Systems and methods for plasma-based remediation

Abstract

To provide new systems and plasma reactors for removing NOX compounds from diesel exhaust gas.SOLUTION: A system for exhaust gas remediation includes an engine, a plasma reactor, and a pulse source. The engine emits exhaust gas that includes NO molecules and NOX molecules. The plasma reactor includes an internal chamber that is fluidly connected to the engine such that the exhaust gas flows into the internal chamber. An electrode is disposed within the internal chamber of the plasma reactor. The electrode is electrically coupled to an electrical pulse source. The electrical pulse source delivers electrical pulse to the electrode to form a plasma from the exhaust gas, thereby removing at least a portion of the NO molecules and at least a portion of the NOX molecules.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of and priority to U.S. Provisional Patent No. 62 / 816,694, filed March 11, 2019, which is incorporated herein by reference in its entirety.

[0002] Technical Field The present invention relates to a transient plasma-based purification system, and more particularly to an electrode configuration for the transient plasma-based purification system. [Background technology]

[0003] background Diesel engines are used to move large commercial ships across ocean routes. When diesel engines are operating, they produce large amounts of exhaust gases. The exhaust gases are NO X NOx emitted from diesel engines can contain multiple harmful substances, such as X This compound is a source of air pollution. X There is a need for new systems and methods for removing these compounds from diesel exhaust. Summary of the Invention

[0004] overview According to some embodiments of the present disclosure, a system for plasma-based purification includes an engine including an exhaust port, the engine exhausting exhaust gases through the exhaust port, the exhaust gases condensing NO molecules and NO Xand a plasma reactor including a reactor tube and an electrode, the reactor tube defining an interior chamber, the electrode being at least partially disposed within the interior chamber inside the reactor tube, the interior chamber being fluidly coupled to an exhaust port of the diesel engine such that exhaust gases flow from the exhaust port into the interior chamber of the plasma reactor; and a high voltage source electrically coupled to the electrode of the plasma reactor, for delivering an electrical pulse to the electrode, thereby forming a plasma from the exhaust gases and purifying NO molecules and NO from the exhaust gases. X and a high voltage source configured to remove at least a portion of the molecules.

[0005] According to some embodiments of the present disclosure, a plasma reactor for plasma-based purification includes a first reactor tube and a second reactor tube, an inlet port coupled to a first end of the first reactor tube and a second end of the second reactor tube, the inlet port configured to fluidly couple an exhaust port of an engine to the first reactor tube and the second reactor tube, such that exhaust gases can flow through the first reactor tube and the second reactor tube, and an inlet port coupled to a first end of the first reactor tube and a second end of the second reactor tube, the inlet port configured to fluidly couple an exhaust port of an engine to the first reactor tube and the second reactor tube, such that exhaust gases can flow through the first reactor tube and the second reactor tube. a first electrode disposed within the first reactor tube and a second electrode disposed within the second reactor tube; and a high voltage connector coupled to the first reactor tube and the second reactor tube, the high voltage connector configured to electrically connect both the first electrode and the second electrode to a high voltage source, the high voltage connector configured to deliver an electrical pulse from the high voltage source to both the first electrode and the second electrode, thereby forming a plasma from the exhaust gas flowing through the first reactor tube and the second reactor tube.

[0006] According to some embodiments of the present disclosure, a system for plasma-based purification includes one or more pairs of reactor tubes, each reactor tube of each pair of reactor tubes having an electrode disposed therein; an inlet port fluidly coupled to the one or more pairs of reactor tubes, the inlet port configured to fluidly couple an exhaust port of an engine to the one or more pairs of reactor tubes such that exhaust gases can flow through the one or more pairs of reactor tubes; and one or more high voltage connectors, each high voltage connector coupled to a respective one of the one or more pairs of reactor tubes, each high voltage connector electrically connected to an electrode of each reactor tube of a respective one or more pairs of reactor tubes, each high voltage connector configured to deliver an electrical pulse from a high voltage source to the electrode of each reactor tube of a respective one or more pairs of reactor tubes, thereby forming a plasma from the exhaust gases flowing through the one or more pairs of reactor tubes.

