Electrowetting Coalescing Device for Use with Organic Process Fluids - Patent application

Abstract

An electrowetting coalescing device is disclosed that may be utilized to coalesce droplets of a dispersed phase within a continuous phase of an organic process fluid. The electrowetting coalescing device coalesces smaller droplets of the dispersed phase into larger droplets of the dispersed phase for subsequent removal of the larger droplets from the continuous phase. Methods for coalescing the droplets are also disclosed. Methods for designing the electrowetting coalescing device with a mechanical model are also disclosed.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Patent Application Serial No. 63 / 309,087, filed February 11, 2022, which is incorporated herein by reference.

[0002] One or more embodiments of the present invention are directed to an electrowetting coalescing device that may be useful for coalescing droplets of a dispersed phase within a continuous phase of an organic process fluid. [Background technology]

[0003] U.S. Publication No. 2020 / 0094167 discloses an electrowetting coalescing device for coalescing droplets of a dispersed phase within a continuous phase. The electrowetting coalescing (EWC) device of '167 Pub. is disclosed as useful for separating water from diesel fuel. The stainless steel (SS) mesh EWC includes bolts in electrical contact with the mesh to apply a desired voltage. For the low conductivity diesel fuel and deionized water used in '167 Pub., the EWC works well. However, for certain organic process fluids, the applied potential difference between the mesh electrodes of the EWC of '167 Pub. generally cannot be sustained at low current due to electrical shorting.

[0004] Separation of the dispersed phase (e.g., aqueous phase) from organic process fluids can be difficult. Certain of these fluids include one or more of carboxylic acids, amines, aldehydes, ketones, and alcohols. Other organic process fluids that are difficult to handle include those with metal ions. This challenge can arise due to the charge of some of the compounds found in such fluids. In this same light, prior literature on electrowetting generally involves avoiding conductive fluids, i.e., fluids with compounds that dissociate into ions. One example is sodium acetate, which can dissociate into sodium and acetate ions. A further challenge in separating the aqueous phase from the organic phase is the safety of handling fluids that have electrical currents, especially those that may or may not have an inherent charge. Another challenge is the practical arrangement of managing potentially volatile liquids and equipment involving electricity.

[0005] These types of organic process fluids are difficult to handle. Application of an external electric field to droplets suspended in an immiscible fluid generally leads to the droplets becoming polarized and eventually forming opposite charges. Due to Maxwell stresses, spherical droplets may assume an ellipsoidal shape. Collision of droplets may then lead to a thin bridge forming between the joined droplets. When droplets collide and form a bridge, ions accumulated on the droplet interface may migrate onto the adjacent interface, which may result in Columbic repulsion between the same ions. This Coulomb repulsion and electrostatic forces tend to pull the two droplets in opposite directions, leading to the destruction of the bridge, which may also be referred to as recoil. And under these principles, droplets with high conductivity tend to recoil. Increasing the electric field strength may help to avoid recoil and promote droplet coalescence, but the critical electric field strength (above which droplets generally recoil) tends to decrease with increasing conductivity.

[0006] There remains a need in the art for improved electrowetting coalescing devices for treating organic process fluids. Summary of the Invention

[0007] In one embodiment, the invention provides an electrowetting coalescing device for coalescing droplets of a dispersed phase within a continuous phase of an organic process fluid, comprising an inlet, a porous first electrode having a first independent electrical connection thereto, the porous first electrode comprising a first plurality of pores having a first average pore size, a porous second electrode having a second independent electrical connection thereto, the porous second electrode comprising a second plurality of pores having a second average pore size, the second average pore size being different from the first average pore size, a voltage applied and maintained on the porous first electrode, the porous second electrode being at a second voltage different from the voltage applied and maintained on the porous first electrode, the second voltage optionally being 0V ground, whereby An electrowetting coalescing device is provided that includes a voltage that creates an electric field between a porous first electrode and a porous second electrode, an outlet, and an organic process fluid, the organic process fluid comprising a dispersed phase within a continuous phase, the continuous phase comprising an organic fluid containing a metal, the dispersed phase comprising aqueous droplets optionally comprising further metal ions or acid salts, the dispersed phase being conductive or non-conductive and the continuous phase having a low conductivity, the electrowetting coalescing device receiving the organic process fluid, the organic process fluid passing through the inlet, the porous first electrode, the electric field, the porous second electrode, and the outlet, whereby the electrowetting coalescing device causes smaller droplets of the dispersed phase to coalesce into larger droplets of the dispersed phase for subsequent removal of the larger droplets from the continuous phase.

[0008] In another embodiment, the invention provides a method for coalescing droplets of a dispersed phase within a continuous phase of an organic process fluid in an electrowetting coalescing device, the method comprising: providing an electrowetting coalescing device; providing an organic process fluid, the organic process fluid comprising a dispersed phase within a continuous phase, the continuous phase comprising a metal-containing organic fluid, the dispersed phase comprising aqueous droplets optionally comprising additional metal ions or acid salts, the dispersed phase being conductive or non-conductive and the continuous phase having a low conductivity; allowing the organic process fluid to flow through the electrowetting coalescing device; electrowetting the droplets of the dispersed phase to form larger droplets; and removing the larger droplets from the continuous phase.

[0009] In another embodiment, the present invention provides a method for designing an electrowetting coalescing device, the method comprising the steps of providing an organic process fluid comprising a dispersed phase within a continuous phase, the continuous phase comprising a metal-containing organic fluid, the dispersed phase comprising aqueous droplets optionally comprising further metal ions or acid salts, and providing a mechanistic model, the mechanistic model comprising:

number

[0010] The advantages of the present invention will become better understood with regard to the following description, the appended claims, and the accompanying drawings.

[0011] [Figure 1] 1 is a cross-sectional schematic diagram of an electrowetting combined device in accordance with one or more embodiments of the present invention. [Diagram 2] FIG. 2 is an exploded view of the electrowetting coalescing device of FIG. 1. [Diagram 3] FIG. 2 is a perspective view of the electrowetting combined device of FIG. 1. [Figure 4] FIG. 2 is a schematic diagram illustrating multiple electrowetting combined devices in a manifold configuration in accordance with one or more embodiments of the present invention. [Diagram 5] FIG. 2 is a schematic diagram illustrating a plurality of electrowetting combined devices in a series configuration with a separator between each electrowetting combined device in accordance with one or more embodiments of the present invention. [Figure 6] FIG. 2 is a schematic diagram illustrating a plurality of electrowetting combined devices in a series configuration without separators between each electrowetting combined device in accordance with one or more embodiments of the present invention. [Figure 7] FIG. 1 is a schematic diagram illustrating an electrowetting combined device including a first electric field between a first electrode and a second electrode and a second electric field between the second electrode and a third electrode in accordance with one or more embodiments of the present invention. [Figure 8] FIG. 2 is a top view of a perforated plate that can be used as an electrode for an electrowetting combined device in accordance with one or more embodiments of the present invention. [Figure 9] FIG. 2 is a perspective view of a subcomponent of an electrowetting combined device including three perforated plates in accordance with one or more embodiments of the present invention. [Figure 10] FIG. 13 is an alternative perspective view of an electrowetting combined device including three perforated plates in accordance with one or more embodiments of the present invention. [Figure 11] FIG. 11 is a cross-sectional view of the electrowetting combined device of FIG. [Figure 12] 1A-1C are top views of an electrowetting combined device having alternative electrode connection locations in accordance with one or more embodiments of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] An embodiment of the present invention is based, at least in part, on an electrowetting coalescing (EWC) device. In use, the electrowetting coalescing device receives a fluid for its treatment, and the electrowetting coalescing device may be particularly useful for treating organic process fluids. The electrowetting coalescing device includes one or more porous layers such that the fluid passes through the pores of the one or more porous layers. Advantageously, the electrowetting coalescing device is effective in separating aqueous droplets containing salts (e.g., one or more of metal ions and acid salts) from organic process fluids, which may also contain one or more of metal ions and metal complexes. If present, the ions can make these fluids more electrically conductive than deionized water and diesel fuel. As discussed further herein, the present results show that the EWC device of one or more embodiments of the present invention can be used to electrowet and separate organic process fluids.

[0013] An electrowetting combined device, which may be referred to herein as an EWC, EWC device, or device, includes a first electrode and a second electrode, where a voltage difference exists between the first electrode and the second electrode, thereby generating an electric field. The electrowetting combined device may include one or more additional electrodes, where a voltage difference exists between each respective pair of electrodes, thereby generating a respective electric field. As is commonly known to those skilled in the art, an electrode is a conductor through which electricity enters or leaves an object, material, or area. An electrode may also be referred to as an electrical conductor that contacts and transmits electric current to a non-metallic part of a circuit.

[0014] As discussed above, the electrowetting combined device includes one or more porous layers. In one or more embodiments, the porous layers are electrodes. That is, in one or more embodiments, a first porous layer may be used as a first electrode and a second porous layer may be used as a second electrode. In other embodiments, the housing may act as an electrode in conjunction with one or more porous layers as electrodes. That is, in these other embodiments, a first porous layer may be used as a first electrode and a housing may be used as a second electrode.

[0015] A voltage difference exists between the first and second electrodes, if a third electrode is present, between the second and third electrodes, etc., thereby generating one or more electric fields within the electrowetting combined device. As is generally understood by those skilled in the art, the voltage difference between the respective electrodes can be realized in a variety of ways. For example, an electric field can be achieved by utilizing a first electrode provided with an applied voltage such that the first electrode is used as a positive electrode, and a second electrode that is grounded and used as a ground electrode. An electric field can also be achieved between a negative electrode and a ground electrode, between a positive electrode and a negative electrode, between a positive electrode and a slightly weaker positive electrode, and between a negative electrode and a stronger negative electrode. Any of these embodiments can be utilized with the electrowetting combined device described herein, so long as one or more suitable electric fields are generated. In embodiments that do not have a ground electrode, it is desirable to ground the external housing or another component for safety purposes.

