WO2025210343A1

WO2025210343A1 - Fluid treatment apparatus

Info

Publication number: WO2025210343A1
Application number: PCT/GB2025/050680
Authority: WO
Inventors: Noel Carroll; William DOWSON
Original assignee: Individual
Current assignee: Individual
Priority date: 2024-04-02
Filing date: 2025-03-28
Publication date: 2025-10-09
Anticipated expiration: 2026-10-02
Also published as: GB2639995A; GB202404688D0

Abstract

Fluid treatment apparatus 10 for undertaking electrolysis of the fluid to thereby produce hydrogen gas, and/or undertake electro-coagulation of the fluid to thereby reduce the presence of suspended solids in the fluid, and/or to undertake desalination of the fluid, the apparatus, comprising a tank 50 containing a fluid comprising water, the tank including electrodes 120, the electrodes connected to an electrical supply 150, the electrical supply arranged to supply electricity to the electrodes such that the voltage between the anode and a reference point at a constant electric potential varies as a function of time, wherein the time-dependence of the voltage between the anode and the reference point is described by a function V_a(t)-

Description

Fluid treatment apparatus

The present invention relates generally to fluid treatment apparatus and a method of treating fluids.

The manufacture of hydrogen by means of the electrolysis of water is well known. Likewise, the removal of solids from water using electro-coagulation, and the desalination of water using electrolysis are well known. However, the processes are relatively inefficient with relatively poor results requiring relatively high amounts of electricity. It is desirable, therefore, to provide improved apparatus and an improved method of treating fluids comprising water.

In a first aspect, the present invention provides a fluid treatment apparatus comprising a tank for containing a fluid comprising water, the tank including electrodes including an anode and a cathode, the electrodes connected to an electrical supply arranged to supply electricity to the electrodes such that the voltage between the anode and a reference point at a constant electric potential varies as a function of time, wherein the time-dependence of the voltage between the anode and the reference point is described by a function , defined for any time as the greatest value of , and , where

;

; and

,

and where is a predetermined constant amplitude, is a predetermined constant frequency, has a value between 0.5 and 1.5, has a value between 0.5 and 1.5, has a value between -0.5 and 0.5, has a value between -1 and 1, has a value between -0.5 and 0.5, has a value between 0.274/ and 0.374/ , has a value between 0.630/ and 0.730/ and has a value between -5 and 5,

wherein the apparatus is configured to undertake electrolysis of the fluid to thereby produce any one or more of the following gases: hydrogen, oxygen, carbon monoxide and a mixture comprising any combination thereof, and/or to undertake electro-coagulation of the fluid to thereby reduce the presence of suspended solids in the fluid, and/or to undertake desalination of the fluid.

The production of hydrogen gas may mean the production of substantially pure hydrogen gas. That is, small quantities of other elements may be present, but the predominant component of the gas will be hydrogen. Similarly, the production of oxygen or carbon monoxide may mean the production of substantially pure oxygen or substantially pure carbon monoxide, respectively. The production of a mixture comprising any combination of hydrogen gas, oxygen and carbon monoxide may comprise, either solely or in addition to small quantities of other elements, any two or all three of hydrogen gas, oxygen and carbon monoxide.

The voltage between the cathode and the reference point may vary as a function of time, and the time-dependence of the voltage between the cathode and the reference point may be described by a function .

The variable may be equal to 0.2. The variable may be equal to 0.75. The variable may be equal to -0.5.

The variable may be equal to 0.96. The variable may be equal to 0.93.

The variable The variable .

The variable may be equal to 0.82.

It has been found that this apparatus may result in substantially improved efficiency of electrolysis resulting in substantially more hydrogen and/or oxygen, being produced per kilowatt of electricity used in the process. If the anode is made from a material comprising carbon (e.g. graphite), carbon monoxide may also be produced. It has also been found that this apparatus more efficiently desalinates water and also more efficiently reduces the amount of suspended solids in fluids.

The fluid may be treated with an electrolyte, prior to or during the application of the electrical supply to the electrodes. For example, bicarbonate of soda, potassium hydroxide or salt may be added to the fluid.

The fluid treatment apparatus may further comprise a pre-treatment device for treating the fluid prior its placement in the tank, the pre-treatment apparatus comprising a tube through which the fluid passes, in use, surrounded by a coil of wire through which a pre-treatment electric current is passed.

