e.g., 104 or 106), while also moving water for thermal management of the system 100. In some embodiments, rainwater management 310 can be used to move water away from the cover 104. For example, water can flow through a formation, collector or runoff, or utilize a pump.In some embodiments, excess rainwater is pumped from the top of the gas cover 104 to the collection area 122, or vice versa.

[0073] Reference now Figure 4A and Figure 4B, showing aspects of a gas buffer storage and / or energy recovery system according to some embodiments. Such storage and energy recovery can be combined with one or more embodiments described herein, including the anaerobic digestion system 100. As an example, the energy storage and recovery system 400 can be used to process and store biogas from the system 100, use the stored biogas to generate power, and then transmit the used biogas back to the system 100. For example, the process can be repeated based on the availability of energy from other sources (such as photovoltaic and wind power equipment). This may be a cost-effective alternative to using batteries, which may be expensive relative to other components. In some cases, the disclosed system can eliminate the need to use batteries for large amounts of energy storage. However, the energy storage and recovery system disclosed herein can be used in conjunction with one or more batteries. Although described in conjunction with an anaerobic digester, according to an embodiment, the system 400 and related methods can be implemented using a buffer that is not part of the digester 100.

[0074] like Figure 4AAs shown, a gas buffer storage element 404 can be used as part of an energy storage and recovery system 400. According to an embodiment, such a gas buffer can be part of an anaerobic digestion system 100. For example, it can be part of a digester 401 (e.g., a covered lagoon with slurry) with a biomass storage 402. In a hybrid power generation system with one or more of photovoltaic and wind energy, the energy storage can be an important buffer for the system when energy from these sources is not available. According to some embodiments, an alternative or auxiliary solution to such a hybrid system is to store materials (e.g., methane) as a cryogenic liquid or a gas under pressure in a cylinder. As an example, when there is a sufficient power supply, the methane 406 in the buffer storage (e.g., methane that was originally fugitive methane but has been captured) can be compressed into a high-pressure bottle. As another example, when the power supply is sufficient, the methane can be liquefied and stored in a similar manner. That is, a sufficient power supply can be used to power a storage system (e.g., to power one or more compressors or other liquefaction stages) to store gas in a high-pressure bottle or a cryogenic storage liquid. One example of a suitable material is methane; however, other materials such as hydrogen or CO2 may be used. When electricity supply is low or energy demand is high, the stored material (e.g., gaseous or liquid methane) can be released by a gas-powered generator 422 (e.g., a turbine) to generate electricity (either directly or indirectly by using additional stages to generate electricity from the gas-powered generator). After processing to generate electricity, the exhaust gas 418 can be released back to a buffer storage (e.g., storage device 116 of system 100), where it is ready for recycling or further processing. One benefit of this approach is that it is a cost-effective way to store energy and collect electrical energy when electrical energy is plentiful. The compressor and bottle storage may already be available as part of the biogas refining process, so the only additional components required are a turbine or other gas-driven generator.

[0075] According to an embodiment, the system 400 may include a covered slurry lagoon 401 including a slurry 402 and a gas buffer 404 stored therein, for example, as described with respect to Figure 1A and Figure 1BAs well as described by system 100. According to some embodiments, the gas buffer in this example can be a separate air bag or storage unit. The gas can be transferred to a bottle storage device 420 (e.g., a compressed gas or cryogenic liquid storage device). Before storage, the gas can be processed. This can include, for example, passing the gas through a dryer 408 and / or a compressor 412 (e.g., running on an AC power supply 410). Other treatments, such as filtering, cooling, etc., can be used. As needed, for example, on demand, energy can be recovered from the stored gas / liquid by transferring the stored gas / liquid to a recovery stage. According to an embodiment, the recovery stage includes a gas pressure driven generator. In some embodiments, the gas is heated 416 (e.g., by an electric heating element) before power generation. For example, heating can be used to increase the volume of the gas, thereby increasing the power from the turbine. The generated electricity can be regulated 424 and output as AC power 426 (e.g., to mains power). The gas used by the generator can be transferred back to the storage element as exhaust gas 418. This may include a buffer storage device, or be transferred back to the bottle storage. In some cases, the buffer storage device may be part of an anaerobic digester, such as system 100. This may include, for example, area 116 or a separate bladder dedicated to energy recovery.

[0076] The system 400 may also include one or more elements for cleaning or liquefying gas (e.g., methane) for cryogenic storage. This may include, for example, the use of a cold storage 438 or other cooler 436. The liquefier element 428 may use one or more cooling / refrigeration components, such as a Joule Thompson device, other cryogenic coolers (e.g., a Stirling cooler), a sacrificial liquid (e.g., liquid nitrogen), or a Brayton cycle device to convert gas from a gas buffer or bottle storage device into liquid form (e.g., converting methane gas into liquid methane). In addition, one or more cooling stages may be cascaded. Additional cooling elements (e.g., a Stirling cooler 430) may be used to reduce the overall temperature of the liquid storage container 434. In Figure 4A In the example shown, the flow of liquid and / or gas can be controlled by one or more valves. A dewar booster element 432 can be used so that liquid methane can be discharged from the dewar for use or storage. A liquefaction element can be used to process gas from a buffer storage, generator exhaust, and / or bottle storage to produce a liquid, such as liquid methane. Such liquid can similarly be transferred back to the bottle storage (e.g., 420). Depending on the embodiment, the storage, cleaning and / or liquefaction stages can be as described with respect to Fig. 9 , Fig. 9A , Fig. 9B and / or Fig. 9C Storage, liquefaction and / or cleaning stages described.

[0077] According to embodiments, system 400 may also include one or more processing and control components, such as device 500. Such processing and control components may be used to monitor the availability of energy from other sources (e.g., photovoltaic or wind energy), receive communications for on-demand processing, open or close one or more connected valves of system 400 (e.g., to exhaust gas from a storage device), monitor storage levels, and activate elements (e.g., generators or compressors). In embodiments, one or more steps of process 450 may be responsive to or otherwise based on such monitoring and / or communications. For example, the system may be configured to store energy (e.g., in a bottle storage device) when energy is available from other sources, and to generate energy (e.g., using a generator) when energy from other sources is not available. For example, in response to an indication of device 500, such actions may be taken by activating one or more components of system 400.

[0078] Reference now Figure 4B According to some embodiments, a process 450 for gas storage and energy recovery is provided. The process can be performed by the system 100 and / or 400, for example.

[0079] In some embodiments, the process can optionally begin at step 452, where gas is produced in an anaerobic digester (e.g., system 100) and then stored in one or more storage containers. Such storage containers may include, for example, high-pressure gas storage devices and / or cryogenic liquid storage devices. The storage step may include cleaning, compression and / or liquefaction of biogas. Although anaerobic digestion is used as an example, the energy recovery process 450 can be used for stored gaseous or liquid materials derived from other sources. That is, the system 400 and process 450 are not limited to biogas in all embodiments. According to an embodiment, one or more aspects of step 452 can be based on and / or in response to the availability or price of energy from other sources (e.g., photovoltaic, wind, mains electricity).

[0080] Step 454 includes exhausting gas from one or more storage containers of gaseous or liquid material (eg, compressed gas or cryogenic liquid, such as methane). In some embodiments, the gas is biogas.

[0081] Step 456 includes using the exhaust gas to generate power. This can include, for example, passing the exhaust gas through a turbine. According to an embodiment, one or more of the exhaust (454) and the power generation (456) can be based on the availability of energy from another source (e.g., a battery, photovoltaic and / or wind-driven device). In some aspects, when other sources are unavailable or inefficient, the gas emissions can be used to generate electricity. Conversely, when electricity from such other sources is readily available, the gas can be stored (e.g., step 452 or 460). In this regard, power generation, storage, and recovery can be optimized as needed.

[0082] Step 458 includes transferring the remaining exhaust gas to a gas buffer. This may include, for example, transferring the gas back to a buffer storage device associated with the anaerobic digestion system 100, or coupled to a storage device (e.g., such as Figure 4A Bottle storage device shown). For example, gas can be stored between the gas cap / membrane 104 and the slurry cap membrane 106. Additional membranes or storage areas can also be used, which can hold the vented gas until it is needed to store the spent waste gas of process 400.

