Plasma / ion reactor for processing fluorocarbon materials.

Abstract

A plasma or ionic reactor or gasifier performs a hyperthermic ionic gasification process that can be used, for example, to generate renewable syngas that can be used to provide heat, power, renewable fuels, renewable hydrogen, and / or renewable chemical production, for example, to dispose of dry biosolids from wastewater treatment plants and other waste feedstocks, such as municipal solid waste (MSW), in an environmentally friendly manner. To do so, the systems described herein generate an electric arc across the interior of the gasifier reaction chamber, which, together with ionized gases or particles (plasma), creates localized, controlled temperatures exceeding 3000°C. This hyperthermic gasification zone and active ionic environment combine to very effectively and efficiently break down molecules into their component atoms in a process called total molecular dissociation. This hyperthermic ionic zone also rapidly decomposes impurities in the feedstock, such as microplastics, PFAS (per- and polyfluorinated compounds), and other fluorocarbon materials.

Description

[Technical Field]

[0001] (Related Applications) This application claims priority to U.S. Provisional Patent Application No. 63 / 426,110, entitled "Plasma / Ionic Reactor for Processing PFAS," filed November 17, 2022, and U.S. Provisional Patent Application No. 63 / 449,886, entitled "Plasma / Ionic Reactor for Processing Fluorocarbon Materials," filed March 3, 2023, the entire disclosures of each of which are expressly incorporated herein by reference.

[0002] FIELD OF THE INVENTION This patent relates generally to plasma arc or ion reactors and / or gasifier systems, and more particularly to advanced plasma arc or ion reactors used to gasify heterogeneous materials to produce various products such as synthesis gas and to reduce or eliminate fluorocarbon materials such as per- or polyfluoroalkyl substances (PFAS). [Background technology]

[0003] Plasma is generally defined as a collection of charged particles, including an equal number of positive ions and electrons as well as excited neutral particles. Plasma exhibits some properties of gases but is also a good conductor of electricity and can be affected by magnetic fields. One method of generating plasma is to pass a gas through an electric arc. The arc heats the gas to very high temperatures within a fraction of a second through resistive and radiative heating. Essentially, any gas can be used to generate plasma in this manner. Thus, inert or neutral gases (e.g., argon, helium, neon, or nitrogen) can be used. Depending on how the plasma is utilized, reducing gases (e.g., steam, hydrogen, methane, ammonia, or carbon monoxide) can also be used, as can oxidizing gases (e.g., steam, oxygen, or carbon dioxide).

[0004] Known plasma generators, which have been used with or as part of plasma torches, plasma jets, and plasma arc reactors, generally generate a discharge in a working gas to produce plasma. Plasma generators have been categorized as direct current (DC) plasma generators, alternating current (AC) plasma generators, radio frequency (RF) plasma generators, and microwave (MW) plasma generators. Plasma generated by RF or MW sources is called inductively coupled plasma. For example, an RF-type plasma generator includes an RF source and an induction coil surrounding the working gas. The RF signal sent from the source to the induction coil ionizes the working gas through inductive coupling to generate plasma. DC-type and AC-type generators may include two or more electrodes (e.g., an anode and a cathode) between which a voltage is applied. An arc may be formed between the electrodes to heat and ionize the surrounding gas, causing the gas to attain a plasma state. The resulting plasma can then be used for specific processing applications.

[0005] Plasma or ion reactors using plasma generators typically come in two types: plasma jet reactors and plasma arc reactors. In a plasma jet reactor (typically called a plasma torch), an arc is generated between a cathode and an anode electrode positioned close to each other within the torch body. A working gas then passes through the arc, generating a plume or flame of plasma within it. This plume or flame then exits the torch output as a stream of high-temperature plasma, typically into a reaction chamber. In a plasma arc reactor, the cathode and anode are spaced apart across a reaction chamber, i.e., on opposite sides of the reaction chamber. A working gas may be introduced to flow through or between the cathode and / or anode to keep these elements cool. In these systems, an unconfined arc generated between the cathode and anode electrodes converts the working gas into plasma within the reaction chamber between the electrodes. Both plasma jet reactors and plasma arc reactors have advantages and disadvantages depending on the application. Nevertheless, both types of plasma reactors can be used to heat material compounds to high temperatures to accommodate chemical or material processing. Such chemical and material processing can include the reduction and decomposition of hazardous substances. In other applications, plasma reactors have been utilized to aid in the extraction of desired materials, such as metals or metal alloys, from compounds containing the desired materials.

[0006] However, processing applications utilizing plasma generators or plasma reactors are often specialized. As a result, the associated plasma reactors must be designed and configured according to very specific criteria required by the particular application to which the reactor is put. Such specialized designs often result in devices of limited usefulness. In other words, a plasma reactor configured to process a particular type of material using a particular working gas is likely not suitable for use in other processes in which different materials are processed using a different working gas.

[0007] U.S. Patent No. 10,208,263 describes an improved plasma gasifier system that uses a set of circumferentially arranged electrodes surrounding a circular or cylindrical reaction or processing chamber through which the material to be processed flows to generate an electric arc. The operation of the system's electrodes generates an electric arc within the reaction chamber, thus allowing direct contact between one or more electric arcs and the material being processed within the chamber, providing better heating of the material being processed than previously known plasma reactors. More specifically, the '263 patent describes a modular DC-DC plasma reactor for industrial applications, including the gasification of biomass and non-biomass combustible materials to produce synthesis gas composed primarily of carbon monoxide (CO) and hydrogen (H). The plasma reactor generates a large, uniform, high-temperature (over 7000 Kelvin) plasma with a long residence time tailored for material processing. The plasma reactor has long electrodes positioned radially opposite each other within a modular plasma unit, with the electrodes arranged circumferentially around the reaction chamber. The plasma units can be stacked to form an elongated plasma zone. As a result, the material being treated can flow continuously from one modular plasma unit to the next, creating an energy cascade effect from the upstream plasma unit to the downstream plasma unit, with the bottom modular plasma unit producing the brightest plasma illumination. Each plasma unit further defines an internal plasma zone accessible through an access port. An electrode assembly extends into the access port, each with an electrode tip positioned within the internal plasma zone at a selected insertion depth. Each electrode tip is mounted within the tubular support jacket such that a gas conduit for supplied working gas surrounds at least a portion of the tubular support jacket. When an arc is generated at the electrode tip, working gas flows through the gas conduit and is directed toward the arc, generating plasma within the internal reaction or plasma zone.

[0008] Furthermore, this system has adjustable control, providing improved flexibility with respect to the plasma generated within the reaction chamber, and the plasma volume generated can be easily adjusted and defined to optimize plasma interactions. Furthermore, U.S. Patent No. 10,926,238 describes an improved electrode assembly that can be used, for example, in the '263 system, to provide improved cooling and control of the electrodes used therein. Summary of the Invention

[0009] The plasma or ionic reactor or gasifier performs a hyperthermic ionic gasification process that can be used, for example, to generate renewable syngas that can be used to provide heat, power, renewable fuels, renewable hydrogen, and / or renewable chemical production, for example, to dispose of dry biosolids from wastewater treatment plants and other waste feedstocks, such as municipal solid waste (MSW), in an environmentally friendly manner. To do so, the systems described herein generate an electric arc across the interior of the gasifier reaction chamber, which, together with ionized gases or particles (plasma), generates localized, controlled temperatures well above 3000°C. This hyperthermic gasification zone and active ionic environment combine to very effectively and efficiently break down molecules into their constituent atoms and ions in a process called complete molecular dissociation and ionization. This hyperthermic ionic zone also rapidly decomposes impurities in the feedstock, such as microplastics, PFAS (per- and / or polyfluorinated compounds), and other fluorocarbon materials.

[0010] In one aspect, the disclosure relates to a method of processing a material, the method including: receiving an input material to be processed in a reaction chamber, the input material including at least one fluorocarbon material (or PFAS); applying electricity to one or more sets of electrodes, each set of electrodes including an anode electrode and a cathode electrode, each anode electrode and cathode electrode having an electrode tip exposed to the reaction chamber; and generating an electric arc between the anode electrode tip and the cathode electrode tip in the reaction chamber, exposing at least a portion of the input material to the electric arc, thereby destroying at least a portion of the fluorocarbon material (or PFAS) and forming a processed material having a lower fluorocarbon material (or PFAS) content than the input material.

[0011] The hybrid plasma or ionic reactor described herein includes the basic components of both a plasma jet reactor and a plasma arc reactor, which operate simultaneously to provide high-temperature ionic gas and an electric arc within the reaction chamber to significantly increase the processing of materials within the reaction chamber. In some cases, the hybrid plasma reactor system includes one or more sets of counter electrodes extending into the reaction chamber and a plasma torch positioned on another side of the chamber, such as the top of the chamber. The counter electrodes operate to directly contact the material being processed within the reaction chamber to cause an arc discharge and plasma gas generation within the reaction chamber, and the plasma torch operates to generate and direct additional plasma (generated within the plasma torch) into the reaction chamber. In this manner, the working material is exposed to the arc discharge and plasma generated by the arc electrodes as well as the plasma generated by the plasma torch, increasing the heat and ionic activity to which the material being processed is exposed within the reaction chamber. The plasma torch can inject plasma into the chamber generally coincident with, or generally perpendicular or orthogonal to, the arc discharge generated by the arc electrodes to provide additional plasma and ionic reactions within the reaction chamber.

[0012] Additionally, the improved plasma or ion reactor described herein uses multiple sets of arc electrodes arranged around the reaction chamber in a unique manner that operates to create a larger area in the center of the reaction or plasma chamber where the arc travels between the anode and cathode of a pair of electrodes, effectively increasing the size of the reaction zone in which the arc resides. Because electric arcs are generally relatively small in size or cross-section, the area within the reaction chamber directly exposed to a particular arc can be relatively small. The improved plasma or ion reactor operates to create expanded arc discharge areas within the plasma or reaction chamber and increase the temperature within those areas by positioning the anodes and cathodes of various pairs of electrodes at angles other than 180 degrees relative to one another, such as acute, 90-degree, or obtuse angles, such that the arc generated by the electrodes does not necessarily travel through the center of the reaction chamber, but rather the arcs generated by different sets of electrodes travel through the reaction chamber on various different paths through the chamber, better distributing the arc throughout the chamber. Distributing the arc more evenly throughout the reaction chamber provides better or more uniform treatment of the material flowing through the chamber and a larger active reaction zone through which the material passes, allowing the chamber to be used for new purposes such as producing carbon nanoparticles.

[0013] Furthermore, the improved plasma or arc reactor includes a structure that introduces the working or cooling gas used to cool the electrodes into the reaction chamber in a swirling flow manner, helping to create a confined or directed gas flow within the reaction chamber. This directed gas flow ionizes in response to the arc discharge, and the flow vortex prevents the gas from rapidly dispersing, exposing the gas to the arc discharge for a longer period of time and promoting gas ionization. The ionized gas then aids in material processing within the chamber. To help maintain a confined flow of the working gas, a rotating vortex is generated within the working gas as it flows into the plasma or reaction chamber, with the central axis of the vortex oriented along the path of the arc. However, if the cathode and anode electrodes are located on opposite sides of the plasma chamber, applying the same rotating vortex to the gas emitted by each of these electrodes will cause the two vortices to spin in opposite directions when they intersect at the center of the plasma or reaction chamber. This interaction can cause significant instabilities to the arc column within the chamber because the opposing spins of the gas vortices cause the vortices to cancel each other out as the gas flows interact, which in turn disperses the working gas more quickly. The improved plasma or ion reactor described herein can discharge the working gases from different electrodes into the reaction chamber so that they have opposing vortices, allowing the working gases to add constructively within the reaction chamber and enabling better or more directed gas flow through the reaction chamber and arc discharge within the reaction chamber. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a front view of an exemplary embodiment of a plasma or ion gasifier including multiple plasma units stacked adjacent to one another to form a reaction chamber. [Figure 2] 2 is a selective cross-sectional top view of a plasma unit or ion unit used in the exemplary embodiment of the plasma gasifier of FIG. 1. [Figure 3] 2 is a partial perspective view of a plasma unit used in the exemplary embodiment of the plasma gasifier of FIG. 1. FIG. [Figure 4] 2 shows a cross-sectional view of an exemplary electrode assembly that may be used in the plasma gasifier of FIG. 1. [Figure 5] 5 illustrates a first configuration of a tubular support jacket within the electrode assembly of FIG. 4. [Figure 6] 5 illustrates a second configuration of the tubular support jacket within the electrode assembly of FIG. 4. [Figure 7] FIG. 1 is a schematic diagram showing a plasma module having a hybrid plasma jet and plasma arc system in a vertical configuration. [Figure 8] 2 is a perspective partial cross-sectional view of a hybrid plasma or ion reactor having a plasma reactor similar to that of FIG. 1 and including a plasma torch positioned vertically above the plasma reactor. [Figure 9] FIG. 1 is a schematic diagram illustrating a plasma module having a hybrid plasma jet and plasma arc system in a transverse configuration. [Figure 10] 2 is a schematic top view of the plasma unit of the gasifier of FIG. 1 including a first offset electrode arrangement. [Figure 11] FIG. 2 is a schematic top view of the plasma unit of the gasifier of FIG. 1 including a second offset electrode arrangement. [Figure 12] FIG. 2 is a schematic top view of the plasma unit of the gasifier of FIG. 1 including a third offset electrode arrangement. [Figure 13] FIG. 2 is a schematic top view of the plasma unit of the gasifier of FIG. 1 including a fourth offset electrode arrangement. [Figure 14] FIG. 2 is a schematic top view of the plasma unit of the gasifier of FIG. 1 including a fifth offset electrode arrangement. [Figure 15] 11 shows a first set of test results for decomposing methane using a plasma gasifier having the plasma unit of FIG. 10. [Figure 16]11 shows a second set of test results for decomposing methane using a plasma gasifier having the plasma unit of FIG. 10. [Figure 17] FIG. 1 shows a schematic diagram illustrating a simple plasma module or unit having a single arc electrode set configured to introduce a working gas having a vortex into a cylindrical reaction chamber. [Figure 18] FIG. 1 shows a schematic diagram of a cross section of a first exemplary embodiment of a plasma arc system having grooves formed on the outer surface of an arc electrode to induce vortices in a working gas introduced into a reaction chamber. [Figure 19] FIG. 1 shows a schematic diagram of a cross section of a second exemplary embodiment of a plasma arc system having grooves formed on an inner surface of an arc electrode body to induce vortices in a working gas introduced into a reaction chamber. DETAILED DESCRIPTION OF THE INVENTION

[0015] 1-3 illustrate a basic plasma or ionizable gasifier 10, to which the improvements described herein can be implemented to make the plasma or ionizable gasifier 10 more efficient, perform better material processing, and / or be applicable to the processing of a wider range of materials or applications. Referring to FIG. 1 , the plasma or ionizable gasifier 10 processes an input material 12 introduced into an input 13 of the gasifier 10 to produce an output material 14 emitted from an output 15 of the gasifier 10. The output material 14 may be, for example, syngas and / or other materials described herein. As shown in FIG. 1 , the plasma gasifier 10 includes one or more circular plasma units 16 stacked in series (i.e., aligned along a longitudinal axis passing through the center of each unit 16) with each plasma unit 16 formed from an outer ring of circular (cross-sectional) shape and with a cylindrical interior space defined in the center of the outer ring. This interior space constitutes a plasma or reaction zone 18 within the gasifier 10. Additionally, each plasma unit 16 has one or more sets of electrodes 20 extending through its outer wall into the reaction chamber 18. Each set of electrodes 20 includes an anode electrode and a cathode electrode extending radially toward the center of the plasma unit 16. Each set of electrodes 20 is coupled to a working gas source 22, a coolant source 24, and a power source 26 by various applicable conductors or electrical connectors. Generally speaking, the working gas source 22 supplies a working gas to each electrode 20, which is transported through the electrode and released from the electrode into the reaction chamber 18, as described in more detail herein. The working gas helps cool the electrode tips of the electrodes 20 and is further exposed to the high electric fields and arc discharge generated by the electrodes 20 within the reaction chamber 18, resulting in ionization and generation of plasma within the reaction chamber 18. The coolant source 24 provides coolant to the electrodes 20 to help prevent the electrodes 20 from overheating during use. This coolant may be recirculated and cooled within the coolant supply 24 to form a closed coolant loop. Additionally, the coolant for each electrode assembly 20 may be supplied via a high-pressure pump.After cooling the electrodes or electrode tips, the coolant may exit the electrode assembly 20 and be stored in a reservoir (not shown), as described in more detail herein. The coolant in the reservoir, where fresh water is available, may be kept cool by a cooling unit (not shown), such as a portable water heat exchanger. In another embodiment, where fresh water is not available, the cooling unit may be a chemical-based chiller or any other cooling unit.

