Patent Application
20250034737
The present disclosure relates to structures, methods, and processes for the selective removal of a target component from a composition, and particularly to structures, methods, and processes for the selective removal of a target component from a composition.
Natural and human activities release components into the environment that are initially present and often relatively inert in reservoirs such as rock or minerals. Many of these components, such as metals and metalloids, are persistent, have little biological utility, and are often toxins to living organisms. They can be prone to accumulation in the environment and/or organisms. Global industrialization, increased water use, and population growth exasperate the challenge and generally raise the incidence and severity of the pervasiveness and interaction with such contaminants through avenues such as metals impacted waters (MIW).
MIW often suffer the presence of persistent toxins in the form of dissolved metals which may exhibit direct toxicity, be subject to inclusion into or creation of hazardous compounds, and/or may bioaccumulate. MIW can thereby degrade water sources and the environment and presents a pervasive and growing problem to society. The large and growing use of mineral resources by society has led to the greater unlocking, generation, distribution, and release of MIW toxins with expectations that the challenge will continue to grow as cleaner mineral sources are depleted and newer sources for materials of interest drive utilization of more complex, contaminated, and difficult to process options than targeted in the past. The growing contamination hurdle is creating mounting barriers to sustainable and safe drinking water, agriculture, mining, and manufacturing in addition to other important societal and economic sectors. In addition to heavy metals, hazardous metalloids such as those used in semiconductor production (As, Se, and Te for example) are particular problems in MIW.
MIW contamination is often addressed via sequestration to remove the target from the environment and relock it into a more inert and less mobile form. A number of treatment routes are commonly employed for this and include: (1) precipitation using various precipitating agents applied in a variety of ways, (2) electro-coagulation, and (3) electrowinning. Other methods may also be employed.
Precipitation and electro-coagulation can work well but often generate large volumes of hazardous sludge consisting of substantial low or non-hazardous components contaminated with higher hazard and/or toxic components removed from the target water. This creates considerable disposal challenges and costs. In contrast, electrowinning treatment can generate modest volumes of compact, often fairly stable and/or useful treatment byproducts in leu of massive amounts of hazardous sludge requiring disposal. However, traditional electrowinning struggles to achieve practical selectivity and treatment rates outside constrained treatment windows.
Electrowinning is usually taken as the direct redox treatment of the target species by interaction with an energized electrode. The process is often cathodic for many MIW contaminants, taking place at the cathode but may also be anodic (taking place and the anode and involving oxidation) when the chemistry is suitable. The electrolysis process may be operating in controlled potential (CP) or controlled current (CC) mode depending on the desired process details and specific chemistry.
Accordingly, it would be desirable to provide a method for extraction of at least one target component that alleviated or addressed one or more of the above-discussed concerns associated with conventional methods, or alleviated or addressed one or more other concerns or disadvantages, or provided one or more advantages by comparison with prior methods.
Embodiments of the method and related methods of operation are disclosed with reference to the accompanying drawings and are for illustrative purposes only. The methods encompassed herein are not limited in their applications to the details of construction, arrangements of components, or other aspects or features illustrated in the drawings, but rather such apparatuses and methods encompassed herein include other embodiments or are capable of being practiced or carried out in other various ways. Like reference numerals are used to indicate like components. In the drawings:
In embodiments of the present disclosure, a method for the extraction of at least one target component from a first composition comprising the at least one target component.
In embodiments, the method comprises providing at least one electrochemical cell.
It may be generally recognized that the operation of electrochemical cells is based on redox reactions and can employ cells which can occur in many forms. In general, the class of split compartment cells (SCC) (in their multitude of forms) can provide examples of suitable apparatus to accomplish the method disclosed herein. One such relevant example typical of the class of Moving Bed Electrode (MBE) cells may be represented by the specific example from the subset of Spouted Bed Electrode (SBE) cells as disclosed in U.S. Pat. No. 7,967,967, herein incorporated by reference. A SBE cell is a single, non-exhaustive example of a device suitable for use with the present method used for illustrative purposes only and may, with reference to
With further reference to
Various physical forms and materials may be employed for the electrodes and feeder/collectors. In some embodiments, the electrodes may act as both anode and cathode. Applied current source H may apply current that is current controlled with current flow that is unidirectional or bidirectional driven with various potential or current amplitudes, polarities, waveform shapes, and repeat unit frequencies imposed by the external source. Internal factors may impose additional variations onto the current flow as a result of physical aspects of the cell configuration(s), operating conditions, and detailed chemistries of the treated solutions. Electrolyte source flows containing catholyte 24 and/or anolyte 14 may be pumped or gravity driven, continuous or intermittent, steady or variable, fully co-current to fully countercurrent between adjacent electrolysis cell chambers and combinations thereof. Each cell chamber may employ a range of fluid or mixture fluxes, particulate sizes, particulate compositions, each of which may utilize a single parameter value or multiple parameter values simultaneously and/or sequentially to exert the desired target reaction control. Some embodiments employ a preferred set of individual operation characteristics or a mixture or combination of multiple values of selected parameters.