[0083] In step 460 (which may be optional in some embodiments), the gas from the gas buffer is stored in one or more storage containers. Depending on the embodiment, process 450 may be repeated as needed. That is, the gas may be compressed and stored, used to generate electricity, and then recompressed and re-stored as needed.

[0084] According to an embodiment, a system or method for obtaining a cryogenic liquid and converting it into a gas at or near room temperature allows for energy recovery at three levels. First, the expansion of the gas (conversion from liquid phase to gas phase) is fed through a pneumatic generator to generate electricity. Secondly, waste heat can be used to enhance the process and increase the volume expansion ratio. Third, the methane gas can be used in an internal combustion (IC) engine to generate additional power. In some embodiments, the third aspect can be omitted and the gas is returned to a storage device, where the gas can remain until needed and used in an IC engine or for other purposes. According to an embodiment, this can be achieved by system 400, which can include an IC engine.

[0085] Reference now Figure 5A and Figure 5B , shows one or more gas level monitoring systems according to some embodiments. In certain aspects, the condition of a lagoon or anaerobic digestion system (e.g., system 100) can be remotely monitored. Remote monitoring and sensing of the lagoon fill status (e.g., in terms of the amount of slurry and / or the amount of biogas) can be used as part of automated control of the anaerobic digestion process. Examples of monitoring can include using, for example, one or more of the following.

[0086] The water head (the end (e.g., bottom) of one or more water-filled weighted tubes on the gas cap (e.g., cap 104 or slurry membrane 106)) can be equipped with a pressure sensor to measure the water head pressure. As the gas tank fills, the center of the gas membrane rises and the water head increases. Similarly, as the slurry level decreases, the slurry membrane drops and the water head decreases. This can be done, for example, using Figure 5A The device 500 is used to calibrate the system to calculate the amount of gas accumulated in the reservoir or available slurry or digestion.

[0087] A sight device (camera) can be installed and calibrated to monitor the top level of the gas or slurry film. This monitoring can use multiple cameras at different levels and locations. Similarly, the result can be processed by the device 500, for example, using computer vision techniques filtered by hue and / or shape detection to map image pixel key points to geometric feature points. In some aspects, a prominent shape with a distinct color can be adhered to a cover or colored object placed behind so that key points of height and angle can be determined due to their presence, invisibility or perspective in the captured image. That is, the cover or other film can include a significant geometric shape or pattern or shape, including at least one shape of a different color from the cover or film.

[0088] Sensor Array - A festoon string array of sensors (e.g., gyro accelerometers or angle sensors) can be used on the surface of a membrane (e.g., gas cap 104 or slurry membrane 106). Such an array can, for example, extend from a ditch (e.g., a water confinement area) to the center of the gas membrane. The cross section of the inflation profile can be determined by modeling the cap shape by interpolating the inflation angles between known points where angle measurements exist. As the membrane moves (e.g., rises or falls), the rope or sensor will move similarly. The motion can be calibrated so that it is associated with a specific level and processed by the device 500.

[0089] Figure 5A A block diagram of an apparatus 500 (eg, associated with an anaerobic digester system 100 or related logistics coordination such as a coordination center) according to some embodiments is shown. Figure 5AAs shown, the apparatus may include: a processing circuit (PC) 502, which may include one or more processors (P) 555 (e.g., a general-purpose microprocessor and / or one or more other processors, such as an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), etc.); a network interface 548, which includes a transmitter (Tx) 545 and a receiver (Rx) 547, for enabling the apparatus to send data to and receive data from other nodes connected to a network 510 (e.g., an Internet Protocol (IP) network), the network interface 548 being connected to the network 510; and a local storage unit (also referred to as a "data storage system") 508, which may include one or more non-volatile storage devices and / or one or more volatile storage devices. In an embodiment where the PC 502 includes a programmable processor, a computer program product (CPP) 541 may be provided. The CPP 541 includes a computer-readable medium (CRM) 542 storing a computer program (CP) 543, and the computer program (CP) 543 includes a computer-readable instruction (CRI) 544. The CRM 542 can be a non-transitory computer-readable medium, such as a magnetic medium (e.g., a disk), an optical medium, a storage device (e.g., a random access memory, a flash memory), etc. In some embodiments, the CRI 544 of the computer program 543 is configured so that when executed by the PC 502, the CRI causes the device to perform the steps described herein (e.g., the steps described herein with reference to the flowchart). In other embodiments, the device can be configured to perform the steps described herein without the need for code. That is, for example, the PC 502 can consist solely of one or more ASICs. Thus, the features of the embodiments described herein can be implemented in hardware and / or software. Although discussed in conjunction with liquid level sensing, the device 500 can be used in conjunction with other embodiments disclosed herein, including for management of energy storage and recovery, control of thermal processes, remote operation of one or more components of the system 100, or network communication for system status.

[0090] Reference now Figure 5B , an anaerobic digestion system having one or more monitoring devices (e.g., level or pressure sensing) is provided according to some embodiments. In this example, the monitoring devices include one or more line-of-sight cameras 560, a string of sensors 566, and one or more pressure sensor weights 562, 564. The pressure sensor can be installed, for example, as part of a weighted tube for a gas membrane (e.g., a gas cap or slurry cap as described with respect to system 100).

[0091] Reference now Fig. 6A and Figure 6B, a pleated cover 600 designed for a covered lagoon, such as that which may be used in system 100, is shown according to some embodiments. In this example, a gas membrane is shown in plan view. In some embodiments, the pleated angle design of the gas membrane (or slurry membrane) may allow the cover to be manufactured entirely in a workshop without requiring any field seams. In some aspects, water-filled weighted tubes (or other elongated weighted elements) may create tension on the membrane to prevent the cover from flapping in the wind. This may prevent damage and may also reduce fatigue failure of the cover.

[0092] Reference now Fig. 6A , shows an arrangement 600 for a lagoon cover according to some embodiments. This can be used, for example, in system 100. In this example, one or more weights 602 and 606 can be used. According to an embodiment, weight 602 is a weighted tube / pipe. For example, it can be filled (or can be filled) with water or other materials, such as gravel. Weight 606 can be, for example, a center weight bag. In some aspects, weight 602 can create one or more wrinkle corners 604. Figure 6B A cross section of a pleat angle along line AA is shown. In this example, a tube 612 (e.g., a water-filled weighted tube) is shown with a pair of folds 610 (e.g., gas membrane fold pleats) formed therein. According to an embodiment, the fold pleats extend from the corners of the ring beam at a 45 degree angle. As an example, on a square lagoon, they may meet (or nearly meet) when folded. In this embodiment, the center weight bag may also have a square shape with its sides aligned with the sides of the lagoon. As another example, for a rectangular lagoon, the center weight would be longer in one dimension, with its length depending on the difference between the width and length of the ring beam forming the sides of the lagoon, where the long sides of the weight bag would be aligned with the long sides of the lagoon. Similarly, the center weight 606 may be a weighted tube. According to an embodiment, the gas membrane of the anaerobic digestion system (e.g., the cover 104 or the slurry membrane 106 of the system 100) may be made of a polymer material, such as a fabric reinforced polymer sheet, including a fabric covered with a polymer material. Examples include those provided by Seaman Corporation. Membrane materials classified as ethylene interpolymer alloys (EIA), or POLYPLAN biogas membranes provided by Sattler Pro-Tex GMBH. In some embodiments, the cover is transparent and is configured to provide solar heating to the anaerobic digester.

[0093] Reference now Figure 7 , according to some embodiments, a lagoon design 700 (e.g., a lagoon excavation plan) is provided. In this example, the equipment package 712 includes pipes to the I / O (710) and pipes 702, 704, 706, and 708 connected to the mixing elements. According to embodiments, the design 700 can be used in the system 100. For example, the mixing elements can correspond to Figure 1A 134, conduits 702, 704, 706, and 708 may correspond to elements 132a-c.