[0016] Furthermore, the power supply 26 supplies power to the electrodes with sufficient power (e.g., voltage and current) to generate an arc discharge between the anode and cathode of each electrode pair 20. The power supply 26 may be, for example, an AC power supply capable of supplying one-phase or three-phase AC power to the electrodes 20, or may be a DC power supply. A separate power supply 26 may be provided for each set or pair of electrodes 20, or a combined power supply may provide power to the multi-polar electrode pairs 20. However, the power signal sent to each pair of electrodes 20 may be electrically isolated from the power signals sent to other pairs or sets of electrodes 20. Furthermore, the electrode assemblies 20 may be connected to the power supply 26 via a water-cooled cable, providing both a cooling path and a current path for the electrode assemblies 20.

[0017] While a single plasma unit 16 can be used, performance can be optimized by using multiple plasma units 16 stacked next to each other or adjacent to each other so that their outer walls or rings are aligned longitudinally. For example, in FIG. 1 , the plasma gasifier 10 is shown as including four stacked plasma units 16 forming an elongated tubular or cylindrical reaction zone 18. However, it should be understood that the plasma gasifier 10 can have any number or multiple stacked plasma units 16, including only one. By stacking the plasma units 16, the plasma zone or reaction zone 18 is elongated along the longitudinal axis of the gasifier 10, and this elongated space or reaction chamber 18 can extend or increase the processing time of the influent material 12 introduced into the reaction chamber 18 of the plasma gasifier 10, as the influent material 12 flows sequentially through each of the different plasma units 16 as it moves from the input 13 to the output 15 of the gasifier 10. Additionally, the modular configuration created by stacking multiple plasma units 16 adjacent to (e.g., on top of) one another allows an operator to independently manipulate the power settings, e.g., at the electrodes 20, in each of the plasma units 16 to achieve the overall temperature profile of the plasma gasifier 10. An operator or designer can further add or remove modular plasma units 16 to achieve a desired residence time for complete gasification of a particular class of influent material 12.

[0018] As more clearly shown in FIG. 2 , which shows a longitudinal view of one of the plasma units 16 of FIG. 1 , each plasma unit 16 has an annular body 28 with an inner wall 30 and an outer wall 32. The inner wall 30 defines a central plasma zone or reaction chamber 34 (e.g., forming part of the reaction chamber 18 of FIG. 1 ). The inner wall 30 is refractory and can contain the heat of the plasma without significant degradation. A preferred material for the inner wall 30 is graphite. However, certain refractory ceramics can also be used. A gap space 36 exists between the inner wall 30 and the outer wall 32. The gap space 36 is filled with an insulating material 38, such as high-temperature ceramic fiber. In one embodiment, the insulator 38 (e.g., ceramic fiber) may be, but is not limited to, zirconia fiber. Alternatively and / or additionally, granular sand and / or granular oxide material can be used as the insulator 38. Ceramic fiber or granular oxide material has significant advantages over conventional solid, high-density block oxide insulation because the granular oxide and / or ceramic fiber blanket constitutes a very low-density packing material with significant voids therein. These voids have very low thermal conductivity and provide excellent insulating properties. The very low-density insulating material further reduces the overall weight of the gasifier 10.

[0019] In any event, the annulus 28 and the central plasma zone 34 are concentrically aligned when the plasma units 16 are stacked. Furthermore, the central plasma zone 34 of each plasma unit 16 is accessible via multiple access ports 40. Preferably, each plasma unit 16 includes at least eight access ports 40, although any other number, including more or fewer access ports 40, can be used. Each of the access ports 40 is lined with a sleeve of a refractory material, such as a ceramic material, that can maintain the integrity of the thermal field of the plasma generated within the reaction chamber 34. Furthermore, each access port 40 can be used to insert or hold an electrode 42 therein. Accordingly, having at least two access ports 40 in each plasma unit 16, and an even number of access ports 40, is preferred, although this is not strictly necessary. Furthermore, one or more of the access ports 40 can be used to house or insert a sensor of some kind to provide measurement or observation of the reaction within the reaction chamber 34.

[0020] A majority of the access port 40 of each plasma unit 16 receives an electrode or electrode assembly 42. Each electrode assembly 42 is surrounded by an insulator sized to fit within the access port 40 with close tolerances. The tolerances prevent significant gaps between the insulator and the interior of the access port 40 that could allow plasma to escape from the plasma gasifier 10. As will be explained in more detail below, each electrode assembly 42 includes an electrode tip 46 and a gas conduit 47 (shown in dashed relief in one electrode 42 in FIG. 2). The electrode tip 46 extends into the central plasma zone 34 and generates an arc with another electrode tip 46 during operation. The gas conduit 47 introduces working gas from the working gas supply 22, FIG. 1, into the plasma or reaction zone 34, where the working gas is converted to plasma by the arc generated between the two electrode tips 46. Each electrode assembly 42 is cooled by coolant from the coolant supply 24, FIG. 1. It will further be appreciated that each of the electrode assemblies 42 is coupled to the power source 26 of FIG. 1 for receiving power (voltage and current).

[0021] Generally speaking, each plasma unit 16 receives two sets of electrode assemblies 42. Therefore, each plasma unit 16 can receive two, four, six, eight, or more of the electrode assemblies 42, depending on the number of access ports 40 present. The electrodes of the first set of electrode assemblies 42 are positioned at a first position P1 and a second position P2 on opposite sides of the central plasma zone or reaction chamber 34. Similarly, the electrodes of the second set of electrode assemblies 42 are positioned at positions P3 and P4, and the electrodes of the third set of electrode assemblies 42 are positioned at positions P5 and P6. Thus, in the example of FIG. 2 , there are three sets of electrode assemblies 42, each of which includes one anode electrode and one cathode electrode. However, any other number of sets of electrode assemblies 42 may be used on each plasma unit 16, including one set, two sets, four sets, etc.

[0022] Positions P1 and P2 of the first set of electrode assemblies 42 are disposed radially or circumferentially relative to positions P3 and P4 of the second set of electrode assemblies 42 and relative to positions P5 and P6 of the third set of electrode assemblies 42 within each plasma unit 16. The angle of separation between the second set of electrode assemblies 42 and the third set of electrode assemblies 42 is shown in FIGS. 1 and 2 as 90 degrees. The angle of separation between the first set of electrode assemblies 42 and the second set of electrode assemblies 42 is shown as 45 degrees. Furthermore, the angle of separation between the first set of electrode assemblies 42 and the third set of electrode assemblies 42 is also 45 degrees. However, these are merely examples, and other angles of separation between different sets of electrode assemblies can be used.

[0023] 3 shows one embodiment of a configuration of electrode assemblies 42 connected to a mechanical drive or actuator for radially reciprocating the electrodes 42 or electrode tips 46 of the electrodes 42 in and out of the reaction chamber 34 while the electrode assemblies 42 are positioned within the access port 40. The reciprocating motion is controlled by a corresponding linear actuator 48 attached to each of the electrode assemblies 42. Each set of electrode assemblies 42 can be moved synchronously or independently of one another. In a single plasma unit 16, the separation (arc gap) between any set of electrode assemblies 42 can be adjusted by moving the electrode assemblies 42 in and out of the access port 40.

[0024] In the exemplary embodiment of FIGS. 1-3 , three sets of electrode assemblies 42 are inserted into each plasma unit 16 through the access ports 40. Preferably, in this case, one or both of the remaining access ports 40 are used for observing the plasma gasifier 10 during operation, such as for holding any sensors (e.g., temperature sensors, pressure sensors, video cameras, etc.). Of course, electrode assemblies 42 are attached (inserted) into the access ports 40 not being used for observation. Furthermore, as shown in FIG. 3 , each of the electrode assemblies 42 has a linear actuator 48 that controls the movement of the electrode assembly 42 in and out of the access port 40. Each linear actuator 48 may be connected to a control mechanism or controller that allows a user to control the movement of the electrode assembly 42 during use. The mechanical or linear actuators 48 may be electric actuators, hydraulic actuators, or any other desired type of mechanical or linear actuator.

[0025] During operation, one or more arcs can be ignited between the cathode and anode of each pair of electrodes by (i) a high voltage discharge, (ii) a radio frequency discharge, or (iii) by bringing one electrode set into contact with and retracting one another. When a high voltage or radio frequency discharge is used to ignite an arc, the electrode tips 46 of one set of electrodes 42 are brought into close proximity to one another, such as by operation of an actuator 48. After the power supply 26 supporting the electrode assembly 42 in question is energized, a high voltage or radio frequency discharge is applied across the central plasma zone 34 between the electrode tips 46 to ignite an arc.

[0026] In the contact-and-retract method of igniting an arc, the anode and cathode electrode tips 46 from a particular set of electrode assemblies 42 are momentarily brought into contact with each other after the associated power supply 26 is energized. As soon as a spark occurs, the electrode assemblies 42 are rapidly separated, and an arc is ignited. Furthermore, after the first arc is ignited, a second set of electrode assemblies 42 may be moved into the first arc region for ignition. The second set of electrode assemblies 42 may require several seconds of thermal conditioning within the arc before self-igniting. In particular, thermal conditioning may be required to heat the electrode tips 46 to a temperature sufficient for thermionic emission of electrons to occur. Different plasma units 16 within the same plasma gasifier 10 can be used to form a combined arc system. In this configuration, the arc systems complement each other in heating the combined plasma to achieve a much higher energy state than is possible using a single plasma unit 16. Additional plasma units 16 within the plasma gasifier 10 can be ignited in the same manner.

[0027] As can be appreciated, the use of a plasma gasifier 10 with two or more plasma units 16 can generate very large, significantly higher temperature arcs within a common plasma zone or reaction chamber 34 using relatively low input power from each participating plasma unit 16. Furthermore, plasma units 16 can be duplicated and stacked on top of each other. In this manner, when one or more plasma units 16 sustain an arc, there exists a field-free (current- and voltage-free) high-energy plasma tail flame that can flow into the other plasma units 16. In this case, the electrode assemblies 42 in the other plasma units 16 superimpose and reignite the discharges in the tail flames, returning them to an arc state, so that the stacked plasma units 16 generate very large plasma columns with very high energy content. This modular, stacked configuration of plasma units 16 can operate such that a “field-free” (current- and voltage-free) plasma flame from an upstream unit is reheated to a “field-active” (current- and voltage-active) arc state by superimposing discharges in downstream plasma units 16. The net flow of plasma energy from one plasma unit 16 to another is called an "energy cascade" and adds energy to downstream plasma units 16, allowing the downstream plasma units 16 to operate with lower energy requirements.

[0028] FIG. 4 illustrates an exemplary electrode assembly 42 that can be used in the gasifier 10 described herein. In particular, the electrode assembly 42 includes an electrode tip 46. The electrode tip 46 extends into the central plasma zone or reaction chamber 34 and generates an arc with another electrode tip 46 from a different electrode assembly 42 (not shown in FIG. 4). Each of the electrode assemblies 42 is preferably made of tungsten, a tungsten alloy, or some other high-temperature conductive material. The electrode tip 46 is attached to the end of a tubular support jacket 49, which is highly electrically conductive and has a first end 49A and an opposite second end 49B. The second end 49B of the tubular support jacket 49 terminates in the electrode tip 46, which either seals the second end 49B or is directly attached to the sealed second end 49B. An opposite first end 49A of the tubular support jacket 49 is coupled to an electrode base 50 that is connected to the power supply 26 (FIG. 1) and receives electrical current from the power supply 26. The electrical current received at the electrode base 50 travels through the electrode base 50 and into the tubular support jacket 49. The electrical current then flows through the material of the tubular support jacket 49 to the electrode tip 46.

[0029] The tubular support jacket 49 defines an interior compartment or space 51. Coolant from the coolant source 24 (FIG. 1) is introduced into the interior compartment 51 through a supply tube 52. The supply tube 52 has a distribution end 52A that terminates within the interior compartment 51 just short of the electrode tip 46. This configuration creates a small gap 54, e.g., 5 millimeters, between the distribution end 52A of the supply tube 52 and the electrode tip 46. In this manner, any coolant pumped through the supply tube 52 directly impinges on the electrode tip 46, actively cooling it directly.

[0030] The supply tube 52 has an outer diameter that is smaller than the inner diameter of the interior section 51. As a result, a drainage gap 56 exists between the interior of the tubular support jacket 49 and the exterior of the supply tube 52. This drainage gap 56 receives the coolant after it is pumped to the electrode tip 46. The drained coolant is returned to the electrode base 50, which includes one or more conduits 58 that direct the coolant to a coolant outlet. The coolant may surround at least some portions of the power cable 62 extending from the power source 26 (FIG. 1). In this manner, the coolant may also actively cool the power cable 62. Thus, the flow of coolant into and out of the interior section 51 of the tubular support jacket 49 directly cools the electrode tip 46, the tubular support jacket 49, and the power cable 62 during operation.

[0031] An insulator structure 64, including an insulating base 66, an elongated insulating tube 68, and a protective insulating cap 70, surrounds the tubular support jacket 49. The insulating cap 70 is annular and defines a central opening 72. The tubular support jacket 49 extends through the central opening 72 of the insulating cap 70 and supports the electrode tip 46 immediately forward of the insulating cap 70. Because the insulating cap 70 is exposed to the high heat of the central plasma chamber or reaction chamber 34 (FIG. 2), the insulating cap 70 is preferably made of a ceramic material that can withstand the high operating temperatures of this region. The insulating base 66 is also annular and surrounds the tubular support jacket 49 proximate the first end 49A of the tubular support jacket 49. The elongated insulating tube 68 extends around the tubular support jacket 49 between the insulating base 66 and the insulating cap 70. The insulating base 66 and the elongated insulating tube 68 may be manufactured as a single piece, with the two elements being molded from tempered glass, ceramic, and / or high temperature resistant polymers.

[0032] The elongated insulating tube 68 does not contact the inner tubular support jacket 49. Rather, a gap space separates the elongated insulating tube 68 from the tubular support jacket 49, forming a gas supply conduit 74 therein. Similarly, the insulating cap 70 does not contact the tubular support jacket 49, such that a gap separates the insulating cap 70 from the tubular support jacket 49, and continues therein to the gas supply conduit 74. A gas supply line 76 extends within the insulating base 66 of the insulator structure 64 and connects the working gas supply 22 ( FIG. 1 ) to the gas supply conduit 74. When working gas enters the gas supply line 76 from the working gas supply 22, the working gas enters the gas supply conduit 74, flows along the length of the tubular support jacket 49, and then passes through the electrode tip 46 and into the reaction chamber 34.

[0033] As shown in FIG. 4 , a protective collar 80 is attached around the electrode tip 46. The protective collar 80 is dielectric and can maintain its integrity in the high-temperature environment of the central plasma zone or reaction chamber 34. The protective collar 80 has a first open end that connects to the insulating cap 70 and a second open end 82 at or near the small end of the electrode tip 46. The gas supply conduit 74 extends through the insulating cap 70 and discharges into the protective collar 80 between the protective collar 80 and the electrode tip 46. The working gas enters the protective collar 80 and is confined around the electrode tip 46, and can only enter the central plasma zone or reaction chamber 34 by flowing past the electrode tip 46, which forms an arc. In this manner, when the working gas enters the central plasma zone or reaction chamber 34, the arc converts the working gas into a plasma.

