Patent Publication Number: US-2020299592-A1

Title: Electro-kinetic separation of salt and solid fines from crude oil

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to U.S. Provisional Application Ser. No. 62/820,448 filed Mar. 19, 2019 which is herein incorporated by reference in its entirety. 
    
    
     BACKGROUND 
     Crude oil normally contains impurities like water, salts in solution, and solid particulate matter or “fines.” Impurities can corrode and build up solid deposits in refinery units, to and thus should be removed before the crude oil is refined. 
     Crude oil impurities are commonly removed by “desalting,” in which the crude oil is mixed with water and a suitable demulsifying agent to form a water-in-oil emulsion. The emulsion provides intimate contact between the oil and the water so that the salts and solid particles pass into solution in the water. The emulsion is then subjected to a high voltage electrostatic field inside a closed separator vessel, often referred to as a “settler.” The electrostatic field helps coalesce and break the emulsion into an oil phase and a water phase. The oil phase rises to the top of the settler and forms an upper layer that is continuously drawn off. The water phase (commonly called “brine”) sinks to the bottom of the settler from where it is also continuously removed. Conventional desalting processes are capable of removing 50-65% of the solid fines from the crude oil, and the generated brine is subsequently treated or disposed of per environmental regulations. 
     With the availability of higher solid content crude oil or “tight” crude, solid fines removal via electrostatic desalting is becoming progressively more difficult. Moreover, future expected environmental regulations and constraints on water usage and disposal in desalting operations may make electrostatic desalting processes more complex and costly. Consequently, it is expected that electrostatic desalting processes will be less effective in removing fines for reliable and smoother downstream operations. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The following figures are included to illustrate certain aspects of the present disclosure, and should not be viewed as exclusive embodiments. The subject matter disclosed is capable of considerable modifications, alterations, combinations, and equivalents in form and function, without departing from the scope of this disclosure. 
         FIG. 1  is a schematic diagram of an example system for removing salt and solid particles from a hydrocarbon stream, according to one or more embodiments. 
         FIG. 2A  is a schematic diagram of one example of the electro-kinetic separator of  FIG. 1 , according to one or more embodiments. 
         FIG. 2B  is a cross-sectional end view of one example of the electro-kinetic separator media of  FIG. 2A , according to one or more embodiments. 
         FIG. 3  is a schematic diagram of another system for removing salt and solid particles from the hydrocarbon stream of  FIG. 1  and further including cleaning and regeneration capabilities, according to one or more embodiments. 
         FIG. 4  is a schematic of particle motion in a linear channel under the influence of an electric field. 
         FIG. 5  is a plot depicting solids concentrations of four crudes compared against the predictive model. 
     
    
    
