Systems and methods for processing organic substrates

Abstract

Systems and methods are provided for pre-treating an organic substrate in order to increase the anaerobic and aerobic digestion efficiency of the organic substrate, the system comprising: a conduit adapted to have a flow therethrough, the flow comprising a liquid medium and the organic substrate; an electromagnetic field generator disposed circumferentially around the conduit, the electromagnetic field generator adapted to induce an electromagnetic field into the conduit such that the electromagnetic field is applied to the liquid culture medium when the liquid culture medium flows through the conduit; and a microwave emitter attached to the conduit, the microwave emitter adapted to emit microwave radiation into the conduit such that the microwave radiation is applied to the liquid medium when the liquid medium flows through the conduit.

Description

[0001] This application claims priority to U.S. Provisional Patent Application No. 63 / 447,534, filed on February 23, 2023, which is incorporated by reference for all purposes as if fully set forth herein. Technical Field

[0002] The present invention generally relates to systems and methods for treating or digesting organic substrates, and more particularly, to systems and methods for pretreating organic substrates to improve the efficiency of anaerobic and aerobic digestion of the organic substrates. Summary of the Invention

[0003] According to one embodiment of the present invention, a system for improving digestion of an organic substrate in a liquid culture medium is provided, the system comprising: a conduit adapted to have a flow flowing therethrough, the flow comprising the liquid culture medium and the organic substrate; an electromagnetic field generator circumferentially disposed around the conduit, the electromagnetic field generator adapted to induce an electromagnetic field into the interior of the conduit such that the electromagnetic field is applied to the liquid culture medium as the liquid culture medium flows through the conduit; and a microwave emitter attached to the conduit, the microwave emitter adapted to emit microwave radiation into the conduit such that the microwave radiation is applied to the liquid culture medium as the liquid culture medium flows through the conduit.

[0004] In embodiments, the conduit is a tubing adapted to be in fluid communication with the source of liquid culture medium in an operational mode of the system.

[0005] In embodiments, the system further comprises: at least one valve disposed between the source of the liquid culture medium and the conduit, and in the operating mode of the system, the valve opens and allows the liquid culture medium to flow from the source to the conduit.

[0006] In embodiments, the system further comprises a pump, and in the operational mode of the system, the pump is adapted to pump the liquid culture medium from the source to the conduit.

[0007] In embodiments, the conduit is a cannula adapted to be disposed around a conduit adapted to be in fluid communication with the source of liquid culture medium in an operational mode of the system.

[0008] In an embodiment, the electromagnetic field generator comprises a wire coiled around the catheter and is adapted to generate the electromagnetic field when electricity is passed through the wire.

[0009] In an embodiment, the electromagnetic field generator is adapted to induce an electromagnetic field having a first frequency in the range of 5 Hz to 500 Hz.

[0010] In an embodiment, the electromagnetic field generator is adapted such that the electromagnetic field is an alternating current (AC) electromagnetic field.

[0011] In an embodiment, the microwave emitter is adapted to emit microwave radiation having a second frequency or microwave frequency in the range of 1 GHz to 20 GHz.

[0012] In embodiments, the microwave transmitter comprises a microwave generator and at least one antenna extending from the microwave generator into the conduit.

[0013] In an embodiment, the system further comprises a controller functionally associated with the microwave emitter and the electromagnetic field generator, the controller being adapted to electronically control or modulate the operation of the electromagnetic field generator and the microwave emitter based on at least one criterion of the conduit or the liquid culture medium within the conduit.

[0014] In an embodiment, the system further comprises at least one sensor functionally associated with the controller and adapted to provide input to the controller related to the at least one criterion.

[0015] In an embodiment, the at least one sensor comprises a flow rate sensor. In an embodiment, the at least one sensor comprises a temperature sensor. In an embodiment, the at least one sensor comprises a pH sensor. In an embodiment, the at least one sensor comprises a chemical sensor.

[0016] In an embodiment, the conduit has a length in the range of 1 m to 5 m.

[0017] In embodiments, the conduit has an inner diameter in the range of 75 mm to 250 mm.

[0018] In embodiments, the electromagnetic field generator is positioned closer to the upstream end of the conduit than the microwave emitter, such that as the liquid culture medium flows through the conduit, the electromagnetic field is applied to the liquid culture medium before the microwave radiation is applied to the liquid culture medium.

[0019] In embodiments, the electromagnetic field generator is positioned closer to the downstream end of the conduit than the microwave emitter, such that as the liquid culture medium flows through the conduit, the electromagnetic field is applied to the liquid culture medium after the microwave radiation is applied to the liquid culture medium.

[0020] In an embodiment, the electromagnetic field generator is configured to induce the electromagnetic field in the section of the conduit, and the microwave emitter is adapted to emit microwave radiation into the section of the conduit, such that when the liquid culture medium flows through the section of the conduit, the liquid culture medium simultaneously has the electromagnetic field and the microwave radiation applied thereto.

[0021] In embodiments, the output end of the conduit is in fluid communication with a digester such that after flowing through the conduit, the liquid culture medium reaches the digester. In embodiments, the digester is an anaerobic digester. In embodiments, the digester is an aerobic digester.

[0022] In an embodiment, the system further comprises: the liquid culture medium, the liquid culture medium comprising the organic substrate.

[0023] In embodiments, the temperature of the liquid culture medium during passage through the conduit is in the range of 5° C. to 60° C. In embodiments, the temperature of the liquid culture medium during passage through the conduit is in the range of 15° C. to 60° C. In embodiments, the temperature of the liquid culture medium during passage through the conduit is in the range of 30° C. to 55° C.

[0024] In embodiments, the pH of the liquid culture medium during passage through the catheter is in the range of 3 to 11. In embodiments, the pH of the liquid culture medium during passage through the catheter is in the range of 4 to 10. In embodiments, the pH of the liquid culture medium during passage through the catheter is in the range of 5 to 10. In embodiments, the pH of the liquid culture medium during passage through the catheter is in the range of 6 to 9.

[0025] In embodiments, the concentration of the organic substrate within the stream is in the range of 1% to 20%.

[0026] In embodiments, the organic substrate comprises biomass.

[0027] In embodiments, the organic substrate comprises a complex organic polymer. In embodiments, the complex organic polymer comprises lignin. In embodiments, the complex organic polymer comprises cellulose. In embodiments, the complex organic polymer comprises pectin.

[0028] In embodiments, the organic substrate comprises industrial waste. In some embodiments, the organic substrate comprises sanitary waste. In embodiments, the organic substrate comprises agricultural waste.

[0029] According to one aspect of the present invention, there is provided a method for pretreating an organic substrate in a liquid culture medium to promote its anaerobic or aerobic digestion, the method comprising: allowing a flow of the liquid culture medium containing the organic substrate to flow through a conduit; and during the passage of the liquid culture medium through the conduit: inducing an electromagnetic field into the interior of the conduit such that the electromagnetic field is applied to the liquid culture medium; and emitting microwave radiation into the conduit such that the microwave radiation is applied to the liquid culture medium.

[0030] According to another aspect of the present invention, a method for producing biogas from an organic substrate in a liquid culture medium is provided, the method comprising: allowing a flow of the liquid culture medium containing the organic substrate to flow through a conduit; during the passage of the liquid culture medium through the conduit: inducing an electromagnetic field into the interior of the conduit so that the electromagnetic field is applied to the liquid culture medium; and emitting microwave radiation into the conduit so that the microwave radiation is applied to the liquid culture medium; and after applying the electromagnetic field and the microwave radiation to the liquid culture medium, producing biogas by digesting the liquid culture medium leaving the conduit.

[0031] In embodiments, the allowing the liquid culture medium to flow through the conduit comprises: opening a valve between the conduit and a source of the liquid culture medium to allow the liquid culture medium to flow into the conduit.

[0032] In embodiments, the allowing the liquid culture medium to flow through the conduit comprises: pumping the liquid culture medium into the conduit.

[0033] In an embodiment, the inducing the electromagnetic field comprises passing electricity through a metal wire formed into a spiral around the conduit.

[0034] In an embodiment, the electromagnetic field generator is adapted to induce an electromagnetic field having a first frequency in the range of 5 Hz to 500 Hz.

[0035] In an embodiment, the inducing the electromagnetic field comprises inducing an alternating current (AC) electromagnetic field.

[0036] In embodiments, the microwave emitter is adapted to emit microwave radiation having a second frequency or microwave frequency in the range of 0.5 GHz to 20 GHz. In embodiments, the method further comprises electronically controlling or modulating the induction of the electromagnetic field generator and the emission of the microwave radiation based on at least one criterion of the conduit or the liquid culture medium within the conduit.