The pre-treatment electric current passed through the coil of wire may have a DC element which may have a voltage of 6 to 24 volts, a current of approximately 8.6 amps and which may be pulsed at a frequency between 60 and 500 Hz, and may have a superimposed AC element which may have a voltage of 1.5 to 6 volts and a frequency of 5 to 80Hz.

The fluid treatment apparatus may further comprise a carbon ultrafine bubble generator including a hydrocarbon-based media, and means for passing the gases, resultant from the electrolysis in the tank, to the ultrafine bubble generator to thereby pass through the hydrocarbon based-media.

This may increase the octane rating of the resultant gases to 130. The hydrocarbon media may comprise diesel or turpentine.

The fluid treatment apparatus may further comprise a pump to circulate the fluid between the tank and the pre-treatment apparatus. This may also circulate the fluid through an electrolyte adding station.

The fluid treatment apparatus may further comprise a conductivity monitor for monitoring the conductivity of the fluid in the tank, and a controller arranged to adjust the electrical supply to thereby alter one or more of its voltage, current and frequency. This may improve the efficiency of the fluid treatment processes. The controller may automatically alter these characteristics according to predetermined settings.

In a second aspect, the invention provides a method of treating fluid to undertake electrolysis of the fluid to thereby produce any one or more of the following gases: hydrogen, oxygen, carbon monoxide and a mixture comprising any combination thereof, and/or undertake electro-coagulation of the fluid to thereby reduce the presence of suspended solids in the fluid, and/or to undertake desalination of the fluid, the method comprising the steps of placing a fluid comprising water in a tank with electrodes, comprising an anode and a cathode, and supplying electricity to the electrodes such that the voltage between the anode and a reference point at a constant electric potential varies as a function of time,

wherein the time-dependence of the voltage between the anode and the reference point is described by a function , defined for any time as the greatest value of , and , where

;

; and

,

and where is a predetermined constant amplitude, is a predetermined constant frequency, has a value between 0.5 and 1.5, has a value between 0.5 and 1.5, has a value between -0.5 and 0.5, has a value between -1 and 1, has a value between -0.5 and 0.5, has a value between 0.274/ and 0.374/ , has a value between 0.630/ and 0.730/ and has a value between -5 and 5.

The electricity supplied may have a voltage in the range 0.5 to 42 volts, a current of between 30 and 2400 amps, and a variable frequency of 15 kHz to 40 kHz.

The apparatus may be arranged to supply electricity to the electrodes, such that the voltage between the anode and a reference point at a constant electric potential varies as a function of time, in accordance with any of the method steps described herein.

The method may further comprise the step of adding an electrolyte to the fluid.

The method may further comprise the step of passing the fluid through a pre-treatment device prior to it being placed in the tank, wherein the pre-treatment apparatus comprises a tube through which the fluid passes, the tube surrounded by a coil of wire, the method including the step of passing a pre-treatment electric current through the coil.

The pre-treatment electric current may have a DC element having a voltage of 6 to 24 volts, a current of approximately 8.6 amps and may be pulsed at a frequency between 60 and 500 Hz, and a superimposed AC element having a voltage of 1.5 to 6 volts and a frequency of 5 to 80Hz.

The method may further comprise the step of collecting gases resultant from electrolysis of the fluid in the tank, and passing them through a carbon ultrafine bubble generator including a hydrocarbon-based media.

The above and other characteristics, features and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention. This description is given for the sake of example only, without limiting the scope of the invention. The reference figures quoted below refer to the attached drawings.

is a schematic layout of a water treatment apparatus.

Figure 2 shows an example waveform of a voltage .

Figure 3 shows an example waveform of the voltage between a cathode and the reference point.

The present invention will be described with respect to certain drawings but the invention is not limited thereto but only by the claims. The drawings described are only schematic and are non-limiting. Each drawing may not include all of the features of the invention and therefore should not necessarily be considered to be an embodiment of the invention. In the drawings, the size of some of the elements may be exaggerated and not drawn to scale for illustrative purposes. The dimensions and the relative dimensions do not correspond to actual reductions to practice of the invention.

Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequence, either temporally, spatially, in ranking or in any other manner. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that operation is capable in other sequences than described or illustrated herein. Likewise, method steps described or claimed in a particular sequence may be understood to operate in a different sequence.