Cells can use static or dynamic electrodes. When using static electrodes, the cathodes may need to be pulled from the cell and stripped of product deposits, which could require at least a partial cell shutdown. In other embodiments, static electrodes may also be configured for on-the-fly harvesting. Dynamic electrodes offer the potential for continuous product harvest. The DeMet product offered by Blue Planet Strategies allows for transporting the “ripe” particulate electrode outside the cell for continuous on-the-fly harvesting without interrupting cell operation. Other technologies, such as rotating drum cathode cells, allow continuous on-the-fly knife peeling of the plated product to create long roll foils, etc.
In accordance with embodiments of the present disclosure, the method comprises introducing to or creating within the catholyte chamber of the at least one electrochemical cell a starter electrolyte composition comprising at least one target component and one or more additives capable of facilitating the targeted electrochemical manipulation of the at least one target component.
In some embodiments, the starter electrolyte composition comprises, or in some embodiments, consists of, a raw, or unaltered, feed at the electrochemical cell entry point. Such raw or unaltered compositions include, but are not limited to, metals impacted water (MIW) or wastewater containing at least one target component and the suitable one or more additives incorporated into the stream at an upstream point.
In other embodiments, the starter electrolyte composition comprises a combination of (a) a first composition comprising the at least one target component and absent the one or more additives and (b) a second composition comprising the one or more additives and absent the at least one target component. In such embodiments, the two streams are mixed prior to entry into the electrochemical cell, or at the point of entry, or within the electrochemical cell (e.g., in the catholyte chamber), or at an appropriate point along a catholyte recirculation path. In still further embodiments, the starter electrolyte composition comprises two or more of a raw wastewater composition and feed streams of first or second compositions, as described above.
In an embodiment, the target component is a metal. As used herein, the term “metal” refers to both metals and metalloids as identified on the Periodic Table of Elements. Exemplary metals include, but are not limited to, Fe, Co, Ni, Cu, Zn, Mo, Pd, Ag, Cd, Re, Ir, Pt, Au, Hg, Pb, Bi, Sn, Sb, In, As, Se, and Te. In an embodiment, the target component includes, but is not limited to, at least one of the hazardous metalloids As, Se, and Te.
In an embodiment, the target component is selected from the group consisting of Fe, Co, Ni, Cu, Zn, Mo, Pd, Ag, Cd, Re, Ir, Pt, Au, Hg, Pb, Bi, Sn, Sb, In, As, Se, Te, and combinations thereof. In further embodiments, the target component is selected from the group consisting of As, Se, Te, and combinations thereof.
In an embodiment, the at least one additive is selectively chosen to produce a desired effect within the at least one electrochemical cell.
In an embodiment, the at least one additive has a reactivity greater than that of the at least one target component towards at least one reaction competing with the targeted removal reaction of the at least one target component.
In an embodiment, the at least one additive lowers the reactivity of the at least one target component towards at least one reaction competing with the targeted removal reaction of the at least one target component.
Exemplary additives include, but are not limited to, inorganic weak acids such as acetic acid, arsenic acid, ascorbic acid, citric acid, chloroacetic acid, chlorous acid, formic acid, hydrogen peroxide, oxalic acid, phosphoric acid, sulfurous acid, and sulfuric acid; weak bases, including but not limited to, ammonia, aniline, ethanolamine, ethylenediamine, hydroxylamine, pyridine, and urea; organic acids, including but not limited to 2-propylpentanoic acid, butanoic acid, propanoic acid, pentanoic acid, ethanedioic acid, propanedioic acid, butanedioic acid, and pentanedioic acid; transition metals, including but not limited to Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, La, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, Pb, Bi, Sn, and Sb, as well as compounds containing such transition metals; bioorganic acids, including but not limited to alanine, arginine, cysteine, glutamic glutamine, glycine, leucine, lysine, serine, tryptophan, and tyrosine; and combinations thereof.
In accordance with embodiments of the present disclosure, the method comprising controlling operation of the at least one electrochemical cell to achieve the targeted electrochemical manipulation of the at least one target component to form a manipulated composition having a modified concentration of the at least one target component.
The cell operation may be by either flow-through or batch mode operation.
In an embodiment, an example of controlling operation of the at least one electrochemical cell includes electrolysis in a current controlled mode at current densities of greater than or equal to 20 Amp/m2 applied geometric (2D) cell operational current density where current is applied in a unidirectional or bi-directional manner. In an embodiment, the current may be applied as a constant and unidirectional current or as a frequency modulated unidirectional or bi-directional current with modulations applied in the range of 0.001 Hz to 1000 Hz with voltage amplitude between-0.5 V(NHE) and +9.0 V from 0.00 [V(NHE)].
In an embodiment, an example of controlling operation of the at least one electrochemical cell includes maintaining a bulk solution pH of less than or equal to 5.
In an embodiment, an example of controlling operation of the at least one electrochemical cell includes maintaining a bulk solution temperature of less than or equal to 90° C.
In an embodiment, the method comprises the step of extracting at least a portion of the at least one target component from the starter electrolyte composition as a metal (that is, metal or metalloid, as “metal” is defined above) or a metal oxide (that is, metal oxide or metalloid oxide, as “metal” is defined above) reduction product comprised of substantially the at least one target component as a deposit or dispersed morphology solid.