[0037] In embodiments, the at least one criterion comprises the flow rate of the liquid culture medium within the conduit. In some embodiments, the at least one criterion comprises the temperature of the liquid culture medium within the conduit. In some embodiments, the at least one criterion comprises the temperature of the conduit. In some embodiments, the at least one criterion comprises the pH of the liquid culture medium within the conduit.

[0038] In an embodiment, the controlling includes determining whether the at least one criterion is satisfied based on at least one sensor input.

[0039] In embodiments, the at least one sensor input comprises an input from a flow rate sensor. In some embodiments, the at least one sensor input comprises an input from a temperature sensor. In some embodiments, the at least one sensor input comprises an input from a pH sensor. In some embodiments, the at least one sensor input comprises an input from a chemical sensor.

[0040] In embodiments, the flow rate is in the range of 1 cm / second to 10 cm / second.

[0041] In embodiments, the inducing the electromagnetic field occurs prior to the emitting the microwave radiation, such that as the liquid culture medium flows through the conduit, the electromagnetic field is applied to the liquid culture medium before the microwave radiation is applied to the liquid culture medium.

[0042] In embodiments, the inducing the electromagnetic field occurs after the emitting the microwave radiation, such that as the liquid culture medium flows through the conduit, the electromagnetic field is applied to the liquid culture medium after the microwave radiation is applied to the liquid culture medium.

[0043] In embodiments, the inducing the electromagnetic field and the emitting the microwave radiation occur simultaneously such that the liquid culture medium simultaneously has the electromagnetic field and the microwave radiation applied thereto as the liquid culture medium flows through the section of the conduit.

[0044] In embodiments, the method further comprises: conveying the output of the conduit to an anaerobic digester for anaerobic digestion of the organic substrate in the liquid culture medium.

[0045] In embodiments, the method further comprises: conveying the output of the conduit to an aerobic digester for aerobic digestion of the organic substrate in the liquid culture medium.

[0046] In embodiments, the temperature of the liquid culture medium is in the range of 5°C to 60°C.

[0047] In embodiments, the pH of the liquid culture medium is in the range of 3 to 11 during passage through the catheter.

[0048] According to another aspect of the present invention, a method for retrofitting an anaerobic digestion plant to pretreat an organic substrate to be anaerobically digested is provided, the anaerobic digestion plant comprising: an input conduit that guides the organic substrate to an anaerobic digester, the method comprising: placing a pretreatment sleeve around the input conduit, the pretreatment sleeve comprising: an electromagnetic field generator that is circumferentially arranged around the pretreatment sleeve; and a microwave emitter that is arranged on or in the pretreatment sleeve, wherein, during the flow of a liquid culture medium containing the organic substrate through the input conduit: the microwave emitter is adapted to emit microwave radiation into the conduit such that the microwave radiation is applied to the liquid culture medium as it flows through the input conduit, and the electromagnetic field generator is adapted to induce an electromagnetic field inside the input conduit such that the electromagnetic field is applied to the liquid culture medium as it flows through the input conduit.

[0049] According to another aspect of the present invention, a method for retrofitting an aerobic wastewater treatment plant to pretreat biosolids to increase their biodegradability is provided, the aerobic wastewater treatment plant comprising: an input conduit directing the organic substrate to an aerobic digester, the method comprising: placing a pretreatment sleeve around the input conduit, the pretreatment sleeve comprising: an electromagnetic field generator disposed circumferentially around the pretreatment sleeve; and a microwave emitter disposed on or in the pretreatment sleeve,

[0050] Wherein, during the period when the liquid culture medium containing the organic substrate flows through the input conduit: the microwave emitter is suitable for emitting microwave radiation into the conduit, so that when the liquid culture medium flows through the input conduit, the microwave radiation is applied to the liquid culture medium, and the electromagnetic field generator is suitable for inducing an electromagnetic field inside the input conduit, so that when the liquid culture medium flows through the input conduit, the electromagnetic field is applied to the liquid culture medium. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In combination with Figures (1A to Figure 4 ) when understood from the following detailed description of the invention, in which:

[0052] Figure 1A 、 Figure 1B and Figure 1C are schematic diagrams of three configurations of systems for pretreating organic matter in a liquid culture medium to improve digestion of the organic matter according to embodiments of the disclosed technology;

[0053] Figure 2 is a schematic diagram of a configuration of a system for pre-treating organic matter in a liquid culture medium according to an embodiment of the disclosed technology, the system being suitable for retrofitting onto existing piping in a facility for digesting organic matter;

[0054] Figure 3A 、 Figure 3B and Figure 3C is a schematic diagram of three configurations of anaerobic digestion systems for digesting organic matter in a liquid culture medium according to an embodiment of the disclosed technology, each of the anaerobic digestion systems comprising Figures 1A to 2 any of the systems; and

[0055] Figure 4 is the use of embodiments according to the disclosed technology Figures 1A to 2 A flow chart of a method for pretreating an organic substrate in a liquid culture medium to promote anaerobic digestion of the organic substrate. DETAILED DESCRIPTION

[0056] The principles of the present system and method for improving digestion of organic matter in liquid culture media by pre-treating the organic matter may be better understood with reference to the drawings and accompanying description.

[0057] Before explaining at least one embodiment of the present invention in detail, it should be understood that the application of the invention is not limited to the details of construction and arrangement of parts set forth in the following description or illustrated in the accompanying drawings. The present invention is capable of other embodiments or can be practiced or implemented in various ways. Likewise, it should be understood that the phrases and terms employed herein are for descriptive purposes only and should not be considered as limiting.

[0058] Referring now to the accompanying drawings, Figure 1A 、 Figure 1B and Figure 1C are schematic diagrams of three configurations of a system 100 for pretreating organic matter in a liquid culture medium to improve digestion of the organic matter, according to embodiments of the disclosed technology.

[0059] like Figure 1A 、 Figure 1B and Figure 1C As can be seen, system 100 includes conduit 102, which is typically in fluid communication with a source 104 of liquid culture medium. In an operational state of system 100, conduit 102 has a stream 105 flowing therethrough from source 104, the stream comprising liquid culture medium and organic matter. For example, the flow can be controlled by opening valve 106 (at Figure 1A As another example, the pump 108 (shown clearly in FIG) facilitates the mode of operation by allowing the liquid culture medium and organic matter to flow from the source 104 into the conduit 102 to form a flow. Figure 1B ) can be operated to pump liquid culture medium and organic matter from source 104 to conduit 102 to form stream 105.

[0060] In some embodiments, the conduit 102 has a length in the range of 1 m to 3 m. In some embodiments, the conduit 102 has a length in the range of 1.5 m to 2.5 m. In some embodiments, the conduit 102 has a length of 2 m.

[0061] In some embodiments, the catheter 102 has an inner diameter in the range of 75 mm to 250 mm, 75 mm to 200 mm, 75 mm to 150 mm, 100 mm to 250 mm, 100 mm to 2000 mm, or 100 mm to 150 mm.

[0062] The system 100 further includes an electromagnetic field generator 110 disposed circumferentially around the conduit 102. The electromagnetic field generator 110 is adapted to induce an electromagnetic field into the interior of the conduit 102 such that when the liquid culture medium flows through the conduit, the induced electromagnetic field is applied to the flowing liquid culture medium. The electromagnetic field generator 110 may be any suitable electromagnetic field generator. However, in Figures 1A to 1C In the embodiment of the present invention, the electromagnetic field generator is implemented as a metal wire 112, such as a copper wire, which is spirally wound around the conduit 102. The wire 112 is adapted to generate an electromagnetic field when electricity passes through it. Typically, the electromagnetic field generator 110 is such that the generated electromagnetic field is an alternating current (AC) electromagnetic field.

[0063] In some embodiments, the electromagnetic field generator 110 is adapted to induce an electromagnetic field having a first frequency in the range of 5 Hz to 500 Hz. More typically, the first frequency is at least 10 Hz, at least 20 Hz, at least 25 Hz, at least 30 Hz, at least 35 Hz, or at least 40 Hz. More typically, the first frequency is at most 400 Hz, at most 300 Hz, at most 250 Hz, at most 200 Hz, at most 150 Hz, at most 125 Hz, at most 100 Hz, at most 80 Hz, at most 70 Hz, or at most 60 Hz.

[0064] System 100 also includes a microwave emitter 120 attached to conduit 102. Microwave emitter 120 is adapted to emit microwave radiation into conduit 102 such that the emitted microwave radiation is applied to the liquid culture medium as it flows through the conduit. In some embodiments, microwave emitter 120 may be attached to an exterior surface of conduit 102. In some embodiments, at least a portion of microwave emitter 120 may be disposed within conduit 102.