[0094] Reference now Figure 8 According to some embodiments, a process 800 for assembling an anaerobic digestion system is provided. This can be used, for example, Figure 1A and Figure 1B system 100. In step 802, the process can begin by placing a cover on an anaerobic digester cover (e.g., a lagoon). In step 804, one or more weights are placed on the cover to form one or more pleated features (e.g., corners). In step 806, the weights are filled (e.g., with water or gravel), which may be optional in some embodiments. In step 808, one or more additional systems are implemented, which may be optional in some embodiments. This can include, for example, assembling, attaching and / or operating a thermal management system, a gas level sensing system, and / or a water recovery system using at least one weight. An energy storage and recovery system may also be incorporated at step 808. Depending on the type of biomass storage container, process 800 may also include excavating and preparing (e.g., applying one or more liners or coverings) the container. Depending on the embodiment, process 800 may also include information about Figure 2A and Figure 2B One or more steps described.

[0095] Fig. 9 An exemplary biogas separation and methane liquefier 900 is shown for use with one or more embodiments. Fig. 9A An exemplary CO 2 removal unit (eg, cold box) 906 is shown according to some embodiments. Fig. 9B An exemplary liquefaction cell (eg, a Joule Thompson cell) 912 is shown in accordance with some embodiments. Fig. 9C An exemplary CO2 removal and liquefaction unit according to some embodiments is shown. Fig. 9 , Fig. 9A , Fig. 9B and Fig. 9C A biogas separation and methane liquefier 900 is described.

[0096] The biogas mixture (e.g., methane-rich biogas, such as one or more methane-rich spaces from the anaerobic digester 100) is optionally first compressed to a processing pressure (e.g., between 100 bar and 300 bar) by a compressor (not shown), filtered by one or more filters (not shown), and then fed to the gas inlet 902. In general, the lower the processing pressure, the less energy is required for liquefaction, while the higher the processing pressure, the easier it is to separate carbon dioxide and methane (e.g., because there is more separation in the phase diagram, allowing carbon dioxide to become a liquid while methane remains a gas). In an embodiment, the processing pressure can be as low as 30 bar and can be higher than 300 bar. Moreover, as the pressure increases, the size of the components can generally become smaller, for example, because the volume of the gas decreases at high pressure. As noted, in an exemplary embodiment, the processing pressure is approximately 100 bar to 300 bar. In some embodiments, the biogas entering at inlet 902 will be about 85% methane and about 15% carbon dioxide at from about 100 bar to 300 bar and about 20° C. (or whatever temperature the biogas is at after leaving the anaerobic digester 100). In embodiments, the biogas may be pre-treated so that one or more of compression and / or filtration is not required.

[0097] The biogas mixture passes from the gas inlet 902 through line 921 to the heat exchanger 904, and then through line 923 to the CO2 removal unit (e.g., cold box) 906. In some embodiments, the heat exchanger 904 can be cooled by CO2 (e.g., at around -60°C) before the biogas flows through the pipe 923 into the cold box 906. The CO2 (e.g., in liquid form) that cools the heat exchanger 904 can be supplied by the removal unit 906 through line 933 (in which case it will be approximately at the temperature of the cold box), and the liquid CO2 then leaves the system through line 925 to the CO2 outlet 910. In some cases, such CO2 can also be provided to the liquefaction unit 912, such as a cold source.

[0098] Inside the removal unit 906, there may be a second heat exchanger 914 (see e.g. Fig. 9A), which can be cooled by a high-power cascade refrigerator 908 (or other cooling methods, such as a cryogenic cooler or liquid cryogen) driving a cooling refrigerant circuit. The cold box 906 can be cooled to a temperature suitable for liquefying carbon dioxide (or precipitating it in solid form) while keeping methane as a gas by cooling by the cascade refrigerator. The exact temperature will depend on the process pressure. For example, at a pressure of about 100 bar-300 bar and a temperature of about -40°C to -60°C, methane is a gas and CO2 condenses to form a liquid. In an embodiment, the temperature to which the cold box 906 is cooled can be approximately from about -40°C to -60°C, and can be approximately -60°C in an embodiment. The refrigerator 908 is connected to the cold box 906 by pipelines 927 and 929, which carry refrigerant into and out of the cold box 906, respectively.

[0099] According to an embodiment, when passing through the heat exchanger 914, the methane is cooled, but remains as a gas, while the CO2 condenses into a liquid (or, in some embodiments, a solid) and falls to the bottom 906a of the cold box 906. The extracted CO2 can then leave the cold box 906 through pipeline 933. In some embodiments, the solid CO2 can be retained in solid form until a batch of biomethane has been refined or the box is full, at which time the system can be shut down, the equipment warmed up, and the CO2 can be removed in gaseous or liquid form. As described above, in some embodiments, it can first pass through the heat exchanger 904 to take advantage of the fact that the liquid CO2 is cooled by the cold box (e.g., to about -60°C). Doing so can save a lot of energy requirements because in this case, the cascade refrigerator 908 will not need to cool the gas entering the cold box as much. When the CO2 leaves the heat exchanger 904 through line 925 and reaches the outlet 910, it may have an approximate temperature of about 20°C (or approximately whatever temperature the biogas entering the heat exchanger 904 had), and be at about 100 bar to 300 bar. The cold box 906 is insulated (insulation shown by the dashed lines around the cold box 906) to conserve cold and reduce cooling power requirements.

[0100] The now cold but still pressurized methane is sent via line 931 to a liquefaction unit (e.g., a Joule Thompson unit) 912. The liquefaction unit may also serve as a storage unit. However, the system 900 may include an additional methane storage unit (not shown) which may be removed as needed. When passing through line 931, the gas is approximately 99% pure methane, with approximately 1% carbon dioxide, still at approximately 100 bar to 300 bar, and is cooled (e.g., to approximately -60°C) due to the cold box 906. Fig. 9BIn the example of , Joule Thompson cell 912 is where the liquefaction stage of methane gas processing occurs. Cell 912 is insulated (shown in dashed lines), which can help conserve cold and reduce cooling power requirements. The pressurized methane passes through a heat exchanger 916 (see FIG. 1 ) within cell 912. Fig. 9B ). Heat exchanger 916 can be cooled by the outflowing low pressure methane (which passes through line 935) so that the pressurized methane is further cooled before passing through orifice 918 (e.g., a Joule Thompson orifice), where the methane is ultimately cooled to a sufficiently low temperature to liquefy. The pressure of the methane entering through line 931 is approximately the pressure of the methane in cold box 906, for example, approximately 100 bar to 300 bar in some embodiments. The pressure of the gas as it passes through orifice 918 is reduced to a low pressure, for example, approximately 1 bar. The methane is cooled by heat exchanger 916 to a temperature at which the methane will liquefy. This depends on the pressure of the gas after it passes through orifice 918, but in some embodiments, the temperature can be approximately -161°C or lower. If the temperature is too cold, the methane may solidify, thereby blocking the output piping system. Therefore, the temperature is preferably cold enough to make the methane become liquid, but not too cold to solidify the methane. The liquefied methane falls to the bottom 912a of unit 912, which is at an approximate temperature of approximately -161°C in some embodiments. Because the methane is already cold and at high pressure when it enters unit 912, the liquefaction fraction will be high, typically 70%-80%, resulting in a very efficient process. That is, most of the methane will liquefy and be discharged as liquid methane through line 937, for example, upon retrieval or when moved to onboard storage. However, some of the methane will remain in gaseous form and will be discharged as a gas via line 935 at a lower pressure of about 1 bar. At this point, both the liquid and gaseous methane can be very pure, in embodiments exceeding 99% pure methane.

[0101] The Joule Thompson unit 912 just described is an exemplary mechanism for liquefying methane gas. In some embodiments, a cryocooler, a Brayton cycle device, or other devices for liquefying methane may be used. In addition, while the above description notes that the cold box is configured to liquefy CO2 gas but not methane gas, in embodiments, the cold box may be configured to liquefy and / or solidify CO2 gas instead of methane gas.

[0102] For high levels of methane refining, where CO2 is a small fraction of the total volume (e.g., about 1-10%), the CO2 can be conveniently removed as a solid without the need for equipment (e.g., cold boxes or heat exchangers) that is bulky or too large to be used as part of a mobile biogas treatment plant. The methane can then be removed simultaneously as a liquid at low pressure. By appropriately sizing the heat exchanger, this can occur within a common liquefaction and low-pressure CO2 removal unit (e.g., a cold box enclosure), such as Fig. 9CAs shown. In certain situations where there is limited electricity on site to drive the compressor, this can provide a more energy efficient solution and can be further enhanced by using a low cost sacrificial cold source (e.g. an inert liquid cryogen, such as liquid nitrogen). Where appropriate, it can be conveniently brought to the site in sufficient quantities of liquid to carry out the gas processing required for the relevant period. In some embodiments, the gas inlet 902 is suitable for receiving CO2-rich biogas. In an embodiment, the methane-rich and CO2-rich inlets comprise a single inlet 902.