[0016] As alluded to above, a fluid having a continuous phase and a dispersed phase (e.g., an organic process fluid) in the form of small droplets can be provided to the electrowetting coalescing device, particularly at its inlet, and then to one or more porous layers. That is, all of the fluid flow through the EWC passes through one or more porous layers and one or more electric fields. The small droplets are generally micron-sized, and although the micron-sized droplets are initially much smaller than the pore openings of the one or more porous layers, the one or more electric fields attract most of the droplets to the surface of the one or more porous layers. Others of these droplets may spread over the surface of the porous layer, and a small amount of the small droplets may pass through without being captured, especially at relatively high flow rates.

[0017] As a further description of the coalescence mechanism, one or more electric fields generated by each electrode pair promote the coalescence of dispersed phase droplets (e.g., water) by increasing the attractive forces between the droplets. The coalescence of dispersed phase droplets generally involves two or more dispersed phase droplets coming together, the droplets remaining in contact for a sufficient duration such that a thin film of continuous phase present between the droplets ruptures, thereby forming a larger droplet from the two or more dispersed phase droplets. The electric field can modify the wetting properties of one or more porous layers based on the principle of electrowetting, thereby improving the adhesion of the dispersed phase droplets on the surface of the porous layer. The porous layer provides an increased surface area for fluid contact, thereby obtaining a larger area for the dispersed phase droplets to contact.

[0018] In other words, the small droplets continue to be attracted to the first porous layer and begin to grow by electro-coalescence and collision of the small droplets with other small droplets. The small droplets can be one or more of electrolytic, polarizable, or otherwise capable of conducting electric current or being charged. If the small droplets are water (e.g., deionized water), they can be non-electrolytic. Based on the presence of an electric field and corresponding principles commonly known to those skilled in the art, the small droplets are attracted to the first porous layer, such as by the force resulting from the applied electric field. The growth of the small droplets continues until the combined droplet formed from the multiple smaller droplets is carried away when the gravitational or drag force of the continuous phase flow dominates over the electric attraction force.

[0019] These combined droplets, which may also be referred to as larger droplets, then proceed to a second porous layer. In order to form larger droplets of larger size, thereby coalescing and collecting the larger droplets, the second porous layer may have a pore size larger than that of the first porous layer. Yet, in other embodiments, the second porous layer may have a pore size smaller than that of the first porous layer. These combined droplets may also be one or more of electrolytic, polarizable, or otherwise capable of conducting electric current or being charged. These combined droplets may also be non-electrolytic. Based on the presence of an electric field and the corresponding principles, the combined droplets are attracted to the second porous layer, such as by the force resulting from the applied electric field. That is, the second porous layer achieves further coalescence of the combined droplets generated from the first porous layer.

[0020] These combined droplets continue to be attracted to the second porous layer and begin to grow by electro-coalescence and collision of the combined droplets with other combined droplets. This growth continues until an ejected droplet formed from the multiple combined droplets is carried away when the gravity and / or drag forces of the continuous phase flow dominate over the electrical attraction. If the second porous layer has a smaller pore size than the pore size of the first porous layer, this may include some breakage of the ejected droplets into smaller droplets. Nevertheless, these smaller droplets should still remain of a size sufficient to be suitably collected.

[0021] The discharged droplets, which may also be referred to as collected droplets or largest droplets, pass through the second porous layer and are sent to an outlet. The collected droplets may be collected in a drain for eventual removal of the largest droplets. In these or other embodiments, the flow from the outlet may be provided to a downstream device to remove the collected droplets from the continuous phase. Exemplary downstream devices may include membranes, molecular sieves, barrier filters, gravity settlers, centrifugal inertial separators, or other separators. A new amount of fluid is then provided to the EWC device and the above process is repeated.

[0022] Further details of the one or more porous layers are now provided. The porous layer can be any suitable two-dimensional or three-dimensional structure. An exemplary two-dimensional structure is a sheet. An exemplary three-dimensional structure includes balls (e.g., steel wool balls) and encapsulated multi-layer grids (e.g., metal grids). The porous layer can be woven or non-woven. Other examples for the one or more porous layers include woven and non-woven meshes, perforated plates, porous sintered metal, and parallel layered metal strips. An example of a parallel layered metal strip includes a wedge-shaped metal layer that produces rectangular slot openings as holes.

[0023] In one or more embodiments, the porous layer can be a mesh. A mesh can be defined as having one or more of attached strands and woven strands. In one or more embodiments, the mesh can be a wire mesh. In one or more embodiments, the porous layer is a woven mesh, such as a woven metal mesh. An exemplary woven metal mesh is a stainless steel woven mesh. In one or more embodiments, the porous layer can be non-woven randomly oriented fibers.

[0024] In one or more embodiments, the porous layer can be a perforated plate, which can also be referred to as a perforated sheet. In one or more embodiments, the perforated plate can be metal. An exemplary metal is stainless steel. As shown in FIG. 8, in one or more embodiments, the holes in the perforated plate can be square shaped. As shown in FIG. 9, in one or more embodiments, the holes in the perforated plate can be circular shaped.

[0025] Both mesh plates and perforated plates, among other suitable porous layers, work well as electrodes, but the design of one or more porous layers may depend on the desired characteristics of any given EWC device and / or fluid. Meshes tend to be more flexible, depending on the diameter of the material used to make the mesh. Meshes tend to have smaller holes. Plates tend to be stiffer and do not bend easily, which can reduce the possibility of plates touching each other against the mesh. Perforated plates may provide more uniformity to the hole size. For larger EWC devices, stiffer meshes and / or plates may need to be used to prevent deformation and contact. For EWC devices with larger gap distances and where mesh is preferred, there may be a non-conductive spacer between the mesh electrodes to prevent contact. Any of these design parameters may be utilized to select the desired EWC device for a given fluid.

[0026] The pores of one or more of the porous layers described herein can be formed by any suitable technique. In one or more embodiments, the porous layer can be formed by drilling a substrate to provide holes in the substrate. In one or more embodiments, the porous layer can be formed by sintering, such as sintering a metal sheet made of small metal particles sintered together. If the porous layer is a mesh, the pores are formed as part of making the mesh.

[0027] As used herein, the term porous layer should be broadly interpreted as including at least one layer of porous material. In one or more embodiments, the porous layer may be embodied by multiple layers of porous material. As used herein, the term porous layer may be defined to include one or more layers of porous material that allow fluid flow therethrough and enable the electrowetting coalescence function described.

[0028] The porous layer can be characterized by its dimensions, such as thickness, length, width, and diameter, although the porous layer can have any suitable dimensions. In one or more embodiments, the porous layer can have a thickness of about 0.5 mm to about 5 mm, in other embodiments about 0.5 mm to about 3 mm, and in other embodiments about 1 mm to about 3 mm.

[0029] In one or more embodiments, the porous layer can have a length or diameter of from about 0.01 m to about 100 m, in other embodiments from about 0.05 m to about 10 m, and in other embodiments from about 0.1 m to about 0.5 m.

[0030] The porous layers can be characterized by pore size. In one or more embodiments, the porous layers can be characterized by the pore size of the first porous layer relative to the pore size of the second porous layer. In one or more embodiments, each subsequent porous layer in the flow path can have a pore size larger than the pore size of the preceding porous layer. In other embodiments, each subsequent porous layer in the flow path can have a pore size smaller than the pore size of the preceding porous layer. In still other embodiments, all of the porous layers have relatively similar pore sizes.

[0031] In connection with the pore size and other features disclosed herein, the mechanism of droplet coalescence should be considered in conjunction with the mechanism of droplet collection, i.e., pore size and other features can be tailored to best coordinate the two mechanisms.

[0032] In one or more embodiments, the pore size ranges from about 0.05 mm to about 10 mm, in other embodiments, from about 0.1 mm to about 5 mm, in other embodiments, from about 0.1 mm to about 3 mm, and in other embodiments, from about 0.5 mm to about 2 mm. In one or more embodiments, the pore size ranges from about 0.5 mm, in other embodiments, from about 1 mm, in other embodiments, from about 2 mm, and in other embodiments, from about 5 mm. These pore sizes are applicable to both inlet and outlet pore sizes, in addition to the pore sizes further disclosed below. The pore sizes disclosed herein are applicable to both the porous layer as a mesh and the porous layer as a perforated plate. When the porous layer is a perforated plate, the pore size may also be referred to as the diameter of the perforated holes.

[0033] In one or more embodiments, the pore size of the outlet porous layer ranges from about 1 mm to about 1.5 mm, in other embodiments from about 1 mm to about 1.3 mm, and in other embodiments from about 1.1 mm to about 1.2 mm. In one or more embodiments, the pore size of the outlet porous layer is about 1 mm, in other embodiments about 1.1 mm, in other embodiments about 1.18 mm, and in other embodiments about 1.2 mm.

[0034] In one or more embodiments, the pore size of the inlet porous layer ranges from about 0.3 mm to about 1 mm, in other embodiments from about 0.5 mm to about 0.9 mm, and in other embodiments from about 0.6 mm to about 0.8 mm. In one or more embodiments, the pore size of the inlet porous layer is about 0.5 mm, in other embodiments about 0.7 mm, in other embodiments about 0.9 mm, and in other embodiments about 1 mm.