[0065] In some embodiments, microwave transmitter 120 may include a magnetron 122 and at least one antenna 124 extending from the magnetron to catheter 102. In some embodiments, magnetron 122 may be attached to the exterior of catheter 102, while antenna 124 may extend to the interior of the catheter.

[0066] In some embodiments, microwave emitter 120 is adapted to emit microwave radiation having a second frequency or a microwave frequency in the range of 1 GHz to 20 GHz, 1 GHz to 18 GHz, 1 GHz to 12 GHz, 1 GHz to 10 GHz, 1 GHz to 8 GHz, 1 GHz to 6 GHz, 1 GHz to 5 GHz, 1 GHz to 4 GHz, 1 GHz to 3 GHz, 1.25 GHz to 3 GHz, 1.5 GHz to 3 GHz, 1.5 GHz to 2.75 GHz, 1.5 GHz to 2.5 GHz, or 1.75 GHz to 2.25 GHz.

[0067] In some embodiments, system 100 may further include a controller 130 functionally associated with electromagnetic field generator 110 and microwave emitter 120. Controller 130 is adapted to electronically control or modulate the operation of electromagnetic field generator 110 and microwave emitter 120 based on various criteria for their operation, such as the flow rate of the liquid culture medium within conduit 102, the temperature of the liquid culture medium in conduit 102 or the conduit itself, the pH of the liquid culture medium in conduit 102, and the like. In some embodiments, controller 130 may further be associated with at least one sensor 132 disposed in or on conduit 102. Sensor 132 may provide input to controller 130 regarding parameters of the liquid culture medium or conduit 102. For example, sensor 132 may be or include a flow rate sensor, a temperature sensor, or a pH sensor.

[0068] In an operational state of system 100 , liquid culture medium passing through conduit 102 is output downstream for further processing, as explained in further detail below.

[0069] Now turn to Figure 1A , it can be seen that the electromagnetic field generator 110 is disposed at or near the upstream end of the conduit 102, proximate to the source 104, and the microwave emitter 120 is disposed at or near the downstream end of the conduit 102. Thus, as the liquid culture medium flows through the conduit 102, the electromagnetic field is applied to the liquid culture medium before the microwave radiation impinges on the liquid culture medium.

[0070] exist Figure 1B , it can be seen that electromagnetic field generator 110 is disposed at or near the upstream end of conduit 102, proximate source 104, and microwave emitter 120 is disposed at or near the downstream end of conduit 102. Thus, as liquid culture medium flows through conduit 102, microwave radiation affects the liquid culture medium before the electromagnetic field is applied to the liquid culture medium.

[0071] exist Figure 1CIn the embodiment of the present invention, the electromagnetic field generator 110 induces an electromagnetic field in the section 102a of the conduit 102, and the microwave emitter 120 emits microwave radiation into the same section of the conduit 102. Therefore, when the liquid culture medium flows through the section 102a, the liquid culture medium is affected by both the electromagnetic field and the microwave radiation.

[0072] Now refer to Figure 2 , which is a schematic diagram of a configuration of a system 100' for pre-treating organic matter in a liquid culture medium. According to an embodiment of the disclosed technology, the system 100' is suitable for retrofitting onto existing piping in a facility for digesting organic matter.

[0073] Figure 2 The system 100' is substantially similar to Figures 1A to 1C 1 , wherein like reference numerals indicate like components. However, in system 100', conduit 102' is a sleeve that is adapted to be wrapped around an existing pipe 150 in a facility for digesting organic matter, such as an anaerobic digestion facility. Thus, in some embodiments, conduit 102' may include longitudinal slots to facilitate wrapping pipe 150 around conduit 102'. In some other embodiments, conduit 102' may be a complete cylinder and may be slid onto conduit 150 from a longitudinal end of conduit 150. For example, conduit 102' may be placed by disconnecting conduit 150 from a pipe or container that is in communication therewith at its upstream and downstream ends, sliding conduit 102' onto conduit 150, and then reconnecting the conduit to its adjacent pipe or container.

[0074] In some embodiments where the antenna 124 is disposed within the liquid culture medium to be processed, mounting the catheter 102 ′ to the pipe 150 may include inserting the antenna 124 into the interior of the pipe 150 .

[0075] Now refer to Figure 3A 、 Figure 3B and Figure 3C , which are schematic diagrams of three configurations of anaerobic digestion systems for digesting organic matter in a liquid culture medium. According to an embodiment of the disclosed technology, each anaerobic digestion system includes Figures 1A to 1C System 100 or Figure 2 system 100'.

[0076] like Figure 3AAs can be seen, system 200 can be or form part of a sanitary treatment plant for digesting organic substrates derived from manure. As can be seen, system 100 is applied to inlet line 208, which feeds a liquid culture medium containing manure into anaerobic digester 210. Thus, the liquid culture medium flowing toward the anaerobic digester is subjected to an electromagnetic field and microwave radiation applied thereto. In anaerobic digester 210, the organic substrate is further digested, for example to form biogas. As indicated by arrow 214, the resulting digestate is removed from anaerobic digester 210, and the resulting biogas flows out of anaerobic digester 210 into a suitable tank, as is known in the art.

[0077] Go to Figure 3B , system 220 can be or form part of a wastewater digestion plant that digests organic substrates derived from wastewater, such as those found in municipal waste systems. Typically, the wastewater is initially subjected to an activated sludge process, in which the wastewater is converted into waste activated sludge or return activated sludge, which is a liquid solution of organic substrate (typically comprising biomass). For example, the wastewater can be aerated in a suitable tank 222. System 100 (or 100') is applied to an inlet line leading from tank 222 to anaerobic digester 230. Thus, the liquid culture medium flowing from tank 222 to anaerobic digester 230 is subjected to the application of electromagnetic fields and microwave radiation. In anaerobic digester 230, the organic substrate is further digested, for example to form biogas. As indicated by arrow 234, the digestate biogas is removed from anaerobic digester 230, and the resulting biogas flows out of anaerobic digester 230 into a suitable tank, as known in the art.

[0078] exist Figure 3C In the embodiment, system 240 may be or form part of an agricultural digestion plant which digests organic substrates derived from animal feedstock. System 240 differs from systems 200 and 220 in that it may be cyclic, so that some organic substrates may be digested more than once. Figure 3C As seen, organic feedstock, typically in a liquid medium, is fed into an anaerobic digester 242 via an inlet conduit 243. The output of the anaerobic digester 242 is provided to a digestate buffer tank 244 for further processing.

[0079] Indicated by arrow 245, a first portion of the output of digestate buffer tank 244 is fed into a sludge filter press 246, which separates the treated liquid from the treated solids. As indicated by arrow 247, the treated solids (also known as biosolids) are removed from sludge filter press 246 for further use, such as application to a field to provide organic matter to the soil and improve crops. As indicated by arrow 248, the treated liquid is removed from sludge filter press 246 and can be reused or safely disposed of.

[0080] A second portion of the output of the digestate buffer tank 244 flows into a dilution line 250, to which the system 100 (or 100') is applied for applying an electromagnetic field and microwave radiation to the liquid culture medium in the dilution line. The pretreated liquid culture medium in the dilution line is conveyed back to the anaerobic digester 242 or may be combined with the inlet line before being conveyed to the anaerobic digester. As described above, in the anaerobic digester, the organic substrate is further digested, for example to form biogas, as is known in the art.

[0081] It will be appreciated that in some applications, the system 100 may be applied to the inlet conduit 243 for pre-treatment of an initial undiluted solution. The effectiveness of applying the system 100 to the inlet conduit 243 depends on the solids content or dry matter content of the liquid culture medium.

[0082] Now additionally refer to Figure 4 , which is the use of embodiments according to the disclosed technology Figures 1A to 1C System 100 or Figure 2 The system 100 ′ is a flow diagram of a method for pretreating an organic substrate in a liquid culture medium to facilitate anaerobic digestion of the organic substrate.

[0083] As seen in step 300, a stream comprising a liquid culture medium containing an organic substrate is introduced or allowed to flow into and through conduit 102 ( Figures 1A to 1C ) or by the catheter 102′( Figure 2 ) surrounded by pipe 150.

[0084] In some embodiments, the concentration of organic substrate within the stream ranges from 1% to 20%, 3% to 15%, 3% to 12%, 5% to 12%, or 5% to 10%.

[0085] In some embodiments, the concentration of organic substrate within the stream is at least 2.5%, at least 3.5%, or at least 4%.

[0086] In some embodiments, the concentration of organic substrate within the stream is at most 16%, at most 14%, at most 12%, at most 10%, at most 8%, or at most 7%.

[0087] As described above, in some embodiments, the organic substrate comprises waste material and may comprise any one or more of industrial waste, sanitary waste, and agricultural waste. For example, the industrial waste may comprise waste from paper processing, beer making, food manufacturing, or tanneries.