[0103] In addition to the cold source being a sacrificial cryogenic liquid, it can also be a mechanical chiller or alternatively a closed-cycle refrigeration circuit for liquefying air on site, where convenient. Whichever source is used, it should provide sufficient cooling for the phase change of CO2 gas to solid and methane gas to liquid. When the refrigerant is a sacrificial cryogenic liquid (such as liquid nitrogen or liquid argon) with a boiling point below the freezing point of methane, care must be taken to ensure that the methane liquefaction process temperature remains above the freezing point of methane at the process operating pressure, otherwise solid methane will be formed, resulting in blockage of the heat exchanger path. At atmospheric pressure, methane freezes at about -182°C, which is higher than the boiling point of liquid nitrogen and liquid argon. A safe liquefaction operating temperature can be conveniently achieved by maintaining the sacrificial cryogenic liquid at a pressure above atmospheric pressure through a pressure relief valve. This also has the advantage of providing a fail-safe system, ensuring that its boiling point remains above the freezing point of methane without the need for active control. For example, for liquid nitrogen, a pressure of 5 bar will maintain a boiling point of about 172°C, ensuring that the methane gas stream will never freeze.

[0104] According to an embodiment, solid CO2 can be used to improve the liquefaction process in stage 912. For example, a refrigerant liquid can be introduced to cause solid CO2 to accumulate in stage 912, which in turn can provide a cold source for methane liquefaction. Thus, liquefaction stage 912 can include a refrigerant liquid input and output, such as Fig. 9C In some embodiments, liquid refrigerant may be provided in an external region of stage 912 that is separate from the liquefaction chamber, such as Fig. 9C In some embodiments, the dotted box may alternatively represent an insulating layer. Fig. 9C As shown, a sacrificial refrigerant liquid (e.g., liquid nitrogen or liquid air) can be introduced through a flexible tube or pipe. Similarly, it can be extracted (e.g., in gaseous form) through an outlet tube or pipe. In some embodiments, as shown Fig. 9CAs shown, the refrigerant pipe or pipe can be located within the input pipe or pipe of the biogas (e.g., methane-rich biogas). That is, the liquefaction stage can use a pipe-in-pipe (or pipe-in-pipe, or pipe-in-pipe) arrangement, in which the cold liquid flows within the biogas flow path (or vice versa). This arrangement can advantageously cause solid CO2 to accumulate in the biogas path, which is beneficial for both purification and cooling of the biogas. That is, the biogas can flow through CO2 in solid or liquid form extracted from the biogas or generated from a sacrificial source.

[0105] One or more embodiments are described further below.

[0106] In a first example, an anaerobic digester (or anaerobic digestion system) is provided, comprising: a biomass storage container (e.g., a slurry lagoon having one or more tapered sidewalls); and a cover (e.g., a gas membrane) located above the biomass storage container, wherein the cover is sealed at the outer edge of the anaerobic digester to form a water (e.g., rainwater) collection area. The digester may also include an angled bracket (e.g., a trench ring beam), wherein the bracket is configured to confine water in the water collection area. The digester may also include a mounting post (e.g., including a post, an insulating material, and a covering). In some aspects, the biomass storage container includes a lagoon lining membrane. The digester of this example may also include one or more membranes (e.g., a slurry cover membrane) between the biomass storage container and the cover. At least one membrane is selectively permeable between methane and CO2, or at least one membrane is impermeable to biogas and its constituent materials. In this example, the cover, bracket, slurry cover membrane, and lagoon lining membrane may all be attached to the mounting post. In addition, at least one of the cover, the bracket, the slurry cover film and the lagoon lining film is attached to the mounting post by one or more clamps (e.g., an outer film clamp and an inner film clamp). The assembly may also include a gasket (e.g., a PVC closed-cell foam gasket) located on the top surface of the mounting post and below one or more of the cover, the bracket, the slurry cover film and the lagoon lining film. In some aspects, the cover is configured to protect the biomass storage container and its contents from rain and wind. In some aspects of this example, the cover is transparent and is configured to provide solar heating for the anaerobic digester. The cover can be made of a fabric-reinforced polymer material (e.g., including a plurality of sheets). A gas filtration system may also be included, wherein the gas filtration system is configured to process the acid gas extracted from the biomass storage container and provide refined biogas to the area between one or more membranes (e.g., the slurry cover film) and the cover. In some aspects, the processing of the acid gas includes removing one or more of hydrogen sulfide and CO2. Other systems and features may be included, such as: a thermal management system (e.g., as described with respect to Example 2); a gas or slurry condition monitoring system (e.g., as described with respect to Example 3); an energy recovery system (e.g., as described with respect to Example 4); and / or one or more cover weights (e.g., as described with respect to Example 5). In some embodiments, the cover has a rectangular or square shape and includes one or more pleated corners. Another system that may be used in Example 1 is a water recovery and reuse system, wherein the water recovery and reuse system is configured to transfer water from a water collection area to a second system (e.g., a water storage tank, a cleaning station, a livestock drinking system, an irrigation system). The water recovery and reuse system may include a water cleaning stage inserted between the collection area and the second system. In some cases, the digester may also include a mixer for circulating the slurry within the biomass storage container, for example using an input / output pipe and one or more angled mixing outlets (e.g., angled to match the angle of one or more of the side walls of the biomass storage container).The digester may also have a pump, wherein the pump is configured to move water from the cover to the water collection area (or vice versa). In some embodiments, the cover, bracket, slurry cover membrane, and lagoon liner membrane are arranged so that biogas produced in the anaerobic digester does not come into contact with metal parts (e.g., to prevent corrosion). Additionally, the water collection area may cover all gas seals at the mounting post so that gas leaks may be identified by monitoring the water collection area.

[0107] According to an embodiment, a method for operating a digester according to Example 1 is provided. The method may include one or more of the following steps: (i) providing slurry or other biomaterial to a container, such as pumping the slurry to a covered lagoon; (ii) operating or controlling the anaerobic digestion process within the digester (e.g., temperature control, mixing, aeration); (iii) extracting and / or treating gas from the digester; (iii) monitoring the water collection area for gas leaks; (iv) operating an associated thermal management system (e.g., flowing warm water between the cover and the slurry area to provide heat to the digestion process or melt ice / snow on the cover), for example, based on feedback from one or more liquid level or temperature sensors (e.g., as described in Example 3); (v) operating a water management system; (vi) performing energy storage or recovery.

[0108] According to an embodiment, the cover or membrane used in Example 1 is an inflatable membrane (e.g., having a plurality of stretchable members coupled to the inflatable membrane and configured to compress the inflatable membrane, and a plurality of limiting members coupled to the inflatable membrane and configured to limit the expansion of the inflatable membrane).

[0109] In a second example, a thermal management system for an anaerobic digester is provided. The system includes: a circulation device (e.g., including one or more pumps); and a plurality of tubes (or pipes) connected to the circulation device, wherein the plurality of tubes include: (1) one or more tubes on the surface of the anaerobic digester cover; and / or (2) one or more tubes on the surface of the biomass storage container of the anaerobic digester (e.g., on the surface of its liner) or in the biomass storage container of the anaerobic digester. The plurality of tubes can be filled with water. In this example, the circulation device is configured to allow warm water to flow from the surface of the anaerobic digester cover to the biomass storage container (e.g., to improve the anaerobic digestion process in the container), and / or to allow warm water to flow from the surface of the biomass storage container of the anaerobic digester to the cover (e.g., to melt snow on the cover, which may damage the digester and / or its components). In some aspects, at least one tube on the surface of the digester cover is a weighted tube arranged to hold the cover in place (e.g., as described with respect to Examples 1, 3, and 5). In this example, the biomass storage container may include a thermal storage area (eg, filled with pea gravel), wherein the system is configured to flow warm water to the thermal storage area.