     DETAILED DESCRIPTION 
     This present disclosure is related to hydrocarbon separation processes and, more particularly, to waterless electro-kinetic separation processes for removing salts and solid particles from crude oil. 
     Embodiments disclosed herein describe systems and methods to reduce and/or remove salt and solid fines from crude oil without the use of water. More specifically, the embodiments described herein incorporate an electro-kinetic separation process, which is an environmentally friendly process for salt and solid fines removal without requiring the addition of water, and thus, does not generate brine that must be properly disposed of. The electro-kinetic separation processes described herein can be used as standalone processes or in combination with conventional desalting or filtering processes for crude oil, especially heavier crudes that include more contaminants such as fines and hydraulic fracturing contaminants. Advantages of the presently described systems and methods include waterless recovery, an environmentally friendly process, and more efficient removal of salt and fines as compared to conventional desalting processes. 
     Electro-kinetic separation can be used to effectively reduce solid (inorganic) particles, even solid particles with exceptionally small size, from a crude oil process stream with or without the need of a separate mechanical or electro-mechanical filtration aid. The filtration media of the electro-kinetic separators may become laden with collected solid particles and can be conveniently regenerated in-situ or ex-situ to reclaim utilized particle-abatement capacity of the electro-kinetic separator. In one aspect, the principles of the present disclosure describe a process for treating a crude oil process stream by removing at least a portion of the solid particles by passing the process stream through at least one electro-kinetic separator. In another aspect, the principles of the present disclosure describe a process for treating a hydrocarbon stream comprising a hydrocarbon and solid particles, the process comprising removing at least a portion of the solid particles from the process stream by passing the process stream through at least one electro-kinetic separator. 
       FIG. 1  is a schematic diagram of an example system  100  for removing salt and solid particles from a hydrocarbon stream  102 , according to one or more embodiments. In contrast to conventional desalting systems that require the introduction of water into the process stream, the system  100  includes an electro-kinetic separator (“EKS”)  104  that removes salts and solid particles from the hydrocarbon stream  102  without the aid of water. Electro-kinetic separation refers to a filtration process that captures solid particles entrained in a liquid-containing fluid stream (e.g., the hydrocarbon stream  102 ) according to electrostatic principles and produces a product stream with reduced salts and solid particle counts. 
     The hydrocarbon stream  102  may alternately be referred to herein as a “process stream.” In some applications, the hydrocarbon stream  102  may comprise virgin crude oil originating from a subterranean hydrocarbon reservoir, or its products. In at least one embodiment, the hydrocarbon stream  102  may comprise a portion of crude oil remaining after the removal of distillates or the like. For example, the hydrocarbon stream  102  may comprise atmospheric tower bottoms, vacuum tower bottoms, or similar residuum products found in the refining of crude oil. The principles of the present disclosure, however, are equally applicable to treating other types of hydrocarbon process streams such as, but not limited to, or any combination thereof. 
     The hydrocarbon stream  102  may be laden with or otherwise have entrained therein impurities, such as salt and solid particles. Example salts that may be included in the hydrocarbon stream  102  include, but are not limited to, sodium chloride, metal sulfides, magnesium and calcium chlorides, other metal salts commonly originating from subterranean hydrocarbon-bearing formations, or any combination thereof. 
     The solid particles entrained in the hydrocarbon stream  102 , alternately be referred to as “particulates” or “fines,” may have an average particle size of from about 1 to 1000 micrometers (μm) measured by using ASTM D7596-14. In at least one embodiment, the solid particles exhibit an average particle size ranging from sub-micron to about 25 μm. Example solid particles that may be included in the hydrocarbon stream  102  include, but are not limited to, sand, proppant, rock, salt, a corrosion product (e.g., iron oxide, iron sulfide, etc.), or any combination thereof. 
     The hydrocarbon stream  102  may include solid particles in a concentration as measured by ASTM D4807-5 in a range from p1 ppmw (parts per million by weight) to p2 ppmw, based on the total weight of the hydrocarbon stream  102  entering the EKS, where p1 and p2 can be, independently: 1,000; 2,000; 3,000; 4,000; 5,000; 6,000; 7,000; 8,000; 9,000; 10,000; 12,000; 14,000; 15,000; 16,000; 18,000; 20,000; 22,000; 24,000; 25,000; 26,000; 28,000; 30,000; as long as p1&lt;p2. In some embodiments, as discussed in more detail below, the solid particles may include a filtration aid, such as diatomaceous earth. 
     The hydrocarbon stream  102  may be introduced into the system  100  via an inlet conduit  106 . In some embodiments, the hydrocarbon stream  102  may be conveyed directly into the EKS  104  for salt and solid particle removal, and the EKS  104  may discharge a purified product stream  108  into an outlet conduit  110 . Electro-kinetic separation is performed by applying a direct current (DC) or alternating current (AC) voltage to electrodes that are separated by a dielectric medium, and thus creating an electric field. The hydrocarbon stream  102  flows through the resulting electric field and, based on Coulomb&#39;s Law, solid particles bearing an electrical charge or polarized electric charge distribution will tend to move in desirable directions in the electric field, attach to a dielectric medium of the EKS  104 , and become immobilized. The net result is the product stream  108  exiting the EKS  104  with abated salt and solid particle count. 
     In other embodiments, however, the system  100  may further and optionally include one or both of a separation device  112  and a heat exchanger  114 . In such embodiments, the hydrocarbon stream  102  may optionally be circulated through one or both of the separation device  112  and the heat exchanger  114  prior to being introduced into the EKS  104 . However, one or both of the separation device  112  and the heat exchanger  114  may follow or otherwise be arranged after the EKS  104 , without departing from the scope of the disclosure. Moreover, while only one separation device  112  and one heat exchanger  114  are depicted in the system  100 , the system  100  may incorporate a plurality of separation devices  112  and/or a plurality of heat exchangers  114 , without departing from the scope of the disclosure. In such embodiments, the system  100  may include one or more separation devices  112  and/or heat exchangers  114  arranged prior to and/or after the EKS  104 , without departing from the scope of the disclosure. 
     The separation device  112  may comprise any conventional system or process configured to generally separate salts and/or solid particles from a fluid (e.g., the hydrocarbon stream  102 ) and discharge a process stream  116 . In at least one embodiment, the separation device  112  may comprise a conventional desalter or “settler” that uses a high voltage electrostatic field to separate the hydrocarbon stream  102  into an oil phase and a water phase and in the process remove salts and solid particles from the oil phase. In other embodiments, however, the separation device  112  may comprise a water washing device or the like that helps remove salts and solid particles. 
     In yet other embodiments, or in addition thereto, the separation device  112  may comprise a mechanical filter comprising a filtration system that separates solid matter from a solid/fluid mixture effected only through traditional mechanical forces resulting from gravity, centrifugation, pressure gradient (vacuum or positive pressure), or any combination thereof, without intentionally exerting an external force to the solid matter to be separated from a liquid by an electric field. A rotary drum filter assisted with a vacuum, for example, is a widely used mechanical filtration device for separating solids from liquids. In such embodiments, the hydrocarbon stream  102  may be circulated through a porous membrane with pores small enough to exclude a portion of the solid particles. The porous membrane filter may require a filtration aid, typically in the form of diatomaceous earth, which forms a layer on the membrane filter to help collect solids that would otherwise bypass or clog the filter. 
     In embodiments including the heat exchanger  114 , the process stream  116  discharged from the separation device  112  may optionally be circulated through the heat exchanger  114  prior to being introduced into the EKS  104 . Alternatively, the separation device  112  may be omitted and the hydrocarbon stream  102  may be conveyed directly to the heat exchanger  114 , without departing from the scope of the disclosure. In yet other embodiments, the heat exchanger  114  may precede the separation device  112  in the system  100 . 
     The heat exchanger  114  may be designed to adjust the temperature of the process stream  116  (or the hydrocarbon stream  102 ) to a desirable level and discharge a temperature-adjusted process stream  118 . The heat exchanger  114  may be configured to discharge the temperature-adjusted process stream  118  at a temperature ranging from T1 (° F.) to T2 (° F.), where T1 and T2 can be, independently, 300, 290, 280, 270, 260, 250, 240, 230, 220, 210, 200, 190, 180, 170, 160, 150, 140, 130, 120, 110, 100, 90, 80, 70, 60, or even 50, as long as T1&lt;T2. In at least one embodiment, the heat exchanger  114  may be configured to reduce the temperature of the process stream  116  to a desirable level. In other embodiments, the heat exchanger  114  may be configured to adjust the temperature of the process stream  116  to above ambient temperature, such as about 25° C. (77° F.). The temperature-adjusted process stream  118  may then be conveyed to the EKS  104  for further processing. 