[0088] In some embodiments, the organic substrate comprises biomass and biosolids. Typically, the biomass and biosolids contribute to the anaerobic digestion process.

[0089] In some embodiments, the organic substrate comprises complex organic polymers that are difficult to biodegrade, such as lignin, cellulose, and pectin.

[0090] In some embodiments, during the flow of the liquid culture medium through conduit 102 or 102', the liquid culture medium has a temperature in the range of 5° C. to 60° C., 10° C. to 60° C., 15° C. to 60° C., 20° C. to 60° C., 25° C. to 60° C., 25° C. to 55° C., or 30° C. to 55° C. It will be appreciated that temperatures outside of these ranges may damage or even inactivate the biomass (e.g., bacteria) within the organic substrate, which would limit, slow, or stop anaerobic digestion of the organic substrate after it passes through the conduit.

[0091] In some embodiments, during the time the liquid culture medium flows through conduit 102 or 102', the liquid culture medium has a pH in the range of 6 to 9. It will be appreciated that a pH outside of this range may damage or even inactivate the biomass (e.g., bacteria) within the organic substrate, which would limit, slow, or stop anaerobic digestion of the organic substrate after it passes through the conduit.

[0092] In some embodiments, the flow rate of the liquid culture medium through the conduit 102 or 102' is in the range of 1 cm / sec to 10 cm / sec. Figures 1A to 1C The conduit 102 or 102' in question is sized to facilitate the desired flow rate while minimizing energy consumption by a pump or other mechanism to provide liquid culture medium to the conduit 102.

[0093] In some embodiments, the time for the liquid culture medium to flow through the entire conduit is no more than 15 minutes, 10 minutes, 8 minutes, 6 minutes, 4 minutes, or 2 minutes. In some embodiments, the time for the liquid culture medium to flow through the entire conduit is in the range of 15 seconds to 15 minutes, 15 seconds to 10 minutes, 15 seconds to 8 minutes, 15 seconds to 6 minutes, 15 seconds to 4 minutes, 15 seconds to 2 minutes, 30 seconds to 2 minutes, 30 seconds to 90 seconds, or 30 seconds to 1 minute.

[0094] It will be appreciated that a short flow time through conduit 102 or 102' is desired to ensure that the application of the electromagnetic field and microwave radiation to the liquid culture medium does not raise the temperature of the liquid culture medium beyond the operating ranges listed above and to ensure continued effectiveness of the anaerobic digestion process. In some embodiments, the temperature increase may be maintained below 5°C, below 3°C, or below 2°C.

[0095] As seen at step 302, several steps occur during the passage of liquid culture medium through conduit 102 or 102'.

[0096] At step 304, an electromagnetic field is induced into the interior of the conduit 102 or 102', for example, by the electromagnetic field generator 110. The induced electromagnetic field affects the liquid culture medium flowing through the conduit. When the liquid culture medium containing the organic substrate flows through the electromagnetic field, an electrochemical current is also generated in the liquid culture medium.

[0097] At step 306, microwave radiation is emitted into the conduit 102 or 102', for example, by the microwave emitter 120. The emitted microwave radiation is applied to the liquid culture medium flowing through the conduit.

[0098] In some embodiments, step 304 may occur before step 306. In some embodiments, step 306 may occur before step 304. In some embodiments, steps 304 and 306 may occur at least partially simultaneously.

[0099] Typically, after the liquid culture medium passes through conduit 102 or 102', at step 308, the pretreated liquid culture medium exposed to the electromagnetic field and microwave radiation is transferred to an anaerobic digester for further digestion.

[0100] In some embodiments, such as those using catheter 102', the method includes an initial setup step 310, in which catheter 102' is placed around tubing 150, as described above. In such embodiments, step 310 occurs before any of steps 300, 302, 304, 306, and 308.

[0101] In the experimental results, the inventors have found that using Figure 4 The method of pretreating the liquid culture medium before its anaerobic digestion increases the biodegradability of the organic substrate in the liquid culture medium by at least 5%. In some applications, the biodegradability of the organic substrate is increased from 80% (when simply using anaerobic digestion) to 85% (when using Figure 4 In some other applications, the biodegradability of organic substrates increases from 70% (when simply using anaerobic digestion) to 90% (when using Figure 4 Improvements in the biodegradability of organic substrates are beneficial for at least one of the following reasons:

[0102] Increase the amount of biomethane that can be produced from organic substrates;

[0103] Reduced retention time required for processing organic substrates and, therefore, also reduced processing energy;

[0104] Increase digester capacity and, therefore, overall system profitability;

[0105] Reducing the amount of waste remaining at the end of anaerobic digestion; and

[0106] Improve the quality of the effluent collected at the end of the anaerobic digestion process.

[0107] The inventors surprisingly found that Figure 4 In the method of applying the combination of electromagnetic field and microwave energy to the liquid culture medium is more energetically more effective than the equivalent application of only one of these methods.

[0108] Thus, the inventors surprisingly discovered that the combination of an electromagnetic field and microwave energy application has a synergistic effect, resulting in a significant reduction in the energy required to pretreat the liquid culture medium using both methods, compared to pretreating the liquid culture medium using only one of the two methods. To achieve the same conversion, the energy consumption of the method of the present invention is significantly lower than when only electromagnetic field application or only microwave energy application is used.

[0109] The inventors have also surprisingly discovered that applying microwave energy to the liquid culture medium while it is flowing through the electromagnetic field does not suppress or reduce the effects of the electromagnetic field on the liquid culture medium. Additionally, by simultaneously applying microwave energy, the electrochemical effects of the solution flowing through the electromagnetic field remain unimpaired and, in some cases, can even be made more effective.

[0110] Example

[0111] Reference is now made to the following examples, which together with the above descriptions illustrate the invention in a non limiting fashion.

[0112] Example 1: Substrate

[0113] Laboratory experiments were performed on the following substrate materials:

[0114] Pig manure

[0115] Cow dung

[0116] Biosolids from municipal wastewater treatment plants

[0117] FOG (grease trap waste)

[0118] DAF sludge from poultry slaughterhouse wastewater treatment plants

[0119] Brewer's grains (ground)

[0120] ·Grinded seeds

[0121] Corn silage

[0122] Samples of brewer's grains, ground seeds, and corn silage were diluted to a concentration of 3% to 5% of DM before being processed by MW&EMF.

[0123] Example 2: Biomethane Potential Test (BMP)

[0124] The BMP test was conducted according to ISO 15985:2014, which specifies a method for evaluating the ultimate anaerobic biodegradability of plastics based on organic compounds under high-solids anaerobic digestion conditions by measuring the biogas released at the end of the test. This method is designed to simulate typical anaerobic digestion conditions for the organic fraction of mixed municipal solid waste.

[0125] BMP testing is used to determine biogas production, methane concentration, and methane production. The chemical parameters of the raw and treated substrates are analyzed according to the procedures under the American Water Works Association (AWWA) Standard Methods for the Examination of Water and Wastewater.

[0126] After adding the treated substrate sample, the batch bottle was flushed with N2 for 2 minutes, and 2 mL of saline solution (containing NH4Cl, NaCl, CaCl2.2H2O and MgCl2.6H2O), 20 mL of inoculum and 20 mL of Milli-Q water were added, and then sealed with an EPDM rubber stopper and an aluminum screw cap. The headspace of the batch bottle was exchanged with a gas mixture of CO2 and N2, after which 0.3 ml of Na2S.3H2O (100 mM) was added via syringe.

[0127] The treatment combinations and the control group were run three times. All samples were incubated at 37°C. During the incubation period, biogas production and methane content were measured on days 1, 3, 7, 12, 20, 28 and 35. Before the methane analysis, biogas production was measured using a Testo 312-3 digital manometer. After this analysis, 1 mL of the headspace gas was extracted with a syringe and transferred to an 11 mL glass vial filled with air. 1 mL was extracted from this vial and analyzed in a gas chromatograph with flame ionization detector (GC-FID) from an HP58880A series using a Poraplot T column and N2 as carrier gas (130 mL min -1 ) was used to analyze the methane content. The injector and detector temperatures were 150°C and 250°C, respectively. The detector gas was H2 (30 mL min -1 ) and air (250 mL min -1 ). Methane content was calculated by fitting the measured values ​​to a linear regression of the GC-FID readings of three controls.

[0128] The prepared samples were analyzed on a GC-FID (Clarus 580 Perkin-Elmer) with a BP21 column and helium as the carrier gas (2 mL min -1 ), with a split ratio of 1:10 (1 μL sample). The injector and detector temperatures were 250°C and 280°C, respectively. The detector gas was H2 (at 45 mL min -1 ) and air (at 450 mL min-1 The oven temperature was increased linearly from 160°C to 225°C in 15 minutes and then to 240°C in 3 minutes.