[0035] Pore ​​size can be characterized relatively as the ratio between the pore size and the size of the droplets. In one or more embodiments, the pore size of the inlet porous layer ranges from about 10 times to about 1,000 times, in other embodiments from about 50 times to about 750 times, and in other embodiments from about 100 times to about 500 times the size of the inlet droplets. In one or more embodiments, the pore size of the inlet porous layer ranges from about 50 times, in other embodiments from about 100 times, in other embodiments from about 250 times, and in other embodiments from about 500 times the size of the inlet droplets.

[0036] In one or more embodiments, the pore size of the outlet porous layer is in the range of about 0.1 times to about 2 times, in other embodiments about 0.5 times to about 2 times, and in other embodiments about 0.5 times to about 1.5 times the size of the outlet droplets. In one or more embodiments, the pore size of the outlet porous layer is about 0.5 times, in other embodiments about 1 time, in other embodiments about 1.5 times, and in other embodiments about 2 times the size of the outlet droplets.

[0037] Pore ​​size can be characterized relatively as the ratio between the inlet pore size and the outlet pore size. In one or more embodiments, the pore size of the inlet porous layer ranges from about 0.1 times to about 10 times, in other embodiments from about 0.5 times to about 5 times, and in other embodiments from about 0.5 times to about 2 times the pore size of the outlet porous layer. In one or more embodiments, the pore size of the inlet porous layer ranges from about 0.1 times, in other embodiments from about 0.5 times, in other embodiments from about 2 times, and in other embodiments from about 5 times the pore size of the outlet porous layer.

[0038] In embodiments where the porous layer is a perforated plate, the pore size can be defined by the open area, which may also be referred to as the area fraction, which refers to the open area of ​​the holes compared to the area of ​​the solid plate, and can be 0 to 1, or as a percentage from 0% to 100%. The porous layer can have any desired open area in the range of 0 to 1. In one or more embodiments, the porous layer has an open area of ​​0.01 to 0.99, in other embodiments 0.2 to 0.8, in other embodiments 0.3 to 0.7, and in other embodiments 0.4 to 0.6.

[0039] In embodiments where the porous layer is a mesh, the pore size can be defined by the porosity, which is a measure of the void space in a material and is the fraction of the volume of voids over the total volume, from 0 to 1, or as a percentage from 0% to 100%. In one or more embodiments, the porous layer has a porosity of 0.15 to 0.9, in other embodiments from 0.3 to 0.8, and in other embodiments from 0.4 to 0.6.

[0040] In embodiments where the porous layer is a mesh, the pore size can be characterized by a mesh number, which refers to the number of openings per linear inch. In one or more embodiments, the porous layer has a mesh number of 40×40 or less, in other embodiments 30×30 or less, in other embodiments 20×20 or less, and in other embodiments 10×10 or less. In one or more embodiments, the porous layer has a mesh number of 10×10 or more, in other embodiments 20×20 or more, in other embodiments 30×30 or more, and in other embodiments 40×40 or more. As with other quantitative disclosures herein, any of these mesh number endpoints may be utilized to form suitable ranges. In one or more embodiments, the porous layer has a mesh number of about 10×10, in other embodiments about 20×20, in other embodiments about 30×30, and in other embodiments about 40×40.

[0041] Values ​​disclosed herein and elsewhere herein should be understood to be arithmetic means generally consistent with the understanding of one of ordinary skill in the art, unless otherwise disclosed.

[0042] In one or more embodiments, the pore size of the pores in the porous layers is constant or substantially constant across each respective porous layer, i.e., a first porous layer can have pores of a first substantially constant size and a second porous layer can have pores of a second substantially constant size.

[0043] In other embodiments, the pore size of the pores in the porous layers may vary across each porous layer, i.e., a first porous layer may have pores of a different size and a second porous layer may have pores of another different size.

[0044] A gap, which may also be referred to as the gap distance, must exist between each electrode (e.g., the first and second porous layers). In one or more embodiments, the first gap exists between the first and second porous layers, and the second gap exists between the second and third porous layers.

[0045] In one or more embodiments, an EWC device utilizing an organic process fluid may have one or more gap distances ranging from about 0.25 mm to about 5 mm, in other embodiments from about 0.4 mm to about 2.0 mm, in other embodiments from about 0.5 mm to about 1.5 mm, and in other embodiments from about 0.5 mm to about 1 mm. In one or more embodiments, the one or more gap distances are about 0.5 mm, in other embodiments about 1 mm, in other embodiments about 1.25 mm, and in other embodiments about 1.5 mm.

[0046] In one or more embodiments, the wires and / or the porous layer may be coated, which may include partial and / or complete coating. In one or more embodiments, all of the internal components are coated; that is, in one or more embodiments, everything inside the housing along the fluid flow path may be coated. In one or more embodiments, the coating is applied after the wires are connected (e.g., welded).

[0047] In one or more embodiments, the coating may include a dielectric coating, a hydrophobic coating, and combinations thereof. In one or more embodiments, the coating may be a single coating having both dielectric and hydrophobic functions. In other embodiments, separate coatings serve each function. The coating may generally serve to prevent potential shorting and provide a high initial drop contact angle. The dielectric coating may be referred to as an insulating dielectric coating.

[0048] In one or more embodiments, the coating includes first applying a layer of insulating dielectric coating, and then applying a layer of hydrophobic coating on the insulating dielectric coating. Exemplary insulating dielectric coatings include insulating dielectric polymers such as poly(methyl methacrylate) (PMMA) and poly(styrene-co-methyl methacrylate) (PS / PMMA). An exemplary hydrophobic coating is a fluoropolymer-based film. An exemplary fluoropolymer-based film is derived from a material commercially available under the trade name FluoroPel (e.g., FluoroPel 1601V). These materials are commonly known to those skilled in the art and include solutions of fluoropolymers in fluorosolvents. These materials can be varied based on the amount, boiling point, and surface area of ​​the fluoropolymer that can be selected for the desired design.

[0049] As alluded to above, in one or more embodiments, the coating may be a polymer that serves both a dielectric function and a hydrophobic function.

[0050] In view of the discovery that coated meshes having certain coatings (e.g., PS / PMMA) may be problematic using the dip coating method described in the '167 Pub. referenced in the Background (i.e., meshes having hole openings smaller than 1 mm were generally found to have a tendency to clog under this method), a spray coating method may be utilized to apply the coating without or with minimal clogging and still achieve a coating sufficient to prevent short circuits. Other techniques for applying the coating are also suitable.

[0051] The coating can be characterized by its thickness. The thickness of the coating can be from a few nanometers to the gap distance. In one or more embodiments, the coating of the first porous layer can be in contact with the coating of the second porous layer. In one or more embodiments, the coating can have a thickness of about 2 nm to about 2 mm, in other embodiments, about 0.2 μm to about 1 mm, and in other embodiments, about 0.5 mm to about 1 mm. In one or more embodiments, the coating can have a thickness of about 2 nm to about 50 nm, in other embodiments, about 0.2 μm to about 10 μm, and in other embodiments, about 0.5 mm to about 2 mm. The coating thickness generally should not be too thick to block the pores, but thicker coatings can be used in conjunction with larger pore sizes.

[0052] Suitable coatings and their thicknesses can be further understood to analyze the effectiveness of the coating. This can include performing a conductivity test that can measure the effectiveness of the coating in preventing current leakage and thus reducing the potential for short circuits. An exemplary test involves immersing the coated porous layer and steel wire in a 5% NaCl solution and connecting each to a respective end of a circuit to create a complete circuit. The current flowing through the circuit can then be measured (e.g., source measurement equipment Keithley 2400 source meter). An effective coating should have a relatively minimal current (e.g., less than 2 microamps) passing through the coated porous layer.

[0053] Further details of the fluid are now provided. As discussed elsewhere herein, the electrowetting coalescing device of the present disclosure coalesces droplets from the fluid. In one or more embodiments, the fluid comprises a dispersed phase within a continuous phase. In one or more embodiments, the fluid is an organic process fluid having a dispersed phase and a continuous phase. As is commonly known to those skilled in the art, the term organic generally refers to any chemical compound that contains carbon-hydrogen bonds.

[0054] In one or more embodiments, the continuous phase may be an organic fluid containing metals, which may be referred to as a metal-containing organic fluid. As is commonly known to those skilled in the art, the metal-containing organic fluid may originate from a metal recovery operation known as an extraction step. In these operations, an extractant (e.g., organic in a diluent) may be used to extract one or more metals from an aqueous solution via an ion exchange phenomenon at the contacting surfaces when the two phases are in contact. The extraction step produces a containing organic fluid containing the valuable metal, and a metal-depleted aqueous phase. Extraction or metal containing within the metal-containing organic fluid may generally depend on extraction efficiency, distribution ratio, separation factor, molar concentration, and mass transfer. The amount of metal within the metal-containing organic fluid may affect the amount of dispersing fluid (e.g., aqueous) in the continuous fluid (e.g., organic), and thus may lead to the utilization of a certain number of stages for multiple EWC devices.

[0055] In one or more embodiments, the dispersed phase comprises aqueous droplets that include additional metal ions or acid salts, which may optionally be referred to as a conductive aqueous fluid.

[0056] The organic process fluid, and its dispersed and continuous phases, can be characterized in terms of their relative conductivities. Generally speaking, the dispersed phase can be conductive or non-conductive, and the continuous phase should have a low conductivity.

