UV-c based polishing system for disinfecting biogas

Abstract

A system and method disinfecting high-pressure, low-gravity fluids, with a linear high-pressure vessel containing an axial fluid chamber comprising quartz comprises the steps of flowing the high-pressure, low-gravity fluid through the axial fluid chamber; generating ultraviolet-C radiation using a UV-C light source positioned along the length of the axial fluid chamber within unique pressure tolerate quartz vessels (transversally mounted); and exposing the high-pressure, low-gravity fluid to the ultraviolet-C radiation as it passes through the axial fluid chamber, thereby inactivating targeted microorganisms.

Description

UV-C BASED POLISHING SYSTEM FOR DISINFECTING BIOGASCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 582,817, filed September 14, 2023, the entire disclosure of which is incorporated herein by reference.TECHNICAL FIELD

[0002] The present disclosure relates to a system and method for the disinfection of high- pressure, low-gravity fluids using ultraviolet-C radiation in an inline treatment zone of a biogas transmission line.BACKGROUND

[0003] Microbial contamination in biogas / bio-methane production will result in bacterial causing corrosion (biofilm formation) in pipelines, storage tanks, and equipment; thus leading to leaks, failures, and reduced effectiveness of transport systems. This results in extensive maintenance and repair costs. Additionally, certain bacteria reduce sulfates which results in the production of hydrogen sulfide, a toxic and corrosive gas that lowers the quality of the biogas. This may also increase emissions, lower combustion efficiency, and result in a loss of product value. For example, bacterial contamination causes fouling, plugging, and sludge formation in pipelines and storage tanks while the production of hydrogen sulfide may result in toxic exposure for workers and the environment (with decreased product quality).

[0004] Disinfection of high-pressure, low-gravity fluids, such as natural gas, is essential for reducing the presence of harmful microorganisms that produce impurities, lead to corrosion, and may impact the overall quality of the gas. Traditional methods of disinfection are not effective (as evidenced by the massive cost of corrosion mitigation). No current treatment mechanism is efficient (to manage gaseous effluents in high-pressure environments). Utilization of UV-C to disinfect fluids has historically been limited to low and medium pressure environments and / or high gravity fluids. There is a need for a commercially scalable disinfection method that can effectively target specific microorganisms, including but not limited to sulfate-reducing bacteria (SRB), acid producing bacteria (APB), methanotrophs, and acidophiles; in a high-pressure (e.g. pressures exceeding 100 psi), in a low-gravity fluid.SUMMARY

[0005] The present disclosure includes one or more of the features recited in the appended claims and / or the following features which, alone or in any combination, may comprise patentable subject matter.

[0006] According to one aspect of the present disclosure, a method for disinfecting high- pressure, low-gravity fluids, with a linear high-pressure vessel containing an axial fluid chamber (including unique pressure seal design), and transverse quartz chambers in the flow stream of the high-pressure, low-gravity fluid. Within the transversally oriented quartz chambers through the axial fluid vessel; ultraviolet-C radiation using a UV-C light source positioned along the length of each quartz chamber espouses the high-pressure, low-gravity fluid to the ultraviolet-C radiation as it passes through the axial fluid chamber, thereby inactivating targeted microorganisms.

[0007] In some embodiments of this aspect, the targeted microorganisms comprise chemo-lithotrophs, methanotrophs, and acidophiles (including but not limited to all SRBs and APBs).

[0008] In some embodiments of this aspect, the high-pressure, low-gravity fluid is natural gas.

[0009] According to another aspect of the present disclosure, an apparatus for disinfecting high-pressure, low-gravity fluids, comprises: a linear high-pressure vessel; transverse quartz chambers located within the linear high-pressure vessel; a UV-C light source positioned along the length of each transverse quarts chamber; and a means for flowing the high-pressure, low- gravity fluid through the axial fluid chamber and exposing it to the ultraviolet-C radiation generated by the UV-C light source to deactivate microorganisms in the high-pressure, low- gravity fluid.

[0010] In some embodiments of this aspect, the targeted microorganisms comprise chemo-lithotrophs, methanotrophs, and acidophiles (including but not limited to all SRBs and APBs).

[0011] In some embodiments of this aspect, the high-pressure, low-gravity fluid is natural gas.

[0012] In some embodiments of this aspect, the apparatus further comprises a means for controlling the intensity and duration of the ultraviolet-C radiation to deliver a sufficient fluence for the inactivation of the targeted microorganisms.

[0013] In some embodiments of this aspect, the apparatus further comprises a means for monitoring the treatment dose in real time; and presence / concentration of targetedmicroorganisms in the high-pressure, low-gravity fluid before and after exposure to the ultraviolet-C radiation.

[0014] In some embodiments of this aspect, the apparatus further comprises a means for managing gaseous effluents generated during the disinfection process.

[0015] According to yet another aspect of the present disclosure, a system for enhancing the specifications of natural gas, comprises a linear high-pressure vessel (axial flow chamber for high pressure low gravity fluids); transverse quartz chambers that house a UV-C light source with multiple positions along the length of the axial fluid chamber; a means for flowing the high- pressure, low-gravity fluid through the axial fluid chamber and exposing it to the ultraviolet-C radiation generated by the UV-C light source; and a means for managing gaseous effluents generated during the disinfection process.