[0110] According to an embodiment, a method of operating the thermal management system of Example 2 is provided. The method may include the following steps: pumping heated water through a weighted pipe to remove ice from the cover and / or recovering heat from the outer cover and pumping the heat into the slurry to increase the digestion rate. One or more thermal management operations may be based on a determination of the state of the digester (e.g., based on sensor output as described in Example 3).

[0111] According to an embodiment, the cover or membrane used in Example 2 is an inflatable membrane (e.g., having multiple stretchable members coupled to the inflatable membrane and configured to compress the inflatable membrane, and multiple limiting members coupled to the inflatable membrane and configured to limit the expansion of the inflatable membrane).

[0112] In a third example, an anaerobic digester (or anaerobic digestion system) is provided, comprising: a biomass storage container (e.g., a slurry lagoon); a cover (e.g., a gas membrane or a slurry membrane) located above the biomass storage container; and one or more sensors configured to indicate a gas or slurry state (e.g., a liquid level) of the anaerobic digester. The anaerobic digester may also include a cover counterweight, wherein at least one sensor is a pressure sensor attached to the counterweight (e.g., within the counterweight). In some embodiments, at least one sensor is a line of sight sensor (e.g., a camera) configured to monitor the top level of the cover. In some embodiments, at least one sensor is an array of angle sensors on the cover (e.g., a festoon of gyroscope sensors). In this example, the digester may also include a processing circuit (e.g., a processor, a memory, and a transmitter) configured to determine and report (e.g., locally, via a wireless channel, using the Internet, etc.) a gas or slurry state based on measurements of one or more sensors.

[0113] According to an embodiment, a method of operating the anaerobic digester of Example 3 is provided. The method may include, for example, monitoring the amount of fugitive methane in the bag, which is necessary for remote control of monitoring of the lagoon and associated gas recovery plant. In addition, one or more systems may be operated in response to sensing. For example, this may include activating a thermal system, starting / stopping a slurry mixing process (e.g., adjusting gas levels up or down or otherwise affecting digestion rates); venting (e.g., if gas levels or pressures are too high); or starting gas processing (e.g., if the liquid level reaches a predetermined volume or pressure threshold).

[0114] According to an embodiment, the cover or membrane used in Example 3 is an inflatable membrane (e.g., having multiple stretchable members coupled to the inflatable membrane and configured to compress the inflatable membrane, and multiple limiting members coupled to the inflatable membrane and configured to limit the expansion of the inflatable membrane).

[0115] In a fourth example, an energy storage system is provided. The system includes: one or more gaseous or liquid material (e.g., compressed gas or cryogenic liquid) storage containers; a gas pressure driven generator (e.g., a turbine) coupled to one or more storage containers and configured to use gas generated (e.g., discharged) from one or more storage containers to generate power (e.g., electricity); and a gas buffer configured to store at least a portion of the exhaust gas after the exhaust gas is used by the generator (e.g., by the generator). The gas or liquid can be, for example, methane, CO2, hydrogen, or a mixture thereof. In some aspects, the gas buffer is part of an anaerobic digester (e.g., as described with respect to Examples 1, 3, and 5). For example, the gas buffer can be an area located between a slurry area and a cover of an anaerobic digester. In some aspects, a gas processing system (e.g., including a compressor, a dryer, a cooler, a liquefaction stage, a liquid storage vessel) may be included, and the gas processing system is configured to extract gas from the gas buffer and store it in one or more storage containers. In some embodiments, where the energy storage system is part of a hybrid power generation system, the hybrid power generation system includes one or more of photovoltaic and wind power devices (e.g., windmills), and / or an internal combustion (IC) engine configured to operate using gas (e.g., after expansion). Although an IC engine is used as an example, other engines (e.g., other combustion engines or non-combustion engines) may also be used in this example and other embodiments.

[0116] In some embodiments, the gas buffer or other gas storage device of Example 4 is an inflatable membrane (e.g., having a plurality of stretchable members coupled to the inflatable membrane and configured to compress the inflatable membrane, and a plurality of restricting members coupled to the inflatable membrane and configured to restrict the expansion of the inflatable membrane) that is configured to retain gas within the inflatable membrane, for example, as described with respect to Figure 11-19 shown.

[0117] According to an embodiment, a method of operating an energy storage system according to Example 4 is provided. For example, an energy recovery process may be performed, which includes: exhausting gas from one or more storage containers of gaseous or liquid materials (e.g., compressed gas or cryogenic liquid); generating electricity using the exhaust gas; and transmitting the remaining exhaust gas to a gas buffer. Power generation may include using the exhaust gas to operate a turbine. According to an embodiment, other types of power or mechanical energy may be generated. In some aspects, the method may also include storing gas from a gas buffer in one or more storage containers, for example by compressing the gas from the gas buffer, wherein the gas from the buffer was previously used to generate electricity in a power generation step. In an embodiment, at least one of the exhaust gas and the stored gas is at least partially based on a power supply from a photovoltaic, wind power device, or battery, and / or the energy for the storage step is provided by a photovoltaic, wind power device, or battery. In an embodiment, transmitting the remaining exhaust gas to the gas buffer includes transmitting the remaining exhaust gas to an anaerobic digester (e.g., as described with respect to Example 1). The method of this example may also include transmitting the generated electricity to a mains power system. The method of this example may also include passing the exhaust gas through a heating element before the power generation step. In some embodiments, the method includes: generating gas in an anaerobic digester prior to the exhaust step; storing the gas in one or more storage containers, wherein the step of passing the remaining exhaust gas to a gas buffer includes passing the remaining exhaust gas to the anaerobic digester for generating the gas. Embodiments may include using the exhaust gas to power an engine (e.g., after expansion of the gas using waste heat).

[0118] In a fifth example, an anaerobic digester is provided, comprising: a biomass storage container; a cover, which is located above the biomass storage container; and one or more counterweights, wherein at least one counterweight is located on the top surface of the cover. In some embodiments, the cover is rectangular or square and at least one counterweight forms a fold corner of the cover. In some embodiments, a counterweight is arranged at each corner of the cover. Counterweights can also be arranged on the central area of ​​the cover or on the slurry film of the biomass storage container. In some aspects, at least one counterweight includes a pressure sensor. In some aspects, at least one counterweight is a tube (or pipe). In an embodiment, at least one counterweight is a hollow tube, a solid tube, a tube filled with rocks, or a tube filled with water. In some aspects, the counterweight pipe is connected to the water collection area of ​​the anaerobic digester and is configured to move water from the cover to the collection area (or vice versa). In some aspects, the counterweight pipe is connected to a water circulation device. In some aspects, the counterweight pipe is filled with gravel or hot water. In some aspects, one or more counterweights are arranged to generate tension on the cover and prevent the cover from flapping in the wind. As gas generation in the biomass storage container increases, the cover may expand (eg, via one or more pleats).

[0119] According to an embodiment, a method of assembling the anaerobic digester of Example 5 is provided. The method may include steps such as placing a cover, placing weights to form pleat corners, assembling / attaching any thermal management system, and optionally filling one or more weights. For example, a similar method may be used to assemble the digester of Example 1.

[0120] According to an embodiment, the cover or membrane used in Example 5 is an inflatable membrane (e.g., having multiple stretchable members coupled to the inflatable membrane and configured to compress the inflatable membrane, and multiple limiting members coupled to the inflatable membrane and configured to limit the expansion of the inflatable membrane).

[0121] Although one or more of the examples provided herein are described with respect to an anaerobic digester, according to embodiments, individual components and systems may be implemented separately from the digester described in the embodiments of the present disclosure.

[0122] Fig. 10A and Fig. 10B A typical open slurry system is shown. The slurry lagoon can have an irregular shape. When the slurry lagoon is "open", i.e. not covered, biogas (e.g. methane) can therefore escape from the lagoon. This can be harmful to the environment. In addition, the lagoon is exposed to the elements including precipitation such as rain and snow. Over time, this precipitation can account for a significant portion of the slurry volume. This can result in the need for a larger slurry lagoon to accommodate the precipitation that will also be stored.

[0123] Embodiments described herein relate to a cover for a lagoon. The cover may be used in a covered slurry lagoon system having a slurry lagoon and a cover for the slurry lagoon. Embodiments also relate to a covered slurry lagoon system. In embodiments, the cover for the lagoon may be used in an existing open slurry lagoon to convert such an open slurry lagoon into a covered slurry lagoon system.