[0034] The cylindrical casing 84 surrounds most of the elongated insulating tube 68, and the cylindrical casing 84 is inserted between the insulating base 66 and the insulating cap 70. The gas supply conduit 74 and the elongated insulating tube 68 separate the cylindrical casing 84 from the tubular support jacket 49. The cylindrical casing 84 is made of a highly thermally conductive material and is hollow. The interior of the cylindrical casing 84 is cooled by the flow of coolant through the cylindrical casing 84 from the input port 86 to the output port 88. Thus, the cylindrical casing 84 functions as an actively cooled heat sink, absorbing heat directly from the insulating cap 70. The cylindrical casing 84 also absorbs heat passing through the elongated insulating tube 68. Finally, the cylindrical casing 84 absorbs heat from the insulating base 66. It will thus be appreciated that during operation, the tubular support jacket 49 is internally cooled by coolant flowing within the interior compartment 51 and externally cooled by coolant flowing through the cylindrical casing 84. Furthermore, the working gas flowing within the gas supply conduit 74 cools the tubular support jacket 49, which in turn cools the electrode tip 46. This active cooling reduces overheating of the electrode tip 46, preventing excessive wear and erosion of the electrode tip 46. Furthermore, the high conductivity of the tubular support jacket 49 reduces junction resistance heating and allows high Joule heating to occur at the electrode tip 46 due to better thermionic emission of electrons that form and maintain the arc. Of course, the electrode assembly 42 shown and described with respect to FIG. 4 is one example of an electrode assembly that may be used to provide power, coolant, and working gas to the electrodes used in the gasifier 10 of FIG. 1, and other electrode assemblies may be used instead or in addition. For example, the electrode assembly shown and described in Figure 4 of US Patent No. 10,208,263, which is expressly incorporated herein, may be used instead.

[0035] As previously mentioned, the working gas exiting the gas supply conduit 74 in FIG. 4 is ejected in a circular pattern around the electrode tip 46. However, plasma or ion gas generation is most effective when the working gas surrounding the electrode tip 46 does not disperse from the arc emanating from the electrode tip 46. One way to help ensure that the working gas remains in a tight flow state is to eject the working gas in a directed, laminar flow rather than a random, turbulent flow. With reference to FIGS. 5 and 6, it can be seen that laminar flow profiles can be induced in the working gas by providing flow passages external to the tubular support jacket 49. FIG. 5 illustrates a straight flow passage 94. FIG. 6 illustrates a spiral or swirling flow passage 96. As the working gas flows through the flow passages 94 and 96, the working gas is provided with a directed flow, whether straight or spiral. This directed flow tends to be laminar or vortex for typical flow rates used. Furthermore, the directed flow of the working gas through the flow passages 94 and 96 has other unique performance characteristics. In particular, the tubular support jacket 49 may be fabricated from a copper alloy, which has much better thermal conductivity than the tungsten alloy of the electrode tip 46. In this case, the tubular support jacket 49 acts as a heat sink for the electrode tip 46. As the working gas flows through the passages 94 and 96, the working gas cools the tubular support jacket 49, which in turn cools the electrode tip 46. This configuration helps reduce overheating of the electrode tip 46 and prevent excessive wear and erosion of the electrode tip 46. Furthermore, the high conductivity of the tubular support jacket 49 reduces junction resistance heating within the electrode tip 46 and allows for high Joule heating to occur at the electrode tip 46 due to better thermionic emission of electrons that form and sustain the arc.

[0036] 7-9 illustrate a hybrid gasifier system 100 that includes both a set of plasma arc electrodes 102 and one or more plasma torches 104 positioned adjacent to a reaction chamber 106 to generate and introduce plasma or ionized materials into the reaction chamber 106 and generate an electric arc within the reaction chamber 106 to enhance material processes such as waste-to-energy conversion, wastewater decomposition, nanomaterial synthesis, and methane decomposition to produce hydrogen. In particular, the hybrid gasifier system 100 of FIG. 7 includes plasma torches 104 positioned in a vertical configuration relative to the arc electrodes 102. Thus, the plasma torches 104 are positioned perpendicular (e.g., above) the plasma chamber or reaction chamber 106. Of course, more than one plasma torch 16 can be used depending on the size of the plasma chamber or reaction chamber 106, and the plasma torches 104 can be positioned in other locations relative to the arc electrode 102, such as below the electrode 102 in the embodiment of FIG. 7 where the plume 108 faces downward. In any event, the plasma torch 104 is positioned to inject plasma or ion material into the chamber 106 in a direction perpendicular to, e.g., perpendicular to, the direction of the arc discharge and / or working gas introduced or generated within the chamber 106 by the arc electrodes 102. As will be appreciated, the plasma torch 104 of Figure 7 generates a plasma jet 108 that emanates from the plasma torch 104 and projects downward in a vertical path through the center of the plasma or reaction chamber 106, and may interact with or intersect one or more arcs 110 within the reaction chamber 106 formed between the electrodes 102.

[0037] Of course, more than one set of arc electrodes 102 can be arranged in the system of FIG. 7. For example, one to four sets of arc electrodes 102 can be used, although more sets can also be used. Additionally, these arc electrodes 102 can be any of the electrodes described herein with respect to FIGS. 1-6. In this example, the arc electrodes 102 are arranged in a transverse configuration to generate a free-expanding arc 110 within the plasma chamber or reaction chamber 106. The free-expanding arc 110 interconnects with the vertical plasma jet 108 from the plasma torch 104, and together with the plasma (generated by both the arc electrode 102 and the plasma torch 104) and the electric arc (generated by the arc electrode 102), enhances the heating and processing of material introduced into the reaction chamber 106 via an input (not shown in FIG. 7).

[0038] More specifically, each set of arc electrodes 102 includes an anode electrode and a cathode electrode. Free-expanding arcs 110 generated across the plasma chamber or reaction chamber 106 between the anode and cathode electrodes of the various different sets of arc electrodes 102 interact with the plasma jet 108 passing through the center of the plasma chamber or reaction chamber 106 to provide a powerful ionization source for generating ionized material (e.g., gas) within the reaction chamber 106. This ionization facilitates ignition and sustainment of the free-expanding arcs 110 generated by the various different sets of arc electrodes 102. The free-expanding arcs 110 then generate an electric field within the plasma chamber or reaction chamber 106. Due to the presence of the electric field, a portion of the plasma jet 108 becomes an active arc, increasing the temperature of that portion of the plasma jet. Thus, the free-expanding arcs 110 can be formed without the supply of an electrode working gas. However, various working gases can be supplied to and emitted from the arc electrodes 102 to form the free-expanding arcs 110 using the electrode configuration described in FIG. 4 . The hybrid plasma jet and plasma arc system 100 generates a uniform, high-energy, large-volume plasma field to enable high-temperature environments for waste-to-energy conversion, hazardous solid waste and wastewater decomposition, nanomaterial synthesis, methane decomposition to produce hydrogen, and other plasma processing applications.

[0039] FIG. 8 shows a partial cutaway perspective view of a hybrid gasifier 120 implementing the vertical plasma torch configuration of FIG. 7. The hybrid gasifier 120 is essentially the gasifier 10 of FIG. 1 modified to include the vertically mounted plasma torch 104 of FIG. 7. The same or similar reference numbers used in FIGS. 1-7 are used in FIG. 8 to indicate the same or similar components. As shown in FIG. 8, the hybrid gasifier 120 includes multiple plasma units 16 stacked vertically on top of each other with electrode assemblies 20 (FIG. 1) or electrode assemblies 42 (FIGS. 2-6) attached to ports 40 (as shown in FIGS. 2-3), such that the anodes and cathodes of a particular set of electrode assemblies 42 are positioned on opposite sides of the unit 16, i.e., 180 degrees around the unit 16 in which the electrodes are located, and the electrodes 42 extend radially into the reaction chamber 34. 8 is shown as including three plasma units 16 each having three sets of electrodes 42, more or fewer plasma units 16 may be used and more or fewer sets of electrodes 42 may be disposed in each plasma unit 16. Additionally, while the sets of electrodes in adjacent plasma units 16 are shown as being mounted perpendicular to one another, the various electrodes 42 of different plasma units 16 may be offset from the electrodes in adjacent plasma units 16 by any desired angle (e.g., 15 degrees, 20 degrees, 30 degrees, etc.).

[0040] Similarly, as shown in FIG. 8 , the plasma torch 104 is mounted on top of the hybrid gasifier 120 and has an output 122 that extends or is located above the top of the reaction chamber 34 above or higher than the top plasma unit 16. The plasma torch 104 is connected to a source of working gas and receives the working gas. Typically, the plasma torch 104 (also called a plasma jet reactor or generator) generates or generates an arc between a cathode electrode and an anode electrode that are positioned closely together within the body of the torch 104 (not shown in FIG. 8 ). The working gas then passes through the arc, generating a tongue of plasma therein, which is then emitted from the output 122 of the plasma torch 104 into the reaction chamber 34 as a stream of high-temperature plasma 108. Here, in response to the flow of working gas into the plasma torch 104, the flow of high temperature plasma 108 moves downward through the center of the reaction chamber 34 (i.e., longitudinally relative to the longitudinal axis of the plasma unit 16), intersecting one or more reaction zones of the plasma unit 16 and providing additional plasma or ion material within the reaction chamber 34 to process the material therein.

[0041] As shown in FIG. 8 , the material to be treated may be introduced into the reaction chamber 34 through one or more openings or inputs 124 located on the top of the gasifier 120 around or near the plasma torch 104. However, the process material input 124 of the hybrid gasifier 120 may be located in one or more other locations on the gasifier 120, such as on the side above the first (top) plasma unit 16 of the gasifier 120. Once introduced through the input 124, the material to be treated is gravity-fed and flows down through the reaction chamber 34, passing through each of the stacked plasma units 16. Of course, this material, particularly near the input 124, will come into contact with or interact with ionized gases generated by the plasma torch 104, and with electric arcs (shown in some cases in FIG. 8 ) emanating from or formed between the electrode tips of the various pairs of anode and cathode electrodes of the electrode assembly 42 extending into the reaction chamber 34. If the electrode assembly 42 also supplies a working gas into the chamber 34, which is also ionized (i.e., forms a plasma), the material being processed further interacts with this plasma, all of which aids in heating and decomposing the material. Thus, as will be appreciated, the plasma from the plasma torch 104 provides additional heating and ionized gas that interacts with and decomposes the material being processed. Similarly, the plasma flow 108 generated by the plasma torch 104 can be used to ignite one or more of the set of electrodes 42 during start-up by providing plasma and heat within the chamber 42. This action may reduce or eliminate the need to move or contact the anode and cathode electrodes of a pair of electrode assemblies together to initiate arc activity. This action may further reduce or eliminate the need to provide a working gas into the reaction chamber 34 via the electrodes 42. In any event, after the material to be treated moves generally vertically (from top to bottom) through the reaction chamber 34 and is exposed to the plasma generated by the plasma torches 104, as well as the plasma and arc generated by the various pairs of electrode assemblies 42 in each of the plasma units 16, the treated material exits the reaction chamber 34 via one or more outputs 15 at the bottom (lower vertical end) of the gasifier 120.8 as being located near the input 124, it may be located near the output 15 and extend longitudinally from the bottom into the reaction chamber 34, emitting or emitting a plasma (e.g., a plasma plume or flame) directed upward through the center of the reaction chamber 34. If the feed or input materials and / or product or processed materials contain solids, the plasma torch 104 is suitably positioned longitudinally to direct the plasma plume 108 downward or otherwise co-current with the flow of material through the reactor or gasifier 120 (e.g., as shown in FIG. 7), or laterally to direct the plasma plume 108 radially inward (e.g., as shown in FIG. 9 and discussed below).

[0042] As another example of a hybrid gasifier, FIG. 9 shows a simplified schematic diagram of a gasifier 130 having a transverse configuration in which one or more plasma torches 104 are positioned at lateral positions around the outer wall of the plasma unit 16, interspersed with arc electrodes 102 similarly attached to the plasma unit 16 as previously described. The plasma torches 104 generate a plasma jet 108 that projects laterally (radially) toward the center of the plasma chamber or reaction chamber 34, and the arc electrodes 102 generate a free-expanding arc 110. The plasma jet 104 can operate to ignite the free-expanding arc 110 and further move toward the center of the plasma unit 16 to provide a strong source of ionization within the plasma chamber 34. This ionization facilitates ignition and maintenance of the free-expanding arc 110, which in turn generates an electric field. Due to the presence of an electric field within the plasma chamber 34, a portion of the plasma jet 108 becomes an active arc, increasing the temperature of that portion of the plasma jet. The free-expanding arc 110 can form in this case without the supply of an electrode working gas. Alternatively, various working gases can be supplied to the arc electrode 102 in the manner described herein to ignite the free-expanding arc 110 and provide additional ionizable material within the chamber 34. It will be appreciated that the lateral configuration shown in FIG. 9 can, in one example, be obtained by attaching one or more plasma torches 104 to one or more of the unused ports 40 of FIG. 2. Furthermore, although only a single plasma torch 104 is shown in the embodiment of FIG. 9, multiple different plasma torches can be attached to a single plasma unit 16 and / or multiple different plasma torches 104 can be attached to different ones of the stacked plasma units 16 of FIG. 1, for example.

[0043] Both the vertical hybrid configurations of Figures 7 and 8 and the horizontal hybrid configuration of Figure 9 generate uniform, high-energy, large-volume plasma fields that enable high-temperature environments for waste-to-energy conversion, hazardous solid waste and wastewater decomposition, nanomaterials synthesis, methane decomposition to produce hydrogen, and other plasma processing applications. Furthermore, both of these types of plasma torch arrangement configurations can be implemented in hybrid gasifiers with any of the electrode configurations, spacings, and arrangements described herein, including any of the offset electrode configurations (e.g., Figures 10-14), non-offset electrode configurations, and gas vortex-inducing configurations (e.g., Figures 17-19) described in more detail herein.

[0044] Note that in each of the above-described embodiments, each set of arc electrodes 20, 42, 102, and 104 is arranged around the plasma unit 16 and oriented radially inward, with the anode and cathode electrodes of each set or pair of electrodes positioned on opposite sides of the plasma unit 16 such that the two electrodes are offset 180 degrees from one another circumferentially around the plasma unit 16. As a result, the arc traveling between these electrodes passes through the center of the reaction chamber 34. Of course, if more than one set of electrodes is so arranged around the plasma unit 16, the arc from each of these sets of electrodes will pass through the center (or very near the center) of the reaction chamber 34. These multiple arcs at or near the center of the reaction chamber 34 create a very high temperature region near the center of the chamber 34, providing significant processing of materials in the center of the chamber. This feature can be beneficial in some instances. However, this configuration may result in less plasma and arc processing and / or heat in other, non-central regions of the reaction chamber 34. It may be beneficial to have the arcs from different ones of the set of electrodes follow one or more paths that do not pass through the center of the chamber to more evenly distribute the arcs and plasma generation throughout the reaction chamber 34. This feature results in more uniform processing of the material within the chamber 34, regardless of whether the material is moving through the chamber 34 in the center or off-center.