[0016] In some embodiments of this aspect, the targeted microorganisms comprise chemo-lithotrophs, methanotrophs, and acidophiles (including but not limited to all SRBs and APBs).

[0017] In some embodiments of this aspect, the system further comprises a means for controlling the intensity and duration of the ultraviolet-C radiation to deliver a sufficient fluence for the inactivation of the targeted microorganisms.

[0018] In some embodiments of this aspect, the system further comprises a means for monitoring the presence and concentration of targeted microorganisms in the high-pressure, low- gravity fluid before and after exposure to the ultraviolet-C radiation.

[0019] In some embodiments of this aspect, the enhanced specification natural gas has a reduced presence of harmful microorganisms, leading to improved gas quality and reduced maintenance costs associated with corrosion and impurity formation.

[0020] According to still another aspect of the present disclosure, a method for disinfecting a high-pressure, low-gravity fluid, comprises the steps of: providing a linear high- pressure vessel; providing a quartz site window in series; providing an axial fluid chamber made of quartz, located within the linear high-pressure vessel; providing a UV-C light source positioned along the length of the axial fluid chamber; flowing the high-pressure, low-gravity fluid through the axial fluid chamber; exposing the high-pressure, low-gravity fluid to ultraviolet-C radiation generated by the UV-C light source to inactivate targeted microorganisms; and managing gaseous effluents generated during the disinfection process.

[0021] In some embodiments of this aspect, the targeted microorganisms comprise chemo-lithotrophs, methanotrophs, and acidophiles (including but not limited to all SRBs and APBs).

[0022] In some embodiments of this aspect, the method further comprises controlling the intensity and duration of the ultraviolet-C radiation to deliver a sufficient fluence for the inactivation of the targeted microorganisms.

[0023] In some embodiments of this aspect, the method further comprises monitoring the presence and concentration of targeted microorganisms in the high-pressure, low-gravity fluid before and after exposure to the ultraviolet-C radiation.

[0024] In some embodiments of this aspect, the high-pressure, low-gravity fluid is natural gas.

[0025] In some embodiments of this aspect, the enhanced specification natural gas has a reduced presence of harmful microorganisms, leading to improved gas quality and reduced maintenance costs associated with corrosion and impurity formation.

[0026] According to yet still another aspect of the present disclosure, a method for enhancing the specifications of natural gas, comprising the steps of: providing a system for disinfecting a high-pressure, low-gravity fluid; flowing the natural gas through the system; and inactivating targeted microorganisms in the natural gas through exposure to ultraviolet-C radiation, thereby improving gas quality and reducing maintenance costs associated with corrosion and impurity formation.

[0027] According to even another aspect of the present disclosure, a method for reducing the presence of sulfate-reducing bacteria (SRB) in a high-pressure, low-gravity fluid, comprises the steps of: providing a linear high-pressure vessel; providing an axial fluid chamber made of quartz, located within the linear high-pressure vessel; providing a UV-C light source positioned along the length of the axial fluid chamber; flowing the high-pressure, low-gravity fluid through the axial fluid chamber; exposing the high-pressure, low-gravity fluid to ultraviolet-C radiation generated by the UV-C light source to inactivate SRB such as Desulfovibrio, Desulfotomaculum, and Desulfobacter; and managing gaseous effluents generated during the disinfection process.

[0028] In some embodiments of this aspect, the high-pressure, low-gravity fluid is natural gas.

[0029] In some embodiments of this aspect, the method further comprises controlling the intensity and duration of the ultraviolet-C radiation to deliver a sufficient fluence for the inactivation of SRB.

[0030] In some embodiments of this aspect, the method further comprises monitoring the presence and concentration of SRB in the high-pressure, low-gravity fluid before and after exposure to the ultraviolet-C radiation.

[0031] In some embodiments of this aspect, the method further comprises the step of pretreating the high-pressure, low-gravity fluid to remove particulate matter, which may interfere with the effectiveness of the ultraviolet-C radiation during the disinfection process.

[0032] In some embodiments of this aspect, the method further comprises the step of posttreating the high-pressure, low-gravity fluid to remove any residual gaseous effluents or byproducts generated during the disinfection process.

[0033] According to even yet another aspect of the present disclosure, a method for reducing the presence of methanotrophs in a high-pressure, low-gravity fluid, comprises the steps of: providing a linear high-pressure vessel; providing an axial fluid chamber made of quartz, located within the linear high-pressure vessel; providing a UV-C light source positioned along the length of the axial fluid chamber; flowing the high-pressure, low-gravity fluid through the axial fluid chamber; exposing the high-pressure, low-gravity fluid to ultraviolet-C radiation generated by the UV-C light source to inactivate methanotrophs; and managing gaseous effluents generated during the disinfection process

[0034] In some embodiments of this aspect, the high-pressure, low-gravity fluid is natural gas.

[0035] In some embodiments of this aspect, the method further comprises controlling the intensity and duration of the ultraviolet-C radiation to deliver a sufficient fluence for the inactivation of methanotrophs.