     In at least one embodiment, the temperature-adjusted process stream  118  may include a filtration aid for the purpose of conglomerating very fine solid particles contained therein, much similar to the filtration aids used in processes using only conventional mechanical filtration. The filtration aid may comprise, for example, diatomaceous earth. The EKS  104  may be configured to capture very fine particles that may have bypassed the filtration and separation capabilities of the preceding separation device(s)  112 . While in certain situations it may be desirable to use a special filtration aid to facilitate solid particle abatement through the EKS  104 , the EKS  104  may nevertheless be configured to reduce the quantity of filtration aid required as compared to conventional particle abatement processes that do not incorporate electro-kinetic separation. Accordingly, as mentioned above, it is contemplated herein to use the EKS  104  for solid particle abatement only, thus wholly or partially eliminating the need of the separation device  112 . 
       FIG. 2A  is a schematic diagram of one example of the EKS  104 , according to one or more embodiments. It is noted that the EKS  104  is depicted merely as an illustrative embodiments and, thus, should not be considered limiting to the scope of the present disclosure. Indeed, various alternative designs or modifications to the EKS  104  may be incorporated, without departing from the scope of the disclosure. 
     As illustrated, the EKS  104  may include a cylindrical body  202  (alternately referred to a “cleaning chamber”) having a first end  204   a  and a second end  204   b  opposite the first end  204   a . The first end  204   a  may comprise an input end designed to receive a process stream  205 , and the second end  204   b  may comprise an output end that discharges the purified product stream  108 . The process stream  205  may comprise the hydrocarbon stream  102  ( FIG. 1 ) and/or the temperature-adjusted process stream  118  ( FIG. 1 ). While not shown, the first and second ends  204   a,b  may be generally sealed and capable of receiving the process stream  205  and discharging the product stream  108 . 
     The EKS  104  comprises at least two electrodes made of electrically conductive materials and, therefore, capable of conducting electricity at the operating conditions. In the illustrated embodiment, the electrodes comprise first and second electrodes  206   a  and  206   b  in the form of concentric outer and inner cylinders with opposite polarity. In other embodiment, however, the electrodes  206   a,b  may take on other forms or geometric shapes capable of generating an electric field, without departing from the scope of the disclosure. Suitable electrically conductive materials that may be used for the electrodes  206   a,b  include, but are not limited to, carbon, silicon, a metal (e.g., steel, aluminum, copper, silver, gold, other precious metals, etc.), a metal alloy, a conductive ceramic, or any combination thereof. 
     The EKS  104  may comprise EKS media  208  (i.e., a dielectric medium) interposing the electrodes  206   a,b . While the process stream  205  can directly contact the electrodes  206   a,b  applying the electric field, it is contemplated to position the EKS media  208  as a dielectric barrier between the electrodes  206   a,b  and the process stream  205 . This may be especially advantageous if a high voltage is applied between the electrodes  206   a,b , and/or the process stream  205  has a high conductivity, which can result in large currents if direct contact between the process stream  205  and the electrodes  206   a,b  is allowed. 
     Suitable EKS media  208  that may be used in the EKS  104  include any solid material that has a low electrical conductivity under the operating conditions of the EKS  104 . In some embodiments, for example, the EKS media  208  may exhibit an electrical conductivity lower than the material used for the electrodes  206   a,b . In at least one embodiment, the EKS media  208  has an electrical conductivity lower than the process stream  205  under the operating conditions. Non-limiting examples of suitable EKS media  208  include, but are not limited to, fibers, fibrous materials (e.g., glass wool, rock wool, synthetic plastic fibers, filamentary materials, etc.), a fabric to (e.g., non-woven or woven cellulose and the like), flakes, foams (e.g., polyurethane foam, an open-foam material), a mesh, pellets or beads (e.g., made of materials such as glass, ceramic, glass-ceramic, inorganic oxides, etc.), a cellulosic material (e.g., wood), or any combination thereof. 
       FIG. 2B  is a partial cross-sectional end view of one example of the EKS media  208  of  FIG. 2A , according to one or more embodiments. As illustrated, the EKS media  208  may comprise a cartridge  210  radially disposed between the electrodes  206   a,b  and including three layers  212   a ,  212   b ,  212   c  of a pleated fabric material (e.g., a non-woven cellulosic pleated material). The cartridge  210  is bounded on inner and outer surfaces with the electrodes  206   a,b  and each layer  212   a,b  may be separated longitudinally by corresponding dielectric dividers  214 . The dielectric dividers  214  may be made of any dielectric material mentioned herein. In at least one embodiment, the dielectric dividers  214  may be made of cotton. 
     The pleated material of each layer  212   a - c  may form distinct, longitudinally extending channels  216  that extend generally between the first and second ends  204   a,b  ( FIG. 2A ) of the EKS  104  ( FIG. 2A ). The channels  216  form individual flow passageways through which the process stream  205  may flow between the first and second ends  204   a,b . In some embodiments, as illustrated, the channels  216  may comprise triangular-shaped channels, but may otherwise form any suitable geometry through which the process stream  205  may flow. 
     Referring jointly to  FIGS. 2A-2B , during example operation of the EKS  104 , a voltage (DC or AC) is applied to the electrodes  206   a,b , which generates an electric field that extends through the EKS media  208 . The process stream  205  is circulated through the electric field and salts and solid particles bearing electrical charges are forced to travel in the electric field as a result of Coulomb forces exerted thereto. Neutral solid particles can also be induced to become electrically polarized in the electric field, and then move in certain directions as a result of Coulomb forces. 
     The EKS media  208  and the process stream  205  have different permittivities, which according to Laplace&#39;s equation, alters the electric field and results in regions of high field gradient near the corners of the cartridge  210 . The non-uniformity in the electric field is the driving force for dielectrophoresis, thus the geometry of the cartridge  210  may be critical to the separation performance. Consequently, the material of the EKS media  208  (e.g., each layer  212   a - c  of the cartridge  210 ) may be configured to collect solid particles when the electric field is applied between the electrodes  206   a,b . More specifically, as the process stream flows through the channels  216  and the electric field, solid particles may be attracted to the fabric, adhere to the fabric, and collected on the fabric, without being carried to the downstream equipment, to achieve the particle abatement to effect. 
     The amplitude of the voltage applied and the characteristics of the voltage profile (e.g., constant DC or AC, alternating sinusoid, alternating flat pulses, or other profiles), the type of electrode material, shape, dimension, and position of the electrodes  206   a,b , as well as the distance between the electrodes  206   a,b , can be chosen by one skilled in the art to meet the need of the specific application, flow rate of the feed stream, operating temperature, particle concentration in the feed stream, number of EKSs used, particle concentration required for the stream passed on to the downstream equipment, recycle ratio, and the like. 
     In some embodiments, the process stream  205  may be a poor electrical conductor under the operating conditions. Thus, any electric current flowing through the process stream  205  during operation of the EKS  104  may be negligible, and upstream and downstream equipment may not be electrified to an unsafe level through the process stream  205  in direct contact with the electrodes  206   a,b.    
     The EKS  104  may be operated at a pressure of about 100 kPaa (kilopascal absolute pressure) to about 3500 kPaa or about 100 kPaa to about 3000 kPaa, or about 100 kPaa to about 2500 kPaa, or about 100 kPaa to about 2000 kPaa, or about 100 kPaa to about 1500 kPaa, or about 100 kPaa to about 1000 kPaa, or about 100 kPaa to about 500 kPaa, or about 250 kPaa to about 3500 kPaa, or about 250 kPaa to about 3000 kPaa, or about 250 kPaa to about 2500 kPaa, or about 250 kPaa to about 2000 kPaa, or about 250 kPaa to about 1500 kPaa, or about 250 kPaa to about 1000 kPaa, or about 250 kPaa to about 500 kPaa, or about 500 kPaa to about 3500 kPaa, or about 500 kPaa to about 3000 kPaa, or about 500 kPaa to about 2500 kPaa, or about 500 kPaa to about 2000 kPaa, or about 500 kPaa to about 1500 kPaa, or about 500 kPaa to about 1000 kPaa. 
     The product stream  108  exiting the EKS  104  has a reduced content of solid particles as compared to the process stream  205  entering the EKS  104 . In various aspects, the product stream  108  may comprise solid particles in a concentration, as measured by ASTM D4807-05, of less than about 10,000 ppmw (parts per million by weight), less than about 7,500 ppmw, less than about 5,000 ppmw, less than about 2,500 ppmw, less than about 1,000 ppmw, less than about 750 ppmw, less than about 500 ppmw, less than about 250 ppmw, less than about 100 ppmw, less than about 75 ppmw, less than about 50 ppmw, less than about 25 ppmw, less than about 10 ppmw, less than about 1.0 ppmw, or less than about 0.50 ppmw or about 0.010 ppmw, based on the total weight of the process fluid exiting the EKS. Additionally or alternatively, the product stream  108  may comprise solid particles in a concentration of about 0.010 ppmw to about 10,000 ppmw, about 0.010 ppmw to about 5,000 ppmw, about 0.010 ppmw to about 1,000 ppmw, about 0.010 ppmw to about 100 ppmw, about 0.010 ppmw to about 50 ppmw, about 0.010 ppmw to about 10 ppmw, or about 0.010 ppmw to about 1.0 ppmw. 