[0007] The foregoing and other advantages of the present disclosure will become apparent from a reading of the following detailed description and a review of the drawings. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a block diagram of a system for plasma-based purification of diesel exhaust gases, according to some embodiments of the present disclosure. [Diagram 2] 2A-2C are diagrams of profiles of a three-wire electrode, a four-wire electrode, and an extruded electrode, all of which can be used in the system of FIG. 1, according to some embodiments of the present disclosure. [Diagram 3]Figure 3A is a perspective view of a plasma reactor including four pairs of reactor tubes and four high voltage connectors for use in the system of Figure 1 according to some embodiments of the present disclosure, and Figure 3B is a top plan view of the plasma reactor of Figure 3A according to some embodiments of the present disclosure. [Figure 4] Figure 4A is a top plan view of a pair of reactor tubes for use in the system of Figure 1 according to some embodiments of the present disclosure, and Figure 4B is a cross-sectional view of one end of the pair of reactor tubes of Figure 4A according to some embodiments of the present disclosure. [Figure 5A] FIG. 2 is a perspective view of a high voltage connector for use in the system of FIG. 1 according to some embodiments of the present disclosure. [Figure 5B] FIG. 5B is a perspective view of a portion of the high voltage connector of FIG. 5A and an electrode disposed within a plasma reactor according to some embodiments of the present disclosure. [Figure 5C] FIG. 5B is a plan view of the high voltage connector of FIG. 5A coupled to two spacers according to some embodiments of the present disclosure. [Figure 6A] FIG. 2 is a first perspective view of an extruded electrode coupled to a spacer for use in the system of FIG. 1 according to some embodiments of the present disclosure. [Figure 6B] FIG. 6B is a second perspective view of the extruded electrode and spacer of FIG. 6A according to some embodiments of the present disclosure. [Figure 6C] FIG. 6B is a third perspective view of the extruded electrode and spacer of FIG. 6A according to some embodiments of the present disclosure. [Figure 7] FIG. 2 is a perspective view of a capacitor bypass network for use in the system of FIG. 1 according to some embodiments of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] While the present disclosure is susceptible to various modifications and alternative forms, specific embodiments and implementations have been shown by way of example in the drawings and will be described in detail herein. It is to be understood, however, that the disclosure is not intended to be limited to the particular forms disclosed. Rather, the disclosure is intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims.

[0010] Detailed Description While the invention is susceptible to embodiment in many different forms, preferred embodiments of the invention are illustrated in the drawings and described in detail herein, with the understanding that the present disclosure is to be taken as illustrative of the principles of the invention and is not intended to limit the broad aspects of the invention to the illustrated embodiments. For the purposes of this detailed description, the singular includes the plural and vice versa (unless expressly stated otherwise). The terms "and" and "or" are intended to be both conjunctive and disjunctive. The term "all" means "any and all." The term "any" means "any and all." The term "including" means "including without limitation." Furthermore, the singular terms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

[0011] Large commercial ships (general cargo ships, container ships, tankers, dry bulk carriers, multipurpose ships, refrigerated ships, etc.) operate using diesel engine methods that produce large amounts of exhaust gas. These diesel engine exhaust emissions contain nitrogen-based NOx, such as nitric oxide (NO), nitrogen dioxide (NO2), and other compounds. X These NO compounds may be included. X These compounds are considered to be pollutants and can be harmful to the environment. In order to reduce these harmful emissions from diesel engines, the exhaust gas of the diesel engine is treated with NO2 to reduce the NO2 in the exhaust gas.X The composition may be purified to reduce and / or remove the amount of compounds.

[0012] 1 shows a system 100 for exhaust gas purification that includes a high voltage source 108 and a plasma reactor 110. In operation, the plasma reactor 110 is fluidly coupled to an outlet of an engine 102 via a valve 111. The valve 111 is operable to control the amount of exhaust gas exhausted by the engine 102 that is directed to an inlet port 112 of the plasma reactor 110. Any gases and / or materials exhausted by the plasma reactor may be exhausted at an outlet port 114. Exhaust gas not directed to the engine 102 may be sent to an exhaust port 104. In some embodiments, the exhaust gas of the engine 102 is a mixture of NO 2 , 100 psi ... X The exhaust gas includes molecules. In some embodiments, the engine 102 is a diesel engine and the exhaust gas is diesel exhaust. For example, the engine 102 may be a diesel engine of a large commercial ship. However, the engine 102 may also be other types of diesel engines, such as diesel engines of smaller boats, trucks, sport utility vehicles (SUVs), submarines, trains, or any other type of vehicle that may include a diesel engine. In yet other embodiments, the engine 102 is a diesel engine of equipment such as a crane, bulldozer, excavator, etc. The engine 102 may also be a diesel engine of a power plant, or a diesel engine from any other source. In further embodiments, the engine 102 is a non-diesel engine.