[0057] In one or more embodiments, the dispersed phase has a conductivity of less than 1 μS / cm, in other embodiments less than 10 μS / cm, and in other embodiments less than 100 μS / cm. In one or more embodiments, the dispersed phase has a conductivity of about 1 μS / cm to about 150,000 μS / cm, in other embodiments about 100 μS / cm to about 100,000 μS / cm, in other embodiments about 50,000 μS / cm to about 100,000 μS / cm, and in other embodiments about 60,000 μS / cm to about 80,000 μS / cm. In one or more embodiments, the dispersed phase has a conductivity of about 75,000 μS / cm to about 150,000 μS / cm, and in other embodiments about 100,000 μS / cm to about 150,000 μS / cm.

[0058] In one or more embodiments, the continuous phase has a conductivity of less than 1 μS / cm, in other embodiments less than 10 μS / cm, and in other embodiments less than 100 μS / cm. In one or more embodiments, the continuous phase has a conductivity of about 1 μS / cm to about 100 μS / cm, in other embodiments about 10 μS / cm to about 100 μS / cm, in other embodiments about 10 μS / cm to about 50 μS / cm, and in other embodiments about 50 μS / cm to about 100 μS / cm. In one or more embodiments, the continuous phase has a conductivity of about 1 μS / cm to about 50 μS / cm, and in other embodiments about 1 μS / cm to about 50 μS / cm.

[0059] In view of these disclosed preferred numerical conductivities, the conductivities of the dispersed and continuous phases may also be characterized relative to one another for one or more embodiments.

[0060] In one or more embodiments, the dispersed phase may have a different conductivity than the continuous phase. In one or more embodiments, the dispersed phase differs from the continuous phase by one order of magnitude, in other embodiments by two orders of magnitude, in other embodiments by three orders of magnitude, in other embodiments by four orders of magnitude, and in other embodiments by five orders of magnitude.

[0061] In one or more embodiments, the dispersed phase may be more conductive than the continuous phase, in one or more embodiments, the dispersed phase is one order of magnitude, in other embodiments, two orders of magnitude, in other embodiments, three orders of magnitude, in other embodiments, four orders of magnitude, and in other embodiments, five orders of magnitude more conductive than the continuous phase.

[0062] As alluded to above, the organic process fluid may include ions. These ions may include a variety of ions and may be either or both of the dispersed and continuous phases. Exemplary ions generally range from Li to Po, including the left two-thirds of the periodic table, including the lanthanides and actinium series elements. The ions may be formed from one or more of monovalent, divalent, and polyvalent metallic elements. Exemplary monovalent metallic elements include Li, Na, K, and Rb. Exemplary divalent metallic elements include Be, Mg, and Ca. And, as is commonly known to those skilled in the art, transition metals (e.g., Ni, Cu, Zn, and Pd) may be in stable forms of several valence states.

[0063] In one or more embodiments, the organic process fluid is from industrial organic chemical production and processing (e.g., synthetic, coal, bio, and petrochemicals), mining and extraction processing (e.g., minerals, metals, coal, gas, oil), petroleum refining, products, and processes, hydrometallurgical and solvent extraction processing, battery materials processing, battery recycling processing (e.g., lithium ion battery waste, lithium ion battery production scrap, lithium ion cell production scrap, lithium ion cathode active material), and / or combinations thereof. In one or more embodiments, the organic process fluid is a nickel-containing petroleum distillate, a copper / nickel-containing petroleum distillate, a lithium-containing petroleum distillate, and / or combinations thereof.

[0064] In one or more embodiments, the organic process fluid is conductive or non-conductive with the entrained aqueous droplets. In one or more embodiments, the organic process fluid may include charged particles or ions contained in the fluid, such as metal ions and / or salt ions. In one or more embodiments, the metal ions and / or salt ions are in the continuous phase. In one or more embodiments, the metal ions and / or salt ions are in the entrained aqueous droplets. In one or more embodiments, the organic process fluid may be a solution containing one or more of an extractant, a modifier, and solubilized metals / minerals.

[0065] Organic process fluids can be characterized based on polarity. In one or more embodiments, the organic process fluid includes a continuous phase, which may be a relatively non-polar liquid, and a dispersed phase, which may be a relatively polar liquid. Insofar as the term polarity is used herein, the polarity of the continuous phase and dispersed phase should be considered relative to one another. That is, the polarity (and other intermolecular forces) of the continuous phase and dispersed phase should be such that the dispersed phase exists as a dispersion within the continuous phase. This may be referred to as a dispersed phase that is relatively more polar than the continuous phase. This may also be referred to as an organic process fluid that includes a polar solution (i.e., dispersed phase) and a solution of much less polarity (i.e., continuous phase). It may be desirable for the organic process fluid to be devoid or substantially devoid of components (e.g., modifiers) that would otherwise make the interface relatively polar. The dispersed phase should generally be immiscible with the continuous phase, and if the relative polarities are the same or too similar, the dispersed phase will not be immiscible in the continuous phase. Exemplary relatively polar liquids include water, wastewater from different processing steps and / or production, such as lithium ion battery waste. Exemplary relatively non-polar or slightly polar liquids include hydrocarbons. In one or more embodiments, exemplary hydrocarbons include petroleum distillates and dearomatized hydrocarbons.

[0066] In one or more embodiments, the continuous phase comprises a metal salt (i.e., a metal ion), a complex of a metal, a metal chelate, and / or a combination thereof. The continuous phase may be referred to as a metal-containing organic phase. In one or more embodiments, the continuous phase generally does not contain free ions. In one or more embodiments, the continuous phase comprises one or more of a carboxylic acid, an amine, an aldehyde, and a ketone.

[0067] In one or more embodiments, the dispersed phase comprises one or more of an acid salt, a metal salt, an alcohol, and an aqueous solution.

[0068] The organic process fluid can be characterized relative to the amount of dispersed phase within the continuous phase. Various suitable amounts of dispersed phase within the continuous phase can be utilized, including relatively low amounts of dispersed phase and relatively high amounts of dispersed phase.

[0069] In one or more embodiments, the amount of dispersed phase, which may also be referred to as concentration, in the continuous phase may be from about 0.01% to about 3% by volume, in other embodiments from about 0.1% to about 2% by volume, in other embodiments from about 0.5% to about 1.5% by volume, and in other embodiments from about 0.6% to about 1% by volume. In one or more embodiments, the amount of dispersed phase in the continuous phase may be less than 3% by volume, in other embodiments less than 2% by volume, in other embodiments less than 1.5% by volume, in other embodiments less than 1% by volume, in other embodiments less than 0.6% by volume, and in other embodiments less than 0.5% by volume.

[0070] In one or more embodiments, the amount of the dispersed phase in the continuous phase can be about 0.01% to about 1.5% by weight, in other embodiments about 0.1% to about 1.2% by weight, in other embodiments about 0.3% to about 1% by weight, and in other embodiments about 0.5% to about 1% by weight. In one or more embodiments, the amount of the dispersed phase in the continuous phase can be less than 1.5% by weight, in other embodiments less than 1.2% by weight, in other embodiments less than 1% by weight, in other embodiments less than 0.6% by weight, in other embodiments less than 0.5% by weight, and in other embodiments less than 0.3% by weight.

[0071] One of ordinary skill in the art will understand that concentrations and conductivities can be related, and thus, the disclosed concentrations and conductivities disclosed herein can be utilized in a correlated manner.

[0072] Further details of suitable process conditions for EWC are now provided.

[0073] The electrowetting coalescing device can be characterized by the flow rate through the electrowetting coalescing device. The flow rate can affect, for example, droplet capture and / or droplet breakup. In the context of face velocity, suitable flow rates are provided herein. As is commonly known to those skilled in the art, face velocity refers to the flow rate divided by the area of ​​the porous layer, so the following quantified face velocity can be used in conjunction with the desired area of ​​the porous layer to calculate the flow rate. That is, for a given flow, the face velocity can be reduced by making the area larger. If the face velocity is too high, small droplets may not be captured properly and large droplets may break up into smaller droplets.

[0074] In one or more embodiments, the face velocity through the electrowetting combined device ranges from about 0.1 cm / min to 2,000 cm / min, in one or more embodiments from about 0.1 cm / min to 1,000 cm / min, in one or more embodiments from about 0.1 cm / min to 400 cm / min, in one or more embodiments from about 0.1 cm / min to 300 cm / min, and in one or more embodiments from about 0.1 cm / min to 200 cm / min. In one or more embodiments, the face velocity through the electrowetting combined device ranges from about 0.1 cm / min to about 40 cm / min, in one or more embodiments from about 0.1 cm / min to about 30 cm / min, in one or more embodiments from about 0.1 cm / min to about 20 cm / min, in one or more embodiments from about 0.1 cm / min to about 10 cm / min, in one or more embodiments from about 1 cm / min to about 10 cm / min, in one or more embodiments from about 2 cm / min to about 8 cm / min, in one or more embodiments from about 4 cm / min to about 6 cm / min, and in one or more embodiments from about 1 cm / min to about 3 cm / min. In one or more embodiments, the face velocity through the electrowetting combined device may be about 1 cm / min, in one or more embodiments about 4 cm / min, in one or more embodiments about 5 cm / min, in one or more embodiments about 6 cm / min, in one or more embodiments about 10 cm / min, in one or more embodiments about 15 cm / min, in one or more embodiments about 20 cm / min, and in one or more embodiments about 30 cm / min.