[0036] In some embodiments of this aspect, the method further comprises monitoring the presence and concentration of methanotrophs in the high-pressure, low-gravity fluid before and after exposure to the ultraviolet-C radiation.

[0037] In some embodiments of this aspect, the method further comprises the step of pretreating the high-pressure, low-gravity fluid to remove particulate matter, which may interfere with the effectiveness of the ultraviolet-C radiation during the disinfection process.

[0038] In some embodiments of this aspect, the method further comprises the step of posttreating the high-pressure, low-gravity fluid to remove any residual gaseous effluents or byproducts generated during the disinfection process.

[0039] According to even still another aspect of the present disclosure, a linear high- pressure vessel comprises: a cylindrical body having an inlet and an outlet for the high-pressure, low-gravity fluid; a pressure-resistant sealing mechanism at both ends of the cylindrical body to maintain the high pressure within the vessel; an internal support structure to hold the axial fluid chamber securely in place; and a heat dissipation mechanism to regulate the temperature within the vessel during the disinfection process.

[0040] In some embodiments of this aspect, the vessel further comprises the pressureresistant sealing mechanism comprises high-pressure gaskets and mechanical fasteners, such as bolts or clamps.

[0041] In some embodiments of this aspect, the internal support structure comprises clamps configured to hold the axial fluid chamber in position without obstructing the flow of the high-pressure, low-gravity fluid.

[0042] In some embodiments of this aspect, the internal support structure comprises brackets configured to hold the axial fluid chamber in position without obstructing the flow of the high-pressure, low-gravity fluid.

[0043] In some embodiments of this aspect, the internal support structure comprises clamps configured to hold the axial fluid chamber in position without obstructing the flow of the high-pressure, low-gravity fluid.

[0044] In some embodiments of this aspect, the heat dissipation mechanism comprises a cooling jacket surrounding the cylindrical body, through which a coolant fluid is circulated to regulate the temperature within the vessel.

[0045] In some embodiments of this aspect, the internal support structure comprises brackets configured to hold the axial fluid chamber in position without obstructing the flow of the high-pressure, low-gravity fluid.

[0046] In some embodiments of this aspect, the heat dissipation mechanism comprises a cooling jacket surrounding the cylindrical body, through which a coolant fluid is circulated to regulate the temperature within the vessel.

[0047] In some embodiments of this aspect, the vessel further comprises a UV-C light source having a plurality of UV-C emitting lamps arranged transversally along the length of the axial fluid chamber; a power supply and control system to regulate the intensity and duration of the ultraviolet-C radiation; and a monitoring system to measure the fluence delivered to the high- pressure, low-gravity fluid during the disinfection process.

[0048] In some embodiments of this aspect, the UV-C emitting lamps are mercury vapor lamps, low-pressure mercury lamps, medium-pressure mercury lamps, or light-emitting diodes (LEDs).

[0049] In some embodiments of this aspect, the power supply and control system includes an automated control algorithm to adjust the intensity and duration of the ultraviolet-C radiation based on the concentration of microorganisms in the high-pressure, low-gravity fluid.

[0050] Additional features, which alone or in combination with any other feature(s), such as those listed above and / or those listed in the claims, can comprise patentable subject matter and will become apparent to those skilled in the art upon consideration of the following detaileddescription of various embodiments exemplifying the best mode of carrying out the embodiments as presently perceived.BRIEF DESCRIPTION OF THE DRAWINGS

[0051] The detailed description particularly refers to the accompanying figures in which:

[0052] Fig. 1 is a schematic diagram of a network of biogas producing sites feeding a biogas processing plant which transfers processed biogas to a storage and distribution network;

[0053] Fig. 2 is a schematic diagram of the processing plant utilizing a polishing / scrubbing system of the present disclosure to treat biogas to deactivate microorganisms in the biogas;

[0054] Fig. 3 is perspective view of an embodiment of a polisher according to the present disclosure;

[0055] Fig 4A is a perspective view of a portion of the polisher of Fig. 3 with portions removed;

[0056] Fig. 4B is an end view of the portion of the polisher in Fig. 4A;

[0057] Fig. 5 is a perspective view of a portion of an alternative embodiment of a polisher of the present disclosure;

[0058] Fig 6 is a perspective view of a portion of yet another alternative embodiment similar to the embodiment shown in Fig. 5 with portions omitted;

[0059] Fig. 7 is an exploded view of a portion of the alternative embodiment shown in Fig. 6;

[0060] Fig. 8 is a cross-sectional view of a portion of the embodiment of Fig. 6; and

[0061] Fig. 9 is a block diagram of a control system of the polisher of Fig. 3.DETAILED DESCRIPTION