[0013] The plasma reactor 110 is generally formed of at least one reactor tube that defines an interior chamber 116 (see FIG. 5B). The interior chamber 116 is fluidly connected to the engine 102 through an inlet port 112, thereby allowing exhaust gases to flow through the reactor tube. Electrodes are disposed within the interior chamber 116 of the reactor tube. The electrodes are electrically coupled to a high voltage source 108. The high voltage source 108 delivers an electrical pulse to the electrodes when the interior chamber 116 contains exhaust gases from the engine 102 to form a plasma from the exhaust gases. The electrical pulse, and resulting formation of the plasma, dissipates at least a portion of the NO molecules and NO X At least a portion of the molecules are removed from the exhaust gas, thereby at least partially purifying the exhaust gas.

[0014] In some embodiments, additional components can be added to the system 100 to test the plasma reactor 110. These components can include a gas analyzer 105, an oscilloscope 107, and one or more sensors 109. The gas analyzer 105 can be used to analyze the gases exhausted from the outlet port 114 of the plasma reactor 110. The sensor 109 can be coupled to the high voltage source 108 and is used to measure the voltage and current of the pulses supplied to the plasma reactor 110. The sensor 109 is used to measure the induction of the electric and magnetic fields of these pulses. The output of the sensor 109 is sent to an integrator coupled to the oscilloscope 107 to obtain an oscilloscope waveform. This waveform is numerically reconstructed to form the actual voltage and current waveforms. The oscilloscope 107 can be housed in an electromagnetically compatible (EMC) cabinet or another suitable enclosure to protect the oscilloscope from any electromagnetic interference from the plasma reactor. In some embodiments, some or all of the components of system 100 are grounded to help reduce electromagnetic interference problems.

[0015] In some embodiments, one of the sensors 109 measures only the electric field D and is located near the cable connecting the high voltage source 108 and the plasma reactor 110. The sensor can be formed from a metal plate placed adjacent to the cable, thereby measuring the capacitance C. D Therefore, the voltage of the pulse from the high voltage source 108 is given by the following equation: TIFF2025063060000002.tif10128, Z cable is the impedance of the cable (for example, 50 ohms) and V HV is the reconstructed voltage waveform, and V D is the output of the electric field sensor 109.

[0016] In some implementations, one of the sensors 109 measures only the electric field B and is located near the cable connecting the high voltage source 108 and the plasma reactor 110. The sensor can be formed from a single metal loop placed adjacent to the cable. The magnetic field generated by the current in the cable is measured by the mutual inductance M between the metal loop and the cable. B The resulting change in magnetic flux in the metal loop induces a voltage across the loop, given by the following equation: TIFF2025063060000003.tif10128In formula, I HV is the reconstructed current waveform, and V B is the output of the magnetic field sensor 109.

[0017] The complete numerical reconstruction of the voltage and current waveforms is given by the following equations: TIFF2025063060000004.tif21128In the formula, Z0 is the input impedance of the oscilloscope 107, and C D and M. B Both ω and ω are predetermined calibration values. The last integral term is a correction term for the impedance of the oscilloscope 107.