[0124] Fig.111 is a cross-sectional schematic diagram showing a covered slurry lagoon system 1100 according to an embodiment. The covered slurry lagoon system 1100 includes a slurry lagoon 1102 having a bottom wall 1104 and a side wall (or bank) 1106. The covered slurry lagoon system 1100 also includes a cover 1108. The cover 1108 can be an inflatable membrane having a plurality of sections 1110. In an embodiment, the sections 1110 can inflate differently from each other, for example, some may stretch more than others, and some may stretch less than others. The sections 1110 can be in a single row, or can include a plurality of different rows, such that there is a matrix-like pattern of sections 1110. In the case where two sections 1110 are brought together (e.g., as shown at points 1111 and 1113), ropes 1112 and elastic materials 1114 are coupled to the cover 1108, extending between and attached to points 1111 and 1113. Cord 1112 is used to limit the expansion of cover 1100. As gas fills the membrane and points 1111 and 1113 tend to expand, cord 1112 becomes taut and prevents further expansion. Elastic material 1114 is used to compress cover 1100. Elastic material 1114 pulls between points 1111 and 1113 and helps to provide shape to cover 1100. In some embodiments, elastic material 1114 is an elastic band or tubular elastic member that extends between points 1111 and 1113 and compresses the membrane.

[0125] In an embodiment, the rope 1112 can be replaced with any limiting member capable of limiting or controlling the expansion of the inflatable membrane. The limiting member can be coupled to the inflatable membrane and configured to limit the expansion of the inflatable membrane, for example, in a manner similar to the rope 1112. In an embodiment, the elastic material 1114 can be replaced with any stretchable member (e.g., such as a Fig.21A and Fig.21B The stretchable member may be coupled to the inflatable membrane and configured to compress the inflatable membrane, for example, in a manner similar to the elastic material 1114.

[0126] In an embodiment, the covered slurry lagoon system 1100 also includes a skirt 1116 around the periphery of the cover 1108. The skirt can be weighted so that it remains submerged in the slurry lagoon 1102. The covered slurry lagoon system 1100 can also include one or more gas inlets and gas outlets. For example, the gas outlet takes raw gas from the slurry lagoon 1102 via a pipeline 1118, such as through a valve in the skirt 1116, and allows the raw gas to be fed into the gas treatment system 1122. Then, the treated gas can be fed back into the cover 1108 via the gas inlet via a pipeline 1120, such as through a valve in the cover 1108. In this way, the cover 1108 acts as a storage device for the treated gas from the slurry lagoon 1102. In an embodiment, different types of gas (e.g., differently purified carbon dioxide or methane) can be stored separately in the cover 1108. For example, a gas permeable / semi-permeable membrane (such as those described above) can be used in the cover 1108 to provide different storage areas. In this case, the membrane can be selected so that the heavier gas can be located in the lower layer, and the lighter gas can be allowed to rise through the permeable membrane to properly separate the different types of gases. Similarly, an airtight membrane can also be used in the cover 208 to provide different storage areas. In this case, the gas handling system 1122 will have separate gas outlets for the different types of gases, which can then be directed to the appropriate storage areas. The gas handling system 1122 can include any gas handling system disclosed herein.

[0127] The cover 1108 effectively acts as a storage space for the gas. A mobile processing station (such as those described elsewhere herein) can be used to recover the gas stored in the cover 1108. The cover 1108 can also provide one or more of insulation and thermal management, water collection and reuse, and / or energy recovery systems, such as those described elsewhere herein. For example, any of the systems, devices, and methods described with respect to FIGS. 1-9 can be implemented using the covered slurry lagoon system 1100. Similarly, with respect to Fig.11 The described cover 1108 and related components may be used in the systems and methods of Figures 1-9. For example, any of the covers / membranes 104, 106, and 138 may be configured as described with respect to the cover 1108 and / or skirt 1116 according to some embodiments.

[0128] The cover 1108 can be made of a variety of different materials, including one or more of polypropylene, polyethylene, polyetheretherketone (PEEK), polyvinyl chloride (PVC), polytetrafluoroethylene (PTFE), polyphenylene sulfide (PPS), and ethylene tetrafluoroethylene (ETFE). Exemplary trade name materials include XR-5 geomembrane and Sattler Pro-tex Polyplan composite material.

[0129] like Fig.11 As shown in the example of , the cover 1108 is empty, which means that there is no biogas from the slurry lagoon 1102. In this case, the cover 1108 is in an unexpanded state. Fig.11 The rightmost segment 1110 shown in FIG. 1 has a height h1 in the unexpanded state. Fig.12 As shown, cover 1108 is full, meaning that it has reached its capacity to store biogas from slurry lagoon 1102. In this case, cover 208 is in an inflated state. Fig.12 The rightmost section 1110 shown in the expanded state has a height h2. The height h2 is greater than h1, and the difference between h2 and h1 represents the amount of expandability of the cover 1108. In this embodiment, the amount of expandability can be controlled by the length of the rope 1112. As will be explained, the expandability of the different sections 1110 can vary in some embodiments. The amount of storage capacity of the cover 1108 is proportional to the expandability of the different sections 1110.

[0130] like Fig.12 As shown, the endmost portion 1110 also has ropes 1112 and elastic material 1114 at the outer edge, rather than just having ropes 1112 and elastic material 1114 inside where two or more portions 1110 meet. In this embodiment, the outer edge of the inflatable membrane is allowed to move as the gas volume in the storage is emptied, and to be pulled in as the gas volume in the storage is filled. When the storage space is full, the total width and length of the membrane can drop to the location of the outermost elastic material 1114 and ropes 1112.

[0131] Fig.131 is a cross-sectional schematic diagram showing a covered slurry lagoon system 1300 according to an embodiment. As shown, only half of the slurry lagoon system 1300 is shown, and the rest is symmetrical. The slurry lagoon system 1300 is similar to the slurry lagoon system 1100, and the same reference numerals represent the same or functionally similar elements. This embodiment shows a water collection area 1302, which allows rainwater to collect at the area 1302 and then leave the system through a pipeline 1304. In some embodiments, a pump can be used to make the water leave the system, while other embodiments can rely on gravity. In the illustrated configuration, gravity can guide rainwater from the water collection area 1302 through the pipeline 1304 and out of the slurry lagoon system 1300. Rainwater leaving the slurry lagoon system 1300 can be collected and used. The inclined profile of the cover 1308 allows rainwater to collect in the water collection area 1302. As shown, each portion 1110 can have a different height, such as d1, d2, d3, and d4, each shown as monotonically decreasing. Similarly, the height of the portion 1110 of the portion not shown can be symmetrical to the height of the portion shown so that the water collection area 1302 is located approximately in the center of the cover 1108. The cover 1108 can be designed so that the water collection area 1302 is located in another location, for example, depending on the needs of the particular slurry lagoon 1102 and surrounding environment.

[0132] As shown, there is a gap 1306 between the skirt 1116 and the sidewall (or bank) 1106. In this case, the sidewall 1106 is sloped and slopes inwardly toward the slurry lagoon 1102. In this embodiment, the perimeter of the cover 1108 is aligned with the bottom wall 1104 of the slurry lagoon 1102, as shown in FIG. Fig.13 1308. The gap 1106 allows water 1308 to accumulate in this area. The accumulation of water 1308 in this area of ​​the gap 1106 can have the advantage of covering one or more gas seals, such as the seals at the connection of the cover 1102, skirt 1116, and / or liner. When filled with water 1308, leaks in the seals can be monitored and detected. For example, if gas escapes the seal, it will form bubbles in the water 1308 that can be detected visually or audibly. For example, pipeline 1118 can be connected to a gas inlet in the skirt 216, wherein the gas inlet includes a valve that can be covered by water 1308 in the area of ​​the gap 206.

[0133] Fig.1414 is a top view and a schematic cross-sectional view showing a rigid body 1400 according to an embodiment. As shown, the rigid body 1400 includes a pipe (e.g., a pressurized pipe) that forms an outer perimeter 1402 with an internal support structure 1404. Tubes such as those disclosed in the "Anaerobic Digestion" section may also be used here. In some embodiments, the skirt 1116 may be composed entirely or partially of the rigid body 1400. Although the perimeter is square in the top view, the shape of the perimeter 1404 and the internal support structure 1404 may vary, for example, depending on the design of the particular slurry lagoon 1102 and the surrounding environment.