Moreover, the terms top, bottom, over, under and the like in the description and the claims are used for descriptive purposes and not necessarily for describing relative positions. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that operation is capable in other orientations than described or illustrated herein.

It is to be noticed that the term “comprising”, used in the claims, should not be interpreted as being restricted to the means listed thereafter; it does not exclude other elements or steps. It is thus to be interpreted as specifying the presence of the stated features, integers, steps or components as referred to, but does not preclude the presence or addition of one or more other features, integers, steps or components, or groups thereof. Thus, the scope of the expression “a device comprising means A and B” should not be limited to devices consisting only of components A and B. It means that with respect to the present invention, the only relevant components of the device are A and B.

Reference throughout this specification to “an embodiment” or “an aspect” means that a particular feature, structure or characteristic described in connection with the embodiment or aspect is included in at least one embodiment or aspect of the present invention. Thus, appearances of the phrases “in one embodiment”, “in an embodiment”, or “in an aspect” in various places throughout this specification are not necessarily all referring to the same embodiment or aspect, but may refer to different embodiments or aspects. Furthermore, the particular features, structures or characteristics of any one embodiment or aspect of the invention may be combined in any suitable manner with any other particular feature, structure or characteristic of another embodiment or aspect of the invention, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments or aspects.

Similarly, it should be appreciated that in the description various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Moreover, the description of any individual drawing or aspect should not necessarily be considered to be an embodiment of the invention. Rather, as the following claims reflect, inventive aspects lie in fewer than all features of a single foregoing disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this invention.

Furthermore, while some embodiments described herein include some features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form yet further embodiments, as will be understood by those skilled in the art. For example, in the following claims, any of the claimed embodiments can be used in any combination.

In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the invention may be practised without these specific details. In other instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.

In the discussion of the invention, unless stated to the contrary, the disclosure of alternative values for the upper or lower limit of the permitted range of a parameter, coupled with an indication that one of said values is more highly preferred than the other, is to be construed as an implied statement that each intermediate value of said parameter, lying between the more preferred and the less preferred of said alternatives, is itself preferred to said less preferred value and also to each value lying between said less preferred value and said intermediate value.

The use of the term “at least one” may mean only one in certain circumstances. The use of the term “any” may mean “all” and/or “each” in certain circumstances.

The principles of the invention will now be described by a detailed description of at least one drawing relating to exemplary features. It is clear that other arrangements can be configured according to the knowledge of persons skilled in the art without departing from the underlying concept or technical teaching, the invention being limited only by the terms of the appended claims.

shows a water treatment apparatus 10 which includes a fluid circuit 20 comprising a valved inlet 30 for introducing fluid, comprising water, to the circuit. The fluid may be dosed with electrolyte from a dosing station 40 before passing through a pre-treatment device 60. The pre-treatment device 60 comprises a coil of wire through which a pre-treatment current of electricity is passed from a power source 90. The power source 90 may be controlled by a controller 100. The coil of wire creates an electromagnetic field which affects the fluid and promotes the production of hydrogen by means of electrolysis.

The fluid then passes to a tank 50 in which several rod-like electrodes 120 are placed such that they extend substantially vertically into the fluid. These may comprise various materials, as described herein, and may be approximately 500mm long, and have a substantially circular cross-section with a diameter of 8mm. Other shapes and sizes are contemplated as described herein. They extend through the lid of the tank into the fluid. Hollow borosilicate glass, or other insulating material, covers 130 surround the upper 100mm of each electrode. Alternatively, the electrodes can be extended through the bottom or the side of the tank. The electrodes 120 are connected to a power source 150 which may also be controlled by the controller 100. Dashed lines 110, 160 indicate a connection between the controller 100 and the power supplies 90, 150. It is to be understood that the means of connection may be wireless or wired. Moreover, the controller 100 may be split into more than one sub-controller such that each sub-controller controls each power supply 90, 150.

Some of the electrodes will be cathodes and some will be anodes. With the electrodes energised, hydrogen gas may be formed at the cathodes. Oxygen gas may be formed at the anodes. This bubbles to the surface of the fluid in the tank and may be collected and directed by a pipe 170 to a gas compressor 180 to compress the gas, and then to a gas separator 190 to remove the hydrogen from any other gasses present such as oxygen and/or carbon monoxide. The resultant hydrogen is then passed to a hydrogen gas storage means 200. The oxygen and/or carbon monoxide and/or a mixture thereof may be collected separately and passed to a separate storage means (not illustrated).