[0018] FIG. 2 illustrates various embodiments and configurations of electrodes, which may be solid extruded electrodes or may be formed from multiple wires. Wire-based electrodes may be 1-wire electrodes, 2-wire electrodes, 3-wire electrodes, 4-wire electrodes, 5-wire electrodes, 6-wire electrodes, or any other number of wires. The electrodes may include two different types of electrodes. Additionally, the plasma reactor 110 may include one electrode or more than two electrodes. Shown in FIG. 2 are a 3-wire electrode 118A, a 4-wire electrode 118B, and an extruded electrode 118C. Multi-wire-based electrodes (such as the 3-wire electrode 118A and the 4-wire electrode 118B) may have a cross-section generally defined as the diameter of a circle connecting all the wires of the electrode as shown. The cross-section of the extruded electrode 118C has a central portion 120 and four arms 122A to 122D. The cross section of the extruded electrode 118C is defined as the distance between the ends of two opposing arms, such as arm 122A and arm 122B, or arm 122C and arm 122D. In some implementations, the three-wire electrode 118A and the four-wire electrode 118B have a cross section of about 2.0 inches, about 2.25 inches, or about 2.5 inches. In other implementations, the three-wire electrode 118A and the four-wire electrode 118B have a cross section between about 1.0 inches and about 5.0 inches. Other electrode types and configurations are also contemplated. For example, the extruded electrode 118C can have more or less than four arms 122A to 122D, and can also have a different overall shape. In other implementations, the cross section of the electrode can be between about 0.4 inches and about 1.1 inches. Additionally, the electrode can have an impedance between about 70 ohms and about 300 ohms.

[0019] FIG 3A is a perspective view of one embodiment of the plasma reactor 110, while FIG 3B is a top plan view of one embodiment of the plasma reactor 110. In this embodiment, the plasma reactor includes a first pair of reactor tubes 124A and 124B, a second pair of reactor tubes 126A and 126B, a third pair of reactor tubes 128A and 128B, and a fourth pair of reactor tubes 130A and 130B. Each of the reactor tubes 124A-130B defines a hollow interior chamber (such as the hollow interior chamber 116 shown in FIG 5B) in which an electrode may be disposed. The plasma reactor 110 of FIGS 3A and 3B also includes four high voltage connectors 132A-132D.

[0020] High voltage connector 132A is coupled to an electrode located within the first pair of reactor tubes 124A, 124B. High voltage connector 132B is coupled to an electrode located within the second pair of reactor tubes 126A, 126B. High voltage connector 132C is coupled to an electrode located within the third pair of reactor tubes 128A, 128B. High voltage connector 132D is coupled to an electrode located within the fourth pair of reactor tubes 130A, 130B. High voltage connectors 132A-132D deliver electrical pulses from high voltage source 108 to electrodes located within reactor tubes 124A-130B. Inlet port 112 and outlet port 114 are located at opposite ends of reactor tubes 124A-130B and both are fluidly coupled to all of the interior chambers of reactor tubes 124A-130B, allowing exhaust gases from engine 102 to flow through the plasma reactor. In some embodiments, each of the high voltage connectors 132A through 132D is coupled to the same high voltage source 108. In other embodiments, each of the high voltage connectors 132A through 132D is coupled to its own respective high voltage source 108.

[0021] FIG. 4A shows a top plan view of a pair of reactor tubes 134A and 134B. An inlet port 112 is coupled to one end of both reactor tubes 134A, 134B. An outlet port is coupled to the other end of both reactor tubes 134A, 134B. A single high voltage connector 136 is coupled to both the first reactor tube 134A and the second reactor tube 134B. The reactor tubes 134A and 134B may be the same as or similar to the reactor tubes 124A to 130B. The high voltage connector 136 may be the same as or similar to the high voltage connectors 132A to 132D. The high voltage connector 136 generally extends between the reactor tubes 134A and 134B in a direction perpendicular to the direction along which the reactor tubes 134A, 134B extend.

[0022] In some embodiments, the pair of reactor tubes 134A, 134B and the high voltage connector 136 form their own separate plasma reactor 110. In other embodiments, the pair of reactor tubes 134A, 134B and the high voltage connector 136 are components of a larger plasma reactor 110, such as the plasma reactor 110 illustrated in Figures 3A and 3B. The high voltage connector 136 includes a housing 137 and a cable 138 extending from the housing 137. A distal end of the cable 138 is electrically connected to the high voltage source 108, while a proximal end of the cable extends into the housing 137 of the high voltage connector 136.