[0134] Fig.15 1 is a cross-sectional schematic diagram showing a covered slurry lagoon system 1500 according to an embodiment. As shown, only a portion of the slurry lagoon system 1500 is shown, wherein the line 1502 indicates that the slurry lagoon system 1500 will continue to extend further. The slurry lagoon system 1500 is similar to the slurry lagoon systems 1100 and 1300, and the same reference numerals represent the same or functionally similar elements. As shown, there is a solid edge ring 1504. This can be, for example, a concrete barrier that surrounds the slurry lagoon 1500 and forms an outer perimeter. A liner 1506 can be used, which is connected to the skirt 1116 and limits the area of ​​the gap 1306 where water 1308 can accumulate. The liner 1506 can also be connected to the solid edge ring 1504.

[0135] Fig.16 1 is a cross-sectional schematic diagram showing a covered slurry lagoon system 1600 according to an embodiment. As shown, only a portion of the slurry lagoon system 1600 is shown, wherein line 1602 indicates that the slurry lagoon system 1600 will continue to extend further. The slurry lagoon system 1600 is similar to the slurry lagoon systems 1100, 1300 and 1500, and the same reference numerals represent the same or functionally similar elements. As shown, the portion 1110 is configured to form a dished upper surface on the outside of the cover 1108. For example, each portion 1110 can have a different height (shown as d1 to d8), such as so that rainwater can be collected in a common area. In some embodiments, the shortest portion 1110 (shown here as having a height d6) can be approximately in the middle of the cover 1108, wherein the portions 1110 on both sides of the shortest portion 1110 gradually become higher as they move away from the shortest portion 1110. The height of a given portion 1110 can be constructed based on a rope 1112 and an elastic material 1114. For example, from the outside toward the shortest portion 1110, the elastic material 1114 may start out weaker and the cord 1112 may be longer as it moves inward, the elastic material 1114 gradually becomes stronger and the cord 1114 gradually becomes shorter. In this way, a dished upper surface can be formed so that rainwater is collected in a designated collection area.

[0136] Fig.171 is a cross-sectional schematic diagram showing a covered slurry lagoon system 1700 according to an embodiment. As shown, only a portion of the slurry lagoon system 1700 is shown, wherein line 1702 indicates that the slurry lagoon system 800 will continue to extend further. The slurry lagoon system 1700 is similar to the slurry lagoon systems 1100, 1300, 1500, and 1600, and the same reference numerals represent the same or functionally similar elements. As shown, rainwater can be collected at the water collection area 1302 and then leave the system via the outlet 1704 through the pipeline 1304. The outlet 1704 can help redirect the rainwater to other uses.

[0137] Fig.18 1 is a cross-sectional schematic diagram illustrating a covered slurry lagoon system 1800 according to an embodiment. Slurry lagoon system 1800 is similar to slurry lagoon systems 1100, 1300, 1500, 1600, and 1700, and like reference numerals represent like or functionally similar elements. As shown, rainwater can be collected at water collection area 1302 and then leave the system through pipeline 1802. In this embodiment, pipeline 1802 does not rely on gravity, but the water in water collection area 1302 must be pumped out through pipeline 1802 by a water pump.

[0138] Fig.19 is a cross-sectional schematic diagram illustrating a covered slurry lagoon system 1900 according to an embodiment. The slurry lagoon system 1900 is similar to the slurry lagoon systems 1100, 1300, 1500, 1600, 1700, and 1800, and like reference numerals represent identical or functionally similar elements.

[0139] Fig. 20 A schematic perspective view of a slurry lagoon system as described herein is shown. For example, a rope 1114 of elastic material is Fig. 20 As can be seen in the rendering shown, it extends in a grid-like pattern in which two or more portions 1110 intersect.

[0140] Fig.21A and Fig.21B A clock spring with a rotating pulley system 2100 is shown in accordance with an embodiment. In some embodiments, the elastic material 1114 can be replaced with any stretchable member, such as a spring or a spring and pulley system. For example, a clock spring can provide greater expansion capabilities than an elastic polymer expansion rope. Elastic polymers are fundamentally limited by their elastic constant, which is a material property. Typical elastomers (such as silicone rubber) have the ability to stretch 3-4 times from their resting length before they are permanently damaged and therefore stretched. This limits the maximum height that a cover 1108 used as a gas storage device can be maintained under tension compared to the minimum height. However, with a rotating pulley system (such as Fig.21A and Fig.21B 2104) can provide a much higher ratio between the fully extended state and the fully original state. For example, a rotating steel tape measure can easily achieve a linear expansion coefficient of 20:1. As shown, the clock spring with a rotating pulley system 2100 includes a clock spring 2102 in a housing 2104. Two hooks 2106 can be provided, one hook attached to the housing 2104 and the other hook attached to one end of the steel band of the clock spring 2102. Fig.21A shows a winding system 2100, and Fig.21B An unwinding system 2100 is shown (as shown by the steel strip breaking).

[0141] Thus, when using a spring or spring and pulley system like this, a very large amount of biogas can be retained within the storage bag relative to an empty state, while still maintaining sufficient tension between the top and bottom of the cover 208 to ensure stability in high wind and rain conditions. Furthermore, the tension level can be easily adjusted by selecting the spring strength.

[0142] Although various embodiments of the present disclosure are described herein, it should be understood that they are presented only by way of example and not limitation. Therefore, the breadth and scope of the present disclosure should not be limited by any of the above exemplary embodiments. In addition, unless otherwise noted herein or otherwise clearly contradictory to the context, the present disclosure encompasses any combination of the above elements in all possible variations thereof.

[0143] In addition, although the processes described above and shown in the accompanying drawings are shown as a sequence of steps, this is done for illustrative purposes only. Therefore, it is expected that some steps can be added, some steps can be omitted, the order of the steps can be rearranged, and some steps can be performed in parallel.

[0144] Brief description of the embodiments

[0145] A1. A cover for a lagoon, the cover comprising:

[0146] Expandable membrane;

[0147] a plurality of stretchable members coupled to the expandable membrane and configured to compress the expandable membrane; and

[0148] A plurality of restraining members are coupled to the inflatable membrane and are configured to restrain inflation of the inflatable membrane.

[0149] A1'. The cover according to embodiment A1, wherein the expandable membrane is capable of storing gas.

[0150] A1". The cover according to any one of embodiments A1 and A1', wherein the inflatable membrane comprises a gas inlet capable of allowing gas to flow into the space within the inflatable membrane.

[0151] A1a. A cover according to any one of embodiments A1, A1' and A1", wherein the expandable membrane includes a plurality of parts, and each of the plurality of stretchable members is located at a position where two or more of the plurality of parts intersect, and each of the plurality of limiting members is located at a position where two or more of the plurality of parts intersect.

[0152] A1b. The cover of embodiment A1a, wherein the plurality of portions form a matrix.

[0153] A2. The cover according to any one of embodiments A1, A1' and A1", A1a and A1b, further comprising a skirt surrounding the outer perimeter of the expandable membrane.

[0154] A3. The cap of embodiment A2, wherein the skirt comprises a pressurized tube.

[0155] A4. The cover according to any one of embodiments A1-A3, further comprising a gas processing unit configured to process raw biogas from the gas outlet and feed the processed biogas into the gas inlet of the expandable membrane.

[0156] A5. The cover of any of embodiments A1-A4, wherein the plurality of stretchable members comprises an elastic material located within the expandable membrane and connected to top and bottom surfaces of an interior of the expandable membrane.

[0157] A5'. The cover according to any one of embodiments A1-A5, wherein the plurality of stretchable members include springs and pulleys.

[0158] A5". The cover according to embodiment A5', wherein the spring comprises a clock spring.

[0159] A6. The cover according to any one of embodiments A1-A5, A5' and A5", wherein the top surface of the exterior of the expandable membrane has an inclined profile.

[0160] A7. The cover according to any one of embodiments A1-A5, A5' and A5", wherein the top surface of the exterior of the expandable membrane has a concave shape.

[0161] A8. The cover of any of embodiments A6-A7, wherein the elasticity of the plurality of stretchable members varies so as to define a top surface of an exterior of the expandable membrane.