[0062] The present disclosure is directed to a polishing / scrubbing system for renewable natural gas (RNG) which are biogases including biomethane and liquefied biomethane and which are hereinafter may be referred to as either a biofluid or biogas. RNG is the gaseous product of the decomposition of organic matter that is processed to be readily usable as a direct substitute to naturally occurring natural gas. As will be described in more detail, the disclosed method and the system 100 utilizes a UV-C based approach to target bacteria in untreated RNG, whether it is gaseous or liquefied, with continuous dose verification to confirm anti-bacterial efficiency. Utilizing the method disclosed herein, the system 100 targets bacteria such that it is deactivated before reaching pipeline and storage facilities, thereby reducing the wear typically associated with biogases the acids normally present in RNG, the acids being formed by the bacteria that isnaturally present in the biogas. The biogas includes a number of microorganisms including, but not limited to chemo-lithotrophs, methanotrophs, and acidophiles. The microorganisms may specifically include sulfate-reducing bacteria (SRB) such as Desulfovibrio, Desulfotomaculum, Desulfobacter and other known ARBs. The biogas is typically transported through at high pressures, such as pressures greater than 145 pounds per square inch. The biogas is normally a low gravity fluid in either the gaseous or liquid states. More specifically, the present disclosure includes targeting chemo-lithotrophs, methanotrophs, and acidophiles and other acid and biofilm producing bacteria, in natural gas, reclaimed natural gas (RNG) biogas, sustainable aviation fuels, and other fluids, including but not limited to reclaimed commercial sources, utilizing radiation transmitted through an axial flow chamber comprised of a combination of radiation impermeable alloy, unique and previously undescribed junction seals further combined with specific and required quartz or a synthetic analogue produced of radiation transmissible chambers tolerant of a high (and variable) pressure treatment environment.

[0063] Referring to Fig. 1, a typical biogas delivery system 10 includes a number of biogas producers 12 that may be dispersed over a geographical area and operable to generate biogas. Examples of biogas producers 12 include landfills, animal manure digesters, and wastewater treatment facilities. It should be understood that while the term biogas is used throughout the remainder of this disclosure, the term refers to the material, not the state. Those of ordinary skill in the art will understand that the biogas may be in a gaseous or liquefied state throughout the processing and delivery cycle, depending on the operating conditions. The present disclosure is applicable to both gaseous and liquefied biogas. As shown in Fig. 1, one might think of the various biogas producers 12 as being different leach fields or beds in landfill. The native gas is pumped from its respective sources by pumps 14 to a central processing plant 16. One or more compressors 18 may be used to increase the pressure of a supply line 20 to the processing plant 16, depending on the needs of the particular processing plant 16 and the volume biogas being produced and treated. Once the biogas is treated by the processing plant 16, the clean biogas is transferred by a pump 22 where it may be accumulated in a storage vessel 24, such as underground storage. While not germane to this disclosure, the stored clean biogas is delivered to a distribution system by a pump 22 where it may be mixed with other sources of natural gas and delivered to end users.

[0064] Referring now to Fig. 2, a schematic of a typical biogas processing scheme is shown. The biogas enters the processing plant 16 and may enter a compressor 26. The biogas is then processed through a dehydration circuit 28 where excess water is removed from the biogas as condensate at outlet 30. The dehydrated biogas is then fed to the polisher 32 of the present disclosure. When referring to the various circuits in Fig. 2, it should be understood that the solidlines indicate a combustible gas, dashed lines indicate a flow of air, and dotted lines indicate a flow of water. Once the biogas is treated by the polisher 32, the biogas may be further treated by a system that includes a water scrubber 34, a flash tank 36, and a stripper 38. A cooling circuit 40 cools water in a recirculation loop 48 from the stripper 38 to the water scrubber 34. As shown in Fig. 2, the finally treated biogas from the water scrubber 34 is further treated by a drying circuit 42 and the clean biogas is fed to the pump 22 as indicated at 44. While the scheme shown in Fig. 2 is one example of a potential processing circuit for processing biogas using the polisher 32 of the present disclosure, a number of other processing schemes are known in the art and the polisher 32 may be integrated into such other schemes, as will be understood by those of ordinary skill in the art.

[0065] Referring now to Fig. 3, an exemplary embodiment of the polisher 32 is shown. The polisher 32 is shown to be embodied as an inline structure with three separate treatment zones 50, 52, and 54 interposed between two pipe segments 56 and 58. The treatment zones 50 and 54 are each configured to be coupled to a pipeline such that the entire polisher 32 occupies a portion of the piping structure in the processing plant 16. The polisher 32 includes a frame 60 that supports a controller 62 (shown in Fig. 8) which occupies two enclosures 64 and 66 in the illustrative embodiment.

[0066] Referring to Fig. 9, the controller 62 is shown as part of an overall control system 68 which also includes a sensor system 70 and a user interface 72. The controller 62 is a conventional controller that includes a processor 74 and a memory device 76. The memory device 76 includes non-volatile storage of instructions that, when executed by the processor 74, control the operation of the polisher 32. The controller 62 is in communication with the user interface 72 which also includes a processor 80 and a memory device 82. The user interface 72 is operable to perform functions that provide information and data to a user regarding the operation of the polisher 32, but which are not part of the critical operation of the controller 62 such that a user may review historical data and access real-time data from the controller 62. As such, the memory device 82 includes non-volatile storage of instructions that, when executed by the processor 80, provide an interface and output for a user.