     The EKS  104  can be advantageously used for process streams containing solid particles that have small sizes, such as those having an average particle size of at most 1000 micrometer (μm), such as at most: 700 μm, 600 μm, 500 μm, 400 μm, 300 μm, 200 μm, 100 μm, 80 μm, 60 μm, 50 μm, 40 μm, 20 μm, 10 μm, 9 μm, 8 μm, 6 μm, 5 μm, 4 μm, 3 μm, or 5 μm. 
     As the process stream  205  flows through the EKS  104 , the EKS media  208  may reach a desired level of captured solid particles, such as any convenient amount up to the maximum capacity of the EKS media  208  for capturing and retaining solids. This desired capacity of the EKS  104  can be determined by many factors, including but not limited to the voltage profile applied to the electrodes  206   a,b , flow rate of the process stream  205 , solid particle density and particle size distribution in the process stream  205 , the type and capacity of the EKS media  208  used for collecting solid particles, and the like. 
     When the EKS media  208  reaches its particle collection capacity, it may be desirable to regenerate the EKS media  208  to remove at least a portion of the collected solid particles from the EKS media  208 , thereby reclaiming or restoring at least part of the capacity. One contemplated regeneration process includes removing the soiled EKS media  208  from the EKS device  104 , cleaning the EKS media  208  using mechanical means, chemical means, electrical means, or any combination thereof, and re-installing the cleaned EKS media  208  into the EKS  104 . Solvents, detergents, flames, oxidizing agents, plasma, brushes, stirring devices, flushing fluid streams, and the like, may be used for cleaning the soiled EKS media  208 . 
     In at least one embodiment, however, an in-situ regeneration process may be used. In such embodiments, the EKS media  208  may be allowed to remain in the EKS  104  during regeneration. During such in-situ regeneration process, the supply of the process stream  205  to the EKS  104  may be turned off partly or completely, and voltage applied to the electrodes  206   a,b  may be reduced to zero or changed to a profile favorable for releasing captured solid particles so that they may be flushed out of the EKS  104 . During in-situ regeneration of the EKS media  208 , a process compatible fluid, such as a backwash fluid, may be passed through the EKS  104 , whereby at least a portion of the solid particles collected in the EKS media  208  is flushed out. The process compatible fluid may be any suitable fluid (including liquids, gases and mixtures thereof), including but not limited to: air, nitrogen, a hydrocarbon (e.g., methane, ethane, butane, hexane, cyclohexane, kerosene, naphtha, diesel fuel, etc.), a solvent, or an aqueous liquid. In at least one embodiment, the process-compatible washing fluid may be miscible with the process stream  205 . 
       FIG. 3  is a schematic diagram of another system  300  for removing salt and solid particles from the hydrocarbon stream  102  and further including cleaning and regeneration capabilities, according to one or more embodiments. The system  300  may be similar in some respects to the system  100  of  FIG. 1  and therefore may be best understood with reference thereto, where like numerals will correspond to like components not described again in detail. The system  300  can be operated in cleaning mode where a process stream passes through the EKS  104  to be cleaned, or alternatively, in regeneration mode where a cleaning/washing fluid is conveyed through the EKS  104  to remove at least a portion of the solid particles collected and accumulated inside the EKS  104  and thereby reclaim at least a portion of the particle abatement capacity thereof. 
     As illustrated, the hydrocarbon stream  102  may be conveyed into the system  300  via the inlet conduit  106  and may have salts and solid particles entrained therein. To abate the solid particles contained therein, hydrocarbon stream  102  may be temperature-adjusted to a suitable temperature by the heat exchanger  114  to obtain the temperature-adjusted process stream  118 . In some embodiments, an optional EKS feed tank  302  may be used for storing the temperature-adjusted process stream  118  and supplying a process stream  304  at suitable temperature to the EKS  104 . 
     During cleaning mode, the process stream  304  is supplied to the EKS  104  where at least a portion of the solid particles are adsorbed by the EKS media  208  ( FIGS. 2A-2B ) and the product stream  108  is discharged into the outlet conduit  110  with an abated quantity of solid particles. In at least one embodiment, the product stream  108  may subsequently pass through the separation device  112  to obtain a further treated product stream  306  comprising solid particles at a further reduced concentration therein compared to the product stream  108 . The product stream  306  may then be conveyed downstream to other processing equipment. 
     During in-situ regeneration, the process stream  304  to the EKS  104  may be turned off, and a process-compatible backwash fluid stream  308  (e.g., air, nitrogen, a hydrocarbon, a solvent, an aqueous liquid, etc.) supplied from a process-compatible backwash fluid supply tank  310  may be introduced to the EKS  104 . The backwash fluid stream  308  may be configured to flush out of the EKS  104  at least a portion of the solid particles collected in the EKS media  208  ( FIGS. 2A-2B ). In some embodiments, at least 50 wt %, 60 wt %, 70 wt %, 80 wt %, or 90 wt %) may be flushed out of the EKS  104  with the backwash fluid stream  308 , and a solid particle-laden process-compatible backwash fluid stream  312  (shown in dashed line) may be produced. 
     In at least one embodiment, the stream  312  may be introduced into a settling tank  314  (or another solid-liquid separation device) where the solid particles may settle to the bottom. After separation, a fluid stream  316  (in dashed line) containing solid particles at a concentration lower than the stream  312  may be obtained, which may be partly or completely recycled back to the process-compatible backwash fluid tank  310  as stream  318 . In some embodiments, the separation device  112  may make use of a washing fluid stream to wash the filter cake to remove residual liquid entrained in the filter cake. In such embodiments, additionally or alternatively, at least a portion of the stream  316 , shown as stream  320  may be supplied to the separation device  112  as at least a portion of the washing fluid for removing residual liquid entrained in the filter cake. 
     Additionally or alternatively, instead of regenerating the EKS media  208  ( FIGS. 2A-2B ), the EKS media  208  may be replaced once the EKS media  208  reaches a desired level of captured solid particles as described herein. For example, the EKS media  208  may be replaced after one separation cycle, two separation cycles, three separation cycles, four separation cycles, or five separation cycles. For example, a first separation cycle can comprise passing a designated process stream volume through the EKS  104  to produce the product stream  108  and a second cycle can comprise passing at least a portion of the product stream  108  back through the EKS  104 , and so on. Alternatively, a first separation cycle can comprise passing a first designated process stream volume through the EKS  104  to produce a first product stream  108  and a second cycle can comprise passing a second designated process stream volume through the EKS  104  to produce a second product stream  108 . In at least one embodiment, however, a continuous fresh feed stream supplied from the equipment upstream from the EKS  104  may be passed through the EKS  104  to obtain a solid particulate abated stream, which is then split into at least two streams, one of which is recycled to the EKS  104 , and the other to the downstream equipment, which can be a downstream EKS, a distillation column, a storage unit, or other vessels. 
     The ratio of the weight of the stream recycled to the EKS  104  to the weight of the process stream  304  entering the EKS  104  can vary significantly, depending on the particle concentration in the fresh feed stream entering the EKS  104 , the efficiency and capacity of the EKS  104 , and the desired particle concentration in the stream allowed to leave to the downstream equipment. In at least one embodiment, the recycle ratio can range from r1 to r2, where r1 and r2 can be, independently, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, as long as r1&lt;r2. At a given capacity and efficiency of the EKS  104 , and all other process conditions held equal, the higher the recycle ratio, the lower the concentration of solid particles in the stream passed on to the downstream equipment will be. 
     It is noted that the EKS  104  is described herein as a single unit. It is contemplated herein, however, to employ a plurality of electro-kinetic separators, which may be connected in parallel or in series to meet the solid particle abatement performance requirements of the process. In at least one embodiment, at least two of the multiple electro-kinetic separators may be configured such that they are capable of being operated in parallel, i.e., both receiving a fresh feed stream from the same upstream equipment. A system having the capability of operating multiple electro-kinetic separator units in parallel permits the possibility of operating one electro-kinetic separator in cleaning mode (i.e., a mode where fresh feed stream is accepted and a treated product stream is produced) and operating the other electro-kinetic separator in regeneration mode or idling mode if needed, thus allowing for a steady and uninterrupted operation of the whole product manufacture system. 
     Examples 
     Crude oil feed and crude oil processed through an electro-kinetic separator similar to the EKS  104  described herein were analyzed both for salt content via ASTM D3230 and fines (solid particle) concentration via ASTM D4807-05 using a 0.45 μm filter/hot toluene wash. Results of four experiments using different crude oils are presented in Table 1 below: 
     