[0129] For kinetic analysis, the degradation rate of BMP was calculated using equation (1),

[0130] Y(t)=Ym·e -kt (1)

[0131] where Y(t) is the cumulative methane production on day t (NmL g VS -1 ), Ym is the total methane production (NmL g VS -1 ), and k is the degradation rate (days -1 ).

[0132] Example 3: Semi-continuous digestion experiment (SCADE)

[0133] The AD process was operated under mesophilic conditions in a five-liter glass continuously stirred tank reactor (CSTR) with a working volume of 4 L. Digester mixing was facilitated by a mechanical stainless steel stirrer operated at a constant rate. SCADE utilized a set of two digesters: a control and a single digester. The digesters were inoculated with digestate from a WWTP.

[0134] During the SCADE period, volatile fatty acid (VFA) analysis was performed on the control and MW&EMF treated digesters. The VFA assay monitored changes in VFA concentrations before and after feeding (8 hours).

[0135] The digestate was analyzed weekly for pH, conductivity, total and volatile solids content, ammonia, VFA, and long-chain fatty acids (LCFA) content.

[0136] Biogas production was measured daily using a custom gas meter, and overnight gas samples were collected and analyzed weekly using a Biogas 5000 Geotech unit to determine biogas composition.

[0137] Examples 4-11

[0138] Experiments were conducted on the feedstocks of Example 1. These feedstocks contained a variety of microorganisms responsible for the subsequent conversion to biogas and were representative of organic wastes generated and / or managed by agricultural and wastewater treatment operations - relevant to most of our target customers.

[0139] Demonstrating the synergy in performance and cost-effectiveness resulting from combined MW / EMF treatment, we found that substrate samples treated with MW+EMF ​​could increase methane production by up to 20% at an operating cost of $0.60 per pound of organic dry matter. In comparison, samples treated with MW or EMF alone showed no more than a 2% to 3% increase in methane production, at an estimated operating cost of $1.60 per pound of organic dry matter (oDM).

[0140] The subsequent experiments involved the treatment of different types of organic feedstock: mixed with anaerobic biomass as inoculum for the anaerobic fermentation process. The data presented in Table 1 are the average results of experiments performed for each type of feedstock, with at least 6 replicates per experiment, including a control or blank (untreated) test.

[0141] Table 1

[0142]

[0143] Laboratory investigations showed that the combination of MW radiation and EMF treatment increased methane production by >20%, due to increases in biogas production and methane concentration. For each of the eight feedstock types tested, the improvements in biogas production, methane concentration (i.e., % methane in biogas), and methane production were found to be statistically significant (p < 0.05).

[0144] Excellent results were obtained within the following operating ranges: hydraulic retention time 30 seconds to 60 seconds; AC frequency 30 Hz to 120 Hz; electromagnetic flux density 1 mT to 3.5 mT; microwave frequency 1.5 GHz to 4 GHz.

[0145] Typical electricity consumption in processed feedstock is about 50W*h per pound of oDM.

[0146] Additional Implementation Plans

[0147] Additional embodiments 1 to 174 are provided below.

[0148] 1. A system for improving digestion of an organic substrate in a liquid culture medium, the system comprising: a conduit adapted to have a flow flowing therethrough, the flow comprising the liquid culture medium and the organic substrate; an electromagnetic field generator circumferentially disposed about the conduit, the electromagnetic field generator adapted to induce an electromagnetic field into the interior of the conduit such that the electromagnetic field is applied to the liquid culture medium as it flows through the conduit; and a microwave emitter attached to the conduit, the microwave emitter adapted to emit microwave radiation into the conduit such that the microwave radiation is applied to the liquid culture medium as it flows through the conduit.

[0149] 2. The system of embodiment 1, wherein the conduit is a tubing adapted to be in fluid communication with the source of the liquid culture medium in an operating mode of the system.

[0150] 3. The system of embodiment 2 further comprises: at least one valve disposed between the source of the liquid culture medium and the conduit, and wherein in the operating mode of the system, the valve opens and allows the liquid culture medium to flow from the source to the conduit.

[0151] 4. The system of embodiment 2, further comprising: a pump, wherein in the operating mode of the system, the pump is adapted to pump the liquid culture medium from the source to the conduit.

[0152] 5. The system of embodiment 1, wherein the conduit is a cannula adapted to be disposed around a conduit adapted to be in fluid communication with a source of the liquid culture medium in an operational mode of the system.

[0153] 6. The system of any one of embodiments 1 to 5, wherein the electromagnetic field generator comprises a metal wire spiraled around the catheter and adapted to generate the electromagnetic field when electricity is passed through the metal wire.

[0154] 7. The system of any one of embodiments 1 to 6, wherein the electromagnetic field generator is adapted to induce an electromagnetic field having a first frequency in the range of 5 Hz to 500 Hz.

[0155] 8. The system of embodiment 7, wherein the first frequency is at least 10 Hz.

[0156] 9. The system of embodiment 7, wherein the first frequency is at least 20 Hz.

[0157] 10. The system of embodiment 7, wherein the first frequency is at least 25 Hz.

[0158] 11. The system of embodiment 7, wherein the first frequency is at least 30 Hz.

[0159] 12. The system of embodiment 7, wherein the first frequency is at least 35 Hz.

[0160] 13. The system of embodiment 7, wherein the first frequency is at least 40 Hz.

[0161] 14. The system of any one of embodiments 7 to 13, wherein the first frequency is at most 400 Hz.

[0162] 15. The system of embodiment 14, wherein the first frequency is at most 300 Hz.

[0163] 16. The system of embodiment 14, wherein the first frequency is at most 250 Hz.

[0164] 17. The system of embodiment 14, wherein the first frequency is at most 200 Hz.

[0165] 18. The system of embodiment 14, wherein the first frequency is at most 150 Hz.

[0166] 19. The system of embodiment 14, wherein the first frequency is at most 120 Hz.

[0167] 20. The system of embodiment 14, wherein the first frequency is at most 100 Hz.

[0168] 21. The system of embodiment 14, wherein the first frequency is at most 80 Hz.

[0169] 22. The system of embodiment 14, wherein the first frequency is at most 70 Hz.

[0170] 23. The system of embodiment 14, wherein the first frequency is at most 60 Hz.

[0171] 24. The system of any one of embodiments 1 to 23, wherein the electromagnetic field generator is adapted such that the electromagnetic field is an alternating current (AC) electromagnetic field.

[0172] 25. The system of any one of embodiments 1 to 24, wherein the microwave emitter is adapted to emit microwave radiation having a second frequency or a microwave frequency in the range of 0.5 GHz to 20 GHz.

[0173] 26. The system of embodiment 25, wherein the second frequency or microwave frequency is in the range of 1 GHz to 18 GHz.

[0174] 27. The system of embodiment 25, wherein the second frequency or microwave frequency is in the range of 1 GHz to 16 GHz.

[0175] 28. The system of embodiment 25, wherein the second frequency or microwave frequency is in the range of 1 GHz to 14 GHz.

[0176] 29. The system of embodiment 25, wherein the second frequency or microwave frequency is in the range of 1 GHz to 12 GHz.

[0177] 30. The system of embodiment 25, wherein the second frequency or microwave frequency is in the range of 1 GHz to 10 GHz.

[0178] 31. The system of embodiment 25, wherein the second frequency or microwave frequency is in the range of 1 GHz to 8 GHz.

[0179] 32. The system of embodiment 25, wherein the second frequency or microwave frequency is in the range of 1 GHz to 6 GHz.

[0180] 33. The system of embodiment 25, wherein the second frequency or microwave frequency is in the range of 1 GHz to 5 GHz.

[0181] 33A. The system of embodiment 25, wherein the second frequency or microwave frequency is in the range of 1 GHz to 4.5 GHz.

[0182] 34. The system of embodiment 25, wherein the second frequency or microwave frequency is in the range of 1 GHz to 4 GHz.

[0183] 35. The system of embodiment 25, wherein the second frequency or microwave frequency is in the range of 1 GHz to 3 GHz.

[0184] 36. The system of embodiment 25, wherein the second frequency or microwave frequency is in the range of 1.25 GHz to 3 GHz.

[0185] 37. The system of embodiment 25, wherein the second frequency or microwave frequency is in the range of 1.5 GHz to 3 GHz.

[0186] 38. The system of embodiment 25, wherein the second frequency or microwave frequency is in the range of 1.5 GHz to 2.75 GHz.

[0187] 39. The system of embodiment 25, wherein the second frequency or microwave frequency is in the range of 1.5 GHz to 3.5 GHz.

[0188] 40. The system of embodiment 25, wherein the second frequency or microwave frequency is in the range of 1.75 GHz to 3.5 GHz.