[0067] The treatment zones 52, 54, and 56 each include a treatment controller 100 having a memory device 102 and a processor 104 and a number of light sources 106 which, are controlled by the treatment controller 100 and are operable to have a variable intensity and wavelength, which is modified under the operation of the treatment controller 100 to compensate for changes in the biogas, as detected by the sensor system 70, to effectively treat the biogas. The light sources 106 generate ultraviolet-C radiation. The light sources 106 may be embodied as mercury vapor lamps, low-pressure mercury lamps, medium-pressure mercury lamps, light-emitting diodes(LEDs), or any other appropriate light source capable of delivering a variable intensity and wavelength to generate ultraviolet-C radiation. The memory device 102 includes non-volatile storage of instructions that, when executed by the processor 104, receives information from the polisher controller 62 and, based on the information received from the polisher controller 62, modifies the operation of the treatment controller 100 associated with the specific treatment zone 52, 54, and 56 to operate the specific treatment zone 52, 54, or 56 as indicated by the polisher controller 62.

[0068] The sensor system 70 includes pressure sensors 90, flow sensors 92, intensity sensors 94, gas sniffers 96, and biomaterial sensors 98 in the illustrative embodiment. Any of a number of other sensors may be included in the sensor system 70, as understood by those of ordinary skill in the art. In the present embodiment, the pressure sensors 92 and flow sensors 94 provide information to the controller 62 regarding the flow of gas through the polisher 32 so that the controller 62 may control the operation of the UV-C sources to maintain an effective level of light generation to treat the biogas traveling through the polisher 32. The treatment is operated to irradiate the biogas at sufficient fluence to effectively deactivate any microorganisms, such as bacteria. The intensity sensor 94 is operable to confirm the proper operation of the UV-C sources. The sniffer 96 is operable to monitor the area around the polisher 32 to detect for any leakage of biogas such that the controller 32 may provide an alarm to a central monitoring system or to modify operation of the polisher 32 to mitigate risks associated with such a leakage. The biomaterial sensors 98 are operable to detect the level, and in some cases, the identity of particular organisms in the flow of biogas to provide a control signal for the treatment controller 100 to vary the operation of the light sources 106 to effectively treat the biogas. In some embodiments, one or more biomaterial sensors 98 may be positioned up-stream from the treatment zones 52, 54, and 56. In some embodiments, one or more biomaterial sensors 98 may be positioned up-stream from the treatment zones 52, 54, and 56 to confirm the efficacy of the treatment.

[0069] It is contemplated by the present disclosure that the processors 74, 80, 102 may be embodied as, or otherwise be included in, without limitation, an embedded computing system, a System-on-a-Chip (SoC), a multiprocessor system, a processor-based system, a microcontroller, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), and / or any other similar computing device. The present disclosure also contemplates that memory devices 76, 82, 104 may be embodied as one or more of volatile memory, non-volatile memory, random access memory (RAM), read only memory (ROM), a media disk, magnetic disk, optical storage, flash memory devices, and other similar devicescapable of storing software for controlling functions. The memory devices 76, 82, 104 may be an independent device or integrated with any device serving as a processor 74, 80, 100.

[0070] It should be understood that the control system 68 may employ the RS-485 communications protocol over a twisted-pair bus. It should be understood that any of a number of communications protocols known in the art may be used for the communications between components of the control system 68, including, but not limited to, Echelon, CAN, SPI, USB, and LIN or another suitable electronic communications protocol. In still other embodiments, the communications may include circuitry that allows for a hardwired connection using an IEEE 802.3 connection, an RS-232 compliant connection, an RS-483 compliant connection, or other protocols known in the art including other wireless protocols. For example, the control system 68 may use of any one or more communication technologies (e.g., wired or wireless communications) and associated protocols (e.g., Ethernet, InfiniBand®, Wi-Fi®, WiMAX, 3G, 4G LTE, 5G, etc.) to effect communications between components within the control system 68 and to external systems.

[0071] Referring again now to Fig. 3, the treatment zones 52, 54, and 56 are shown to include an enclosure structure 110 with intensity sensors 94 positioned about the periphery of the respective zone 52, 54, and 56. Each intensity sensor 94 is operable to measure the respective portion of the intensity within the treatment zone 52, 54, or 56. The pipe segments 56 and 58 include the appropriate pressure sensors 90 and flow sensors 92 positioned in the pipe segments 56 and 58 as is known in the art.

[0072] Now, turning to Figs. 4A and 4B, a portion of the polisher 32 is shown to provide an example of the structure. A treatment controller 100 is shown in the treatment zone 56 with a light source 106. The light source 106 operates a number of illuminated elements 112 arranged along an axial direction of the treatment zones 52, 54, and 56 and about the circumference of the respective treatment zone 52, 54, or 56. The illuminated elements 112 are adjacent a sight glass 114 which is a cylindrical structure formed of polished quartz which provides an uninterrupted media allowing the light from the illuminated elements 112 to impinge upon the biogas traveling through the polisher 32, to thereby treat the biogas. The enclosure structure 110 has a reflective interior surface which increases the amount of light energy that is impinged upon the biogas.

[0073] The sight glass 114 is placed under compression by a number of bolts 120, some of which are shown in Fig. 4A. The bolts 120 extend between flanges 122 of the treatment zones 52, 54, and 56 and are torqued to a pre-set pressure to provide the compression necessary for the sight glass 114 to be able to withstand a maximum allowable pressure (MAOP) in excess of 145 pounds per square inch (PSI). The use of polished quartz for the sight glass is appropriate here as quartz may be used in applications having temperatures exceeding 500 degrees Fahrenheit, itexhibits excellent thermal shock resistance, corrosion resistance, abrasion resistance, with has good pressure performance a reasonable impact resistance. In some embodiments, another crystal structure, such as a sapphire based crystal structure may be used for the sight glass.