[0023] FIG. 4B shows a cross section of one end of the plasma reactor 110 of FIG. 4A, showing the interior of the reactor tubes 134A, 134B, and the interior of the high-voltage connector 136. The high-voltage connector 136 includes two insulating members 142A, 142B extending from a housing 137. A first portion of each of the insulating members 142A, 142B is disposed within the housing 137. A second portion of the insulating member 142A extends from the housing 137 and is disposed within the internal chamber of the reactor tube 134A. Meanwhile, a second portion of the insulating member 142B extends from the housing 137 and is disposed within the internal chamber of the reactor tube 134B. Each of the first portions of the insulating members 142A, 142B has a generally cylindrical shape. The second portion of each of the insulating members 142A, 142B is generally cone-shaped and tapers toward the end disposed in the respective reactor tube 134A, 134B.

[0024] Cable 138 extends into housing 137, where it is electrically connected to two separate conductive members 140A, 140B. Conductive member 140A extends through the interior of insulating member 142A to a tapered end disposed within reactor tube 134A. Conductive member 140B extends through the interior of insulating member 142B to a tapered end disposed within reactor tube 134B. Thus, conductive members 140A, 140B generally extend perpendicular to the length of reactor tubes 134A, 134B.

[0025] Electrode 144A is coupled to conductive member 140A and extends along the length of the interior chamber of reactor tube 134A. Similarly, electrode 144B is coupled to conductive member 140B and extends along the length of the interior chamber of reactor tube 134B. Electrode 144A is formed from wires 145A, 145B, and 145C. Electrode 144B is formed from wires 145D, 145E, and 145F. Spacers 146A, 146B may be coupled to electrodes 144A, 144B, respectively. Spacers 146A, 146B help maintain the position of electrodes 144A, 144B within the interior chambers of their respective reactor tubes 134A, 134B and prevent electrodes 144A, 144B from contacting the interior surfaces of reactor tubes 134A, 134B. Electrodes 144A and 144B may be three-wire electrodes (such as electrode 118A), four-wire electrodes (such as 118B), extruded electrodes (such as electrode 118C), or any other suitable electrode type or shape. If the electrodes are multi-wire electrodes, spacers 146A, 146B also help maintain the spacing of the wires. In some implementations, spacers 146A, 146B are formed of an electrically insulating material such as fiberglass.

[0026] The arrangement of high voltage connector 136 and electrodes 144A, 144B can be used for any embodiment of plasma reactor 110. For example, plasma reactor 110 can include four pairs of reactor tubes 124A to 130B as shown in Figures 4A and 4B. Plasma reactor 110 can include a single reactor tube coupled to an inlet port 112 and an outlet port 114, a single pair of reactor tubes coupled to an inlet port 112 and an outlet port 114, or any number of reactor tubes coupled to any number of inlet ports 112 and any number of outlet ports 114.

[0027] 5A is a perspective view of the high voltage connector 136 without the cable 138 attached. In some embodiments, the housing 137 includes one or more ports 139A, 139B, 139C that open to the interior of the housing. The ports 139A, 139B, and 139C can be used to circulate a coolant or other fluid within the housing 137 to cool the high voltage connector 136 and maintain the high voltage connector 136 at a desired temperature. In some embodiments, the coolant is oil. In some embodiments, the conductive members 140A, 140B extend from their respective insulating members 142A, 142B parallel to the length of the reactor tubes 134A, 134B. Thus, the conductive members 140A, 140B can have a right angle shape, for example an "L" shape.

[0028] Figure 5B is a view of the end of reactor tube 134A with the end cap removed so that interior chamber 116 is visible. As shown, electrode 144A extends away from insulating member 142A toward the opposite end of interior chamber 116. In the embodiment shown in Figure 5B, electrode 144A is a three-wire electrode formed from wires 145A, 146B, and 145C, with spacer 146A helping to maintain spacing between the three wires 145A, 145B, and 145C.

[0029] Figure 5C shows the high voltage connector 136 from the opposite side as Figure 5B. In the embodiment shown in Figure 5C, the spacers 146A, 146B have a large circular shape with an outer diameter generally equal to the inner diameter of the reactor tubes 134A, 134B. These types of spacers 146A, 146B are typically used with extruded electrodes 118C.