[0189] 41. The system of any one of embodiments 1 to 40, wherein the microwave transmitter comprises: a microwave generator; and at least one antenna extending from the microwave generator into the conduit.

[0190] 42. The system of any one of embodiments 1 to 41, further comprising: a controller functionally associated with the microwave emitter and the electromagnetic field generator, the controller being adapted to electronically control or modulate the operation of the electromagnetic field generator and the microwave emitter based on at least one criterion of the conduit or the liquid culture medium within the conduit.

[0191] 43. The system of embodiment 42, wherein the at least one criterion comprises a flow rate of the liquid culture medium within the conduit.

[0192] 44. The system of embodiment 43, wherein the flow rate is in the range of 1 cm / sec to 10 cm / sec.

[0193] 45. The system of embodiment 43 or 44, wherein the liquid culture medium has a treatment hydraulic retention time in the range of 1 second to 120 seconds.

[0194] 46. ​​The system of embodiment 45, wherein the treatment hydraulic retention time is at least 10 seconds.

[0195] 47. The system of embodiment 45, wherein the treatment hydraulic retention time is at least 25 seconds.

[0196] 47A. The system of embodiment 45, wherein the treatment hydraulic retention time is at least 30 seconds.

[0197] 48. The system of any one of embodiments 45 to 47, wherein the treatment hydraulic retention time is at most 90 seconds.

[0198] 48A. The system of embodiment 48, wherein the treatment hydraulic retention time is at most 75 seconds.

[0199] 48B. The system of embodiment 48, wherein the treatment hydraulic retention time is at most 60 seconds.

[0200] 49. The system of any one of embodiments 42 to 48, wherein the at least one criterion comprises the temperature of the liquid culture medium within the conduit.

[0201] 50. The system of any one of embodiments 42 to 49, wherein the at least one criterion comprises a temperature of the conduit.

[0202] 51. The system of any one of embodiments 42 to 50, wherein the at least one criterion comprises the pH of the liquid culture medium within the conduit.

[0203] 52. The system of any one of embodiments 42 to 51, further comprising: at least one sensor functionally associated with the controller and adapted to provide input to the controller related to the at least one criterion.

[0204] 52A. The system of embodiment 52, wherein the at least one sensor comprises a flow rate sensor.

[0205] 52B. The system of embodiment 52 or 52A, wherein the at least one sensor comprises a temperature sensor.

[0206] 52C. The system of any one of embodiments 52 to 52B, wherein the at least one sensor comprises a pH sensor.

[0207] 53. The system of any one of embodiments 52 to 53, wherein the at least one sensor comprises a chemical sensor.

[0208] 54. The system of any one of embodiments 1 to 53, wherein the conduit has a length in the range of 1 m to 5 m.

[0209] 55. The system of embodiment 54, wherein the length of the conduit is in the range of 1 m to 4 m.

[0210] 56. The system of embodiment 54, wherein the length of the catheter is in the range of 1.5 m to 3 m.

[0211] 57. The system of any one of embodiments 1 to 54, wherein the length of the conduit is in the range of 1.75 m to 2.25 m.

[0212] 58. The system of any one of embodiments 1 to 57, wherein the catheter has an inner diameter in the range of 75 mm to 250 mm.

[0213] 59. The system of embodiment 58, wherein the inner diameter of the catheter is in the range of 75 mm to 200 mm.

[0214] 60. The system of embodiment 58, wherein the inner diameter of the catheter is in the range of 75 mm to 150 mm.

[0215] 61. The system of embodiment 58, wherein the inner diameter of the catheter is in the range of 100 mm to 250 mm.

[0216] 62. The system of embodiment 58, wherein the inner diameter of the catheter is in the range of 100 mm to 200 mm.

[0217] 63. The system of embodiment 58, wherein the inner diameter of the catheter is in the range of 100 mm to 150 mm.

[0218] 64. The system of any one of embodiments 1 to 63, wherein the electromagnetic field generator is positioned closer to the upstream end of the conduit than the microwave emitter such that when the liquid culture medium flows through the conduit, the electromagnetic field is applied to the liquid culture medium before the microwave radiation is applied to the liquid culture medium.

[0219] 65. The system of any one of embodiments 1 to 63, wherein the electromagnetic field generator is positioned closer to the downstream end of the conduit than the microwave emitter such that when the liquid culture medium flows through the conduit, the electromagnetic field is applied to the liquid culture medium after the microwave radiation is applied to the liquid culture medium.

[0220] 66. The system of any one of embodiments 1 to 63, wherein the electromagnetic field generator is configured to induce the electromagnetic field in the section of the conduit, and the microwave emitter is adapted to emit microwave radiation into the section of the conduit such that the liquid culture medium simultaneously has the electromagnetic field and the microwave radiation applied thereto as the liquid culture medium flows through the section of the conduit.

[0221] 67. The system of any one of embodiments 1 to 66, wherein the output end of the conduit is in fluid communication with a digester such that after flowing through the conduit, the liquid culture medium reaches the digester.

[0222] 68. The system of embodiment 67, wherein the digester is an anaerobic digester.

[0223] 69. The system of embodiment 67, wherein the digester is an aerobic digester.

[0224] 70. The system of any one of embodiments 1 to 69, further comprising the liquid culture medium comprising the organic substrate.

[0225] 71. The system of embodiment 70, wherein the temperature of the liquid culture medium is in the range of 5°C to 60°C during passage through the conduit.

[0226] 72. The system of embodiment 70, wherein the temperature of the liquid culture medium during passage through the conduit is in the range of 15°C to 60°C.

[0227] 73. The system of embodiment 70, wherein the temperature of the liquid culture medium is in the range of 30°C to 55°C during passage through the conduit.

[0228] 74. The system of any one of embodiments 70 to 73, wherein the pH of the liquid culture medium is in the range of 3 to 11 during passage through the conduit.

[0229] 75. The system of any one of embodiments 70 to 73, wherein the pH of the liquid culture medium is in the range of 4 to 10 during passage through the conduit.

[0230] 76. The system of any one of embodiments 70 to 73, wherein the pH of the liquid culture medium is in the range of 5 to 10 during passage through the conduit.

[0231] 77. The system of any one of embodiments 70 to 73, wherein the pH of the liquid culture medium is in the range of 6 to 9 during passage through the catheter.

[0232] 78. The system of any one of embodiments 70 to 77, wherein the concentration of the organic substrate within the stream is in the range of 1% to 20%.

[0233] 79. The system of embodiment 78, wherein the concentration of the organic substrate in the stream is at least 2.5%.

[0234] 80. The system of embodiment 78, wherein the concentration of the organic substrate in the stream is at least 3.5 percent.

[0235] 81. The system of embodiment 78, wherein the concentration of the organic substrate in the stream is at least 4 percent.

[0236] 82. The system of any one of embodiments 78 to 81, wherein the concentration of the organic substrate in the stream is at most 16%.

[0237] 83. The system of any one of embodiments 78 to 81, wherein the concentration of the organic substrate in the stream is at most 14 percent.

[0238] 84. The system of any one of embodiments 78 to 81, wherein the concentration of the organic substrate in the stream is at most 12 percent.

[0239] 85. The system of any one of embodiments 78 to 81, wherein the concentration of the organic substrate in the stream is at most 10 percent.

[0240] 86. The system of any one of embodiments 78 to 81, wherein the concentration of the organic substrate in the stream is at most 8 percent.

[0241] 87. The system of any one of embodiments 78 to 81, wherein the concentration of the organic substrate in the stream is at most 7 percent.

[0242] 88. The system of embodiment 78, wherein the concentration of the organic substrate in the stream is in the range of 3% to 15%.

[0243] 89. The system of embodiment 78, wherein the concentration of the organic substrate in the stream is in the range of 3% to 12 percent.

[0244] 90. The system of embodiment 78, wherein the concentration of the organic substrate in the stream is in the range of 5 percent to 12 percent.

[0245] 91. The system of embodiment 78, wherein the concentration of the organic substrate in the stream is in the range of 5 percent to 10 percent.

[0246] 92. The system of any one of embodiments 70 to 91, wherein the organic substrate comprises biomass.

[0247] 93. The system of any one of embodiments 70 to 92, wherein the organic substrate comprises a complex organic polymer.

[0248] 94. The system of embodiment 93, wherein the complex organic polymer comprises lignin.

[0249] 95. The system of embodiment 93 or 94, wherein the complex organic polymer comprises cellulose.

[0250] 96. The system of any one of embodiments 93 to 95, wherein the complex organic polymer comprises pectin.

[0251] 97. The system of any one of embodiments 70 to 96, wherein the organic substrate comprises industrial waste.