Results illustrating central aspects of the method in accordance with embodiments provided herein are shown with respect to the use of common MIW constituents using simplified, non-exclusive representative scenarios for the salient acid solution electrowinning reactions of model selected target components with hydrogen evolution or arsenic acid reduction providing competing reaction examples.
A batch mode treatment employing direct current and effected near room temperature is considered for exemplary non comprehensive embodiments shown in
In this example, incorporation of an additive comprises of a hydroxide source and a selected buffering cocktail is considered to control the zinc dissolution reaction through the electrolyte proton concentration. The competing reaction (i.e., hydrogen evolution via zinc metal oxidation and dissolution with resultant proton reduction) exhibits higher reactivity and consumes the plated metal (effectively cathodic current) to the exclusion of net accumulated target metal electrowinning. At additive cocktail sufficient to reduce the available proton presence (as observed via the rise in the starter electrolyte pH) to a particular site-specific value, the target component, i.e., Zn, net electrowinning starts and proceeds at a now enhanced rate.
In this example, incorporation of an additive comprises of a reducing agent cocktail is considered to control the arsenic reduction reaction through control of the As(V) availability. Initially the additive has little effect on the target metal electrowinning. The competing reaction, i.e., arsenic acid reduction to arsenous acid, exhibits higher reactivity and consumes cathodic current to the exclusion of the target metal, i.e., Te, electrowinning. At additive cocktail sufficient to deplete the initial As(V) presence to a particular site-specific value (the total arsenic remains steady as just the soluble form is altered), the target component, i.e., Te, electrowinning starts and proceeds at a now enhanced net rate.
In this example the target component is Cu. Electrowinning of the target component with and without the additive in similar scenarios is considered and compared in terms of the onset of the competing reaction of hydrogen at an appreciable (visible) rate. The incorporated additive is comprised of bismuth which acts as an electron sink and suppresses the competing hydrogen evolution reaction. The sample without additive exhibits hydrogen evolution much earlier (at a higher target metal tenor) than the sample with additive. In this scenario, the additive is consumed and its tenor falls; however, hydrogen evolution remained suppressed throughout the full electrowinning window spanned.
In this example, the target component is As in a mixed-metal stream containing background metal interferents acting here as catholyte. The incorporated additive is a cocktail which controls the arsenic species distribution of forms which are amenable to transport through the cell separator membrane and suppresses potential target metal deposit formation. In this example, copper is shown as an example of an interferent. The presence of copper is challenging to plating separation. The additive cocktail enhances the reactivity of the arsenic relative to the additive present in excess. As a result, membrane transport of arsenic is improved and the separation of the target component (i.e., arsenic) via electrolytic manipulation may be increased. That is, the target metal more readily moves into the anolyte stream relative to the confounding constituent (i.e., copper) effecting separation and concentration of the target relative to the confounding constituent.
Looking at
In this example, the target component is rhenium in a mixed metal raffinate stream containing much more concentrated background metal interferents acting here as catholyte. The incorporated additive is an additive cocktail is designed to control the rhenium ion species distribution towards favoring preferred ion forms which are amenable to transport through the cell separator membrane and suppresses potential target metal deposit formation. In this example, copper is a major cocktail additive which is present at a large and challenging excess to the separation. The additive cocktail enhances the reactivity of the rhenium relative to the additive present in excess. As a result, membrane transport of rhenium is improved and the separation of the target component (i.e., rhenium) via electrolytic manipulation may be increased. That is, the target metal more readily moves into the anolyte stream relative to the confounding constituent (i.e., copper) effecting separation and concentration of the target relative to the confounding constituent.
While both the target component and interferent are removed from the catholyte solution, a substantial amount of the target component is transferred to the anolyte while only minimal interferent is transferred. Separating and concentrating of the target component is three orders of magnitude greater compared to the starting interferent ratio. As a result, the relative concentration of the target component in the separate anolyte stream allows it to be cathodically plated in a subsequent cell when the enriched anolyte is employed as a catholyte (or removed by other means).
Additional discussion of embodiments in various scopes now follows:
From the foregoing, it will be appreciated that although specific examples have been described herein for purposes of illustration, various modifications may be made without deviating from the spirit or scope of this disclosure. It is therefore intended that the foregoing detailed description be regarded as illustrative rather than limiting, and that it be understood that it is the following claims, including all equivalents, which are intended to particularly point out and distinctly claim the claimed subject matter.
It is specifically intended that the present invention not be limited to the embodiments and illustrations contained herein, but include modified forms of those embodiments including portions of the embodiments and combinations of elements of different embodiments as come within the scope of the following claims.
This application claims the benefit of U.S. Provisional Application No. 63/528,814, filed Jul. 25, 2023, and titled: STRUCTURES, METHODS, AND PROCESSES FOR THE SELECTIVE REMOVAL OF TARGET COMPONENT FROM A COMPOSITION.
| Number | Date | Country | |
|---|---|---|---|
| 63528814 | Jul 2023 | US |