[0045] Thus, in one embodiment, the improved plasma or ion reactor described herein uses multiple sets of opposing arc electrodes arranged around the reaction chamber in a manner that operates to distribute the arcs from the multiple sets of electrodes over a larger area of ​​the reaction chamber or plasma chamber 34, effectively increasing the size of the reaction zone in which at least one arc exists. This feature, in turn, creates more area within the plasma or reaction chamber in which at least one arc exists, increasing the temperature profile across the horizontal or transverse cross-section of the reaction. In particular, to vary the arc discharge profile within the reaction chamber to be more uniform throughout the reaction chamber, the anodes and cathodes of various pairs of electrodes are arranged at circumferential angles other than 180 degrees relative to each other around the outer wall of the reaction chamber, such that the anodes and cathodes of a particular pair of electrodes are arranged at an acute angle (less than 90 degrees), an obtuse angle (between 90 degrees and 180 degrees), or 90 degrees relative to each other. Furthermore, the anodes and cathodes of different sets of electrodes are juxtaposed around the chamber to distribute the polarity of adjacent electrodes. As a result, some or all of the arcs generated by the electrodes do not necessarily travel directly through the center of the reaction chamber, but rather traverse the chamber offset from the center of the chamber. In this manner, the arcs generated by different sets of electrodes move through the reaction chamber on various different paths through the chamber, distributing the arcs more evenly throughout the reaction chamber. Distributing the arcs more evenly throughout the reaction chamber provides better or more uniform treatment of the material flowing through the chamber and enables the chamber to be used for new purposes, such as producing carbon nanoparticles.

[0046] As one example, Figure 10 illustrates a first offset electrode configuration that may be used to provide better arc coverage within the reaction chamber. In particular, Figure 10 illustrates a longitudinal or top interior view of a gasifier 210 having a plasma unit 212, which may be, for example, one of the plasma units 16 of Figure 1. In this case, the plasma unit 212 includes four pairs of arc electrodes 216 disposed therein, and the walls of the plasma unit 212 define a plasma chamber 217. Further, sets or pairs of arc electrodes 216 are disposed within the walls of the plasma unit 212, with each set of arc electrodes 216 including a cathode electrode 218 and an anode electrode 220.

[0047] To achieve and maintain better plasma arc symmetry and stability, the sets of arc electrodes 216 are arranged in an alternating polarity configuration, with each cathode electrode circumferentially disposed between two anode electrodes and each anode electrode circumferentially disposed between two cathode electrodes. Thus, the electrodes 216 alternate polarity as they move around the plasma unit 112. In the illustrated embodiment, the plasma module 212 has four sets of arc electrodes 216, providing a total of eight electrodes: four cathode electrodes 218A, 218B, 218C, and 218D, and four anode electrodes 220A, 220B, 220C, and 220D. The electrodes 216 are evenly spaced around the walls of the unit 212 and are therefore separated from their nearest neighbors by a 45-degree angle. Furthermore, the two electrodes (anode and cathode) in one set of arc electrodes 216 are positioned at a specific obtuse angle relative to each other, which is 135 degrees in the system of FIG. 10. Therefore, the arrangement of arc electrodes 216 embodies a specific directional rotation to achieve full alternating electrode polarity for the eight electrodes. This arrangement of alternating electrode polarity produces a plasma arc system or unit 210 with very stable arc formation and a more uniform high-temperature plasma field.

[0048] 10, four sets of arc electrodes 216 generate four arcs 222 within the plasma chamber 217. The "A" set of arc electrodes 216 has a first anode electrode 220A located at a 0 degree or top position (FIG. 10), and an associated first cathode electrode 218A is offset clockwise from the first anode electrode 220A by an obtuse angle of 135 degrees. As will be appreciated, electrode 218A and electrode 220A are powered by the same power supply.

[0049] Furthermore, the "B" set of arc electrodes 216 includes a cathode electrode 218B and an anode electrode 220B. The cathode electrode 218B is positioned adjacent to the first anode electrode 220A and is offset 45 degrees (clockwise) therefrom. However, the second anode electrode 220B is offset 135 degrees counterclockwise from the second cathode electrode 218B. Furthermore, electrodes 218B and 220B are powered by the same power supply, which may be a different power supply than the power supply that powers the "A" set of electrodes 218A, 220A.

[0050] Further, the "C" set of arc electrodes 216 includes a cathode electrode 218C and an anode electrode 220C. The third anode electrode 220C is adjacent between the second cathode electrode 218B and the first cathode electrode 218A and is offset 90 degrees clockwise from the first anode electrode 220A and 135 degrees clockwise from the third cathode electrode 218C. Additionally, electrodes 218C and 220C are powered by the same power supply, which may be a different power supply than the power supply that provides power to the "A" set of electrodes 218A, 220A and / or the "B" set of electrodes 218B, 220B.

[0051] Finally, the "D" set of arc electrodes 216 includes cathode electrode 218D and anode electrode 220D. The fourth cathode electrode 218D is positioned adjacent to and between the first anode electrode 220A and the second anode electrode 220B. Similarly, the fourth cathode electrode 218D is offset 180 degrees from the first cathode electrode 218A and 135 degrees counterclockwise from the fourth anode electrode 220D. Furthermore, electrodes 218D and 220D are powered by the same power supply, which may be different from the power supply powering the "A" set of electrodes 218A, 220A, and / or the "B" set of electrodes 218B, 220B, and / or the "C" set of electrodes 218C, 220C.

[0052] In this configuration, anode electrodes 220A and 220D are positioned diametrically opposite each other along a first orthogonal axis, and anode electrodes 220B and 220C are positioned diametrically opposite each other along a second orthogonal axis. Similarly, cathode electrodes 218A and 218D are positioned opposite each other along a third orthogonal axis, and cathode electrodes 218B and 218C are positioned directly opposite each other along the remaining orthogonal axis. This configuration achieves alternating electrode polarity for all adjacent electrodes and provides a highly stable arc configuration with a very large, uniform, high-temperature plasma field for material processing within chamber 217. In particular, arcs 222 generated by different sets of electrodes 216 cross each other and join near, but not directly at, the center of plasma chamber 217, resulting in a larger arc field within chamber 217 where arcs 222 do not all pass through the same point (i.e., the center) within chamber 217. Furthermore, the arcs 222 behave like a single arc in the center of the plasma chamber 217 , so that the combined heating power in the center of the chamber 217 is substantially higher than the sum of all the heating powers of each individual arc 222 .

[0053] Referring to FIG. 11, an alternative plasma arc system or unit 230 is shown. In this plasma arc system 230, there are four sets of arc electrodes 332, marked as Set A, Set B, Set C, and Set D, where each set of electrodes is separately powered, e.g., by a different power supply. Each of the sets of electrodes 332 has an anode electrode 334 (e.g., 334A, 334B, etc.) and a cathode electrode 336 (e.g., 336A, 336B, etc.), and for each set of arc electrodes 332, the anode electrode 334 (A-D) is positioned adjacent to the associated cathode electrode 336 (A-D) at a 45-degree angular separation (circumferential direction). This electrode configuration achieves alternating electrode polarity, where the anode electrodes 334 and cathode electrodes 336 of an associated set of electrodes 332 are positioned in a non-diametrically opposed (i.e., 180-degree) manner around the unit 330. In this configuration, each anode electrode 334 is positioned directly opposite another anode electrode 334 across one or more orthogonal axes, and each cathode electrode 336 is positioned directly opposite another cathode electrode 336 across one or more other bisecting orthogonal axes. This arrangement achieves alternating electrode polarity for all adjacent electrodes, resulting in a set of arc electrodes 332 generating arcs 338 that do not necessarily intersect with each other, as shown in FIG. 11 . However, in some cases, each arc 338 may have a small portion of its arc body overlapping near the center of the plasma chamber 317. This partial overlap of the arcs 338 behaves like a small additional arc in the center of the plasma arc system 330. The heating power of the combined partial arc currents in the center supplements the heating power of each individual arc 338 in the plasma arc system 330, forming a uniform, high-temperature plasma for material processing.

[0054] 12-14 show three alternative plasma arc systems or units 340, 350, and 360. In each embodiment, the anode and cathode electrodes are arranged to achieve alternating electrode polarity that provides systems 340, 350, and 360 with highly stable arc formation and a uniform, high temperature plasma field.

[0055] 12, there are three sets of arc electrodes 342 (labeled the A, B, and C sets of electrodes), with the anode electrodes 344 and cathode electrodes 346 of each set positioned 180 degrees apart. Each anode electrode 344 is positioned adjacent to a cathode electrode 346 on either side. Arcs 348 are generated by the sets of arc electrodes 342, and the arcs 348 merge or intersect at the center of the plasma chamber 317. Furthermore, portions of the merged arcs 348 behave like a single arc. The heating power of this merged arc region is much higher than that of the peripheral arc regions.

[0056] 13 illustrates another asymmetric arrangement of arc electrode sets within plasma unit 350, including three sets of electrodes 351A, 351B, and 351C arranged around unit 350. Each of the sets of electrodes 351A, 351B, and 351C may be powered by a separate power supply. The first set of arc electrodes 351A includes an anode electrode 352 and a cathode electrode 353 arranged 180 degrees apart on (i.e., on either side of) unit 350. This first set of arc electrodes 351A generates a linear arc 354 that moves through the center of chamber 317. The second set of arc electrodes 351B has an anode electrode 356 and a cathode electrode 357 offset by 60 degrees, and the third set of arc electrodes 351C has an anode electrode 358 and a cathode electrode 359 offset by 60 degrees. Additionally, anode electrode 352, anode electrode 356, and anode electrode 358 are each positioned adjacent to and 60 degrees apart from two of cathode electrodes 353, cathode electrode 357, and cathode electrode 359, such that unit 350 has interspersed or alternating anode and cathode electrodes as one moves around unit 350. Furthermore, the 60-degree offset location of the anodes and cathodes of sets of arc electrodes 351B and 351C positions these electrode sets across unit 350 from each other, generating secondary arc 358 that is split by linear arc 354. The result is partial arc mixing in the center of the plasma module, producing higher central heating power than the peripheral arc region, while still providing arc generation across a wider cross-section of unit 350.

[0057] FIG. 14 shows a plasma unit 360 with three sets of arc electrodes 362A, 362B, and 362C, each with an anode electrode 364 and a cathode electrode 366 positioned 60 degrees apart. This configuration is very similar to the four-set electrode configuration shown in FIG. 11. In this configuration, partial mixing and merging of arcs 368 occurs in the center of the plasma chamber 317. This partial mixing and merging of arcs 368 produces higher combined heating power than the peripheral arc regions. In these configurations, all plasma electrodes 364 and 366 are positioned to achieve alternating electrode polarity, which can increase arc stability.

[0058] Of course, while various different arc electrode configurations are illustrated and described with respect to Figures 10-14, it should be noted that for each of these configurations, the arcs generated within the plasma chamber reinforce each other, and all of these configurations involve alternating electrode polarity for all adjacent electrodes. This aspect of the illustrated configuration provides a very stable arc configuration and a very large, uniform, high-temperature plasma field for material processing. Furthermore, in some cases, some or all of the arcs may cross each other, and in other cases, none of the arcs cross each other. Furthermore, in these various configurations, the arcs may not cross through the center of the reaction chamber, or one arc, fewer than all arcs, or all arcs may cross through the center of the reaction chamber. Furthermore, the arcs may or may not cross each other, but may combine near the center of the plasma chamber and behave like a single arc at the center of the plasma unit. Thus, the combined heating power at the center of the reaction chamber may be substantially higher than the sum of the total heating power of each of the individual arcs, while still allowing the arcs to spread more uniformly or dispersively across the entire cross-section of the chamber. Temperatures at or near the central region of the reaction chamber are expected to be at least 3000K, and even 5000K or higher, temperatures that may cause complete decomposition of the feed material.

[0059] Of course, other arc electrode arrangement configurations can be used in place of the configurations specifically described and illustrated herein. For example, while the embodiments of Figures 10-14 show configurations with three and four sets of electrodes, other embodiments can include two sets of electrodes or more than four sets of electrodes. Furthermore, while it is desirable to space the sets of electrodes so that the anode and cathode electrodes are interspersed or adjacent to one another around the entire plasma unit, this feature is not critical, and in some cases, two anode electrodes and / or two cathode electrodes may be positioned adjacent to one another, with other anode and cathode electrodes being interspersed. Similarly, all of the electrodes shown in Figures 10-14 are equally separated around the plasma by an angle calculated as 360 divided by the total number of electrodes. However, in some cases, the electrodes need not be evenly spaced around the plasma unit; thus, some adjacent electrodes may be separated by a first angle, and other adjacent electrodes may be separated by other angles greater or less than the first angle. Furthermore, the anode and cathode electrodes of a particular pair of electrodes can be separated by any desired angle around the circumference of the unit, such as acute, 90 degrees, obtuse, or 180 degrees. While the embodiments of Figures 10-14 show various different anodes and cathodes of electrode pairs separated by 45 degrees, 60 degrees, 90 degrees, 135 degrees, and 180 degrees, other angles can alternatively be used (these angles may depend on or be influenced by the total number of electrodes). Furthermore, different pairs of electrodes within the same unit can have their respective anode and cathode electrodes separated by different angles. Thus, as shown in Figure 13, one pair of electrodes has its respective anode and cathode electrodes separated by 180 degrees, while another pair of electrodes has its respective anode and cathode electrodes separated by 60 degrees. Of course, other combinations of electrode separations can be used instead of or in addition to those described and illustrated herein.Similarly, various different combinations of electrode spacing or offsets can be used so that, in some cases, the arcs generated by the various sets of electrodes do not intersect with one another, in other cases, each arc generated by each set of electrodes intersects with all other arcs generated by the other sets of electrodes, and in other cases, arcs generated by one or more of the sets of electrodes intersect with one or more of the arcs generated by the other sets of electrodes but not all of the arcs generated by the other sets of electrodes. Furthermore, in many cases, the arcs generated by one set of electrodes will not be aligned with (e.g., will not pass through) the center of the reaction chamber because the anode and cathode electrodes of one set of electrodes are spaced apart at an angle other than 180 degrees.

[0060] In any case, the arc discharge environment achieved by the embodiments described in Figures 10-14 is particularly useful for producing carbon nanoparticles, such as carbon nano-onions, and for methane decomposition. More specifically, carbon nano-onions (CNOs), known as multishell fullerenes, were discovered in 1992. Carbon nano-onions are structural concentric shells of carbon atoms. Over the years, various methods for synthesizing carbon nano-onions have been developed and studied. In addition, chemical functionalization of carbon nano-onions has been investigated, and several synthetic routes have been found to be applicable to the introduction of various functional groups. Chemically modified carbon nano-onions have been investigated in different application fields and have been revealed to be promising nanomaterials, attracting increasing interest among researchers and opening new avenues for research. Currently, carbon nano-onions can only be produced in gram-scale quantities by applying mechanical stress to commercially available nanodiamonds. Alternatively, their production can be achieved by combustion of naphthalene and arc flash between graphite electrodes in water. However, current methods for producing carbon nano-onions are not capable of producing industrial-grade products in the short term. The availability of large quantities of CNOs would open up applications for these exotic nanomaterials.

[0061] Advantageously, the plasma arc system described herein can produce large quantities of CNOs. One single small-scale plasma system described herein can produce several kilograms of carbon nano-onions in a few days. Multiple parallel systems can increase production volume and provide rapid delivery on-site and on-demand at the industrial level. This capability is due to the fact that the expanding arc generates a very high-temperature, uniform, and large plasma field for synthesizing CNOs. Generally, the arc electrodes that generate these arcs must be arranged with alternating polarity to maintain a stable, uniform, and coupled arc field. It is this high-temperature, coupled, active arc field that enables the rapid synthesis of carbon nano-onions. Advantageously, the arc electrode plasma system described herein can use any gas, preferably argon, hydrogen, and / or nitrogen, to form the plasma. In one iteration, graphite electrodes can be used to produce high-purity CNOs. Feedstock for this process can be high-purity hydrocarbon gases or liquids, high-purity graphite powder, or high-purity carbon black derived from the decomposition of other carbon-rich materials.

[0062] In addition to producing carbon nanomaterials, the high temperatures of the plasma arc systems described herein can also be used to decompose hydrocarbons such as methane. Methane is a more potent greenhouse gas than carbon dioxide and is a significant global warming problem. Global warming can lead to polar ice cap melting, sea level rise, and land loss. Methane sequestration is an international effort to reduce global warming. Cracking hydrocarbons to produce hydrogen and carbon, followed by carbon sequestration, reduces greenhouse gases and promotes the development of a hydrogen economy.