[0252] 98. The system of any one of embodiments 60 to 96, wherein the organic substrate comprises sanitary waste.

[0253] 99. The system of any one of embodiments 60 to 96, wherein the organic substrate comprises agricultural waste.

[0254] 100. The system of any one of embodiments 1 to 99, wherein the energy of the electromagnetic field generator and the microwave emitter for treating one cubic meter of the liquid culture medium is in the range of 1 kwh to 18 kwh.

[0255] 101. The system of embodiment 100, wherein the energy is in the range of 1 kwh to 16 kwh.

[0256] 101A. The system of embodiment 100, wherein the energy is in the range of 1 kwh to 14 kwh.

[0257] 101B. The system of embodiment 100, wherein the energy is in the range of 1 kwh to 12 kwh.

[0258] 101C. The system of embodiment 100, wherein the energy is in the range of 1 kwh to 10 kwh.

[0259] 101D. The system of embodiment 100, wherein the energy is in the range of 2 kwh to 10 kwh.

[0260] 101E. The system of any one of embodiments 1 to 101D, adapted to provide an electromagnetic flux density of at most 6 mT.

[0261] 101F. The system of embodiment 101E, wherein the system is adapted such that the electromagnetic flux density is at most 4 mT.

[0262] 101G. The system of embodiment 101E, wherein the system is adapted such that the electromagnetic flux density is at most 3.5 mT.

[0263] 101H. The system of embodiment 101E, wherein the system is adapted such that the electromagnetic flux density is at most 3 mT.

[0264] 102. The system of embodiment 101E, wherein the system is adapted to provide an electromagnetic flux density of at most 2.5 mT.

[0265] 103. The system of any one of embodiments 101E to 102, wherein the system is adapted to provide an electromagnetic flux density of at least 1 mT.

[0266] 104. The system of embodiment 103, wherein the system is adapted to provide an electromagnetic flux density of at least 1.5 mT.

[0267] 105. The system of embodiment 103, wherein the system is adapted to provide an electromagnetic flux density of at least 1.75 mT.

[0268] 106. A method for pretreating an organic substrate in a liquid culture medium to promote its anaerobic or aerobic digestion, the method comprising: allowing a flow of the liquid culture medium containing the organic substrate to flow through a conduit; and during the passage of the liquid culture medium through the conduit: inducing an electromagnetic field into the interior of the conduit so that the electromagnetic field is applied to the liquid culture medium; and emitting microwave radiation into the conduit so that the microwave radiation is applied to the liquid culture medium.

[0269] 107. A method for producing biogas from an organic substrate in a liquid culture medium, the method comprising: allowing a flow of the liquid culture medium containing the organic substrate to flow through a conduit; while the liquid culture medium passes through the conduit: inducing an electromagnetic field into the interior of the conduit so that the electromagnetic field is applied to the liquid culture medium; and emitting microwave radiation into the conduit so that the microwave radiation is applied to the liquid culture medium; and after applying the electromagnetic field and the microwave radiation to the liquid culture medium, producing biogas by digesting the liquid culture medium leaving the conduit.

[0270] 108. The method of embodiment 106 or 107, wherein allowing the liquid culture medium to flow through the conduit comprises opening a valve between the conduit and a source of the liquid culture medium to allow the liquid culture medium to flow into the conduit.

[0271] 109. The method of embodiment 106 or 107, wherein allowing the liquid culture medium to flow through the conduit comprises pumping the liquid culture medium into the conduit.

[0272] 110. The method of any one of embodiments 106 to 109, wherein inducing the electromagnetic field comprises passing electricity through a metal wire spiraled around the conduit.

[0273] 111. The method of any one of embodiments 106 to 110, wherein the electromagnetic field has a first frequency within the range of any one of embodiments 7 to 23.

[0274] 112. The method of any one of embodiments 106 to 111, wherein inducing the electromagnetic field comprises inducing an alternating current (AC) electromagnetic field.

[0275] 113. The method of any one of embodiments 106 to 112, wherein the microwave radiation has a second frequency or a microwave frequency within the range of any one of embodiments 25 to 40.

[0276] 114. The method of any one of embodiments 106 to 113, further comprising electronically controlling or modulating the induction of the electromagnetic field generator and the emission of the microwave radiation based on at least one criterion of the conduit or the liquid culture medium within the conduit.

[0277] 115. The method of embodiment 114, wherein the at least one criterion comprises the flow rate of the liquid culture medium within the conduit.

[0278] 116. The method of embodiment 114, wherein the at least one criterion comprises the temperature of the liquid culture medium within the conduit.

[0279] 117. The method of embodiment 114, wherein the at least one criterion comprises the temperature of the conduit.

[0280] 118. The method of embodiment 114, wherein the at least one criterion comprises the pH of the liquid culture medium within the conduit.

[0281] 119. A method as described in any of embodiments 114 to 118, wherein the controlling includes: determining whether the at least one criterion is met based on at least one sensor input.

[0282] 120. The method of embodiment 119, wherein the at least one sensor input comprises an input from a flow rate sensor.

[0283] 121. A method as described in embodiment 119 or 120, wherein the at least one sensor input includes input from a temperature sensor.

[0284] 122. The method of any one of embodiments 119 to 121, wherein the at least one sensor input comprises input from a pH sensor.

[0285] 123. The method of any one of embodiments 119 to 122, wherein the at least one sensor input comprises an input from a chemical sensor.

[0286] 124. The method of any one of embodiments 106 to 123, wherein said inducing the electromagnetic field occurs before said emitting the microwave radiation, such that as the liquid culture medium flows through the conduit, the electromagnetic field is applied to the liquid culture medium before the microwave radiation is applied to the liquid culture medium.

[0287] 125. The method of any one of embodiments 106 to 123, wherein said inducing the electromagnetic field occurs after said emitting the microwave radiation, such that as the liquid culture medium flows through the conduit, the electromagnetic field is applied to the liquid culture medium after the microwave radiation is applied to the liquid culture medium.

[0288] 126. The method of any one of embodiments 106 to 123, wherein said inducing said electromagnetic field and said emitting said microwave radiation occur simultaneously such that said liquid culture medium simultaneously has said electromagnetic field and said microwave radiation applied thereto as said liquid culture medium flows through said section of said conduit.

[0289] 127. The method of any one of embodiments 106 to 126, further comprising: conveying the output of the conduit to an anaerobic digester for anaerobic digestion of the organic substrate in the liquid culture medium.

[0290] 128. The method of any one of embodiments 106 to 126, further comprising conveying the output of the conduit to an aerobic digester for aerobic digestion of the organic substrate in the liquid culture medium.

[0291] 129. The method of any one of embodiments 106 to 128, wherein the temperature of the liquid culture medium is in the range of 5°C to 60°C.

[0292] 130. The method of embodiment 129, wherein the temperature is in the range of 15°C to 60°C.

[0293] 130. The method of embodiment 129, wherein the temperature is in the range of 30°C to 55°C.

[0294] 131. The method of any one of embodiments 106 to 130, wherein the pH of the liquid culture medium is in the range of 3 to 11 during passage through the catheter.

[0295] 132. The method of any one of embodiments 106 to 130, wherein the pH of the liquid culture medium is in the range of 4 to 10 during passage through the catheter.

[0296] 133. The method of any one of embodiments 106 to 130, wherein the pH of the liquid culture medium is in the range of 5 to 10 during passage through the catheter.

[0297] 134. The method of any one of embodiments 106 to 130, wherein the pH of the liquid culture medium is in the range of 6 to 9 during passage through the catheter.

[0298] 135. The method of any one of embodiments 106 to 134, wherein the concentration of the organic substrate in the stream is in the range of 1% to 20%.

[0299] 136. The method of embodiment 135, wherein the concentration of the organic substrate in the stream is at least 2.5%.

[0300] 137. The method of embodiment 135, wherein the concentration of the organic substrate in the stream is at least 3.5 percent.

[0301] 138. The method of embodiment 135, wherein the concentration of the organic substrate in the stream is at least 4 percent.

[0302] 139. The method of any one of embodiments 135 to 138, wherein the concentration of the organic substrate in the stream is at most 16%.

[0303] 140. The method of any one of embodiments 135 to 139, wherein the concentration of the organic substrate in the stream is at most 14 percent.

[0304] 141. The method of any one of embodiments 135 to 138, wherein the concentration of the organic substrate in the stream is at most 12 percent.

[0305] 142. The method of any one of embodiments 135 to 138, wherein the concentration of the organic substrate in the stream is at most 10 percent.

[0306] 143. The method of any one of embodiments 135 to 138, wherein the concentration of the organic substrate in the stream is at most 8 percent.

[0307] 144. The method of any one of embodiments 135 to 138, wherein the concentration of the organic substrate in the stream is at most 7 percent.