       
         
           
               
               
               
               
               
               
             
               
                 TABLE 1 
               
               
                   
               
               
                   
                   
                 Salt  
                 Salt  
                 Feed  
                 Product 
               
               
                 Example  
                 Hydrocarbon 
                 (ptb) 
                 (ptb) 
                 Solids 
                 Solids 
               
               
                 # 
                 Stream 
                 Feed 
                 Product 
                 (ppm) 
                 (ppm) 
               
               
                   
               
             
            
               
                 1 
                 Crude 1 
                  10.6 
                 2.4 
                  300 
                 150 
               
               
                 2 
                 Crude 1 + NaCl 
                 306.7 
                 1.9 
                 1150 
                 270 
               
               
                   
                 (brine) 
                   
                   
                   
                   
               
               
                 3 
                 Crude 1 + Crude 2 
                  18.3 
                 5.6 
                  860 
                 100 
               
               
                 4 
                 Crude 3 
                  6.2 
                 0.7 
                  420 
                  80 
               
               
                   
               
            
           
         
       
     
     The salt product and the product solids in Crudes 1-3 were measured after being processed in an electro-kinetic separator similar to the EKS  104 . Example 1 shows that the salt concentration in Crude 1 was reduced from 10.6 pounds per thousand barrels (ptb) to 2.4 ptb and the total solid fines concentration was reduced from 300 parts per million (ppm) to 150 ppm. 
     In Example 2, Crude 1 was spiked with an aqueous NaCl solution (25% by weight NaCl dissolved in water). More specifically, 100 μm of the NaCl solution was added to 1.5 gallons of Crude 1 and mixed vigorously following which the mixture phase was allowed to separate. The hydrocarbon phase was separated and processed through an electro-kinetic separator similar to the EKS  104 . As shown in Table 1, salt concentration was reduced from about 307 ptb to 1.9 ptb, and the solid fines concentration was reduced from 1150 ppm to 270 ppm. 
     In Example 3, Crude 1 was spiked with a separate, high-salt Crude 2 to again increase the salt and particle content of the hydrocarbon stream processed through the electro-kinetic separator. More specifically, about 1 liter of high-salt Crude 2 was mixed with 1.5 gallons of Crude 1. The mixture had a salt concentration of 18.3 ptb, which when processed in the electro-kinetic separator was reduced to 5.6 ptb. Solid fines concentration reduced from 860 ppm to 80 ppm. 
     In Example 4, a different crude, Crude 3, without any spiking, was tested in an electro-kinetic separator similar to the EKS  104 . The electro-kinetic separator unit reduced the salt concentration from 6.2 ptb to 0.7 ptb and solid fines concentration was reduced from 170 ppm to 80 ppm. 
     The foregoing examples show that electro-kinetic separation can reduce salt content as well as other solid fines concentration in crude samples. The extent of removal, however, is a function of various variables such as electrical field strength and configuration (and also material) of fines capturing media. It is contemplated that by varying certain operating variables, the removal efficiency of salt and fines can be improved. 
     Predictive Modeling of Fines Separation 
     A fundamental model was developed to predict fines removal from hydrocarbon streams. The model predicts the per-pass separation efficiency for an electro-kinetic separator similar to the EKS  104  based on device geometry and physical and electrical properties of the fines and hydrocarbon. The predicted fines concentration matches well to experimental data for clay-bitumen and fines-crude systems. The model may be used to select operating conditions for maximum fines separations. 
     Mathematical Model 
     The model developed for this system is based on a comparison of relevant timescales: the residence timescale for a particle based on the superficial fluid velocity, V f , and the separation timescale, based on the dielectrophoretic particle velocity. Here, electrophoresis is assumed negligible due to a presumed minimal particle surface charge in a hydrocarbon fluid. A schematic of the linear channels is shown in  FIG. 4 , which is a schematic of particle motion in a linear channel under the influence of an electric field. 
     The residence timescale, t res , can be written as: 
     