[0063] In particular, methane can be decomposed and reduced to hydrogen and solid carbon. However, current technology lacks the ability to efficiently generate a temperature environment high enough to completely decompose methane. The result is partial decomposition, with higher molecular weight hydrocarbons as impurities. Of all hydrocarbon gases, methane is the most stable. As a result, completely decomposing methane into hydrogen and solid carbon is extremely difficult due to the very high temperatures required. The plasma arc system described herein has the ability to efficiently generate a temperature field capable of completely decomposing methane.

[0064] With particular reference to Figure 15, test results are shown. When methane was decomposed using the plasma arc system described above, only 0.041% CH4 residue was detected. Therefore, 99.96% of the feed methane was decomposed into hydrogen and solid carbon. The table in Figure 15 shows the product gas analysis. The total concentration of impurity hydrocarbon gases in the product gas was 6.17%, and the hydrogen concentration was 93.83%. For another gas sample, the results of which are shown in Figure 16, only 0.008% CH4 residue was detected, indicating that 99.99% of the feed methane was decomposed into hydrogen and solid carbon. The amount of impurity hydrocarbon gases was significantly reduced, with their total concentration being 3.51% and the hydrogen concentration being 96.49%.

[0065] With the demonstration of near 100% decomposition of CH4 to H2 and solid carbon, it is believed that the decomposition of other hydrocarbon gases in plasma arc systems can approach 100%. It is also understood that carbon black produced from methane or other hydrocarbon decomposition in these arc configurations will contain CNOs and other nanocarbon allotropes.

[0066] As mentioned above, many of the plasma reactors or systems described herein (e.g., with respect to at least FIGS. 1-9 ) have a set of opposing arc electrodes. During operation, an unconfined arc is generated between a cathode electrode and an anode electrode, and then a working gas passes through the arc, generating a plasma therein. The working gas is injected into the plasma chamber around the cathode and anode electrodes, allowing the passing working gas to help cool the cathode and anode electrodes. Furthermore, as described with respect to FIGS. 5 and 6 , it is beneficial to maintain the working gas in a confined flow that follows the path of the arc between the cathode and anode electrodes. In this way, the working gas is exposed to the heat of the arc for a longer period of time. To help maintain the working gas in a confined flow, a rotating vortex can be generated within the working gas as it flows into the plasma chamber, with the central axis of the vortex oriented to follow the path of the arc (as shown in FIG. 6 ).

[0067] When the cathode and anode electrodes are located on opposite sides of the plasma chamber, as has been the case in the past, if identical rotating vortices are generated in the working gas as it exits both the cathode and anode electrodes, the two vortices will spin in opposite directions when they intersect at the center of the plasma chamber. The opposite spins will either cancel out the vortices or cause them to interact destructively, dispersing the working gas. This behavior can create significant instabilities in the arc column.

[0068] 17-19 depict or illustrate a plasma unit, which may be, for example, any of the plasma units 16, 100, 120, 130, 340, and 350 of FIGS. 1-3, 7-9, 12, and 13, and which can be used to better direct the flow of working gas within a reaction chamber. Referring to FIG. 17, a plasma arc system 410 can be used to enhance materials processing, such as waste-to-energy conversion, wastewater decomposition, nanomaterial synthesis, and methane decomposition to produce hydrogen and nanocarbons. In FIG. 17, an anode electrode assembly 412 and a cathode electrode assembly 414 can be seen installed within plasma modules on either side of a plasma chamber 416. The anode electrode assembly 412 and the cathode electrode assembly 414 generate an arc 418 extending across the plasma chamber 416 in any of the manners previously described herein.

[0069] The working gas 420 passes through the anode electrode assembly 412 and the cathode electrode assembly 414, acting to cool these assemblies 412, 414. Additionally, the working gas 420 is converted to plasma by the arc 418. As will be explained, as the working gas 420 passes through the electrode assemblies 412, 414, it is directed into an enhanced vortex 422. The enhanced vortex 422 causes the working gas 420 to spin, allowing the working gas 420 to propagate along the arc 418 without dispersion or with less dispersion than in previous systems that introduced the working gas into a reaction chamber through one or more electrodes.

[0070] However, as better shown in FIG. 18 , the first vortex 424 exiting the anode electrode assembly 412 rotates in a first direction (as viewed from the tip of the first electrode 412), which can be either clockwise or counterclockwise, while the second vortex 426 exiting the cathode electrode assembly 414 is configured to spin in the opposite direction (as viewed from the tip of the electrode 414). Because the anode electrode assembly 412 and the cathode electrode assembly 414 are oriented 180 degrees apart on opposite sides of the plasma chamber 416, they form opposite mirror images of each other, and the first and second vortices 424, 426 are physically aligned. Furthermore, the first vortex 424 and the second vortex 426 spin in the same direction due to the different spins induced in these vortices at the electrodes 412 and 414. As a result, the first vortex 424 and the second vortex 426 reinforce each other to generate a single reinforced vortex 422 that extends completely across the plasma chamber 416. The enhanced vortex 422 moves along the same path as the arc 418, so the working gas 420 remains close to the arc 418 without dispersing. This configuration improves the stability of the arc column and produces more plasma per unit of working gas 420.

[0071] 18 , in both the anode electrode assembly 412 and the cathode electrode assembly 414, the working gas 420 passes through grooves 428 formed on an electrode body or core 430 and between the electrode body or core 430 and a surrounding housing 432. In the anode electrode assembly 412, the grooves 428 are formed in a spiral shape, either clockwise or counterclockwise. Thus, as the working gas 420 passes through the anode electrode assembly 412, the working gas 420 spins within the grooves 428. When the working gas 420 exits the grooves 428, the spin motion remains, and the working gas 420 travels in a vortex (vortex 424).

[0072] However, the cathode electrode assembly 414 has grooves 428 (also disposed within the electrode body or core 430 and surrounding housing 432), but the grooves 428 of the cathode electrode assembly 414 rotate in the opposite direction to those used in the anode electrode assembly 412 (when viewed from the same direction, e.g., from the base toward the tip of the electrode 413, 414). Thus, the working gas 420 exits the cathode electrode assembly 414 with vortices (vortices 426) of opposite spin relative to the electrode 414. However, the first vortex 424 exiting the anode electrode assembly 412 is 180 degrees opposite to the second vortex 426 exiting the cathode electrode assembly 414, and thus are opposite mirror images of each other, and these two vortices 424, 426 spin in the same direction or circular motion within the plasma chamber 416. As a result, the two vortices 424 and 426 constructively add to each other to generate a vortex 422 that spans the entire distance between the anode electrode assembly 412 and the cathode electrode assembly 414. This stable vortex provides better gas column formation and helps prevent the working gas 420 from dispersing to or near the center of the chamber 416, leading to better arc formation and plasma generation within the chamber 416.

[0073] 19 , an alternative embodiment includes an anode electrode assembly 432 and a cathode electrode assembly 434, each of which includes an electrode core 436 and a surrounding housing 438. A groove 440 is formed on the inner surface of the housing 438 (which is part of the working gas passage) so that the working gas 420 passes through the groove 440. In the anode electrode assembly 432, the groove 440 is formed in a spiral shape that spirals either clockwise or counterclockwise when viewed from the longitudinal direction of the housing 438. Thus, as the working gas 420 passes along the anode electrode assembly 432, the working gas 420 spins in a predetermined circular direction within the groove 440. When the working gas 420 exits the groove 440, the spinning motion remains, and the working gas 420 proceeds in a first vortex 442.

[0074] However, the cathode electrode assembly 434 has grooves 440 that rotate in the opposite direction to the grooves used in the anode electrode assembly 432, when viewed longitudinally from the housing 438 of the cathode electrode assembly 434. Thus, the working gas 420 exits the cathode electrode assembly 434 with a second vortex 444 of opposite spin. However, because the first vortex 442 exiting the anode electrode assembly 432 is 180 degrees opposite to the second vortex 444 exiting the cathode electrode assembly 434, they are opposite mirror images of each other, and these two vortices 442, 444 spin in the same direction within the plasma chamber 446. Again, the two vortices 442, 444 constructively add to each other to generate a vortex that spans the entire distance between the anode electrode assembly 432 and the cathode electrode assembly 434. This stable vortex provides better gas plume formation and helps prevent the working gas 420 from dispersing to or near the center of the chamber 446 , leading to better arc formation and plasma generation within the chamber 446 .

[0075] Of course, plasma arc modules having electrode assemblies that generate better gas vortices are described herein in only two exemplary embodiments for purposes of illustration and discussion. However, these modules can be manufactured in other ways, and the illustrated embodiments are merely exemplary and should not be considered limiting when interpreting the claims. For example, the grooves described above can be disposed on other surfaces of the electrodes or electrode assemblies that are exposed to the flow of working gas into the reaction chamber. In addition, the grooves described herein can be disposed on multiple surfaces, such as both on the electrode body or core as illustrated in FIG. 18 and on the inner surface of the electrode housing as illustrated in FIG. 19. Alternatively, one of a pair or set of electrodes (e.g., the cathode electrode) can have a groove formed on one of the inner surfaces of the electrode body or electrode housing, and the other of the pair or set of electrodes (e.g., the anode electrode) can have a groove formed on the other of the inner surfaces of the electrode body or electrode housing. It will further be understood that the use of arc electrodes positioned on opposite sides of a reaction chamber to introduce a working gas into the chamber with vortices in different directions, constructively adding vortices within the chamber, as described herein, may be used in plasma chambers or reaction chambers having any number of such opposing electrode sets (including one or more sets), including, for example, any of the plasma units described herein, particularly the plasma units shown in Figures 1-3, 7-9, 12, and 13. In this case, the oppositely facing electrodes have grooves therein that cause the working gas to swirl in different circular directions as it leaves the electrode assembly, but the opposing electrodes may be from the same or different electrode sets or pairs. Thus, the opposing electrodes (electrodes positioned directly opposite each other across a reaction chamber or reaction zone) may be an anode and a cathode from the same set of electrodes, an anode and a cathode from different sets of electrodes, two anodes from different sets of electrodes, or two cathodes from different sets of electrodes.Furthermore, these electrodes with working gas vortex generation can be used in reaction chambers other than circular or cylindrical, including in rectangular, square, octagonal, etc. chambers or tubular chambers, with the electrodes positioned at the longitudinal ends of the tube. Similarly, the grooves in the various electrode assemblies can have any desired pitch (i.e., groove spacing between adjacent grooves in the spiral) to generate tighter or looser vortices. Furthermore, the groove pitch of different electrode assemblies or electrodes of a particular pair of electrodes (i.e., anode and cathode electrodes) can be the same or different.

[0076] Advantageously, the gasifiers described herein provide or implement a hyperthermic ionic gasification process that can be used, for example, to generate renewable syngas that can be used to provide heat, power, renewable fuels, renewable hydrogen, and / or renewable chemical production, and to dispose of dry biosolids from wastewater treatment plants and other waste materials, such as municipal solid waste (MSW), in an environmentally friendly manner. To do so, the systems described herein generate an electric arc across the interior (e.g., diameter) of the gasifier reaction chamber, which, together with ionized gases or particles (plasma), generates localized, controlled temperatures exceeding 3000°C, and in some cases, 5000°C. This hyperthermic gasification zone and active ionic environment combine to very effectively and efficiently break down molecules into their constituent atoms and ions in a process called complete molecular dissociation and ionization. This hyperthermic ionic zone also rapidly decomposes impurities in the feedstock, such as microplastics and PFAS (per- and polyfluorinated compounds). Furthermore, when the gasification stream exits the gasification zone, a rapid, controlled temperature drop recombines these atoms to form a very pure syngas with little or no system scaling, making it suitable for treating wastewater residues and focusing on drying and gasifying solid residues for energy production and PFAS destruction. This rapid temperature drop also tends to maximize the production of desirable molecules such as hydrogen and carbon monoxide and minimize the production of less desirable molecules such as water, ammonia, and carbon dioxide. The material to be treated is preferably a dry or partially dried solid with a high content of PFAS.

[0077] It will further be understood that the gasifiers described herein may be used in a gasifier mode where oxygen is present in its reaction chamber, or in a pyrolysis mode where no oxygen is present in the reaction chamber or where limited oxygen is introduced into the reaction chamber.

[0078] Thus, the reactors disclosed herein, e.g., plasma or ionic reactors or gasifiers, can be used in a method for treating or remediating (waste) materials. The method includes receiving an input material to be treated in a reaction chamber (e.g., of a plasma reactor or ionic reactor), the input material including at least one fluorocarbon material, such as a PFAS. The method further includes energizing one or more sets of electrodes (e.g., of the plasma reactor or ionic reactor), each set of electrodes including an anode electrode and a cathode electrode, each anode electrode and cathode electrode having an electrode tip exposed to the reaction chamber. The method further includes generating an electric arc between the anode electrode tip and the cathode electrode tip in the reaction chamber, exposing at least a portion of the input material to the electric arc, thereby destroying at least a portion of the fluorocarbon material (or PFAS), and forming a treated material having a lower fluorocarbon material (or PFAS) content than the input material.

[0079] The fluorocarbon material is not particularly limited and may include, for example, one or more low molecular weight fluorocarbon materials (or "fluorocarbons"), medium molecular weight fluorocarbons, high molecular weight fluorocarbons, oligomeric fluorocarbons, and / or polymeric fluorocarbons, including combinations or mixtures of multiple different fluorocarbon species. Fluorocarbon materials or fluorocarbons are characterized by the presence of carbon-fluorine bonds, including fluorinated carbon atoms such as, for example, CF3, CF2, and / or CF, and each of the remaining bonds (i.e., one, two, and three, respectively) in each of the foregoing fluorinated carbon atom species may independently be bonded to another fluorinated carbon atom, a hydrogen atom, another halogen atom (e.g., chlorine, bromine, iodine), a non-fluorinated carbon atom (e.g., a carbonyl group, such as in an anionic carboxylate group), a sulfur atom (e.g., a sulfonic acid group, such as in an anionic carboxylate group), a nitrogen atom (e.g., an amino or ammonium group, such as in a cationic group), or an oxygen atom (e.g., an ether group or a hydroxyl group). In some embodiments, some or all of the fluorinated carbon atoms may be perfluorinated carbon atoms, such as those that are not bonded to hydrogen atoms or other halogen atoms, but may be bonded to other carbon, nitrogen, sulfur, or oxygen atoms. Examples of perfluorinated carbon atoms may include CF3, such as primary carbons at the ends of linear or branched alkyl segments, CF2, such as secondary carbons along the length of linear or branched alkyl segments, and CF, such as tertiary carbons at the branch points in branched alkyl segments.

[0080] In embodiments, the fluorocarbon material may include one or more low molecular weight fluorocarbons, one or more medium molecular weight fluorocarbons, one or more high molecular weight fluorocarbons, one or more oligomeric fluorocarbons, and / or one or more polymeric fluorocarbons. The low molecular weight fluorocarbons may include 1, 2, 3, 4, 5, or 6 carbon atoms, e.g., 1 to 3 carbon atoms. The medium molecular weight fluorocarbons may include 4 to 20 or 3 to 30 carbon atoms, e.g., at least 3, 4, 5, 6, 7, 8, 10, 12, or 14 carbon atoms, and / or up to 10, 12, 14, 16, 18, 20, 25, or 30 carbon atoms. The high molecular weight or oligomeric fluorocarbon may contain 10 to 200, 20 to 150, or 21 to 100 carbon atoms, e.g., at least 10, 15, 20, 21, 25, 30, 40, 50, 60, or 80 carbon atoms, and / or up to 30, 60, 90, 120, 150, 180, or 200 carbon atoms. The polymeric fluorocarbon may contain at least 100 or at least 200 carbon atoms, e.g., at least 100, 150, 200, 300, 500, 1000, 1500, 2000, 3000, or 5000 carbon atoms or more, and / or up to 500, 1000, 2000, 5000, 10,000, 15,000, or 20,000 carbon atoms. The aforementioned carbon ranges for each of the various sizes / weights of fluorocarbon materials can also apply to the number of fluorinated and / or perfluorinated carbon atoms in a given fluorocarbon material. The polymeric fluorocarbon may alternatively or additionally contain at least 5×10 3 ~5×10 4 g / mol, 1×10 4 ~1×10 5 g / mol, 5 × 10 4 ~5×10 5 g / mol, 1×10 5 ~1×10 6 g / mol, 5 × 10 5 ~5×10 6 g / mol and / or 1×106 ~1×10 7 PFASs can be characterized by their molecular weights, which can be in the g / mol range. The aforementioned molecular weight values ​​can represent average molecular weights, e.g., averages based on number or weight. As described in more detail below, the fluorocarbon materials in various embodiments can include at least one anionic group (e.g., anionic PFASs), at least one cationic group (e.g., cationic PFASs), at least one anionic group and at least one cationic group (e.g., zwitterionic PFASs), or can be free of ionic groups (e.g., low molecular weight fluorocarbon refrigerants, fluorinated polymers, etc.).