[0308] 145. The method of embodiment 135, wherein the concentration of the organic substrate in the stream is in the range of 3% to 15%.

[0309] 146. The method of embodiment 135, wherein the concentration of the organic substrate in the stream is in the range of 3% to 12 percent.

[0310] 147. The method of embodiment 135, wherein the concentration of the organic substrate in the stream is in the range of 5 percent to 12 percent.

[0311] 148. The method of embodiment 135, wherein the concentration of the organic substrate in the stream is in the range of 5 percent to 10 percent.

[0312] 149. The method of any one of embodiments 106 to 148, wherein the organic substrate comprises biomass.

[0313] 150. The method of any one of embodiments 106 to 149, wherein the organic substrate comprises a complex organic polymer.

[0314] 151. The method of embodiment 150, wherein the complex organic polymer comprises lignin.

[0315] 152. The method of embodiment 150 or 151, wherein the complex organic polymer comprises cellulose.

[0316] 153. The method of any one of embodiments 150 to 152, wherein the complex organic polymer comprises pectin.

[0317] 154. The method of any one of embodiments 106 to 153, wherein the organic substrate comprises industrial waste.

[0318] 155. The method of any one of embodiments 106 to 154, wherein the organic substrate comprises sanitary waste.

[0319] 156. The method of any one of embodiments 106 to 155, wherein the organic substrate comprises agricultural waste.

[0320] 157. The method of any one of embodiments 106 to 156, wherein the organic substrate comprises biosolids.

[0321] 158. The method of any one of embodiments 106 to 157, wherein the energy used to process one cubic meter of the liquid culture medium during the allowing, the sensing, and the emitting is in the range of 1 kwh to 18 kwh.

[0322] 159. The method of embodiment 157, wherein the energy is in the range of 1 kwh to 16 kwh.

[0323] 160. The method of embodiment 157, wherein the energy is in the range of 1 kwh to 14 kwh.

[0324] 161. The method of embodiment 157, wherein the energy is in the range of 1 kwh to 12 kwh.

[0325] 162. The method of embodiment 157, wherein the energy is in the range of 1 kwh to 10 kwh.

[0326] 163. The method of embodiment 157, wherein the energy is in the range of 2 kwh to 10 kwh.

[0327] 164. The method of any one of the preceding embodiments, wherein the electromagnetic flux density of the electromagnetic field is at most 6 millitesla (mT) or at most 5 mT.

[0328] 165. The system of embodiment 164, wherein the electromagnetic flux density is at most 4 mT.

[0329] 166. The system of embodiment 164, wherein the electromagnetic flux density is at most 3.5 mT.

[0330] 167. The system of embodiment 164, wherein the electromagnetic flux density is at most 3 mT.

[0331] 168. The system of embodiment 164, wherein the electromagnetic flux density is at most 2.5 mT.

[0332] 169. The system of any one of embodiments 164 to 168, wherein the electromagnetic flux density is at least 1 mT.

[0333] 170. The system of embodiment 169, wherein the electromagnetic flux density is at least 1.5 mT.

[0334] 171. The system of embodiment 169, wherein the electromagnetic flux density is at least 1.75 mT.

[0335] 172. The method of any one of embodiments 106 to 171, further comprising any one of the features of embodiments 1 to 105.

[0336] 173. A method for converting an anaerobic digestion plant to pre-treat an organic substrate to be anaerobically digested, the anaerobic digestion plant comprising: an input conduit that directs the organic substrate to an anaerobic digester, the method comprising: providing a system for improving digestion of an organic substrate in a liquid culture medium according to embodiment 5; and placing the casing around the input conduit of the anaerobic digestion plant.

[0337] 174. A method for modifying an aerobic wastewater treatment plant to pre-treat biosolids to increase their biodegradability, the aerobic wastewater treatment plant comprising: an input conduit that directs the organic substrate to an aerobic digester, the method comprising: providing a system for improving digestion of an organic substrate in a liquid culture medium according to embodiment 5; and placing the casing around the input conduit of the aerobic wastewater treatment plant.

[0338] It will be appreciated that certain features of the invention described for clarity in the context of separate embodiments may also be provided in combination in a single embodiment. Conversely, various features of the invention described for clarity in the context of a single embodiment may also be provided separately or in any suitable subcombination.

[0339] Although the present invention has been described in conjunction with specific embodiments thereof, it is apparent that many substitutions, modifications, and variations are apparent to those skilled in the art. Therefore, it is intended to encompass all such substitutions, modifications, and variations that fall within the spirit and broad scope of the appended claims. All disclosures, patents, and patent applications mentioned in this specification are incorporated herein by reference in their entirety, just as each individual disclosure, patent, or patent application is specifically and individually indicated as being incorporated herein by reference. In addition, citation or identification of any reference in this application should not be construed as an admission that the reference can be used as prior art for the present invention.

Claims

1. A system for improving digestion of an organic substrate in a liquid culture medium, the system comprising: a conduit adapted to have a stream flowing therethrough, the stream comprising the liquid culture medium and the organic substrate; an electromagnetic field generator, the electromagnetic field generator being disposed circumferentially around the conduit, the electromagnetic field generator being adapted to induce an electromagnetic field into the interior of the conduit, such that the electromagnetic field is applied to the liquid culture medium when the liquid culture medium flows through the conduit; and a microwave emitter attached to the conduit, the microwave emitter adapted to emit microwave radiation into the conduit such that the microwave radiation is applied to the liquid culture medium as it flows through the conduit; The microwave emitter is adapted to emit microwave radiation having a microwave frequency in the range of 1 GHz to 4 GHz.

2. The system of claim 1, wherein the electromagnetic field generator is adapted such that the electromagnetic field is an alternating current (AC) electromagnetic field having a first frequency in the range of 30 Hz to 120 Hz.

3. The system of claim 1 or 2, wherein the microwave transmitter comprises: microwave generator; and at least one antenna extending from the microwave generator into the conduit.

4. The system according to any one of claims 1 to 3, further comprising: a controller functionally associated with the microwave emitter and the electromagnetic field generator, the controller being adapted to electronically control or modulate operation of the electromagnetic field generator and the microwave emitter based on at least one criterion of the conduit or the liquid culture medium within the conduit.

5. The system of any one of claims 1 to 4, wherein the electromagnetic field generator is configured to induce the electromagnetic field in the section of the conduit, and the microwave emitter is adapted to emit microwave radiation into the section of the conduit such that when the liquid culture medium flows through the section of the conduit, the liquid culture medium simultaneously has the electromagnetic field and the microwave radiation applied thereto.

6. The system of any one of claims 1 to 5, wherein the output end of the conduit is in fluid communication with a digester, such that after flowing through the conduit, the liquid culture medium reaches the digester.

7. A method for pretreating an organic substrate in a liquid culture medium to promote anaerobic or aerobic digestion thereof, the method comprising: Providing a system according to any one of claims 1 to 6; allowing a flow of the liquid culture medium comprising the organic substrate to flow through the conduit; as well as During the passage of the liquid culture medium through the catheter: inducing the electromagnetic field into the interior of the conduit such that the electromagnetic field is applied to the liquid culture medium; and emitting the microwave radiation into the conduit such that the microwave radiation is applied to the liquid culture medium; as well as Biogas is produced by digesting the liquid culture medium exiting the conduit.

8. The method of claim 7, wherein the electromagnetic flux density of the electromagnetic field is in the range of 1 millitesla (mT) to 4 mT.

9. The method of claim 8, wherein the electromagnetic field has an electromagnetic flux density of at most 3.5 mT.

10. The method of claim 8, wherein the electromagnetic field has an electromagnetic flux density of at most 3 mT.

11. The method of any one of claims 7 to 10, wherein the electromagnetic field is an alternating current (AC) electromagnetic field having a first frequency in the range of 30 Hz to 120 Hz.

12. The method of any one of claims 7 to 11, further comprising electronically controlling or modulating the induction of the electromagnetic field generator and the emission of the microwave radiation based on at least one criterion of the conduit or the liquid culture medium within the conduit.

13. The method of claim 12, wherein the at least one criterion comprises a flow rate of the liquid culture medium within the conduit.

14. The method of claim 12 or 13, wherein the at least one criterion comprises the temperature of the liquid culture medium within the conduit.

15. The method of any one of claims 12 to 14, wherein the at least one criterion comprises the temperature of the conduit.

16. The method of any one of claims 12 to 15, wherein the at least one criterion comprises the pH of the liquid culture medium within the conduit.

17. The method of any one of claims 12 to 16, wherein the controlling comprises determining whether the at least one criterion is met based on at least one sensor input.

18. The method of any one of claims 12 to 17, wherein the organic substrate comprises biomass.

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