Alternatively, the hydrogen may not be separated from the oxygen and/or carbon monoxide and, instead, a mixture of hydrogen with oxygen and/or carbon monoxide may instead be passed to a storage means (not illustrated).

It is to be understood that the gas compressor 180 and gas separator 190 may not be essential items and therefore may not be present.

Likewise, the pre-treatment device 60 may not be essential and may not be present. Also, if a fluid is input into the circuit which already includes other electrolysis promoting substances or electrolytes then the electrolyte dosing station 40 may not be present.

The electrolyte may comprise NaHCO3, potassium hydroxide or salt (NaCl). Preferably, the electrolyte is alkaline in nature, although acidic electrolytes are also contemplated.

A conductivity sensor 210 is shown in the tank 50. It is connected by wire or wirelessly to the controller as shown by the dashed line 220. It may constantly sense, and therefore monitor, the conductivity of the fluid in the tank. The controller 100 may vary the characteristics of the electricity directed to the pre-treatment device 60 and/or the electrodes 130 from the respective power supplies 90, 150 by adjusting the settings of the power supplies in response to changes in conductivity.

The characteristics may include any one or more of the current, voltage, frequency, phase, amplitude, etc. In one example, as the conductivity of the fluid in the tank increases the amount of power passed to the electrodes in the electricity supply may be increased. In one example, the voltage of the electrical supply passed to the pre-treatment device 60 may range from 1 to 70 volts.

The pre-treatment device 60 may include a coil, through which the pre-treatment electrical supply is passed. The coil may have 700 to 800 turns of 18 gauge copper wire which may have 1.09474 gauge diameter insulation. Other numbers of turns and gauge are contemplated.

The fluid in the circuit 20 may be continuously moved around the system in use by means of a pump 70.

The electrical supply to the electrodes 120 may be a pulsed DC power supply with a relatively high current from 150amps to in excess of 600amps with a single polarity and a variable voltage.

The electrical supply to the pre-treatment device 60 may have an AC wave and be programmed to produce an intermittent waveform. The waveform may be sine, square, triangular or random but has a pre-selected frequency. It may also have a DC current biased component which is pulsed. The frequency range, of the AC amplitude and the DC carrier (off-set) voltage may be fine-tuned to achieve the desired electrolyte conductivity.

The pulsing of the electrical supply to the electrodes may reduce the resistance, and hence increase the conductivity, of the fluid more efficiently and with greater effect than otherwise.

The polarity of the electrodes may be periodically reversed temporarily to clean the electrodes. For instance, this may occur every 20 minutes and last for 1 minute.

The pulsed sequence and polarity control may allow for greater electrical energy (power) to be supplied to the electrodes without them over-heating.

The power supply 150 for the electrodes 120 may comprise a specially constructed alternator, controlled by the controller 100. The alternator may operate within a pre-defined speed (rpm) range. The output of this power supply 150 may be DC with a high frequency pulsating ripple component, in either standard or reversed polarity, and which can be sustained without equipment failure/overheating, in continuous use.

The alternator may comprise a stationary stator powered with a 12volt DC supply. Other voltages are contemplated such as 24volts. This supply may come from a 12volt 7.2Ah battery. Around the stator, a plurality, such as nine to fifteen or more, of coils, each wound around an armature, may be rotated at between 5,000 and 15,000 rpm, and possibly even higher. They may be rotated by an electric motor, petrol engine, hydraulic motor, pneumatic motor, or by other devices, and a drive belt. The stator produces a magnetic field. The coils cut this field and generate a three-phase alternating current which is then converted into DC via individual full-wave rectifiers for each coil. The individual full-wave rectifiers for each coil may be combined to produce one electrical output which is connected to the electrodes in parallel.

The copper windings used in the apparatus may be heavier in gauge than would typically be used in a vehicle alternator. Also, the windings may be coated with insulating varnish that can withstand continuously elevated operating temperatures exceeding 150°C.

The apparatus may consume 16kWh of energy to produce one kilogram of hydrogen.

A maximum of between 25 amps and 175 amps may be delivered to each electrode.

The controller 100 may also control the electrolyte dosing station to increase or decrease the rate of electrolyte added to the fluid.