[0074] Referring now to Figs. 5-8, an alternative embodiment of a treatment section 152 includes a number of treatment assemblies 120 positioned transverse to an axis 166 of a pressure vessel 154. The treatment assemblies 120 of Figs. 5-8 are positioned in a pipe 126 and extend through holes 124 formed in the pipe 126. The pressure vessel 154 is supported on a frame 156 and includes couplers 170, 172 positioned on flanges 174, 176 of the pressure vessel 154. The couplers 170, 172 serve as vibration dampers that prevent vibrations from sources external to the treatment section 152 from being transferred to the pressure vessel 154.

[0075] The treatment assemblies 120 are supported in an upper manifold 178 and a lower manifold 180, the manifolds 178 and 180 configured to allow cooled air to be transferred between the treatment assemblies 120 to cool the treatment assemblies 120 during use. The frame 156 includes a number of legs 182, each leg 182 secured to adjacent legs 182 by longitudinal stringers 184 and lateral stringers 186. The legs 182 are supported on isolation pads 188 which provide damping of vibrations from the floor 190 from being transferred to the legs 182 and, thereby, the treatment section 152.

[0076] In the embodiment of Fig. 5, each treatment assembly 120 includes a light source 106 supported in a cooling tube 194 that extends through the manifold 178. Each light source 106 includes an illuminated element 112 that extends through the cooling tube 194 into a polished crystal tube 196. The crystal tube 196, illustratively a polished sapphire tube, allows light from the illuminated element 112 to pass through the crystal tube 196. Each crystal tube 196 is secured to the pipe 126 by a compression fitting (not shown) and extends through the pipe 126. This allows the light from the illuminated element 112 to pass through the crystal tube 196 to act on a biogas flowing through the treatment section 152. Each crystal tube 196 engages cooling tube 194 and another cooling tube 200 supported from the manifold 180. Cooled air is passed through both the upper manifold 178 and lower manifold 180 to circulate air among the cooling tubes 194 and 200 to cool the light sources 106.

[0077] Referring now to the embodiment of Figs. 6-8, a treatment zone 250 includes a pressure vessel 252 that includes a longitudinal pipe 254 having an axis 256. The pressure vessel 252 includes flanges 258, 260 secured to the pipe 254. In some embodiments, the treatment zone 250 may also include couplers 170, 172 as discussed above. The pressure vessel 252 may be supported on a frame similar to frame 156. The pressure vessel includes a number of mounts 262 positioned transverse to the pipe 254 with matching mounts 262 positioned on opposite sides of the pipe 254 so that respective mounts 262 are aligned along an axis 264. Each aligned pair ofmounts 262, 262 are configured to support a treatment assembly 270 that extends through an interior space 272 of the pressure vessel 252. Each treatment assembly 270 includes an inlet air line 274 and an outlet air line 276, the inlet air line 274 and outlet air line 276 providing a flow path for cooled air to be passed through the treatment assembly 270 to cool the respective treatment assembly 270.

[0078] Referring now to Figs. 7 and 8, a respective treatment assembly 270 is secured to the aligned mounts 262, 262 such that a crystal tube 280 is positioned in the mounts 262, 262 and extends through the interior space 272. An illuminated element 112 is positioned through the crystal tube 280 so that light from the illuminated element 112 passes through the crystal tube 280 to impinge upon biogas passing through the interior space 272. The crystal tube 280 is positioned between an upper seal 282 and a lower seal 298 which prevents the biogas from escaping past the crystal tube 280. The upper portion of the treatment assembly 270 is secured to a mount 262 by an upper cap 286 which has female threads 288 secured to male threads 290 of the mount 262. The lower portion of the treatment assembly 270 is secured to a mount 262 by a lower cap 292 which includes female threads 294 secured to the male threads 290 of the mount 262.

[0079] The lower cap 292 supports a port 296 which provides a flow path through the lower cap 292 and into a space 284 where the treatment illuminated element 112 is positioned to allow the air from the inlet air line 274 to flow through the crystal tube 280. The treatment assembly 270 includes a light source 106 that includes the illuminated element 112, the light source 106 being sealed by a seal 300 such that an air flow through the space 284 passes around the light source 106 and out a port 296 to the outlet air line 276. The use of the seals 282, 298, and 300 prevents biogas from escaping from the pressure vessel 252 and provides a flow path for chilled air to pass through the space 284 to cool the light source 106.

[0080] Each of the treatment assemblies 270 can be cooled independently by chilled air that may be supplied by a central cooling system. It should be understood that in both of the embodiments of Fig. 5 and Figs. 6-8 could include all of the control components of the control system 68 such that each of the light sources 106 in each embodiment may be controlled independently to provide delivering a variable intensity and wavelength to generate ultraviolet-C radiation as needed to provide effective dosing of the biogas traversing the particular system.