       
         
           
             
               t 
               res 
             
             = 
             
               L 
               
                 V 
                 f 
               
             
           
         
       
     
     where L is the length of the channel. The separation timescale, t sep , is: 
     
       
         
           
             
               
                 t 
                 sep 
               
               = 
               
                 
                   H 
                   
                     V 
                     p 
                   
                 
                 = 
                 
                   
                     3 
                      
                     η 
                      
                     
                         
                     
                      
                     H 
                   
                   
                     
                       ɛ 
                       m 
                     
                      
                     
                       R 
                       2 
                     
                      
                     
                       Re 
                        
                       
                         ( 
                         
                           
                             f 
                             ~ 
                           
                           CM 
                         
                         ) 
                       
                     
                      
                     
                       ∇ 
                       
                          
                         
                           E 
                           2 
                         
                          
                       
                     
                   
                 
               
             
             , 
           
         
       
     
     where η is the fluid viscosity, H is the distance from the center of the channel to the wall, ε m  is the fluid permittivity, R is the particle radius, and E is the electric field. Re( f   m ) is the Clausius-Mossotti factor describing the difference between the particle and fluid complex permittivities. In a DC field, this simplifies to: 
     
       
         
           
             
               Re 
                
               
                 ( 
                 
                   
                     f 
                     ~ 
                   
                   CM 
                 
                 ) 
               
             
             = 
             
               
                 
                   
                     σ 
                     p 
                   
                   - 
                   
                     σ 
                     m 
                   
                 
                 
                   
                     σ 
                     p 
                   
                   + 
                   
                     2 
                      
                     
                       σ 
                       m 
                     
                   
                 
               
               . 
             
           
         
       
     
     The difference between the conductivity of the particle, σ p , and the fluid permittivity, σ m , is crucial to the separation efficiency. These timescales can be combined into a dimensionless separation number, F, 
     
       
         
           
             Γ 
             = 
             
               
                 
                   t 
                   res 
                 
                 
                   t 
                   sep 
                 
               
               = 
               
                 
                   
                     ɛ 
                     m 
                   
                    
                   
                     R 
                     2 
                   
                    
                   
                     LRe 
                      
                     
                       ( 
                       
                         
                           f 
                           ~ 
                         
                         CM 
                       
                       ) 
                     
                   
                    
                   
                     ∇ 
                     
                        
                       
                         E 
                         2 
                       
                        
                     
                   
                 
                 
                   3 
                    
                   η 
                    
                   
                       
                   
                    
                   
                     V 
                     f 
                   
                    
                   H 
                 
               
             
           
         
       
     
     When Γ&gt;1, the separation timescale is shorter than the residence timescale, indicating that separation is possible. When Γ&lt;1, there is minimal separation of particles from the bulk fluid. This construct is a useful check to predict whether or not a fines-hydrocarbon system is a candidate for electro-kinetic separation. However, this does not give any information on the percentage of particles removed. To add in this capability, we switch from a dimensionless group based on average parameters to a spatially-dependent γ(x,y). 
     Spatially-Dependent Separation Number 
     The separation number includes several parameters that are readily re-envisioned as spatially-dependent variables. This includes h(x,y), the distance from a particle to the nearest wall, the fluid velocity profile v z , and the gradient of the electric field squared,  V (x,y) 2 |. For an isosceles triangular channel of angle θ, the distance to the nearest triangle wall can be described as: 
     
       
         
           
             
               h 
                
               
                 ( 
                 
                   x 
                   , 
                   y 
                 
                 ) 
               
             
             = 
             
               
                 min 
                 Δ 
               
                
               
                 { 
                 
                   
                     y 
                     - 
                     H 
                   
                   , 
                   
                     
                       y 
                        
                       
                           
                       
                        
                       tan 
                        
                       
                         θ 
                         2 
                       
                     
                     - 
                     
                        
                       x 
                        
                     
                   
                 
                 } 
               
             
           
         
       
     
     The velocity profile for laminar flow in a triangular channel is given by: 
     
       
         
           
             
               
                 v 
                 z 
               
                
               
                 ( 
                 
                   x 
                   , 
                   y 
                 
                 ) 
               
             
             = 
             
               
                 
                   15 
                    
                   
                     V 
                     f 
                   
                 
                 
                   H 
                   3 
                 
               
                
               
                 ( 
                 
                   y 
                   - 
                   H 
                 
                 ) 
               
                
               
                 ( 
                 
                   
                     
                       x 
                       2 
                     
                      
                     
                         
                     
                      
                     
                       cot 
                       2 
                     
                      
                     
                       θ 
                       2 
                     
                   
                   - 
                   
                     y 
                     2 
                   
                 
                 ) 
               
             
           
         
       
     
     The electric field can be calculated from the potential, e(x,y)=−∇φ, and the differential form of Gauss&#39; law: 
       ∇·(ε∇φ)=0
 
     The boundary conditions for the potential are defined at the four edges of the bounding box, which includes three cartridge pleats sandwiched between the electrode and a cotton spacer (e.g., the dielectric divider  214  of  FIG. 2B ). They are written as a single piecewise continuous function of y as follows: 
     
       
         
           
             
               
                 ϕ 
                 0 
               
                
               
                 ( 
                 y 
                 ) 
               
             
             = 
             
               { 
               
                 
                   
                     
                       
                         
                           V 
                            
                           
                               
                           
                            
                           
                             ɛ 
                             m 
                           
                            
                           y 
                         
                         
                           