[0075] As discussed above, the electrodes described herein are used to create a voltage difference, such as between a first electrode and a second electrode, and in one or more embodiments, between the second electrode and a third electrode, thereby generating one or more electric fields within the electrowetting combined device. In one or more embodiments, the applied voltage provided to the positive electrode can range from about 1 V to about 800 V, in other embodiments from about 1 V to about 700 V, in other embodiments from about 1 V to about 500 V, and in other embodiments from about 1 V to about 450 V. In one or more embodiments, the applied voltage provided to the positive electrode can be in the range of about 50 V to about 800 V, in other embodiments, about 50 V to about 500 V, in other embodiments, about 100 V to about 800 V, in other embodiments, about 100 V to about 300 V, in other embodiments, about 300 V to about 500 V, in other embodiments, about 150 V to about 500 V, in other embodiments, about 200 V to about 250 V, and in other embodiments, about 210 V to about 230 V. In one or more embodiments, the applied voltage provided to the positive electrode can be about 100 V, in other embodiments, about 150 V, in other embodiments, about 200 V, in other embodiments, about 210 V, in other embodiments, about 300 V, and in other embodiments, about 500 V, and in other embodiments, about 700 V.

[0076] The voltage difference and gap distance disclosed herein can be used to develop a suitable electric field. That is, the electric field strength can be referred to as the voltage difference divided by the gap distance. Thus, the values ​​disclosed herein for the voltage difference and gap distance can also be used for the value of the electric field.

[0077] The temperature of the fluids and components of the EWC during operation should be approximately the same. In one or more embodiments, the temperature of the fluids and components of the EWC during operation ranges from approximately room temperature (i.e., 20° C.-22° C. or 68° F.-72° F.) to approximately 60° C. (140° F.). In one or more embodiments, the temperature of the fluids and components of the EWC during operation is approximately room temperature. In one or more embodiments, the temperature of the fluids and components of the EWC during operation is approximately 50° C. (120° F.). In one or more embodiments, the temperature of the fluids and components of the EWC during operation ranges from approximately 0° C. (32° F.) to approximately 80° C. (176° F.). In one or more embodiments, these disclosed ranges may also go down to approximately −20° C. (−4° F.). The temperature may generally be any suitable temperature at which the fluid passing through the EWC is in liquid form. That is, the temperature of the environment in which the EWC is being used and / or applied may range from above the crystallization point and below the boiling point of the fluid passing through the EWC. The liquid fluid must not undergo a phase change during operation of the EWC.

[0078] The EWC can be characterized by its separation efficiency, which is generally a measure of the effectiveness of the EWC in coalescing smaller droplets into collected droplets. The separation efficiency can be calculated by:

number

[0079] The EWC can have any suitable separation efficiency. In one or more embodiments, the EWC has a separation efficiency of about 40% to about 95%, in other embodiments, about 50% to about 90%, in other embodiments, about 60% to about 90%, and in other embodiments, about 80% to about 90%. In one or more embodiments, the EWC has a separation efficiency of about 60% to about 80%, in other embodiments, about 70% to about 80%, and in other embodiments, about 60% to about 70%. In one or more embodiments, the EWC has a separation efficiency of at least 60%, in other embodiments, at least 70%, in other embodiments, at least 80%, and in other embodiments, at least 90%.

[0080] An EWC can be operated in either single pass or multi-pass operation. Single pass operation generally refers to a fluid passing through the EWC once. Multi-pass operation generally refers to a fluid passing through the EWC multiple times, which may also be referred to as recirculation.

[0081] The EWC must collect and fill with water to be effective enough to coalesce the droplets. If the EWC is low due to water saturation (i.e., water filling), as in certain initial scenarios, many of the fine droplets will not coalesce and the resulting separation efficiency will be low. To increase the separation efficiency, the EWC may be pre-wetted and / or must be operated long enough to fill with enough water. Single pass operation can be particularly utilized when there is a very large volume of fluid as a source (e.g., in a source tank). This would generally be a continuous flow operation.

[0082] In one or more embodiments, in steady state operation, the first portion of the fluid passing through the EWC can be recycled back through the EWC once it is operating at a higher efficiency and has separated any dispersed phase that was not initially separated.

[0083] When the volume of the source fluid is relatively small, all of the source fluid may pass through the EWC before reaching a steady state. The end result is a low separation efficiency. In this case, it may be better to operate the EWC in a multi-pass operation to recirculate the fluid multiple times until the saturation increases to a level with higher separation efficiency.

[0084] As alluded to above, in one or more embodiments, the electrowetting coalescing device may be prewetted prior to process operation. That is, it is desirable for the EWC to reach steady state performance (i.e., fully saturated) at an early point in the process operation. Prewetting may be referred to as allowing the EWC to reach full saturation in addition to processing the organic process fluid. If desired, prewetting may be utilized to reach steady state performance more quickly. In one or more embodiments, prewetting may be accomplished by adding water upstream of the EWC, which then reaches the EWC prior to process operation, thereby saturating the EWC with water. The prewetting water may be added to the organic process fluid. This may be before any organic process fluid reaches the EWC, or in other embodiments, after an initial amount of the organic process fluid is delivered to the EWC. Stated differently, the organic process fluid may be provided to an upstream tank and then combined with excess water such that the water, being denser than the organic process fluid, settles below the organic process fluid and is therefore pumped to the EWC. The remainder of the organic process fluids may then be provided to the EWC. Any unsaturated water may be collected as part of the collection techniques disclosed herein.

[0085] With particular reference to Figures 1-3, one or more embodiments of the present invention provide an EWC device 10, which may also be referred to as an EWC assembly 10, an EWC 10, or a device 10. The EWC device 10 includes a housing 12 that includes a porous layer. The porous layer 14A is an inlet porous layer, which may also be referred to as a porous first electrode 14A, and the porous layer 14B is an outlet porous layer, which may also be referred to as a porous second electrode 14B. A suitable electric field exists between the porous first electrode 14A and the porous second electrode 14B.

[0086] The housing 12 includes an inlet 16 and an outlet 18 with porous layers 14A, 14B disposed therebetween. The inlet 16 may include a cone-shaped passageway and the outlet may include a cone-shaped passageway, which may generally help to spread the flow across the porous layers 14A, 14B and may generally avoid jetting of flow from the inlet 16 through the center of the porous layers 14A, 14B. The inlet 16 and outlet 18 areas may be referred to as relatively thick (i.e., thicker than the porous layers 14A, 14B) rectangular shapes that include a flow area that may be a cone-shaped flow area. In one or more embodiments, the inlet 16 and outlet 18 areas may be of similar or identical shapes, but are inverted upside down relative to one another.

[0087] The EWC device 10 can receive an organic process fluid, which comprises a dispersed phase within a continuous phase, that passes through an inlet 16, a porous first electrode 14A, an electric field, a porous second electrode 14B, and an outlet 18. In doing so, the electrowetting coalescing device 10 thereby causes smaller droplets of the dispersed phase to coalesce into larger droplets of the dispersed phase for subsequent removal of the larger droplets from the continuous phase.

[0088] The porous first electrode 14A includes a first independent electrical connection thereto, shown in FIGS. 1-3 as wire 20. Similarly, the porous second electrode 14B includes a second independent electrical connection thereto, shown as wire 22. In FIGS. 1-3, wire 22 is connected to ground 24. A voltage is applied and maintained through wire 20 to the porous first electrode 14A, thereby creating an electric field between the porous first electrode 14A and the porous second electrode 14B. Thus, the EWC 10 may be operated in accordance with the disclosure herein.

[0089] As shown in FIGS. 1-3, the inlet 16 may include a T-joint 26 with the wire 20 passing through one leg of the T-joint 26. The wire 20 extends vertically from the porous first electrode 14A through the T-joint 26. The T-joint 26 includes a sleeve 28 to prevent leakage of liquid. The wire 20 should be insulated, which may include application of a coating as described elsewhere herein. In accordance with the disclosure elsewhere herein, all components of the EWC 10 (e.g., the porous electrodes 14A, 14B) may also include coatings.

[0090] Suitable materials for the sleeve 28, which may also be referred to as a compression fitting 28 or adapter 28, include polytetrafluoroethylene (Teflon™) and heat shrink tubing, which may be made of polyolefin as a cross-linked crystalline polymer.

[0091] Like inlet 16, outlet 18 is also shown with a tee fitting 30, with wire 22 passing through one leg of tee fitting 30. Tee fitting 26 includes a sleeve 32, similar to sleeve 28.

[0092] As a further description of the wires 20, 22, the wires may be soldered to the respective electrodes 14A, 14B. In one or more embodiments, the wires are connected to the center of the electrodes. Other exemplary connection techniques include welding and brazing. A wire or other electrical contact must be provided to each electrode without touching the walls of the EWC 10 and causing a short circuit.

[0093] 1-3 show a porous first electrode 14A within a first outer frame 34 and a porous second electrode 14B within a second outer frame 36. Between the first outer frame 34 and the second outer frame 36 is a spacer 38. The first outer frame 34, second outer frame 36, and spacer 38 are held in place by a threaded rod 40 that is held in place by fasteners 42 at each end.

[0094] The first outer frame 34 and the second outer frame 36 each include a respective cutout for holding a respective porous electrode 14A, 14B. That is, the porous electrode 14A is disposed within the cutout of the first outer frame 34 and is disposed between the cutout lip and the spacer 38, and the porous electrode 14B is disposed within the cutout of the second outer frame 36 and is disposed between the cutout lip and the opposite side of the spacer 38. The spacer 38 may be a straight piece that extends straight across the housing 12, excluding a center hole between the porous electrodes 14A, 14B (i.e., not including a cutout). In one or more embodiments, the porous electrodes 14A and 14B may be of similar or identical shape, but flipped upside down relative to one another.