[0030] 6A, 6B, and 6C all show an extruded electrode 118C having a spacer 147 (which may be the same as or similar to any of the spacers 146 discussed herein). As shown, the extruded electrode 118C is formed from four arms 122A-D extending from a central portion 120. The extruded electrode 118C is attached to a conductive member 141 (which may be the same as or similar to conductive members 140A, 140B). The conductive member 141 extends through the center of the spacer 147 and is used to deliver pulses from the high voltage source 108 to the electrode 118C.

[0031] FIG. 7 shows a bypass network 150 that can be electrically coupled in parallel with the cable 138 of the high voltage connector 136. During use, the plasma reactor 110 can generate a large amount of electromagnetic interference (EMI) due to the operation of the high voltage source 108. In certain circumstances, a large amount of electrical energy can be reflected back to the high voltage source 108. This situation may occur when a connection to one of the electrodes 144A, 144B is shorted or when there is an impedance mismatch between the high voltage source 108 and the plasma reactor 110. The reflected energy can be absorbed by the output of the high voltage source 108 (which can be, for example, a stack of diodes). To avoid this problem, a bypass network 150 can be electrically connected in parallel with the output of the high voltage source 108 and the high voltage connector 136. The bypass network 150 can act as an energy accumulator and can absorb any reflected electrical energy. In the illustrated embodiment, the bypass network 150 is one or more capacitors electrically connected in series. Other types of bypass networks 150 can also be utilized.

[0032] In operation, the system 100 system = η source ×η reactor ×η plasmaThe overall efficiency of the system is defined as η source is the electrical efficiency with which electrical energy is taken from the electrical grid (or other ultimate source of electrical energy) by the high voltage source 108 and converted into short pulses. reactor is the electrical efficiency with which the energy of the pulse is dissipated by the plasma formed in the plasma reactor 110, TIFF2025063060000005.tif9128. In this formula, E plasma is the energy dissipated by the plasma, and E pulse is the total available energy in the pulse. η plasma is the chemical efficiency of the plasma, a measure of the amount of energy used by the plasma that is converted into chemically active species. The overall system efficiency η system is the product of all three efficiencies.

[0033] Reactor efficiency η reactor is affected by the electric field strength within the plasma reactor 110 and the impedance matching of the plasma reactor 110. The impedance matching of the plasma reactor 110 determines how much of the pulse from the high voltage source 108 enters the plasma reactor 110. In a perfectly matched system, the impedance of the cable 138 carrying the pulse matches the impedance of the plasma reactor 110 and the entire pulse enters the plasma reactor 110. If there is any amount of mismatch in the impedance, the pulse will be partially reflected from the plasma reactor 110, which can lead to energy loss and high voltage stress on the system. In some embodiments of the system 100, the cable 138 has an impedance of about 50 ohms and each of the conductive members 140A, 140B connected to the high voltage source 108 through the cable 138 has an impedance of about 100 ohms. In these embodiments, a single high voltage source 108 is used to generate the pulse for each pair of electrodes.

[0034] The reflectance of the system 100 is given by the following equation: TIFF2025063060000006.tif10128, Z cable is the impedance of the cable 138, and Z reactor is the impedance of the plasma reactor 110. For a perfectly matched system, R=0 and there is no reflection. However, in a mismatched system, there is some reflection. The maximum voltage stress V of the system 100 max is the sum of the incoming and reflected pulse voltages, and V peak is the peak voltage applied, V max =(1+R)V peak is generally given by

[0035] NO molecule and NO X The efficiency of the system 100 in removing molecules is NO and NO X This is measured by comparing the initial concentration of TIFF2025063060000007.tif22128

[0036] The NO removal efficiency of the system 100 is defined as how efficiently the formed plasma removes NO, measured in mol / kWh. The NO removal efficiency is measured by the following equation: TIFF2025063060000008.tif10128

[0037] ΔNO is the removed concentration of NO (in ppm), Vm is the molar volume (in L / mol, temperature dependent), and ε is the energy density (in J / L). The energy density is given by the following equation: TIFF2025063060000009.tif10128

[0038] where f rr is the pulse repetition frequency (in Hz), and E plasmais the dissipated energy of the plasma per pulse and F is the gas flow rate (in L / min).