[0162] A9. The cover of any of embodiments A1-A8, wherein the plurality of stretchable members comprises an elastic material located within the expandable membrane and connected to top and bottom surfaces of an interior of the expandable membrane.

[0163] A10. The cover of any of embodiments A1-A9, wherein the plurality of restraining members include cords located within the inflatable membrane and connected to top and bottom surfaces of an interior of the inflatable membrane.

[0164] A11. The cover of embodiment A10, wherein the cord of each restraining member is configured to be slack when the inflatable membrane is empty, and configured to be taut when the inflatable membrane is full.

[0165] A12. The cover of any of embodiments A1-A11, further comprising a water collection area and a water outlet for allowing water on the outer top surface of the inflatable membrane to escape.

[0166] A13. The cover of any one of embodiments A1-A12, wherein the expandable membrane (1108) comprises one or more of: XR-5 geomembrane, Sattler Pro-Tex Polyplan composite, polypropylene, polyethylene, PEEK, PVC, PTFE, PPS, and ETFE.

[0167] A14. The cover of any of embodiments A1-A13, wherein the expandable membrane is expandable in a vertical direction such that an outer perimeter of the expandable membrane resists expansion.

[0168] B1. A system comprising:

[0169] Slurry lagoons; and

[0170] A cover for the slurry lagoon, the cover comprising:

[0171] Expandable membrane;

[0172] a plurality of stretchable members coupled to the expandable membrane and configured to compress the expandable membrane; and

[0173] A plurality of restraining members are coupled to the inflatable membrane and are configured to restrain inflation of the inflatable membrane.

[0174] B1'. The system of embodiment B1, wherein the cover for the slurry lagoon is any one of embodiments A2-A14.

[0175] B2. The system of embodiment B1, further comprising a skirt surrounding an outer perimeter of the expandable membrane, wherein the skirt is located within the slurry lagoon and is configured to remain submerged in slurry in the slurry lagoon.

[0176] B2a. The system of embodiment B2, wherein the skirt is weighted so that it remains submerged within the slurry lagoon.

[0177] B3. The system of any of embodiments B2 and B2a, wherein a gap exists between the edge of the slurry lagoon and the skirt, and the liquid within the gap seals the slurry lagoon to prevent gas leakage.

[0178] B4. The system of embodiments B1-B3, further comprising a water collection area and a water outlet for allowing water on the outer top surface of the expandable membrane to escape.

[0179] B5. The system of embodiment B4 further comprising a pipeline coupled to the water outlet so that escaping water can pass through the pipeline by gravity.

[0180] B6. The system of embodiment B4 further comprising a pump and a pipeline coupled to the water outlet so that escaping water can be pumped through the pipeline.

[0181] B7. The system according to any one of embodiments B1-B6, further comprising a gas processing unit configured to process raw biogas from a gas outlet connected to the slurry lagoon and feed the processed biogas into a gas inlet of the expandable membrane.

[0182] B8. The system according to any one of embodiments B1-B7, further comprising one or more of: (i) a gas processing system, (ii) a mobile processing system, (iii) a thermal management system, (iv) a water collection and reuse system, and (v) an energy recovery system, each as disclosed in the "Anaerobic Digestion" section of the present disclosure.

[0183] C1. A method for converting an uncovered slurry lagoon with a cover, the method comprising:

[0184] Installing a cover on an uncovered slurry lagoon,

[0185] The cover is any one of embodiments A1-A14.

[0186] C2. A method according to embodiment C1, wherein the cover has an average height h1 in an initial state, wherein the method further comprises: treating biogas from the slurry lagoon that has passed through a gas treatment system, and releasing the treated biogas into the cover through an opening so that the treated biogas is stored in the cover, and wherein, after releasing the treated biogas into the cover, the cover has an average height h2 greater than h1.

Claims

1. A cover for a lagoon, the cover comprising: Expandable membrane; a plurality of stretchable members coupled to points on opposite sides within the inflatable membrane and configured to compress the inflatable membrane in a vertical direction; as well as a plurality of restraining members coupled to points on opposite sides within the inflatable membrane and configured to restrain inflation of the inflatable membrane in a vertical direction; wherein the points on the opposite sides within the inflatable membrane are located on the top and bottom surfaces of the interior of the inflatable membrane; wherein the expandable membrane comprises a gas inlet capable of allowing gas to flow into the space within the expandable membrane; and The expandable membrane comprises a plurality of parts, and each of the plurality of stretchable members is located at a position where two or more of the plurality of parts meet.

2. The cover according to claim 1, wherein Each of the plurality of restriction members is located at a position where two or more of the plurality of portions meet.

3. The cover according to claim 1, wherein The plurality of sections form a matrix.

4. The cap of claim 1 further comprising a skirt surrounding an outer perimeter of the expandable membrane.

5. The cover according to claim 4, wherein: The skirt includes a pressurized tube.

6. The cover of claim 1, further comprising a gas processing unit configured to process raw biogas from a gas outlet and feed the processed biogas into a gas inlet of the expandable membrane.

7. The cover according to claim 1, wherein The plurality of stretchable members include an elastic material positioned within the expandable membrane and connected to top and bottom surfaces within the interior of the expandable membrane.

8. The cover according to claim 1, wherein The plurality of stretchable members include springs and pulleys.

9. The cover according to claim 1, wherein: The top surface of the exterior of the expandable membrane has an inclined profile.

10. The cover according to claim 1, wherein The top surface of the exterior of the expandable membrane has a concave shape.

11. The cover according to claim 1, wherein The elasticity of the plurality of stretchable members varies so as to define an exterior top surface of the expandable membrane.

12. The cover according to claim 1, wherein The plurality of restraining members include cords located within the inflatable membrane and connected to top and bottom surfaces of an interior of the inflatable membrane.

13. The cover according to claim 12, wherein: The cord of each restraining member is configured to be slack when the inflatable membrane is empty and configured to be taut when the inflatable membrane is full.

14. The cover of claim 1 further comprising a water collection area and a water outlet for allowing water on the exterior top surface of the inflatable membrane to escape.

15. A system comprising: slurry lagoons; as well as A cover for the slurry lagoon, the cover comprising: Expandable membrane; a plurality of stretchable members coupled to points on opposite sides within the inflatable membrane and configured to compress the inflatable membrane in a vertical direction; and a plurality of restraining members coupled to points on opposite sides within the inflatable membrane and configured to restrain inflation of the inflatable membrane in a vertical direction; a skirt surrounding an outer perimeter of the expandable membrane, wherein the skirt is located within the slurry lagoon and is configured to remain submerged in slurry in the slurry lagoon; and a water collection area and a water outlet for allowing water on the exterior top surface of the expandable membrane to escape; Wherein, the points on the opposite sides within the inflatable membrane are located on the top and bottom surfaces of the interior of the inflatable membrane.

16. The system of claim 15, wherein: The skirt is weighted so that it remains submerged within the slurry lagoon.

17. The system of claim 15, wherein: There is a gap between the edge of the slurry lagoon and the skirt, and the liquid in the gap seals the slurry lagoon to prevent gas leakage.

18. The system of claim 15, further comprising a pipeline coupled to the water outlet so that escaping water can pass through the pipeline by gravity.

19. The system of claim 15, further comprising a pump and a pipeline coupled to the water outlet so that escaping water can be pumped through the pipeline.

20. The system of claim 15, further comprising a gas processing unit configured to process raw biogas from a gas outlet coupled to the slurry lagoon and feed the processed biogas into a gas inlet of the expandable membrane.

21. The system of claim 15, further comprising one or more of: (i) a gas handling system, (ii) a mobile handling system, (iii) a thermal management system, (iv) a water collection and reuse system, and (v) an energy recovery system.

22. A method of converting an uncovered slurry lagoon with a cover, the method comprising: Installing a cover on an uncovered slurry lagoon, Wherein, the cover is the cover according to claim 1.

23. The method according to claim 22, wherein: The cover has an average height h1 in an initial state, wherein the method further comprises treating biogas from the slurry lagoon that has passed through a gas treatment system, and releasing the treated biogas into the cover through an opening so that the treated biogas is stored in the cover, and wherein, after releasing the treated biogas into the cover, the cover has an average height h2 that is greater than h1.

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