                             H 
                              
                             
                                 
                             
                              
                             
                               ɛ 
                               c 
                             
                           
                           + 
                           
                             2 
                              
                             
                               δ 
                                
                               
                                 ( 
                                 
                                   
                                     ɛ 
                                     m 
                                   
                                   - 
                                   
                                     ɛ 
                                     c 
                                   
                                 
                                 ) 
                               
                             
                           
                         
                       
                       , 
                     
                   
                   
                     
                       0 
                       ≤ 
                       y 
                       &lt; 
                       δ 
                     
                   
                 
                 
                   
                     
                       
                         
                           V 
                            
                           
                             ( 
                             
                               
                                 
                                   ɛ 
                                   c 
                                 
                                  
                                 y 
                               
                               + 
                               
                                 δ 
                                  
                                 
                                   ( 
                                   
                                     
                                       ɛ 
                                       m 
                                     
                                     - 
                                     
                                       ɛ 
                                       c 
                                     
                                   
                                   ) 
                                 
                               
                             
                             ) 
                           
                         
                         
                           
                             H 
                              
                             
                                 
                             
                              
                             
                               ɛ 
                               c 
                             
                           
                           + 
                           
                             2 
                              
                             
                               δ 
                                
                               
                                 ( 
                                 
                                   
                                     ɛ 
                                     m 
                                   
                                   - 
                                   
                                     ɛ 
                                     c 
                                   
                                 
                                 ) 
                               
                             
                           
                         
                       
                       , 
                     
                   
                   
                     
                       δ 
                       ≤ 
                       y 
                       &lt; 
                       
                         H 
                         - 
                         δ 
                       
                     
                   
                 
                 
                   
                     
                       
                         V 
                         + 
                         
                           
                             V 
                              
                             
                                 
                             
                              
                             
                               
                                 ɛ 
                                 m 
                               
                                
                               
                                 ( 
                                 
                                   y 
                                   - 
                                   H 
                                 
                                 ) 
                               
                             
                           
                           
                             
                               H 
                                
                               
                                   
                               
                                
                               
                                 ɛ 
                                 c 
                               
                             
                             + 
                             
                               2 
                                
                               
                                 δ 
                                  
                                 
                                   ( 
                                   
                                     
                                       ɛ 
                                       m 
                                     
                                     - 
                                     
                                       ɛ 
                                       c 
                                     
                                   
                                   ) 
                                 
                               
                             
                           
                         
                       
                       , 
                     
                   
                   
                     
                       
                         H 
                         - 
                         δ 
                       
                       ≤ 
                       y 
                       ≤ 
                       H 
                     
                   
                 
               
             
           
         
       
     
     At each of the boundaries of the bounding rectangle, the potential φ=φ 0 . The non-uniformity in the electric field arises because the permittivity ε of the cartridge is different from that of the fluid. To account for differing permittivity in various regions, we solve Gauss&#39; law via finite elements method. 
     The electric field is calculated from e(x,y)=−∇φ. To insert the electric field into the separation number, ∇|e(x,y) 2 | is needed. This gradient is a vector containing both an x and y component. To simplify the model, instead use the magnitude of this quantity, |∇|e(x,y) 2 ∥. 
     The separation number 
     
       
         
           
             
               γ 
                
               
                 ( 
                 
                   x 
                   , 
                   y 
                 
                 ) 
               
             
             = 
             
               
                 
                   ɛ 
                   m 
                 
                  
                 
                   R 
                   2 
                 
                  
                 
                   LRe 
                    
                   
                     ( 
                     
                       
                         f 
                         ~ 
                       
                       CM 
                     
                     ) 
                   
                 
                  
                 
                    
                   
                     ∇ 
                     
                        
                       
                         
                           e 
                            
                           
                             ( 
                             
                               x 
                               , 
                               y 
                             
                             ) 
                           
                         
                         2 
                       
                        
                     
                   
                    
                 
               
               
                 3 
                  
                 η 
                  
                 
                     
                 
                  
                 
                   
                     v 
                     z 
                   
                    
                   
                     ( 
                     
                       x 
                       , 
                       y 
                     
                     ) 
                   
                 
                  
                 
                   h 
                    
                   
                     ( 
                     
                       x 
                       , 
                       y 
                     
                     ) 
                   
                 
               
             
           
         
       
     
     is calculated at each node point. 
     Fraction of Particles Removed 
     In a single pass through the cartridge, a fraction of particles is removed. To predict this, it is first assumed that the particles are uniformly distributed in the triangular channel in x and y at the start of the channel, z=0. With this assumption, the fraction of the area of the triangle where the separation number γ&gt;1 is equal to the fraction of particles removed in a single pass. 
     This area fraction is then equal to the fraction of particles removed per pass through the cartridge, χ 
     
       
         
           
             χ 
             = 
             
               1 
               - 
               
                 
                   Area 
                   , 
                   
                     γ 
                     &lt; 
                     1 
                   
                 
                 
                   Δ 
                    
                   
                       
                   
                    
                   Area 
                 
               
             
           
         
       
     
     In a typical lab-scale experiment, fluid passes through the cleaning chamber (e.g., the electro-kinetic separator) and a holding tank a large number of times. The concentration of particles as a function of passes through the cartridge, n, is given by: 
         C ( n )=( C   0   −C   n )(1−χ) n   +C   n  
 