[0039] The overall efficiency of the system 100 is given by the following equation: System efficiency = Reactor efficiency x NO rem,eff

[0040] The system 100 operates in response to a variety of settings, including engine load, engine speed, pulse source voltage, pulse source repetition frequency, flow through the plasma reactor 110, and electrode type and geometry. The engine speed can be between about 400 rpm and about 1,000 rpm, between about 1,000 rpm and about 1,800 rpm, between about 400 rpm and about 1,800 rpm, about 400 rpm, about 1,000 rpm, or about 1,800 rpm. The pulse source voltage can be about 250 volts, about 300 volts, about 325 volts, about 350 volts, or between about 250 volts and about 350 volts. The pulse source repetition frequency can be about 100 Hz, about 500 Hz, about 1000 Hz, about 1,500 Hz, about 2,500 Hz, or generally any range between any two of these values. In some implementations, the average electrical reactor efficiency (e.g., η reactor ) can be between about 70% and about 90%, between about 78% and about 86%, or between about 80% and about 90%.

[0041] Although the present invention has been described with reference to one or more particular embodiments, those skilled in the art will appreciate that many modifications may be made to these embodiments without departing from the spirit and scope of the present invention. Each of these embodiments and obvious variations thereof is considered to be within the spirit and scope of the present invention. It is also contemplated that additional embodiments according to aspects of the present invention may combine any number of features from any of the embodiments described herein.

Claims

1. 1. A system for plasma-based purification comprising:

1. An engine including an exhaust port, the engine discharging exhaust gases through the exhaust port, the exhaust gases condensing NO molecules and NO Ｘ the engine comprising a molecule; a plasma reactor including a reactor tube and an electrode, the reactor tube defining an internal chamber, the electrode being at least partially disposed within the internal chamber inside the reactor tube, the internal chamber being fluidly coupled to the exhaust port of the diesel engine such that the exhaust gas flows from the exhaust port into the internal chamber of the plasma reactor; a high voltage source electrically coupled to the electrodes of the plasma reactor, An electrical pulse is delivered to the electrode, thereby forming a plasma from the exhaust gas and removing the NO molecules and the NO from the exhaust gas. Ｘ Remove at least a portion of the molecule The high voltage source and The system comprising:

2. The system of claim 1 , wherein the electrodes are selected from the group consisting of extruded electrodes, three-wire electrodes, and four-wire electrodes.

3. 3. The system of claim 2, wherein the extruded electrode has a cross-section selected from the group consisting of about 2.0 inches, about 2.25 inches, or about 2.5 inches.

4. The system of claim 2 , wherein the extruded electrode has a cross-section of between about 1.0 inches and about 5.0 inches.

5. The system of claim 1 , wherein the electrode is a three-wire electrode having a cross-section of approximately 2 inches.

6. The system of claim 1 , wherein the pulse source includes a bypass network in electrical parallel with an output of the pulse source.

7. 7. The system of claim 6, wherein the bypass network is configured to absorb electrical energy reflected back to the pulse source to minimize electromagnetic interference from the pulse source.

8. The system of claim 6 , wherein the bypass network comprises a plurality of capacitors electrically connected in series.

9. The system of claim 1 , wherein the engine is a diesel engine.

10. 10. The system of claim 9, wherein the diesel engine is from a merchant vessel.

11. a high voltage connector coupled to the reactor tube; the high voltage connector electrically couples the high voltage source to the electrode; the high voltage connector is configured to deliver the electrical pulses from the high voltage source to the electrodes. The system of claim 1 .

12. 12. The system of claim 11, wherein the high voltage connector includes a housing, an insulating member, and a conductive member, the housing coupled to the reactor tube, the insulating member disposed partially within the housing and partially within the reactor tube, and the conductive member extending through an interior of the insulating member to the electrode disposed within the reactor tube.

13. The system of claim 12 , wherein the high voltage connector comprises a cable electrically coupling the high voltage source to the conductive member.