[0081] Typical PFASs of interest are medium molecular weight fluorocarbons, for example, having 4-20 or 3-30 carbon atoms, although they can have more or fewer (fluorinated) carbon atoms. Common PFASs have linear or branched perfluoroalkyl structures, with the perfluorinated carbon atoms along a linear or branched chain. In some embodiments, a given PFAS can be a sulfonate (SO ), for example, in the form of an acid or a metal salt (e.g., an alkali metal salt such as sodium or potassium). 3- ) or carboxylate (C(=O)O - In addition to the acid or salt form, the anionic PFAS can exist in other derivative forms, such as (alkyl) esters. The anionic group can be linked to a (per)fluoroalkyl group, R, having 4 to 20 or 3 to 30 (per)fluorinated carbon atoms, with the various subranges described above for medium molecular weight fluorocarbons. In some embodiments, a given PFAS can be present in the form of a halide salt, such as an ammonium ((NR 1 R 2 R 3 )+. 1 , R 2 , and R 3are independently hydrogen (H) or a hydrocarbon group having at least 1, 2, 3, or 4 and / or at most 2, 3, 4, 6, 8, 10, or 12 carbon atoms, e.g., C-C or C-C 12 The cationic group may be a substituted or unsubstituted alkyl group and / or an aromatic group. In one embodiment, the cationic group is R 1 , R 2 , and R 3 is other than H. In one embodiment, the cationic group is a trimethylammonium group (-(N(CH3)3) + In one embodiment, R 1 , R 2 , and / or R 3 may independently contain one or more perfluorinated carbon atoms, for example, in a perfluorinated alkyl or aromatic group. The counterion of the cationic group is not particularly limited, but may suitably be a halide anion such as chloride. The cationic group may be linked to a (per)fluoroalkyl group R having 4 to 20 or 3 to 30 (per)fluorinated carbon atoms, as described above. In some embodiments, a given PFAS may be a zwitterionic PFAS (or zwitterionic PFAS) containing at least one anionic group (e.g., sulfonate or carboxylate) and at least one cationic group (e.g., ammonium). For example, amino acid isomerization reactions, such as NH2(R)CO2H=NH3 + (R)CO2 - produces a zwitterion, and R can be a (per)fluoroalkyl group R having 4 to 20 or 3 to 30 (per)fluorinated carbon atoms, as described above. NH3 + (R)CO2 -is a zwitterion (or dipole ion, also called an inner salt). In various embodiments, a given PFAS, whether anionic, cationic, zwitterion, or not, may contain other groups, such as amide groups, sulfonamide groups, ether groups, hydroxy groups, and / or (non-fluorinated) alkyl or alkylene linking groups containing 1, 2, 3, 4, 5, or 6 carbon atoms. In various embodiments, the input material or reactor feed may contain multiple different PFASs.

[0082] Examples of anionic PFAS include perfluorobutanoic acid (PFBA), perfluoropentanoic acid (PFPeA), 4:2 Fluorotelomer Sulfonic Acid (4:2 FTSA), perfluorohexanoic acid (PFHxA), perfluorobutane sulfonic acid (PFBS), perfluoroheptanoic acid (PFHpA), perfluoropentane sulfonic acid (PFPeS), 6:2 Fluorotelomer Sulfonic Acid (6:2 FTSA), perfluorooctanoic acid (PFOA), perfluorohexane sulfonic acid (PFHxS), and linear perfluorohexane sulfonic acid (Perfluorohexane Sulfonic Acid-Linear (PFHxS-LN), Perfluorohexane Sulfonic Acid-Branched (PFHxS-BR), Perfluorononanoic Acid (PFNA), 8:2 Fluorotelomer Sulfonic Acid (8:2 FTSA), Perfluoroheptane Sulfonic Acid (PFHpS), Perfluorodecanoic Acid (PFDA), N-Methyl Perfluorooctane Sulfonamidoacetic Acid (N-MeFOSAA), N-Ethyl Perfluorooctane Sulfonamidoacetic AcidAcid, EtFOSAA), Perfluorooctane Sulfonic Acid (PFOS), Perfluorooctane Sulfonic Acid-Linear (PFOS-LN), Perfluorooctane Sulfonic Acid-Branched (PFOS-BR), Perfluoroundecanoic Acid (PFUnDA), Perfluorononane Sulfonic Acid (PFNS), Perfluorododecanoic Acid (PFDoDA), Perfluorodecane Sulfonic Acid (PFDS), Perfluorotridecanoic Acid (PFTrDA), Perfluorooctane Sulfonamide (FOSA), Perfluorotetradecanoic Acid Acid (PFTeDA), undecafluoro-2-methyl-3-oxahexanoic acid (GenX), 10:2-fluorotelomersulfonic acid (10:2 FTS), perfluorododecanesulfonic acid (PFDoS), perfluorododecanoic acid (PFDoA), pedluorohexadecanoic acid (PFHxDA), pedluorooctadecanoic acid (PFODA), pedluorotetradecanoic acid (PFTeDA), pedluorotridecanoic acid (PFTeDA),acid (PFTrDA), Pedluoroundecanoic acid (PFUDA), 4,8-dioxa-3H-perfluorononanoic acid (DONA), 9-chlorohexadecafluoro-3-oxanonane-1-sulfonic acid (9Cl-PF3ONS), 11-chloroeicosafluoro-3-oxaundecane-1-sulfonic acid ( ... Examples of cationic PFAS include perfluorooctane quaternary ammonium salt (PFOAAmS) and 6:2 fluorotelomer sulfonamido amine (FtSaAm).

[0083] In embodiments, the fluorocarbon material may include a low molecular weight fluorocarbon (e.g., a chlorofluorocarbon or other halofluorocarbon) having 1, 2, 3, 4, 5, or 6 carbon atoms, e.g., 1 to 3 carbon atoms. Alternatively or additionally, fluorocarbons may be perfluorinated or partially fluorinated, e.g., having 1 to 14 fluorine atoms (e.g., at least 1, 2, 3, 4, 5, 6, 8, 10, or 12 and / or up to 2, 4, 6, 8, 10, 12, or 15 fluorine atoms). Such fluorocarbon materials may include fluoroalkyl compounds commonly used as refrigerants and may be present in various waste streams, such as gaseous feed streams, for treatment according to the disclosed methods. Examples of such fluorocarbons include trichlorofluoromethane, dichlorodifluoromethane, bromochlorodifluoromethane, dibromodifluoromethane, chlorofluoromethane, bromotrifluoromethane, tetrafluoromethane, dichlorofluoromethane, chlorodifluoromethane, trifluoromethane (fluoroform), hexachloroethane, pentachlorofluoroethane, 1,2-dichloro-1,1-difluoroethane, 1,1,2-trichloro-1,2,2-trifluoroethane, 1,1,1-trichloro-2,2,2-trifluoroethane, octafluoropropane, decafluorobutane (perfluorobutane), and the like.

[0084] In embodiments, the fluorocarbon material may include a polymeric fluorocarbon having at least 100 or at least 200 carbon atoms. Alternatively or additionally, the polymeric fluorocarbon may be perfluorinated or partially fluorinated, for example, having 0.5 to 2 fluorine atoms per carbon atom (e.g., at least 0.5, 0.7, 1, 1.2, 1.5, 1.7, 1.8, or 1.9, and / or up to 0.8, 1, 1.2, 1.4, 1.6, 1.8, 2, or 2.1 fluorine atoms per carbon atom in the polymer). Such polymeric fluorocarbon materials may include polytetrafluoroethylene (PTFE) polymers and their derivatives (e.g., tetrafluoroethylene copolymers and / or grafted / substituted PTFE polymers), which are commonly used in low-friction, anti-adherent, and / or lubricating coatings or materials. Such polymeric fluorocarbon materials may be present in various waste streams, such as biosolids or other solid feed streams, for treatment according to the disclosed methods.

[0085] The input or feedstock material to the reactor is not particularly limited and generally can include any solid, liquid, gas, or combination thereof (e.g., a multi-phase mixture) containing one or more fluorocarbon materials to be treated or destroyed. Liquid-phase input materials are suitably introduced into the reaction chamber as an atomized liquid (e.g., a continuous spray of droplets or other feed). Gas-phase input materials are suitably introduced into the reaction chamber as a gaseous feed stream (e.g., a continuous stream of gaseous feed). As noted above, solid-phase input materials can include biosolid waste, which can include some (liquid) water therein, such that the input material can be in the form of a wet biosolids cake. Wet solids input materials (e.g., biosolids, etc.) suitably have a moisture content of 20% or less, or 15% or less, e.g., at least 0.01%, 0.1%, 1%, 2%, or 5% and / or at most 2%, 4%, 6%, 8%, 10%, 12%, 15%, or 20% by weight, expressed on either a wet weight basis (or gross basis) or a dry weight basis. In some embodiments, wet biosolids or other wet solids input materials can have a higher moisture content, for example, in the form of a slurry or dispersion. In such cases, the high-water material may initially contain at least 20%, 30%, 40%, or 50% by weight, and / or up to 50% or 60% by weight water (on a total basis), but it is suitably dried (e.g., to a lower water content as described above) before being fed to the reactor chamber, e.g., in an evaporator, dryer, or other water separation device upstream of the reactor.

[0086] The fluorocarbon content or concentration of the input material is not particularly limited and can vary widely depending on the particular source and nature of the input material (e.g., biosolids waste vs. other contaminated solids, or soil vs. contaminated air, etc.). In the typical case of biosolids input material, one or more fluorocarbon materials, such as PFASs, may initially be present at a concentration of 0.1 ppb to 10,000 ppb, or 0.5 ppb to 4,000 ppb, on a weight basis (e.g., based on the dry weight of the wet (bio)solids feed), such as at least 0.1 ppb, 0.2 ppb, 0.5 ppb, 1 ppb, 1.5 ppb, 2 ppb, 5 ppb, 10 ppb, 20 ppb, 50 ppb, or , 100 ppb, 200 ppb, or 500 ppb and / or up to 10 ppb, 20 ppb, 40 ppb, 60 ppb, 80 ppb, 100 ppb, 150 ppb, 200 ppb, 300 ppb, 400 ppb, 500 ppb, 700 ppb, 1000 ppb, 2000 ppb, 3000 ppb, 4000 ppb, 5000 ppb, 7000 ppb, or 10000 ppb. The foregoing ranges can apply to a particular single fluorocarbon compound (or single PFAS) and / or to the total amount of fluorocarbon materials (or all PFASs) in the input material. Amounts above or below these ranges are possible, whether they are PFASs or other fluorocarbon materials in the input material.

[0087] Methods according to the present disclosure are characterized by their ability to reduce, eliminate, destroy, or convert fluorocarbon materials (e.g., PFAS) in the original input material. In embodiments, the treated material after processing in the reactor has a fluorocarbon material (e.g., PFAS) content of 10%, 20%, or 50% or less relative to the content of the input material. For example, the treated material may have a fluorocarbon material or PFAS content of up to 0.01%, 0.1%, 1%, 2%, 3%, 5%, 10%, 25%, or 50% relative to the content of the input material. Alternatively or additionally, the level of fluorocarbon material or PFAS degradation may be at least 50%, 75%, 90%, 95%, 97%, 98%, 99%, 99.9%, or 99.99%, including, for example, the conversion of the original fluorocarbon to fluorine species other than those containing carbon-fluorine bonds. In embodiments, destroying at least a portion of the fluorocarbon material (e.g., PFAS) includes converting (or mineralizing) at least 95% of the fluorine atoms (e.g., CF3 groups, CF2 groups, or carbon-bonded fluorine atoms in CF groups) originally present in the fluorocarbon material in the input material to fluoride ions. For example, at least 60%, 80%, 90%, 95%, 96%, 97%, 98%, 99%, 99.5%, or 99.8%, and / or up to 98%, 99%, 99.5%, 99.8%, 99.9%, or 100% of the fluorine atoms originally present in the fluorocarbon material in the input material can be converted to fluoride ions during processing in the reactor. However, such fluoride atoms generally exist in the reactor as reactive intermediate species and typically react with other (intermediate) product species in the reactor, typically with hydrogen atoms, to form hydrogen fluoride (HF) products in the treated material. Generally, different specific fluorocarbon materials or PFAS compounds (e.g., PFOA, PFOS, or other specific compounds) may have different degradation or conversion efficiencies for the disclosed methods, so the ranges disclosed herein can apply to all fluorocarbon materials in the original input material collectively and / or to one or more individual fluorocarbon materials.

[0088] The modular design of the reactor or gasifier facilitates a process with desired process efficiency, as reflected, for example, by fluorocarbon content reduction, fluorocarbon conversion, and / or fluorocarbon mineralization. Particularly considering the wide variety of input material types and different fluorocarbon materials that can be processed according to the disclosed methods, different input or feed materials may exhibit different process efficiencies. If higher processing efficiencies are desired, additional plasma modules or units can be stacked or otherwise added to the gasifier unit to increase the residence or exposure time of the input material to the plasma for processing. For example, the plasma gasifier 10 of FIG. 1 includes four plasma units 16 stacked and aligned in series, and an extension of the gasifier 10 of FIG. 1 can include one, two, three, or more plasma units 16 stacked and aligned in series (not shown) to increase fluorocarbon conversion, mineralization, etc. Alternatively or additionally, the number of electrode pairs in one or more of the plasma modules or units can be increased. For example, the plasma unit 16 of FIG. 2 includes three pairs of electrode assemblies 42, and an extension of the plasma unit 16 of FIG. 2 can include one, two, three, or more additional electrode pairs (not shown) to increase fluorocarbon conversion, mineralization, etc., such as through an access port 40 shown in FIG. 2 that does not include the electrode assemblies 42 therein.

[0089] In some embodiments, the reactor or gasifier may include one or more preheating elements for the biosolids or other input material before it enters the plasma module of the gasifier. In other embodiments, the reactor or gasifier may not include such preheating elements. As mentioned above, a typical plasma generation system arcs between two electrodes within the body of the reactor. Preheating elements can be incorporated into the reactor by placing or inserting additional modules on top (e.g., between the feed port 124 for the input material to be processed and the first plasma unit or module 16), which use one, two, three, or more torches to preheat the biosolids before they enter the plasma module. These torches differ in that the cathode and anode are within the same body and create a short arc through which nitrogen (or other working gas) flows. The nitrogen is heated and ionized by the arc and used to carry the heat and ions into the reactor vessel.

[0090] In some embodiments, the treated material (or a component, phase, or fraction thereof) can be further treated or processed to capture, separate, or otherwise remove fluorocarbon decomposition products. For example, as discussed above for the typical case where hydrogen fluoride products are present in the treated material (e.g., gas-phase product stream), such hydrogen fluoride can be removed in a hydrated lime bed, scrubber, or other suitable separator. It is noteworthy, however, that when processing input materials having low (e.g., still harmful) fluorocarbon content (e.g., ppt or ppb levels of PFAS), the resulting low levels of hydrogen fluoride or other fluorocarbon decomposition products may be low enough so as not to adversely affect the quality of the synthesis gas or other product gas formed, and therefore, separation or removal of such decomposition products may not be required or necessarily desirable in all cases. Furthermore, fluorine may be present in biosolids or other input materials from sources other than fluorocarbon materials or PFASs, e.g., at higher ppm levels, which may similarly form hydrogen fluoride in the treated material.