[0081] The transverse approaches shown in the embodiments of Figs. 5-8 may utilize any of a number of sealing approaches to allow the cross-flow of cooled air to traverse the respective treatment assembly 120, 270 while sealing the respective pressure vessel 154, 252 from leaking biogas. Typical sealing approaches, including brazing, welding, o-ring seals, compression seals, or other similar approaches may be used in various embodiments.

[0082] The disclosed crystal tubes 196, 280 may be constructed of quartz, sapphire, or other similar crystal structure which allows the UV-C light to pass through the crystal to effectively dose the biogas. The use of the removable crystal tubes 196, 280 allows for easy removal, replacement, and / or cleaning of the crystal tubes 196, 280, such as to address solarization of the surface of the crystal tubes 196, 280 that are exposed to the biogas during the treatment process. Placing the crystal tubes 196, 280 transverse to the longitudinal axes of the pressure vessels 154, 252 tends to induce chaotic flow in the treatment assemblies 120, 270, thereby improving the effectiveness of the treatment assemblies 120, 270 by increasing the exposure of the biogas to the illumination of the lighting elements 112.

[0083] Although this disclosure refers to specific embodiments, it will be understood by those skilled in the art that various changes in form and detail may be made without departing from the subject matter set forth in the accompanying claims. The disclosure has been illustrated and described in detail in the drawings and the foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive. From reading the present disclosure, other modifications will be apparent to a person skilled in the art. Such modifications may involve other features, which are already known in the art and may be used instead of or in addition to features already described herein or may involve the interchanging or addition of various elements of each separate disclosed embodiment into other disclosed embodiments as would be apparent to those of ordinary skill in the art. In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality.

Claims

WHAT IS CLAIMED IS:

1. A method for disinfecting high-pressure (> 145 psi MAOP), low-gravity fluids, with a linear high-pressure vessel containing an axial fluid chamber comprising quartz, the method comprising: flowing the high-pressure, low-gravity fluid through the axial fluid chamber; generating ultraviolet-C radiation using a UV-C light source positioned along the length of the axial fluid chamber; and exposing the high-pressure, low-gravity fluid to the ultraviolet-C radiation as it passes through the axial fluid chamber, thereby inactivating targeted microorganisms.

2. The method of claim 1, wherein the targeted microorganisms comprise chemo-lithotrophs, methanotrophs, and acidophiles.

3. The method of claim 1, wherein the high-pressure, low-gravity fluid is natural gas.

4. An apparatus for disinfecting high-pressure, low-gravity fluids, comprising: a linear high-pressure vessel; an axial fluid chamber made of quartz, located within the linear high-pressure vessel; a UV-C light source positioned along the length of the axial fluid chamber; and a means for flowing the high-pressure, low-gravity fluid through the axial fluid chamber and exposing it to the ultraviolet-C radiation generated by the UV-C light source to deactivate microorganisms in the high-pressure, low-gravity fluid.

5. The apparatus of claim 4, wherein the targeted microorganisms comprise chemo-lithotrophs, methanotrophs, and acidophiles.

6. The apparatus of claim 4, wherein the high-pressure, low-gravity fluid is natural gas.

7. The apparatus of claim 4, further comprising a means for controlling the intensity and duration of the ultraviolet-C radiation to deliver a sufficient fluence for the inactivation of the targeted microorganisms.

8. The apparatus of claim 4, further comprising a means for monitoring the presence and concentration of targeted microorganisms in the high-pressure, low-gravity fluid before and after exposure to the ultraviolet-C radiation.

9. The apparatus of claim 4, further comprising a means for managing gaseous effluents generated during the disinfection process.

10. A system for enhancing the specifications of natural gas, comprising: a linear high-pressure vessel; a site window chamber; an axial fluid chamber made of quartz, located within the linear high-pressure vessel; a UV-C light source positioned along the length of the axial fluid chamber; a means for flowing the high-pressure, low-gravity fluid through the axial fluid chamber and exposing it to the ultraviolet-C radiation generated by the UV-C light source; and a means for managing gaseous effluents generated during the disinfection process.

11. The system of claim 10, wherein the targeted microorganisms comprise chemo-lithotrophs, methanotrophs, and acidophiles.

12. The system of claim 10, further comprising a means for controlling the intensity and duration of the ultraviolet-C radiation to deliver a sufficient fluence for the inactivation of the targeted microorganisms.

13. The system of claim 10, further comprising a means for monitoring the presence and concentration of targeted microorganisms in the high-pressure, low-gravity fluid before and after exposure to the ultraviolet-C radiation.

14. The system of claim 10, wherein the enhanced specification natural gas has a reduced presence of harmful microorganisms, leading to improved gas quality and reduced maintenance costs associated with corrosion and impurity formation.

15. A method for disinfecting a high-pressure, low-gravity fluid, comprising the steps of:providing a linear high-pressure vessel; providing a quartz site window in series; providing an axial fluid chamber made of quartz, located within the linear high- pressure vessel; providing a UV-C light source positioned along the length of the axial fluid chamber; flowing the high-pressure, low-gravity fluid through the axial fluid chamber; exposing the high-pressure, low-gravity fluid to ultraviolet-C radiation generated by the UV-C light source to inactivate targeted microorganisms; and managing gaseous effluents generated during the disinfection process.