14. 1. A plasma reactor for plasma-based purification comprising: a first reactor tube and a second reactor tube; an inlet port coupled to a first end of the first reactor tube and a second end of the second reactor tube, the inlet port configured to fluidly couple an exhaust port of an engine to the first reactor tube and the second reactor tube such that the exhaust gas can flow through the first reactor tube and the second reactor tube; an outlet port coupled to the first end of the first reactor tube and the second end of the second reactor tube; a first electrode disposed within the first reactor tube and a second electrode disposed within the second reactor tube; a high voltage connector coupled to the first reactor tube and the second reactor tube, the high voltage connector configured to electrically connect both the first electrode and the second electrode to a high voltage source; Equipped with the high voltage connector is configured to deliver an electrical pulse from the high voltage source to both the first electrode and the second electrode, thereby forming a plasma from the exhaust gas flowing through the first reactor tube and the second reactor tube. The plasma reactor.

15. 15. The plasma reactor of claim 14, wherein the first reactor tube and the second reactor tube extend in a first direction between the inlet port and the outlet port, and the high voltage connector extends between the first reactor tube and the second reactor tube in a second direction perpendicular to the first direction.

16. The high voltage connector is a housing coupled to the first reactor tube and the second reactor tube; a first insulating member extending from the housing of the high voltage connector into the first reactor tube; a second insulating member extending from the housing of the high voltage connector into the second reactor tube; 16. The plasma reactor of claim 15, comprising:

17. The high voltage connector is a first conductive member extending through an interior of the first insulating member to the first electrode disposed within the first reactor tube; a second conductive member extending through the interior of the second insulating member to the second electrode disposed within the second reactor tube; 17. The plasma reactor of claim 16, comprising:

18. The high voltage connector is a first end disposed within the housing and electrically connected to the first conductive member and the second conductive member; a second end configured to be electrically connected to the high voltage source; and 20. The plasma reactor of claim 17, comprising a cable having

19. 20. The plasma reactor of claim 18, wherein said first conductive member electrically connects said first electrode to said cable and said second conductive member electrically connects said second electrode to said cable.

20. 20. The plasma reactor of claim 19 wherein said cable has an impedance of about 50 ohms, said first conductive member has an impedance of about 100 ohms, and said second conductive member has an impedance of about 100 ohms.

21. a first spacer disposed within the first reactor tube and coupled to the first conductive member and the first electrode; a second spacer disposed within the second reactor tube and coupled to the second conductive member and the second electrode; Further equipped with the first spacer is configured to maintain the position of the first electrode within the first reactor tube such that the first electrode does not contact an inner surface of the first reactor tube, and the second spacer is configured to maintain the position of the second electrode within the second reactor tube such that the second electrode does not contact an inner surface of the second reactor tube.

20. The plasma reactor of claim 17.

22. 22. The plasma reactor of claim 21 wherein both said first spacer and said second spacer are formed from an insulating material.

23. 15. The plasma reactor of claim 14, wherein the first electrode or the second electrode is a three-wire electrode, a four-wire electrode, or an extruded electrode.

24. 24. The plasma reactor of claim 23 wherein said extruded electrode includes a central portion and one or more arms extending from said central portion.

25. 15. The plasma reactor of claim 14, wherein the engine is a diesel engine.

26. 26. The plasma reactor of claim 25 wherein said diesel engine is from a merchant marine.

27. 1. A system for plasma-based purification comprising: one or more pairs of reactor tubes, each reactor tube of each pair of reactor tubes having an electrode disposed therein; an inlet port fluidly coupled to the one or more pairs of reactor tubes, the inlet port configured to fluidly couple an exhaust port of an engine to the one or more pairs of reactor tubes such that the exhaust gases can flow through the one or more pairs of reactor tubes; one or more high voltage connectors, each high voltage connector coupled to a respective one or more pairs of the reactor tubes, each high voltage connector being electrically connected to the electrode of each reactor tube of the respective one or more pairs of the reactor tubes; Equipped with each high voltage connector is configured to deliver an electrical pulse from a high voltage source to the electrodes of each of the respective reactor tubes of the one or more pairs of reactor tubes, thereby forming a plasma from the exhaust gases flowing through the one or more pairs of reactor tubes. The system.

28. 28. The plasma reactor of claim 27 wherein said engine is a diesel engine.

29. 30. The plasma reactor of claim 28 wherein said diesel engine is from a merchant marine.

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