[0091] The processed material resulting from electric arc processing is generally gaseous with some amount of solid (e.g., ash) by-product. The gaseous product can be syngas, but the composition of the resulting syngas (H2 and CO2 mixture) can vary depending on the composition and nature / source of the feedstock (e.g., source / type of biosolids) and whether / how much oxygen is added to the reactor. Typical syngas concentrations are 25-60% hydrogen gas (H2), 20-50% carbon monoxide (CO), up to about 2% water (H2O) and carbon dioxide (CO2), and the majority of the remainder nitrogen gas (N2). In embodiments, the gaseous product can contain at least 20%, 25%, 30%, 35%, or 40% H2, and / or up to 30%, 35%, 40%, 45%, 50%, 55%, or 60% H2. In embodiments, the gaseous products may comprise at least 20%, 25%, 30%, 35%, or 40% and / or up to 30%, 35%, 40%, 45%, 50%, 55%, or 60% CO. In embodiments, the gaseous products may comprise at least 0.0001, 0.001, 0.01, or 0.1 and / or up to 0.1%, 0.2%, 0.5%, 1%, or 2% HO and / or CO. In embodiments, at least 80%, 85%, 90%, 95%, 98%, or 99% and / or up to 95%, 98%, 99%, or 100% of the remaining gas is N (i.e., gases other than H, CO, CO, and HO). The aforementioned gas concentrations may be in mole percent or volume percent. Small amounts of one or more other compounds may be present, such as hydrogen sulfide (HS), hydrochloric acid or hydrogen chloride (HCl), hydrofluoric acid or hydrogen fluoride (HF), for example, at levels of 1-1000 ppm or 10-100 ppm, ppb, or ppt (e.g., on a molar or volume basis). HF is a product resulting from the decomposition of PFAS or other fluorocarbon materials, although, as noted above, other sources of fluorine may be present in the feed. Thus, any HF present in the treated material may be partially derived or otherwise obtained from the decomposition of PFAS / fluorocarbons, or partially derived or otherwise obtained from the decomposition of fluorine-containing materials in the feed other than PFAS / fluorocarbons.The treated material generally does not contain any liquid or liquid phase, although gaseous treated material may contain water or some small amount of condensable materials, such as oil or tar. The solid portion of the treated material may represent a fairly substantial residual char (ash mixed with some unreacted carbon), e.g., about 15-30% by weight of ash obtained from a biosolids input material (e.g., with the remainder or about 70-85% by weight of the original biosolids input material converted to a gaseous product phase, as described above). The solid portion of the treated material may also include one or more fluorine-containing decomposition products, including, for example, fluorine (metal) salts, such as alkali metal salts (e.g., NaF, KF) or alkaline earth metal salts (e.g., CaCl, MgCl), particularly if the input material also contains alkali or alkaline earth metals in various forms (e.g., metals, salts, oxides, etc.).

[0092] Reactors or gasifiers are generally operated at high temperatures for processing input materials and converting / decomposing fluorocarbon materials. For example, generating an electric arc in a reactor can include forming a localized plasma in a reaction chamber having a temperature of at least 3000°C (or at least 5000°C) to which the input materials are exposed, destroying at least a portion of the fluorocarbon materials / PFASs. Generally, higher processing temperatures correspond to faster rates of fluorocarbon material / PFAS decomposition. While there is no upper temperature limit for the ability to destroy or convert fluorocarbon materials, reactors are typically manufactured to withstand and / or operate at temperatures up to about 8000°C or 10000°C, as representative maximum temperatures.

[0093] As discussed above, a reactor or gasifier according to the present disclosure can be operated to process fluorocarbon materials in a gasifier mode in which oxygen is present in its reaction chamber, or in a pyrolysis mode in which no oxygen is present in the reaction chamber or limited oxygen is introduced into the reaction chamber. For example, the reaction chamber can be maintained or operated in an oxidation process mode, such as a fully or partially oxidizing condition, in which oxygen is supplied to or otherwise present in the reaction chamber during the electric arc and formation of the treated material. Alternatively, the reaction chamber can be maintained or operated in a pyrolysis (or anaerobic) process mode in which no oxygen is supplied to or limited oxygen is supplied to or otherwise present in the reaction chamber during the electric arc and formation of the treated material.

[0094] Operation of the reactor or gasifier during processing may include supplying one or both of a working gas and / or a reactive gas to the reaction chamber. A suitable working gas includes nitrogen. The working gas may be supplied to the reaction chamber before and / or during the formation of the electric arc and / or the treated material. Suitable reactive gases include oxygen-containing gases (e.g., for operation in oxidation or gasifier mode). The reactive gas may be supplied to the reaction chamber before and / or during the formation of the electric arc and / or the treated material. Examples of oxygen-containing reactive gases include oxygen gas, water (e.g., steam), nitrogen oxides (e.g., NO, such as NO and / or NO2), and the like. x ), and carbon dioxide.

[0095] The following includes a summary of the disclosed methods for processing materials and suitable reactors or gasifiers that can be used to carry out the disclosed methods.

[0096] In one aspect, the disclosure relates to a method of processing a material, the method including: receiving an input material to be processed in a reaction chamber, the input material including at least one fluorocarbon material (or PFAS); applying electricity to one or more sets of electrodes, each set of electrodes including an anode electrode and a cathode electrode, each anode electrode and cathode electrode having an electrode tip exposed to the reaction chamber; and generating an electric arc between the anode electrode tip and the cathode electrode tip in the reaction chamber, exposing at least a portion of the input material to the electric arc, thereby destroying at least a portion of the fluorocarbon material (or PFAS) and forming a processed material having a lower fluorocarbon material (or PFAS) content than the input material.

[0097] In a refinement, the method further includes generating a plasma in a plasma torch and injecting the plasma from the plasma torch into the reaction chamber to expose at least a portion of the input material to the plasma from the plasma torch when forming the treated material.

[0098] In a refinement, the fluorocarbon material includes at least one fluorocarbon containing 1 to 3 carbon atoms, a fluorocarbon containing 4 to 20 carbon atoms, a fluorocarbon containing 21 to 100 carbon atoms, and a fluorocarbon containing more than 100 carbon atoms.

[0099] In a refinement, the fluorocarbon material comprises at least one perfluoroalkyl or polyfluoroalkyl compound (“PFAS”). In a further refinement, the PFAS can comprise one or more compounds having 4 to 20 perfluorinated carbon atoms. In a further refinement, the PFAS can comprise at least one of anionic groups, cationic groups, and salts thereof. In a further refinement, the PFAS can comprise at least one anionic PFAS. In a further refinement, the PFAS can comprise at least one cationic PFAS. In a further refinement, the PFAS can comprise at least one zwitterionic PFAS. In a further refinement, the PFAS can comprise at least one of perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS).

[0100] In a refinement, the fluorocarbon material comprises a low molecular weight fluorocarbon containing from 1 to 3 carbon atoms.

[0101] In a refinement, the fluorocarbon material comprises an oligomeric or polymeric fluorocarbon material.

[0102] In a refinement, the input material comprises biosolids. In a further refinement, the method may further comprise drying the biosolids prior to providing the biosolids to the reaction chamber.

[0103] In a refinement, the input material comprises atomized liquid.

[0104] In a refinement, the input material comprises a gas.

[0105] In a refinement, the input material has a fluorocarbon material concentration in the range of 0.1 ppb to 10,000 ppb by weight.

[0106] In a refinement, the treated material has a fluorocarbon material content of 50% or less relative to that of the input material.

[0107] In a refinement, destroying at least a portion of the fluorocarbon material includes converting at least 95% of the fluorine atoms originally present in the fluorocarbon material in the input material to fluoride ions.

[0108] In a refinement, exposing at least a portion of the input material to an electric arc further comprises forming one or more of hydrogen gas, carbon monoxide, and combinations thereof.

[0109] In a refinement, generating the electric arc includes forming a localized plasma in the reaction chamber having a temperature of at least 3000° C. to which the input material is exposed.

[0110] In a refinement, the method includes operating the reaction chamber in an oxidation process mode.

[0111] In a refinement, the method includes operating the reaction chamber in a pyrolysis process mode.

[0112] In a refinement, the method includes supplying a working gas (e.g., nitrogen gas) to the reaction chamber.

[0113] In a refinement, the method includes supplying a reactive gas to the reaction chamber. In a further refinement, the reactive gas may be selected from the group consisting of oxygen gas, water, carbon dioxide, and combinations thereof.

[0114] The disclosed methods can be carried out in any reactor generally disclosed herein, for example, a plasma or ionic reactor or gasifier, including exemplary reactors or gasifiers as summarized below.

[0115] In a first reactor or gasifier embodiment, the reactor or gasifier includes an input for receiving material to be treated, an output, one or more plasma units, each plasma unit having an outer wall defining an internal reaction zone, and one or more sets of electrode assemblies, each set including an anode electrode and a cathode electrode, each of the anode electrode and the cathode electrode including an electrode tip exposed to the reaction zone, each set of electrode assemblies for generating an arc discharge in the reaction zone between the anode electrode and the cathode electrode. the one or more plasma units are connected to a power source for energizing an anode electrode and a cathode electrode with a power signal to generate a plasma, the one or more plasma units being arranged between an input and an output such that a reaction zone of the one or more plasma units defines a reaction chamber, and material to be treated flows from the input to the output through the reaction chamber and is exposed to an arc discharge generated by one or more sets of electrode assemblies in the one or more plasma units; and a plasma torch arranged adjacent to the reaction chamber and having an output for discharging plasma into the reaction chamber.

[0116] In a refinement, the plasma torch is positioned near the input.

[0117] In a refinement, the plasma torch is located near the output.

[0118] In a refinement, the reaction chamber has a longitudinal axis extending from the input to the output, and the plasma torch is oriented to direct a flowing plasma longitudinally into the reaction chamber.

[0119] In a refinement, the reactor or gasifier includes a plurality of plasma units, and the plasma torch is oriented to direct a plasma into the reaction zone of at least two of the plurality of plasma units.

[0120] In a refinement, the plasma torch is disposed in one of the one or more plasma units, extends through an outer wall of the one of the one or more plasma units and directs a plasma radially into a reaction zone of the one of the one or more plasma units.

[0121] In a refinement, each of the electrode assemblies includes one or more working gas passages and a working gas outlet that directs the working gas into a reaction zone of one of the plasma units. In a further refinement, the working gas discharged through the one or more electrode assemblies can be subjected to one or more arcs to form a plasma in the reaction zone of one of the plasma units.

[0122] In a refinement, the plasma emitted by the plasma torch ignites one or more arcs between the anode and cathode electrodes of at least one set of electrode assemblies.

[0123] In a refinement, each of the one or more plasma units is circular in cross section and defines a cylindrical reaction zone. In a further refinement, the gasifier or reactor may include a plurality of plasma units stacked longitudinally to define an elongated cylindrical reaction chamber. In a further refinement, each of the plurality of plasma units may include two or more sets of electrode assemblies. In a further refinement, the plasma torch may emit a plasma flame that passes through the reaction zones of at least two of the plasma units and interacts with one or more arcs generated by the electrode assemblies of each of the at least two plasma units.

[0124] In a second reactor or gasifier aspect, the reactor or gasifier comprises: a reaction chamber formed by a continuous outer wall extending between a first open end and a second open end and defining a longitudinal axis between the first open end and the second open end; at least one set of electrodes extending through the outer wall between the first open end and the second open end and into the reaction chamber, each set of electrodes including an anode electrode and a cathode electrode, each of the anode electrode and the cathode electrode including an electrode tip, each set of electrodes connected to a power source for energizing the anode electrode and the cathode electrode with a power signal to induce an arc discharge within the reaction chamber between the anode electrode tip and the cathode electrode tip; and a plasma torch disposed adjacent the reaction chamber and having an output for discharging a plasma into the reaction chamber.

[0125] In a refinement, the plasma torch emits the plasma as a plasma flame into the reaction chamber.

[0126] In a refinement, the anode and cathode electrodes extend into the reaction chamber in a first plane perpendicular to the longitudinal axis, and the plasma torch is positioned perpendicular to the first plane to emit plasma into the reaction chamber perpendicular to the first plane.

[0127] In a refinement, the anode and cathode electrodes extend into the reaction chamber in a first plane perpendicular to the longitudinal axis, and the plasma torch is positioned to emit a plasma into the reaction chamber in a direction parallel to the first plane.

[0128] In a refinement, the anode electrode and the cathode electrode extend into the reaction chamber in a first plane perpendicular to the longitudinal axis, and the plasma torch is positioned to emit plasma into the reaction chamber in a direction parallel to and within the first plane.

[0129] In a refinement, the anode and cathode electrodes extend into the reaction chamber in a first plane perpendicular to the longitudinal axis, and the plasma torch is positioned to emit a plasma into the reaction chamber in a direction that intersects the first plane at a non-zero angle.

[0130] In a refinement, the reactor further includes a material input and a material output, wherein the at least one set of electrodes are arranged such that the anode and cathode electrodes of the at least one set of electrodes are arranged laterally across the reaction chamber, and the plasma torch is oriented to direct the plasma in the flow longitudinally into the reaction chamber. In a further refinement, the reaction chamber may include a plurality of plasma units, each including an outer wall defining a reaction zone within the boundary of the outer wall and at least one set of electrodes, and the plasma units may be stacked on top of each other such that the outer walls of the plasma units are aligned such that the reaction zones of the plurality of plasma units form the reaction chamber. In a further refinement, the plasma torch is oriented to direct the plasma into the reaction zones of at least two of the plurality of plasma units.

[0131] In a refinement, the reaction chamber includes one or more cylindrical plasma units formed by a cylindrical outer wall, and the plasma torch is disposed in one of the one or more plasma units and extends through the outer wall of one of the one or more plasma units to direct a plasma radially into a reaction zone of one of the one or more plasma units.

[0132] In a refinement, one or more of the electrodes includes one or more working gas passages and a working gas outlet that directs the working gas into the reaction chamber. In a further refinement, the working gas released through the one or more electrodes may be subjected to one or more arcs in the reaction chamber during operation of the gasifier.

[0133] In a refinement, the plasma emitted by the plasma torch ignites one or more arcs between electrodes of one set of electrodes during operation of the gasifier.

[0134] In a third reactor or gasifier embodiment, the reactor or gasifier comprises an input for receiving the material to be treated, an output, and one or more plasma units disposed between the input and the output, each plasma unit including an exterior wall defining an internal reaction zone and a plurality of electrode sets attached to the exterior wall, each set of electrodes including an anode electrode with an anode electrode tip exposed to the reaction zone and a cathode electrode with a cathode electrode tip exposed to the reaction zone, each of the electrode sets connected to a power source for energizing the anode electrode and the cathode electrode with a power signal to induce an arc discharge within the reaction zone between the anode electrode tip and the cathode electrode tip, the individual electrodes of the plurality of electrode sets being offset around the exterior wall, and each adjacent electrode pair including an anode electrode and a cathode electrode.

[0135] In a refinement, the anode and cathode electrodes of at least one of the electrode sets are offset from one another around the outer wall by an angle of less than 180 degrees.

[0136] In a refinement, the anode and cathode electrodes of at least one of the electrode sets are offset from one another by an acute angle around the outer wall.

[0137] In a refinement, the anode and cathode electrodes of at least one of the electrode sets are offset from one another by an obtuse angle around the outer wall.

[0138] In a refinement, the anode and cathode electrodes of at least one of the electrode sets are offset from one another by an angle of 90 degrees around the outer wall.

[0139] In a refinement, the anode and cathode electrodes of a first set of the electrode sets are offset from one another around the outer wall at a first angle that is less than 180 degrees, and the anode and cathode electrodes of a second set of the electrode sets are offset from one another around the outer wall at a second angle that is different from the first angle.