The electrodes may comprise of iron, steel, graphite or aluminium plates, although other materials are contemplated. The plates may have a size of 100 to 550mm, more preferably 120 to 280mm. The plates may have a thickness of 5 to 30mm.

For the electrolysis of a fluid comprising water to produce hydrogen, oxygen, carbon monoxide or a mixture thereof 4 graphite plates having a size of 250mm x 150mm may be used as anodes. The cathode may be one or more 5mm thick steel plates each having a size of 550mm x 50mm. An electrical supply of 150 amps and 23 volts has found to be relatively efficient at producing hydrogen in this arrangement.

For the electrocoagulation of sea water the plates may be 280mm x 280 mm x 3mm thick plates. These may be stacked 25mm apart. Using an electrical supply to the electrodes of 150 amps with a 5 to 7 volt variable driver, 17 plates may be used; 5 comprising mild steel, and 12 comprising aluminium. For less conductive water, such as untreated sewage, more plates, such as 50 plates may be required having the same configuration.

The plates may be mechanically held together using metal (eg steel) rods. The plates may be connected to the electrical supply such that they are alternately anodes and cathodes.

Figure 2 shows an example waveform of the voltage applied between an anode and a reference point at a constant electric potential as a function of time . In this example, the amplitude is 3.12V and the frequency is 2105Hz. The values of the other parameters are 0.96, 0.93, 0.2, 0.75, -0.5, 0.324/ , 0.680/ and 0.82.

As can be seen in , the waveform is sinusoidal in form and comprises a repeating series of peaks, the series of peaks comprising a first peak 310, and second peak 320 and a third peak 330. Each first peak 310 is separated from an adjacent second peak 320 by a first trough 410; each second peak 320 is separated from an adjacent third peak 330 by a second trough 420; and each third peak 330 is separated from an adjacent first peak 310 by a third trough 430.

The variable determines the relative height of the second peak 320 compared with the first peak 310. Similarly, the variable determines the relative height of the third peak 330 compared with the first peak 310. If is set to equal 1, the first and second peaks will be the same height; if is set to equal 1, the first and third peaks will be the same height; and if is set to be equal to , the second and third peaks will be the same height.

The variable determines the horizontal spacing between the first peak 310 and the second peak 320, and consequently affects the depth of the first trough 410. Similarly, the variable determines the horizontal spacing between the first peak 310 and the third peak 330, and consequently affects the depth of the third trough 430. It follows that the spacing between the second peak 320 and the third peak 330 (and the consequent depth of the second trough 420) is determined by the difference between and . If is set to equal 1/(3 ) and is set to equal 2/(3 ), the horizontal spacing between all peaks will be consistent and the troughs will all have the same depth.

The variable , and determine the shape of each peak. If is set to equal zero, each peak will have a shape that is symmetric about a vertical axis passing through the maximum point of the peak. The first peak 310, second peak 320 and third peak 330 will all have the same shape, regardless of the values of , and .

The variable determines the vertical displacement of the waveform relative to the V=0 axis. If the value of is increased, the entire waveform will be shifted “down”, while if the value of is decreased, the entire waveform will be shifted “up”.

The absolute voltage measured between the maximum peak and the minimum trough may lie in the range 1 to 7volts, more preferably 5 to 7 volts.

The current applied to the electrodes may lie in the range 1 to 200amps, more preferably 100 to 200 amps.

Figure 3 shows an example waveform of the voltage between a cathode and the reference point. As can be seen by comparing Figure 2 and Figure 3, the voltage is the voltage between the anode and the reference point multiplied by -1.