[0095] 9-12, one or more embodiments of the present invention provide an EWC device 100, which may also be referred to as an EWC assembly 100, an EWC 100, or a device 100. The EWC device 100 is similar to the EWC 10, except as described herein.

[0096] The EWC device 100 includes a third porous electrode 14C disposed between the upper porous electrode 14D and the lower porous electrode 14E. The function of the porous electrodes is otherwise similar to that disclosed above. An EWC device 100 having three electrodes 14C, 14D, 14E generally operates similarly to two EWC devices 10 in series without an intermediate separator.

[0097] Due to the presence of the intermediate third porous electrode 14C, connecting wires to the third porous electrode 14C can be problematic. Thus, the EWC device 100 includes porous electrodes 14C, 14D, 14E having respective tabs 102 (FIG. 10) protruding from a housing 104, which may generally be similar to the housing 12. Thus, the tabs 102 provide a mechanism for applying independent electrical connections to the porous electrodes 14C, 14D, 14E. The tabs 102 can be integral with the porous electrodes 14C, 14D, 14E, such as by cutting a sheet into a shape that allows the tabs 102, as small pieces of metal, to protrude from the housing 104, as shown particularly in FIG. 10.

[0098] As shown in Figures 9 and 10, the tabs 102 may extend generally from the sides of the porous electrodes 14C, 14D, 14E. In other embodiments, as shown in Figure 12, the tabs 102 may extend generally from the corners of the porous electrodes 14C, 14D, 14E.

[0099] In one or more embodiments, the outer electrodes 14D, 14E have voltages applied and maintained independently, and the middle electrode 14C is grounded at 0 V. In other embodiments, the middle electrode 14C has a voltage applied and maintained, and the outer electrodes 14D, 14E are grounded at 0 V (e.g., FIG. 7).

[0100] In one or more embodiments, the outer electrodes 14D, 14E may include wired connections as disclosed for the EWC 10.

[0101] In one or more embodiments in which the electrodes (e.g., 14D, 14E) are not sized to match the housing (e.g., housing 104), a sealant such as epoxy can be used to seal any holes where flow is not desired.

[0102] One or more embodiments of the invention relate to utilizing multiple EWC devices, such as EWC 10. In one or more embodiments, and referring to Figure 4, multiple EWC devices may be used by manifolding multiple EWCs, such as EWC 10, which generally acts to increase area and reduce face velocity.

[0103] In one or more embodiments, multiple EWC devices can be used by using consecutive EWCs, which generally serves to enable higher face velocities. In one or more embodiments, with reference to FIG. 5, multiple EWC devices can be used by using consecutive EWCs with a separator 200 between every two EWCs. In one or more embodiments, with reference to FIG. 6, multiple EWC devices can be used by using consecutive EWCs without a separator between every two EWCs.

[0104] One or more embodiments of the present invention relate to a mechanical model for the operation and / or design of EWCs. The model utilizes the term E as the capture efficiency of the electrowetting coalescing device, which represents the effectiveness of converting smaller droplets into larger droplets for collection. The model also utilizes the term R as the release coefficient, which represents the ability to release larger droplets from the electrowetting coalescing device. The model also utilizes S as the water saturation content, and a, Eo, b, and n as fitting parameters.

[0105] The model is based on the balance of water accumulated in the EWC. Saturation, S, is defined as the volume of water in the EWC divided by the volume of the EWC. The concentrations of fine (small) and coarse (larger) droplets entering the EWC are f0 and c0. The fine and coarse concentrations leaving the EWC are f and c. The total water concentration, C, in equation (1) (above) in a given flow is related to the fine and coarse concentrations by C=f+c.

[0106] The water mass balance on the EWC shows a time-dependent differential equation, Eq. 3,

number

number

[0107] Evaluation of the experimental data showed that the capture efficiency depends linearly on the water content (saturation, S) in the EWC, while the release coefficient R depends in a power law form, according to the following equations (6) and (7):

number

[0108] In some applications the inlet concentration of coarse droplets is zero, c0 = 0, but in general the inlet concentration of fines, f0, is non-zero. Model equations (3)-(7) may be modified or extended to include operation with a separation device to account for the effectiveness of the separator. The model may also be extended to account for the volume of source fluid and can be applied to single-pass or multi-pass operation, and to EWCs in series or parallel with or without a separator.

[0109] Initially, a, Eo, b, and n were expected to be functions of operation (e.g., flow rate, temperature, voltage, and fluid type) and EWC design (e.g., pore size and gap size). However, analysis has shown that Eo and n vary over a small range and can be considered constants for purposes of EWC operation and design. More specifically, Eo is 0.30 + / - 0.05 and n = 2.9 + / - 0.4. Nevertheless, Eo and n generally depend on the flow (i.e., face velocity) of any given EWC device. Use of this model additionally involves determining a and b by empirically matching different flow rates of a given organic process fluid with the mechanical model. Once a and b are found, equations (3)-(7) become a closed set of equations and can be used to aid in the design of an EWC device for a desired flow rate.

[0110] Embodiments: Without being limited thereto, embodiments of the present disclosure include the following.

[0111] Embodiment 1. An electrowetting coalescing device for coalescing droplets of a dispersed phase within a continuous phase of an organic process fluid, comprising an inlet, a porous first electrode having a first independent electrical connection thereto, the porous first electrode including a first plurality of pores having a first average pore size, a porous second electrode having a second independent electrical connection thereto, the porous second electrode including a second plurality of pores having a second average pore size, the second average pore size being different from the first average pore size, and a voltage applied and maintained on the porous first electrode, the porous second electrode being at a second voltage different from the voltage applied and maintained on the porous first electrode, the second voltage optionally being 0V ground, whereby the porous second electrode is electrically connected to the inlet. an inlet, a porous first electrode, an electric field, a porous second electrode, and an organic process fluid, the organic process fluid comprising a dispersed phase within a continuous phase, the continuous phase comprising an organic fluid containing a metal, the dispersed phase comprising aqueous droplets optionally comprising additional metal ions or acid salts, the dispersed phase being conductive or non-conductive, and the continuous phase having a low conductivity; an electrowetting coalescing device receiving the organic process fluid, the organic process fluid passing through the inlet, the porous first electrode, the electric field, the porous second electrode, and the outlet, whereby the electrowetting coalescing device causes smaller droplets of the dispersed phase to coalesce into larger droplets of the dispersed phase for subsequent removal of the larger droplets from the continuous phase.

[0112] Embodiment 2. The device of embodiment 1, wherein the first independent electrical connection provides an applied and maintained voltage of about 50V to about 500V to the porous first electrode, and the second independent electrical connection is a connection to ground such that the porous second electrode has 0V.

[0113] Embodiment 3. The device of embodiment 1, further comprising a porous third electrode, the porous third electrode being disposed as an intermediate electrode between the porous first electrode and the porous second electrode, the porous third electrode having a third independent electrical connection thereto, the porous third electrode being at a third voltage different from the voltage applied and maintained on the porous first electrode and different from the second voltage.

[0114] Embodiment 4. The device of embodiment 3, wherein the porous first electrode and the porous second electrode have 0V, and a third independent electrical connection provides an applied and maintained voltage of about 50V to about 500V to the porous third electrode.

[0115] Embodiment 5. A device as described in embodiment 3, wherein a first independent electrical connection provides an applied and maintained voltage of about 50V to about 500V to the porous first electrode, a second independent electrical connection provides an applied and maintained voltage of about 50V to about 500V to the porous second electrode, and the porous third electrode has 0V.

[0116] Embodiment 6. A device according to any one of the preceding embodiments, wherein the porous first electrode, the porous second electrode, and the porous third electrode are wire meshes.

[0117] Embodiment 7. A device described in any one of embodiments 1 to 5, wherein the porous first electrode, the porous second electrode, and the porous third electrode are perforated plates.

[0118] Embodiment 8. A device according to any one of the preceding embodiments, wherein the first average pore size is defined by a first plurality of pores having a substantially constant pore size.

[0119] Embodiment 9. A device according to any one of the preceding embodiments, wherein the second average pore size is defined by a second plurality of pores having a substantially constant pore size.

[0120] Embodiment 10. A device described in any one of embodiments 1 to 7, wherein the first average pore size is defined by a first plurality of pores having different pore sizes.

[0121] Embodiment 11. A device described in any one of embodiments 1 to 7, wherein the second average pore size is defined by a second plurality of pores having different pore sizes.

[0122] Embodiment 12. A device as described in any one of the preceding embodiments, wherein the first independent electrical connection comprises a first wire electrically connected to a porous first electrode, and the second independent electrical connection comprises a second wire electrically connected to a porous second electrode.

[0123] Embodiment 13. A device as described in embodiment 12, wherein the first wire and the second wire are made of steel.

[0124] Embodiment 14. A device according to any one of the preceding embodiments, wherein the electrical connections are selected from soldering, welding, and brazing.

[0125] Embodiment 15. A device according to any one of the preceding embodiments, wherein the porous first electrode and the porous second electrode are each coated with a coating.

[0126] Embodiment 16 A device according to any one of the preceding embodiments, wherein the porous third electrode is coated with a coating.

[0127] Embodiment 17. A device according to any one of the preceding embodiments, wherein all internal components of the device, including the first independent electrical connection and the second independent electrical connection, are coated with the coating.

[0128] Embodiment 18. A device according to any one of embodiments 15 to 17, wherein the coating comprises a dielectric coating layer and a hydrophobic coating layer on the dielectric coating layer.