[0140] In a refinement, the anode and cathode electrodes of a first set of the electrode sets are offset from one another by a first angle less than 180 degrees around the outer wall, and the anode and cathode electrodes of a second set of the electrode sets are offset from one another by 180 degrees around the outer wall.

[0141] In a refinement, the plurality of electrode sets includes three sets of electrodes, wherein the anode and cathode electrodes of a first of the three sets of electrodes are offset 180 degrees from one another around the outer wall, and the anode and cathode electrodes of second and third of the three sets of electrodes are offset 60 degrees from one another around the outer wall.

[0142] In a refinement, the plurality of electrode sets includes three sets of electrodes, the anode and cathode electrodes of each of the three sets of electrodes being offset 60 degrees from one another around the outer wall.

[0143] In a refinement, the plurality of electrode sets includes four sets of electrodes, and the anode and cathode electrodes of at least two of the four sets of electrodes are offset from one another by 135 degrees around the outer wall.

[0144] In a refinement, the plurality of electrode sets includes four sets of electrodes, and the anode and cathode electrodes of at least two of the four sets of electrodes are offset 45 degrees from each other around the outer wall.

[0145] In a refinement, the system further includes a plasma torch disposed adjacent to the reaction zone of at least one of the one or more plasma units and having an output for discharging plasma into the reaction zone of the at least one plasma unit. In a further refinement, the plasma torch can be disposed near the input. In a further refinement, the reaction zone of the one or more plasma units can define a reaction chamber having a longitudinal axis extending from the input to the output, and the plasma torch can be oriented to direct the plasma in the flow longitudinally into the reaction chamber. In a further refinement, the plasma torch can be disposed within one of the one or more plasma units and extend through an outer wall of the one of the one or more plasma units to direct the plasma radially into the reaction zone of the one or more plasma units.

[0146] In a refinement, at least one of the electrode sets of one of the one or more plasma units includes an electrode assembly including one or more working gas passages and a working gas outlet that directs the working gas to a reaction zone of one of the one or more plasma units.

[0147] In a refinement, the outer wall of one of the one or more plasma units is circular in cross section and defines a cylindrical reaction zone for the one of the one or more plasma units.

[0148] In a fourth reactor or gasifier aspect, the reactor or gasifier comprises an input for receiving the material to be treated, an output, and one or more plasma units disposed between the input and the output, each plasma unit comprising: an outer annular wall defining an interior reaction zone; and a plurality of electrode sets attached to the outer annular wall, each set of electrodes comprising an anode electrode with an anode electrode tip exposed to the reaction zone and a cathode electrode with a cathode electrode tip exposed to the reaction zone, each set of electrodes connected to a power source for energizing the anode electrode and the cathode electrode with a power signal to induce an arc discharge within the reaction zone between the anode electrode tip and the cathode electrode tip, and wherein the anode electrode and the cathode electrode of at least one of the electrode sets are offset from each other by an angle less than 180 degrees around the outer annular wall.

[0149] In a refinement, the anode and cathode electrodes of at least one of the electrode sets are offset from one another by an acute angle around the outer annular wall.

[0150] In a refinement, the anode and cathode electrodes of at least one of the electrode sets are offset from one another by an obtuse angle around the outer annular wall.

[0151] In a refinement, the anode and cathode electrodes of at least one of the electrode sets are offset from one another by an angle of 90 degrees around the outer annular wall.

[0152] In a refinement, the anode and cathode electrodes of a first set of the electrode sets are offset from one another around the annular outer wall at a first angle that is less than 180 degrees, and the anode and cathode electrodes of a second set of the electrode sets are offset from one another around the annular outer wall at a second angle that is different from the first angle.

[0153] In a refinement, the anode and cathode electrodes of a first set of the electrode sets are offset from one another by a first angle less than 180 degrees around the annular outer wall, and the anode and cathode electrodes of a second set of the electrode sets are offset from one another by an angle of 180 degrees around the annular outer wall.

[0154] In a refinement, the plurality of electrode sets includes three sets of electrodes, wherein the anode and cathode electrodes of a first of the three sets of electrodes are offset 180 degrees from one another around the outer annular wall, and the anode and cathode electrodes of second and third of the three sets of electrodes are offset 60 degrees from one another around the outer annular wall.

[0155] In a refinement, the plurality of electrode sets includes three sets of electrodes, the anode and cathode electrodes of each of the three sets of electrodes being offset 60 degrees from one another around the outer annular wall.

[0156] In a refinement, the plurality of electrode sets includes four sets of electrodes, and the anode and cathode electrodes of at least two of the four sets of electrodes are offset from one another by 135 degrees around the outer annular wall.

[0157] In a refinement, the plurality of electrode sets includes four sets of electrodes, and the anode and cathode electrodes of at least two of the four sets of electrodes are offset 45 degrees from one another around the outer annular wall.

[0158] In a refinement, the gasifier or reactor may further include a plasma torch disposed adjacent to the reaction zone of at least one of the one or more plasma units and having an output for discharging plasma into the reaction zone of the at least one of the one or more plasma units. In a further refinement, the plasma torch is disposed near the input. In a further refinement, the reaction zone of the one or more plasma units may define a reaction chamber having a longitudinal axis extending from the input to the output, and the plasma torch may be oriented to direct the plasma in the flow longitudinally into the reaction chamber. In a further refinement, the gasifier or reactor may include multiple plasma units, and the plasma torch is oriented to direct the plasma into the reaction zone of at least two of the multiple plasma units. In a further refinement, the plasma torch may be disposed within one of the one or more plasma units and extend through an outer annular wall of one of the one or more plasma units to direct the plasma radially into the reaction zone of one of the one or more plasma units. In a further refinement, at least one of the electrode sets of one of the one or more plasma units may include an electrode assembly including one or more working gas passages and a working gas outlet that directs the working gas to a reaction zone of one of the one or more plasma units.

[0159] In a refinement, the one or more plasma units are disposed between the input and the output, the reaction zone of each of the one or more plasma units defining a reaction chamber, and the material to be treated flows through the reaction chamber from the input to the output and is exposed to an arc discharge generated by the plurality of electrode sets in the one or more plasma units.

[0160] In a refinement, the individual electrodes of the plurality of electrode sets in the one or more plasma units are arranged offset around the outer annular wall, with each adjacent electrode pair including an anode electrode and a cathode electrode.

[0161] In a fifth reactor or gasifier embodiment, the reactor or gasifier includes an input for receiving material to be treated, an output, one or more plasma units disposed between the input and output, each plasma unit defining an internal reaction zone, an outer wall, one or more sets of electrode assemblies, each set of electrode assemblies having: (1) an anode electrode with an anode electrode tip exposed to the reaction zone; (2) a first working gas passage; (3) a first working gas outlet exposed to the reaction zone; and (4) a first electrode assembly having a first set of spiral grooves disposed on a surface of the first electrode assembly exposed to the working gas, the spiral grooves forming a spiral in a first circular direction that causes the first working gas to exit the first working gas outlet in a first vortex. and one or more plasma units comprising: (1) a cathode electrode having an electrode tip exposed to the reaction zone; (2) a second working gas passage; (3) a second working gas outlet exposed to the reaction zone; and (4) a second electrode assembly having a second set of spiral grooves disposed on a surface of the second electrode assembly exposed to the working gas, the second electrode assembly having a second set of spiral grooves forming a spiral in a second circular direction that causes the second working gas to exit the working gas outlet in a second vortex, each of the electrode assembly sets being connected to a power source for energizing the anode electrode and the cathode electrode with a power signal, and generating an arc discharge in the presence of the spirally moving first working gas and the second working gas in the reaction zone between the anode electrode tip and the cathode electrode tip.

[0162] In a refinement, the first circular direction and the second circular direction are different circular directions.

[0163] In a refinement, the first circular direction is one of clockwise or counterclockwise and the second circular direction is the other of clockwise or counterclockwise.

[0164] In a refinement, the first electrode assembly is positioned directly across the reaction zone from the second electrode assembly such that a line from the anode electrode tip to the cathode electrode tip bisects the reaction zone.

[0165] In a refinement, the first electrode assembly surface is an electrode core and the second electrode assembly surface is an electrode core.

[0166] In a refinement, the first electrode assembly surface is an interior surface of a first working gas passage and the second electrode assembly surface is an interior surface of a second working gas passage.

[0167] In a refinement, the first electrode assembly surface is one of the electrode core or the inner surface of the first working gas passage, and the second electrode assembly surface is the other of the electrode core and the inner surface of the second working gas passage.

[0168] In a refinement, the first groove set has a first pitch and the second groove set has a second pitch different from the first pitch.

[0169] In a refinement, the first set of grooves and the second set of grooves have the same pitch.

[0170] In a refinement, the outer wall defines a rectangular reaction zone.

[0171] In a refinement, the outer wall defines a cylindrical reaction zone.

[0172] In a refinement, the outer wall forms a tubular reaction zone and the electrode assemblies of one of the electrode assembly sets are disposed at the tubular ends.

[0173] In a sixth reactor or gasifier embodiment, the reactor or gasifier comprises an input for receiving a material to be treated, an output, and one or more plasma units disposed between the input and the output, each plasma unit comprising an annular outer wall defining a cylindrical interior reaction zone and a plurality of sets of electrode assemblies disposed through the annular outer wall, each set of electrode assemblies comprising: a first electrode assembly having an anode electrode with an anode electrode tip exposed to the reaction zone; and a second electrode assembly having a cathode electrode with a cathode electrode tip exposed to the reaction zone, each of the first and second electrode assemblies comprising: (1) a working gas passage; (2) a working gas outlet exposed to the reaction zone; and (3) an electrode passage exposed to the working gas. The plasma unit further includes a set of spiral grooves on the electrode assembly surface that cause the working gas to exit the working gas outlet in a vortex, and each of the electrode assembly sets is connected to a power source for energizing the anode electrode and the cathode electrode with a power signal to generate an arc discharge in a reaction zone between the anode electrode tip and the cathode electrode tip of the electrode assembly set, and the electrode assembly sets are arranged around the annular outer wall of the plasma unit to generate a plurality of oppositely arranged electrode assembly sets, each set of oppositely arranged electrode assemblies including two electrode assemblies from the same set of electrode assemblies that are arranged directly across the reaction zone from each other, or two electrode assemblies from different sets of electrode assemblies that are arranged directly across the reaction zone from each other.

[0174] In a refinement, at least one of the set of oppositely arranged electrode assemblies includes a first set of grooves in a first one of the oppositely arranged electrode assemblies for flowing the working gas in a first circular direction and a second set of grooves in a second one of the oppositely arranged electrode assemblies for flowing the working gas in a second circular direction different from the first circular direction.

[0175] In a further refinement, the first circular direction may be one of clockwise or counterclockwise, and the second circular direction may be the other of clockwise or counterclockwise.

[0176] In a refinement, the electrode assembly surface of a first electrode assembly of a particular set of oppositely arranged electrode assemblies is an electrode core, and the electrode assembly surface of a second electrode assembly of a particular set of oppositely arranged electrode assemblies is an electrode core.

[0177] In a refinement, the electrode assembly surface of a first electrode assembly of a particular set of oppositely arranged electrode assemblies is the interior surface of the fluid / gas passage, and the electrode assembly surface of a second electrode assembly of a particular set of oppositely arranged electrode assemblies is the interior surface of the fluid / gas passage.

[0178] In a refinement, the electrode assembly surface of a first electrode assembly of a particular set of oppositely arranged electrode assemblies is the interior surface of the fluid gas passage, and the electrode assembly surface of a second electrode assembly of the particular set of oppositely arranged electrode assemblies is the electrode core.

[0179] In a refinement, the groove set of a first electrode assembly of the particular set of oppositely arranged electrode assemblies and the groove set of a second electrode assembly of the particular set of oppositely arranged electrode assemblies have the same pitch.

[0180] US Patent Application Publication No. 2023 / 0166227, which is incorporated herein by reference, contains disclosures relating to reactor or gasifier embodiments that may be used with the methods disclosed herein.

[0181] The jet and plasma arc systems described herein can be embodied in many ways, and only a few exemplary embodiments have been selected for purposes of illustration and description. Furthermore, it will be understood that the embodiments of the invention shown and described herein are merely exemplary, and that those skilled in the art could make many modifications to these embodiments. All such embodiments are intended to be within the scope of the present invention, as defined by the claims.

Claims

1. 1. A method of processing a material, comprising: receiving an input material to be processed in a reaction chamber, the input material comprising at least one fluorocarbon material; energizing one or more sets of electrodes, each set of electrodes including an anode electrode and a cathode electrode, each anode electrode and cathode electrode having an electrode tip exposed to the reaction chamber; generating an electric arc between the anode electrode tip and the cathode electrode tip in the reaction chamber and exposing at least a portion of the input material to the electric arc to destroy at least a portion of the fluorocarbon material and form a treated material having a lower fluorocarbon material content than the input material.

2. generating a plasma in a plasma torch; 10. The method of claim 1, further comprising injecting the plasma from the plasma torch into the reaction chamber to expose at least a portion of the input material to the plasma from the plasma torch when forming the treated material.

3. 10. The method of claim 1, wherein the fluorocarbon material comprises at least one fluorocarbon containing 1 to 3 carbon atoms, a fluorocarbon containing 4 to 20 carbon atoms, a fluorocarbon containing 21 to 100 carbon atoms, and a fluorocarbon containing more than 100 carbon atoms.

4. 10. The method of claim 1, wherein the fluorocarbon material comprises at least one perfluoroalkyl or polyfluoroalkyl compound ("PFAS").

5. 5. The method of claim 4, wherein the PFAS comprises one or more compounds having 4 to 20 perfluorinated carbon atoms.

6. The method of claim 4 , wherein the PFAS comprises at least one of an anionic group, a cationic group, and salts thereof.

7. The method of claim 4 , wherein the PFAS comprises at least one anionic PFAS.

8. The method of claim 4 , wherein the PFAS comprises at least one cationic PFAS.

9. 5. The method of claim 4, wherein the PFAS comprises at least one zwitterionic PFAS.

10. 5. The method of claim 4, wherein the PFAS comprises at least one of perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS).

11. The method of claim 1, wherein the fluorocarbon material comprises a low molecular weight fluorocarbon containing 1 to 3 carbon atoms.

12. The method of claim 1 , wherein the fluorocarbon material comprises an oligomeric or polymeric fluorocarbon material.

13. The method of claim 1 , wherein the input material comprises biosolids.

14. 14. The method of claim 13, further comprising drying the biosolids before providing the biosolids to the reaction chamber.

15. The method of claim 1 , wherein the input material comprises an atomized liquid.

16. The method of claim 1 , wherein the input material comprises a gas.

17. 10. The method of claim 1, wherein the input material has a fluorocarbon material concentration in the range of 0.1 ppb to 10,000 ppb on a weight basis.

18. 10. The method of claim 1, wherein the treated material has a fluorocarbon material content of 50% or less relative to that of the input material.

19. 10. The method of claim 1, wherein destroying at least a portion of the fluorocarbon material comprises converting at least 95% of the fluorine atoms originally present in the fluorocarbon material in the input material to fluoride ions.

20. The method of claim 1 , wherein exposing the at least a portion of the input material to an electric arc further comprises forming one or more of hydrogen gas, carbon monoxide, and combinations thereof.

21. 10. The method of claim 1, wherein generating the electric arc comprises forming a localized plasma in the reaction chamber having a temperature of at least 3000°C to which the input material is exposed.

22. The method of claim 1 , comprising operating the reaction chamber in an oxidation process mode.

23. The method of claim 1 , comprising operating the reaction chamber in a pyrolysis process mode.

24. The method of claim 1 , comprising supplying a working gas to the reaction chamber.

25. The method of claim 1 , comprising supplying a reactive gas to the reaction chamber.

26. 26. The method of claim 25, wherein the reactive gas is selected from the group consisting of oxygen gas, water, carbon dioxide, and combinations thereof.

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