Claims

A fluid treatment apparatus comprising a tank for containing a fluid comprising water, the tank including electrodes including an anode and a cathode, the electrodes connected to an electrical supply arranged to supply electricity to the electrodes such that the voltage between the anode and a reference point at a constant electric potential varies as a function of time,
wherein the time-dependence of the voltage between the anode and the reference point is described by a function , defined for any time as the greatest value of , and , where
;
; and
,
and where is a predetermined constant amplitude, is a predetermined constant frequency, has a value between 0.5 and 1.5, has a value between 0.5 and 1.5, has a value between -0.5 and 0.5, has a value between -1 and 1, has a value between -0.5 and 0.5, has a value between 0.274/ and 0.374/ , has a value between 0.630/ and 0.730/ and has a value between -5 and 5,
wherein the apparatus is configured to undertake electrolysis of the fluid to thereby produce any one or more of the following gases: hydrogen, oxygen, carbon monoxide and a mixture comprising any combination thereof, and/or to undertake electro-coagulation of the fluid to thereby reduce the presence of suspended solids in the fluid, and/or to undertake desalination of the fluid.
The fluid treatment apparatus of claim 1, wherein the voltage between the cathode and the reference point varies as a function of time, and wherein the time-dependence of the voltage between the cathode and the reference point is described by a function .
The fluid treatment apparatus of either one of claims 1 and 2, wherein 0.2, 0.75 and -0.5.
The fluid treatment apparatus of any preceding claim, wherein 0.96 and 0.93.
The fluid treatment apparatus of any preceding claim, wherein and .
The fluid treatment apparatus of any preceding claim, wherein 0.82.
The fluid treatment apparatus of any preceding claim, wherein the fluid is treated with an electrolyte.
The fluid treatment apparatus of any preceding claim, further comprising a pre-treatment device for treating the fluid prior its placement in the tank, the pre-treatment apparatus comprising a tube through which the fluid passes, in use, surrounded by a coil of wire through which a pre-treatment electric current is passed.
The fluid treatment apparatus of claim 7, wherein the pre-treatment electric current has a DC element having a voltage of 6 to 24 volts, a current of approximately 8.6 amps and which is pulsed at a frequency between 60 and 500 Hz, and a superimposed AC element having a voltage of 1.5 to 6 volts and a frequency of 5 to 80Hz.
The fluid treatment apparatus of claim 7 or 8, further comprising a pump to circulate the fluid between the tank and the pre-treatment apparatus.
The fluid treatment apparatus of any preceding claim, further comprising a conductivity monitor for monitoring the conductivity of the fluid in the tank, and a controller arranged to adjust the electrical supply to thereby alter the amplitude and/or the frequency .
The fluid treatment apparatus of any preceding claim, further comprising a carbon ultrafine bubble generator including a hydrocarbon-based media, and means for passing gases, resultant from the electrolysis in the tank, to the ultrafine bubble generator to thereby pass through the hydrocarbon based-media.
A method of treating fluid to undertake electrolysis of the fluid to thereby produce any one or more of the following gases: hydrogen, oxygen, carbon monoxide or a mixture comprising any combination thereof, and/or undertake electro-coagulation of the fluid to thereby reduce the presence of suspended solids in the fluid, and/or to undertake desalination of the fluid, the method comprising the steps of placing a fluid comprising water in a tank with electrodes, comprising an anode and a cathode, and supplying electricity to the electrodes such that the voltage between the anode and a reference point at a constant electric potential varies as a function of time,
wherein the time-dependence of the voltage between the anode and the reference point is described by a function , defined for any time as the greatest value of , and , where
;
; and
,
and where is a predetermined constant amplitude, is a predetermined constant frequency, has a value between 0.5 and 1.5, has a value between 0.5 and 1.5, has a value between -0.5 and 0.5, has a value between -1 and 1, has a value between -0.5 and 0.5, has a value between 0.274/ and 0.374/ , has a value between 0.630/ and 0.730/ and has a value between -5 and 5.
The method of claim 12, wherein the voltage between the cathode and the reference point varies as a function of time, and wherein the time-dependence of the voltage between the cathode and the reference point is described by a function .
The method of either one of claims 12 and 13, further comprising the step of adding an electrolyte to the fluid.
The method of any one of claims 12 to 14, further comprising the step of passing the fluid through a pre-treatment device prior to it being placed in the tank, wherein the pre-treatment apparatus comprises a tube through which the fluid passes, the tube surrounded by a coil of wire, the method including the step of passing a pre-treatment electric current through the coil.
The method of claim 15, wherein the pre-treatment electric current has a DC element having a voltage of 6 to 24 volts, a current of approximately 8.6 amps and which is pulsed at a frequency between 60 and 500 Hz, and a superimposed AC element having a voltage of 1.5 to 6 volts and a frequency of 5 to 80Hz.
The method of any one of claim 12 to 16, further comprising the step of collecting gases resultant from electrolysis of the fluid in the tank, and passing them through a carbon ultrafine bubble generator including a hydrocarbon-based media.