[0129] Embodiment 19. The device of embodiment 18, wherein the dielectric coating layer comprises poly(styrene-co-methyl methacrylate).

[0130] Embodiment 20. The device of embodiment 18, wherein the hydrophobic coating layer comprises a fluoropolymer-based film.

[0131] Embodiment 21. The device of embodiment 20, wherein the fluoropolymer-based film is derived from a solution of a fluoropolymer in a fluorosolvent.

[0132] Embodiment 22. A device described in any one of the preceding embodiments, wherein one or more of the porous first electrode, the porous second electrode, and the porous third electrode have a pore size in the range of about 0.1 millimeters to about 3 millimeters.

[0133] Embodiment 23. A device described in any one of the preceding embodiments, wherein the gap distance between each of the porous first electrode, the porous second electrode, and the porous third electrode is in the range of about 0.25 mm to about 5 mm.

[0134] Embodiment 24. A device described in any one of the preceding embodiments, wherein the gap distance between each of the porous first electrode, the porous second electrode, and the porous third electrode is in the range of about 0.5 mm to about 1 mm.

[0135] Embodiment 25. A device according to any one of the preceding embodiments, wherein one or more of the porous first electrode, the porous second electrode, and the porous third electrode are made of stainless steel.

[0136] Embodiment 26. A device described in any one of the preceding embodiments, wherein the first independent electrical connection includes a first insulating joint and the second independent electrical connection includes a second insulating joint to prevent loss or release of organic process fluid.

[0137] Embodiment 27. A device as described in embodiment 26, wherein the first insulating joint and the second insulating joint are compression joints, the compression joints comprising respective polytetrafluoroethylene sleeves having respective ones of the first wire and the second wire passing therethrough.

[0138] Embodiment 28. The device of any one of the preceding embodiments, wherein the organic process fluid is selected from one or more of industrial organic chemicals, industrial organic chemical processing fluids, mining and extraction processing fluids, petroleum refining fluids, hydrometallurgy and solvent extraction processing fluids, battery material processing fluids, and battery recycling processing fluids.

[0139] Embodiment 29. A device according to any one of the preceding embodiments, wherein the organic process fluid is a metal-containing organic fluid.

[0140] Embodiment 30. A device according to any one of the preceding embodiments, wherein the dispersed phase is highly conductive.

[0141] Embodiment 31. A device according to any one of the preceding embodiments, wherein the continuous phase is a relatively non-polar liquid relative to the polarity of the dispersed phase.

[0142] Embodiment 32. The device of embodiment 31, wherein the relatively non-polar liquid comprises one or more of metal ions and metal ion complexes.

[0143] Embodiment 33. A device as described in embodiment 31 or 32, wherein the relatively non-polar liquid comprises one or more of a carboxylic acid, an amine, an aldehyde, a ketone, and an alcohol.

[0144] Embodiment 34. A device according to any one of the preceding embodiments, wherein the dispersed phase is a liquid that is relatively polar relative to the polarity of the continuous phase, the relatively polar liquid comprising one or more of water, an alcohol, an acid salt, and a metal salt.

[0145] Embodiment 35. A device according to any one of the preceding embodiments, wherein the dispersed phase has a conductivity of from about 1 μS / cm to about 150,000 μS / cm and the continuous phase has a conductivity of less than 100 μS / cm.

[0146] Embodiment 36. An assembly comprising a plurality of devices described in any one of the preceding embodiments, wherein the plurality of devices are in a manifold configuration.

[0147] Embodiment 37. An assembly comprising a plurality of devices according to any one of embodiments 1 to 35, wherein the plurality of devices are in a continuous configuration, with or without a separator between every two devices of the plurality of devices.

[0148] Embodiment 38. An assembly according to embodiment 37, wherein a separator is present between each of two devices of the plurality of devices.

[0149] Embodiment 39. A method for coalescing droplets of a dispersed phase within a continuous phase of an organic process fluid in an electrowetting coalescing device, the method comprising the steps of: providing an electrowetting coalescing device; providing an organic process fluid, the organic process fluid comprising a dispersed phase within a continuous phase, the continuous phase comprising an organic fluid containing a metal, the dispersed phase comprising aqueous droplets optionally comprising additional metal ions or acid salts, the dispersed phase being conductive or non-conductive and the continuous phase having a low conductivity; allowing the organic process fluid to flow through the electrowetting coalescing device; electrowetting the droplets of the dispersed phase to form larger droplets; and removing the larger droplets from the continuous phase.

[0150] Embodiment 40. The method of embodiment 39, wherein the electrowetting combined device is part of an assembly.

[0151] Embodiment 41. The method of embodiment 39 or 40, wherein the organic process fluid is selected from one or more of industrial organic chemicals, industrial organic chemical processing fluids, mining and extraction processing fluids, petroleum refining fluids, hydrometallurgy and solvent extraction processing fluids, battery materials processing fluids, and battery recycling processing fluids.

[0152] Embodiment 42. The method of any one of embodiments 39-41, wherein the organic process fluid is a metal-containing organic fluid.

[0153] Embodiment 43. The method of any one of embodiments 39 to 42, wherein the dispersed phase is highly conductive.

[0154] Embodiment 44. The method of any one of embodiments 39-43, wherein the continuous phase is a relatively non-polar liquid relative to the polarity of the dispersed phase.

[0155] Embodiment 45. The method of embodiment 44, wherein the relatively non-polar liquid comprises one or more of metal ions and metal ion complexes.

[0156] Embodiment 46. The method of embodiment 44 or 45, wherein the relatively non-polar liquid comprises one or more of a carboxylic acid, an amine, an aldehyde, a ketone, and an alcohol.

[0157] Embodiment 47. The method of any one of embodiments 39-46, wherein the dispersed phase is a relatively polar liquid relative to the polarity of the continuous phase, and the relatively polar liquid comprises one or more of water, an alcohol, an acid salt, and a metal salt.

[0158] Embodiment 48. A method, assembly, or device according to any one of the preceding embodiments, wherein a mechanical model is utilized for its design or operation, the mechanical model comprising:

number

[0159] Embodiment 49.E o 49. The method of embodiment 48, wherein the .DELTA..times ...

[0160] Embodiment 50. The method of embodiment 48 or 49, further comprising determining a and b based on empirically fitting different flow rates of the organic process fluid to a mechanistic model.

[0161] Embodiment 51. A method of designing an electrowetting coalescing device, comprising the steps of providing an organic process fluid, the organic process fluid comprising a dispersed phase within a continuous phase, the continuous phase comprising a metal-containing organic fluid, the dispersed phase comprising aqueous droplets optionally comprising additional metal ions or acid salts, and providing a mechanistic model, the mechanistic model comprising:

number

[0162] Embodiment 52.E o 52. The method of embodiment 51, wherein the α-kappa-ratio is 0.30+ / -0.05, n=2.9+ / -0.4.

[0163] Embodiment 53. The method of embodiment 51 or 52, further comprising determining a and b based on empirically fitting different flow rates of the organic process fluid to a mechanistic model.

[0164] Embodiment 54. A device as described in embodiment 4, wherein a third independent electrical connection provides an applied and maintained voltage of about 100V to about 300V to the porous third electrode.

[0165] Embodiment 55. A device as described in embodiment 5, wherein a first independent electrical connection provides an applied and maintained voltage of about 100V to about 300V to the porous first electrode, and a second independent electrical connection provides an applied and maintained voltage of about 100V to about 300V to the porous second electrode.

[0166] Embodiment 56. The method, assembly, or device of any one of the preceding embodiments, wherein the dispersed phase has a conductivity of about 50,000 μS / cm to about 100,000 μS / cm and the continuous phase has a conductivity of less than 10 μS / cm.

[0167] In light of the above, it should be appreciated that the present invention advances the art by providing an improved electrowetting coalescing device and corresponding method. Although specific embodiments of the present invention are disclosed in detail herein, it should be appreciated that the invention is not limited thereto or thereby, as variations thereon will be readily apparent to those skilled in the art. The scope of the present invention should be understood from the claims that follow. EXAMPLES

[0168] Following these details, an example was carried out according to an embodiment of the electrowetting coalescing device disclosed herein. An emulsion was prepared, including a dispersed phase and a continuous phase. Equal volumes (400 mL) of an aqueous solution (i.e., dispersed phase) and an organic solution (i.e., continuous phase) were mixed for 6 minutes using a mixer set at a speed of 1750 RPM. The mixture was allowed to stand for 5 minutes to separate the two phases. The aqueous phase was at the bottom and the organic was at the top. The aqueous phase that accumulated at the bottom was decanted, leaving behind the aqueous-organic emulsion. The volume decanted was about 0.5 L. These steps were repeated until the desired volume of the emulsion was reached. These steps were carried out again to obtain various fluid samples.

[0169] For the bulk of the fluids provided to the EWC, the concentration of dispersed aqueous phase in the continuous organic phase was approximately 3,500 + / - 20 ppm.

[0170] The EWC contained two porous layers made of mesh. The inlet and outlet pore size was 1 mm. Polymer coatings of PMMA and FluoroPel (hydrophobic coating) were utilized. The voltage (V), flow rate (mL / min), temperature (°C), and gap distance (mm) were adjusted as shown in Table 1. The final concentration and separation efficiency are reported. Experiments performed at 50 mL / min took 30 min to complete and those performed at 30 mL / min took 50 min to complete.