16. The method of claim 15, wherein the targeted microorganisms comprise chemo-lithotrophs, methanotrophs, and acidophiles.

17. The method of claim 15, further comprising controlling the intensity and duration of the ultraviolet-C radiation to deliver a sufficient fluence for the inactivation of the targeted microorganisms.

18. The method of claim 15, further comprising monitoring the presence and concentration of targeted microorganisms in the high-pressure, low-gravity fluid before and after exposure to the ultraviolet-C radiation.

19. The method of claim 15, wherein the high-pressure, low-gravity fluid is natural gas.

20. The method of claim 15, wherein the enhanced specification natural gas has a reduced presence of harmful microorganisms, leading to improved gas quality and reduced maintenance costs associated with corrosion and impurity formation.

21. A method for enhancing the specifications of natural gas, comprising the steps of: providing a system for disinfecting a high-pressure, low-gravity fluid as described in claim 10; flowing the natural gas through the system; andinactivating targeted microorganisms in the natural gas through exposure to ultraviolet-C radiation, thereby improving gas quality and reducing maintenance costs associated with corrosion and impurity formation.

22. A method for reducing the presence of sulfate-reducing bacteria (SRB) in a high-pressure, low-gravity fluid, comprising the steps of: providing a linear high-pressure vessel; providing an axial fluid chamber made of quartz, located within the linear high- pressure vessel; providing a UV-C light source positioned along the length of the axial fluid chamber; flowing the high-pressure, low-gravity fluid through the axial fluid chamber; exposing the high-pressure, low-gravity fluid to ultraviolet-C radiation generated by the UV-C light source to inactivate SRB such as Desulfo vibrio, Desulfotomaculum, and Desulfobacter; and managing gaseous effluents generated during the disinfection process.

23. The method of claim 22, wherein the high-pressure, low-gravity fluid is natural gas.

24. The method of claim 22, further comprising controlling the intensity and duration of the ultraviolet-C radiation to deliver a sufficient fluence for the inactivation of SRB.

25. The method of claim 22, further comprising monitoring the presence and concentration of SRB in the high-pressure, low-gravity fluid before and after exposure to the ultraviolet-C radiation.

26. A method for reducing the presence of methanotrophs in a high-pressure, low-gravity fluid, comprising the steps of: providing a linear high-pressure vessel; providing an axial fluid chamber made of quartz, located within the linear high- pressure vessel; providing a UV-C light source positioned along the length of the axial fluid chamber; flowing the high-pressure, low-gravity fluid through the axial fluid chamber;exposing the high-pressure, low-gravity fluid to ultraviolet-C radiation generated by the UV-C light source to inactivate methanotrophs; and managing gaseous effluents generated during the disinfection process.

27. The method of claim 26, wherein the high-pressure, low-gravity fluid is natural gas.

28. The method of claim 26, further comprising controlling the intensity and duration of the ultraviolet-C radiation to deliver a sufficient fluence for the inactivation of methanotrophs.

29. The method of claim 26, further comprising monitoring the presence and concentration of methanotrophs in the high-pressure, low-gravity fluid before and after exposure to the ultraviolet-C radiation.

30. A linear high-pressure vessel comprising: a cylindrical body having an inlet and an outlet for the high-pressure, low-gravity fluid; a pressure-resistant sealing mechanism at both ends of the cylindrical body to maintain the high pressure within the vessel; an internal support structure to hold the axial fluid chamber securely in place; and a heat dissipation mechanism to regulate the temperature within the vessel during the disinfection process.

31. The vessel of claim 30, wherein the pressure-resistant sealing mechanism comprises high-pressure gaskets and mechanical fasteners, such as bolts or clamps.

32. The vessel of claim 30, wherein the internal support structure comprises a series of brackets or clamps configured to hold the axial fluid chamber in position without obstructing the flow of the high-pressure, low-gravity fluid.

33. The vessel of claim 30, wherein the heat dissipation mechanism comprises a cooling jacket surrounding the cylindrical body, through which a coolant fluid is circulated to regulate the temperature within the vessel.

34. The vessel of claim 30, further comprising a UV-C light source having: a plurality of UV-C emitting lamps arranged longitudinally along the length of the axial fluid chamber; a power supply and control system to regulate the intensity and duration of the ultra violet-C radiation; and a monitoring system to measure the fluence delivered to the high-pressure, low- gravity fluid during the disinfection process.

35. The vessel of claim 34, wherein the UV-C emitting lamps are mercury vapor lamps, low-pressure mercury lamps, medium-pressure mercury lamps, or light-emitting diodes (LEDs).

36. The vessel of claim 34, wherein the power supply and control system includes an automated control algorithm to adjust the intensity and duration of the ultraviol et-C radiation based on the concentration of microorganisms in the high-pressure, low-gravity fluid.

37. The method of claim 22 or 26, further comprising the step of pre-treating the high-pressure, low-gravity fluid to remove particulate matter, which may interfere with the effectiveness of the ultraviolet-C radiation during the disinfection process.

38. The method of claim 22 or 26, further comprising the step of post-treating the high-pressure, low-gravity fluid to remove any residual gaseous effluents or byproducts generated during the disinfection process.

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