     where C 0  is the initial concentration of fines and C n  is a fitting parameter for the final concentration after the system reaches steady state and no additional particles are removed. The power-law nature of the particle removal is significant because it highlights the importance of increasing the number of passes. Fundamentally, n represents the number of times the particles are mixed resulting in a uniform particle inlet distribution. This expression indicates that to increase per pass removal, it is vital to introduce mixing in the linear channels. 
     Comparison with Experiments 
     Typical experiments involve running a feed in the electro-kinetic separator continuously and samples are drawn periodically throughout the run. To determine the concentration of particulates, the samples are filtered, and then the number of particles on the filter paper is measured. This results in a concentration with units ppm of particles larger than the filter size. 
       FIG. 5  is a plot depicting concentrations of four crudes compared against the predictive model. More specifically,  FIG. 5  depicts solids concentration C for Crude 1, Crude 2, Crude 3, and Crude 4 compared to predicted concentration (the Model) and against the number of passes through the device, n. The number of passes was calculated based on the liquid flow rate and device dimensions. As can be seen in  FIG. 5 , the model agrees quite well with experimental data. The only fitting parameter here is the final concentration at steady state, G. This model can now be used to improve experimental and device design in a predictive manner. 
     EMBODIMENTS DISCLOSED HEREIN INCLUDE 
     A. A method that includes introducing a crude oil process stream into an electro-kinetic separator (EKS), passing the crude oil process stream through an electric field generated by the EKS, removing at least a portion of salt and solid particles from the crude oil process stream as the crude oil process stream passes through the electric field, and discharging a product stream from the EKS with reduced salt and solid particle count as compared to the crude oil process stream. 
     B. A process for treating a hydrocarbon stream comprising salt and solid particles that includes conveying the hydrocarbon stream through at least one of a separation device and a heat exchanger, and thereby generating a process stream, introducing the process stream into an electro-kinetic separator (EKS), passing the process stream through an electric field generated by the EKS, removing at least a portion of the salt and the solid particles from the process stream as the process stream passes through the electric field, and discharging a product stream from the EKS with reduced salt and solid particle count as compared to the hydrocarbon stream. 
     Each of embodiments A and B may have one or more of the following additional elements in any combination: Element 1: wherein the solid particles are selected from the group consisting of sand, proppant, rock, salt, a corrosion product, and any combination thereof. Element 2: wherein the solid particles have an average particle size in the range from 1 to 1000 micrometers. Element 3: wherein the solid particles have an average particle size in the range from sub-micron to about 25 micrometers. Element 4: further comprising conveying the crude oil process stream through a separation device prior to entering the EKS, wherein the separation device is selected from the group consisting of a desalter, a water washing device, a mechanical filter, and any combination thereof. Element 5: further comprising conveying the crude oil process stream through a heat exchanger prior to entering the EKS. Element 6: further comprising adjusting a temperature of the crude oil process stream to at least ambient temperature in the heat exchanger. Element 7: wherein the EKS comprises at least two electrodes and an EKS media disposed between the at least two electrodes, the method further comprising generating the electric field by applying a direct current or alternating current voltage between the at least two electrodes, flowing the crude oil process stream through the EKS media and the electric field, and attaching the portion of the salt and the solid particles from the crude oil process stream to the EKS media, wherein the EKS media is made of a dielectric material selected from the group consisting of fibers, a fibrous material, a fabric, flakes, a foam, a mesh, pellets or beads, and any combination thereof. Element 8: wherein the EKS media comprises a cartridge radially disposed between the at least two electrodes and including one or more layers of a pleated fabric material defining a plurality of longitudinally extending channels, wherein flowing the crude oil process stream through the EKS media comprises flowing the crude oil process stream through the plurality of longitudinally extending channels. Element 9: wherein the EKS media is made of a material selected from the group consisting of an inorganic glass, a ceramic, a glass ceramics, an inorganic oxide, a cellulosic material, and any combination thereof. Element 10: further comprising regenerating the EKS media. Element 11: wherein regenerating the EKS media comprises removing the EKS media from the EKS, cleaning the EKS media using at least one of mechanical means, chemical means, electrical means, and any combination thereof, and replacing the EKS media into the EKS for further operation. Element 12: wherein regenerating the EKS media comprises circulating a process compatible fluid through the EKS media to remove at least a portion of the solid particles collected in the EKS media. Element 13: wherein the process-compatible washing fluid is selected from the group consisting of air, nitrogen, a hydrocarbon, a solvent, an aqueous liquid, and any combination thereof. 
     Element 14: wherein the solid particles are selected from the group consisting of sand, proppant, rock, salt, a corrosion product, and any combination thereof. Element 15: wherein the separation device is selected from the group consisting of a desalter, a water washing device, a mechanical filter, and any combination thereof. Element 16: further comprising adjusting a temperature of the crude oil process stream to at least ambient temperature in the heat exchanger. Element 17: wherein the EKS comprises at least two electrodes and an EKS media disposed between the at least two electrodes, the method further comprising generating the electric field by to applying a direct current or alternating current voltage between the at least two electrodes, flowing the process stream through the EKS media and the electric field, and attaching the portion of the salt and the solid particles from the crude oil process stream to the EKS media, wherein the EKS media is made of a dielectric material selected from the group consisting of fibers, a fibrous material, a fabric, flakes, a foam, a mesh, pellets or beads, and any combination thereof. Element 18: further comprising regenerating the EKS media. 
     By way of non-limiting example, exemplary combinations applicable to A and B include: Element 5 with Element 6; Element 7 with Element 8; Element 7 with Element 9; Element 7 with Element 10; Element 10 with Element 11; Element 10 with Element 12; Element 12 with Element 13; and Element 17 with Element 18. 
     Therefore, the disclosed systems and methods are well adapted to attain the ends and advantages mentioned as well as those that are inherent therein. The particular embodiments disclosed above are illustrative only, as the teachings of the present disclosure may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular illustrative embodiments disclosed above may be altered, combined, or modified and all such variations are considered within the scope of the present disclosure. The systems and methods illustratively disclosed herein may suitably be practiced in the absence of any element that is not specifically disclosed herein and/or any optional element disclosed herein. While compositions and methods are described in terms of “comprising,” “containing,” or “including” various components or steps, the compositions and methods can also “consist essentially of” or “consist of” the various components and steps. All numbers and ranges disclosed above may vary by some amount. Whenever a numerical range with a lower limit and an upper limit is disclosed, any number and any included range falling within the range is specifically disclosed. In particular, every range of values (of the form, “from about a to about b,” or, equivalently, “from approximately a to b,” or, equivalently, “from approximately a-b”) disclosed herein is to be understood to set forth every number and range encompassed within the broader range of values. Also, the terms in the claims have their plain, ordinary meaning unless otherwise explicitly and clearly defined by the patentee. Moreover, the indefinite articles “a” or “an,” as used in the claims, are defined herein to mean one or more than one of the elements that it introduces. If there is any conflict in the usages of a word or term in this specification and one or more patent or other documents that may be incorporated herein by reference, the definitions that are consistent with this specification should be adopted. 
     As used herein, the phrase “at least one of” preceding a series of items, with the terms “and” or “or” to separate any of the items, modifies the list as a whole, rather than each member of the list (i.e., each item). The phrase “at least one of” allows a meaning that includes at least one of any one of the items, and/or at least one of any combination of the items, and/or at least one of each of the items. By way of example, the phrases “at least one of A, B, and C” or “at least one of A, B, or C” each refer to only A, only B, or only C; any combination of A, B, and C; and/or at least one of each of A, B, and C.