[0171] The final separation efficiency in Table 1 is a measure of the effectiveness of the EWC in coalescing fine droplets into coarse droplets that separate by settling. Efficiency is calculated using equation (8).

number

[0172] Based on the above, several experiments ("Experiment No.") were performed on the electrowetting coalescing device (EWC) to investigate the effect of certain parameters, such as voltage, flow rate, gap distance, and temperature. The organic process fluids used included organic acids and petroleum distillates. Table 1 summarizes Experiments 1-30 and provides the final concentrations (ppm) and separation efficiencies (%). Table 2 summarizes three experiments performed at midpoint values ​​of certain parameters. Table 3 summarizes the experimental conditions leading to maximum and minimum separation efficiencies. [Table 1] [Table 2] [Table 3]

[0173] Table 3 lists the EWC operating conditions for which the resulting maximum final separation efficiency of 86% was achieved, corresponding to a final aqueous phase concentration of 490 ppm exiting the EWC. The resulting minimum separation efficiency was 40%, corresponding to a final aqueous phase concentration of 2100 ppm.

[0174] The test fluid was passed through the EWC three times to mimic three EWC devices in series, as provided in Table 4 below. After each pass, the aqueous fluid was separated and the test fluid was re-run through the EWC. The EWC was configured as follows: voltage: 150V, gap distance: 1 mm, flow rate: 40 mL / min, and temperature: 37° C. The test fluid was similar to the fluids described above. [Table 4]

[0175] Table 5 provides additional testing performed at the EWC on different fluids. The test details are similar to those above, except that the initial concentration of the entire fluid provided to the EWC was 1200 + / - 10 ppm relative to the concentration of the dispersed aqueous phase in the continuous organic phase. [Table 5]

[0176] Additional samples were run with various sizes for the exit and entrance holes: the entrance mesh varied from 0.7 to 2 mm, and the exit mesh varied from 0.5 to 1.5 mm. [Table 6]

[0177] Additional samples were performed on an EWC with three electrodes and compared to an EWC with two electrodes: the middle electrode was supplied with a positive charge and the top and bottom were grounded, so that an electric field existed between the top and middle electrodes, and between the middle and bottom electrodes. [Table 7]

[0178] Additional samples were run on a pre-wetted EWC. Pre-wetting was achieved by adding water upstream of the EWC. After preparing and mixing the emulsion, the emulsion was pumped into the EWC. After 5 minutes, the agitator was turned off and 15 mL of the aqueous solution was injected into the mixing tank. The aqueous solution, being denser than the organic liquid, was allowed to settle to the bottom of the tank and was pumped into the EWC. The conditions are shown below. Pre-wetting caused the EWC to reach a steady state sooner. For the pre-wet EWC, the concentration of the aqueous phase leaving the EWC approached a constant after about 30 minutes. For a similar EWC without pre-wetting, the aqueous phase concentration was still decreasing at 50 minutes. The experiment was stopped at 50 minutes, but more time would have been needed for saturation to approach its plateau. The pre-wet EWC also operated more efficiently because less water left the EWC compared to the non-pre-wet case. [Table 8]

[0179] Additional samples were run on the EWC with a perforated plate as the porous layer, the conditions and results being given below. [Table 9]

[0180] For these particular sample data points disclosed herein, as well as other tested data, a statistical model may be created by regression analysis, using the results from the experiments to better understand the relationship that each parameter (e.g., flow rate, voltage, gap distance, pore size, temperature, etc.) has in EWC operation. The statistical model can be used to minimize aqueous phase concentration in organics or maximize separation efficiency.

[0181] With respect to the mechanical model disclosed herein (i.e., with respect to equations (3)-(7) above), certain experimental information is disclosed herein. An EWC was provided with no initial liquid holdup (i.e., saturation) in the mesh porous layer. An emulsion was passed through the EWC. As the emulsion flowed through the EWC, the saturation increased, and the concentration of enlarged droplets in the outlet flow increased with increasing saturation, eventually approaching steady-state performance. A mechanical model was developed to evaluate how EWC performance varies with liquid saturation in the mesh by holding the geometric and operating parameters constant. Evaluation of the experimental data showed that the equations disclosed herein can be used to fit capture efficiency and release coefficients to a function of saturation alone. The model equations fit the experimental data well, thereby indicating that the model accurately predicts the performance of the EWC. As further disclosed above, parameters Eo and n are generally constant over varying operating conditions, whereas parameters b and a vary exponentially with flow rate and remain approximately constant over the remaining operating conditions. Three liquids were tested and the results found for Eo and n are provided below. [Table 10]

[0182] Various modifications and alterations that do not depart from the scope and spirit of this invention will become apparent to those skilled in the art, and this invention should not be unduly limited to the illustrative embodiments set forth herein.

Claims

1. 1. An electrowetting coalescing device for coalescing droplets of a dispersed phase within a continuous phase of an organic process fluid, said electrowetting coalescing device comprising: The entrance and a porous first electrode having a first independent electrical connection thereto and including a first plurality of pores having a first average pore size; a porous second electrode having a second independent electrical connection thereto and including a second plurality of pores having a second average pore size, said second average pore size being different from said first average pore size; a voltage applied and maintained on the porous first electrode, the voltage on the porous second electrode being a second voltage different from the voltage applied and maintained on the porous first electrode, thereby creating an electric field between the porous first electrode and the porous second electrode; The exit and the organic process fluid comprising the dispersed phase within the continuous phase, the continuous phase comprising a metal-containing organic fluid, the dispersed phase comprising aqueous droplets, the dispersed phase being conductive or non-conductive, and the continuous phase having a low conductivity; The electrowetting coalescing device receives the organic process fluid, which passes through the inlet, the porous first electrode, the electric field, the porous second electrode, and the outlet, thereby enabling the electrowetting coalescing device to coalesce smaller droplets of the dispersed phase into larger droplets of the dispersed phase and subsequently remove the larger droplets from the continuous phase.

2. 10. The device of claim 1, wherein the first independent electrical connection applies and maintains a voltage of 50V to 500V to the porous first electrode, and the second independent electrical connection is a connection to ground such that the voltage at the porous second electrode is 0V.

3. 10. The device of claim 1, further comprising a porous third electrode, the porous third electrode disposed as an intermediate electrode between the porous first electrode and the porous second electrode, the porous third electrode having a third independent electrical connection thereto, a voltage of the porous third electrode being a third voltage different from the voltage applied and maintained on the porous first electrode and different from the second voltage, one or more of the porous first electrode, the porous second electrode, and the porous third electrode having a pore size in the range of 0.1 millimeters to 3 millimeters, and an inter-electrode gap distance of each of the porous first electrode, the porous second electrode, and the porous third electrode in the range of 0.25 mm to 5 mm.

4. 4. The device of claim 3, wherein the voltage across the porous first electrode and the porous second electrode is 0V, and the third independent electrical connection applies and maintains a voltage of 50V to 500V to the porous third electrode.

5. 4. The device of claim 3, wherein the first independent electrical connection applies and maintains a voltage of 50V to 500V to the porous first electrode, the second independent electrical connection applies and maintains a voltage of 50V to 500V to the porous second electrode, and the voltage of the porous third electrode is 0V.

6. 6. The device according to claim 1, wherein the porous first electrode, the porous second electrode and the porous third electrode are wire meshes and / or perforated plates, and the aqueous droplets of the dispersion layer contain further metal ions or acid salts.

7. 6. The device of claim 1, wherein the first average pore size is defined by a first plurality of pores having a constant pore size, and / or the second average pore size is defined by a second plurality of pores having a constant pore size.

8. 6. The device of claim 1, wherein the first average pore size is defined by a first plurality of pores having different pore sizes and / or the second average pore size is defined by a second plurality of pores having different pore sizes.

9. 6. The device of claim 1, wherein the porous first electrode and the porous second electrode are each coated with a coating, the coating comprising a dielectric coating layer and a hydrophobic coating layer on the dielectric coating layer.

10. 6. The device of any one of claims 1 to 5, wherein the organic process fluid is selected from one or more of industrial organic chemicals, industrial organic chemical processing fluids, mining and extraction processing fluids, petroleum refining fluids, hydrometallurgy and solvent extraction processing fluids, battery material processing fluids, and battery recycling processing fluids.

11. The device of any one of claims 1 to 5, wherein the organic process fluid is a metal-containing organic fluid.

12. 6. The device of claim 1, wherein the continuous phase is a liquid that is relatively non-polar with respect to the polarity of the dispersed phase, the relatively non-polar liquid comprising one or more of a metal ion and a metal ion complex, and the relatively non-polar liquid comprising one or more of a carboxylic acid, an amine, an aldehyde, a ketone, and an alcohol.

13. 6. The device of claim 1, wherein the dispersed phase is a liquid that is relatively polar to the polarity of the continuous phase, the relatively polar liquid comprising one or more of water, an alcohol, an acid salt, and a metal salt.

14. 6. The device of any one of claims 1 to 5, wherein the dispersed phase has a conductivity of from 1 μS / cm to 150,000 μS / cm and the continuous phase has a conductivity of less than 100 μS / cm.

15. 1. A method for coalescing droplets of a dispersed phase within a continuous phase of an organic process fluid in an electrowetting coalescing device, the method comprising: providing the electrowetting coalescing device; providing the organic process fluid, the organic process fluid comprising the dispersed phase within the continuous phase, the continuous phase comprising a metal-containing organic fluid, the dispersed phase comprising aqueous droplets containing additional metal ions or acid salts, the dispersed phase being conductive or non-conductive, and the continuous phase having a low conductivity; allowing the organic process fluid to flow through the electrowetting coalescing device; electrowetting the droplets of the dispersed phase to allow them to form larger droplets; and removing the larger droplets from the continuous phase.

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