Composition of ultra-pure zinc bromide and zinc chloride blend produced from method of reacting chlorine with mixture of zinc bromide and zinc
Patent Information
- Application Number
- JP2024143997
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2023-08-30
- Filing Date
- 2024-08-26
- Publication Date
- 2025-03-14
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Figure 2025036243000011 
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Abstract
Description
[Technical field]
[0001] The present disclosure generally relates to compositions of zinc bromide and zinc chloride blends produced by reacting chlorine with a mixture of zinc bromide and zinc, the blends having reduced metal impurities for use in battery electrolyte blends. [Background technology]
[0002] 1. The need to build a better zinc bromide flow battery Energy storage devices (batteries) with high energy density, long cycle life, and low cost are a perennial goal to meet the ever-increasing demand from portable electronic devices, electric vehicles, and renewable energy sources (see Armand M., Tarascon JM Building better batteries. Nature. 2008;451:652-657). Electrolytes added to these energy storage devices act as catalysts to make the battery conductive by facilitating the movement of ions from the cathode to the anode during charging and vice versa during discharging. Ions are charged atoms that have lost or gained electrons. Battery electrolytes consist of soluble salts, acids, or other bases in liquid, gelled, and dry formats. Electrolytes are also used in the form of polymers as used in solid-state batteries, solid ceramics as in sodium-sulfur batteries, and molten salts.
[0003] Among several types of batteries, zinc bromide batteries can be divided into two groups: flow batteries and non-flow batteries. A typical ZnBr2 flow battery consists of two reservoirs for the storage of ZnBr2 electrolyte, which are connected to a reactor by pumps or pipes (see Ke XY, Prahl JM, Alexander JID, Wainright JS, Zawodzinski TA, Savinell RF Rechargeable redox flow batteries: flow fields, stacks, and design considerations. Chem. Soc. Rev. 2018; 47: 8721-8743). The basic redox reaction in these batteries is summarized by the following equation: Positive electrode: [ka] Negative electrode: [ka] Overall reaction: [ka]
[0004] This process of preparing metal bromides from free metal and bromine has been reported in the patent literature. For example, U.S. Patent No. 4,138,354 to Sochol et al. discloses a process for preparing manganese and cobalt bromides from manganese, cobalt bromide, and bromine. The process relies on an oxidation-reduction reaction between manganese and cobalt ions and the subsequent reaction of the resulting cobalt with aqueous bromine. U.S. Patent No. 4,248,850 to Keblys teaches the preparation of metal bromides from basic metal compounds and bromine in the presence of formaldehyde as a reducing agent. U.S. Patent No. 4,514,374 to Kirsch teaches the use of lower alkanols as reducing agents. U.S. Patent No. 1,483,852 to Rosenstein discloses the production of zinc chloride by reacting a lead-zinc alloy with chlorine gas in water. Lead metal is alloyed with zinc metal, and the lead serves as a catalyst for the reaction of chlorine with zinc. The chlorine reacts with the zinc-lead alloy to produce zinc chloride. Heat from the reaction causes the water to evaporate as steam. The concentration of zinc chloride is controlled by the rate at which the water falls or flows through the zinc particles in the pipe that receives the zinc. Rosenstein's disclosure states that the process cannot be made to work with pure zinc.
[0005] On the other hand, US Patent 2,415,346 to Farr discloses a process for making zinc bromide by reacting zinc chloride with hydrobromic acid under boiling temperature conditions while a metal salt of MY type (where M is the desired metal, Y is a halogen of lower atomic weight than bromine, and n is the valence of M) is reacted with an aqueous medium of hydrogen bromide. The metal salt is then treated with a substantially equal amount of acid in aqueous solution with sufficient water to form a constant boiling mixture. A few years later, San Lorenzo et al. (US Patent 4,401,531) introduced a process for producing electrolytic zinc or high purity zinc from raw materials by hydrometallurgical processing. The San Lorenzo process discloses leaching at a pH of 2.5±0.4 for 15-45 minutes at temperatures below 70 degrees Celsius, where the raw material is placed in an acidic aqueous solution to dissolve the zinc. San Lorenzo then filters the solid / liquid before extraction using an organic acid. The latter was then stripped in an acidic aqueous solution by two or three washing steps with other aqueous solutions, and the zinc was recovered in a final process by electrowinning or crystallization.
[0006] Following the steps of San Lorenzo, Duyvesteyn et al. (U.S. Pat. No. 4,572,771) disclosed a method for zinc recovery from steel plant dust. Duyvesteyn leached the zinc with inorganic acid and added a solid / liquid separation step, followed by neutralization with lime. The total zinc recovered from the precipitated slurry was about 20%, from the alkaline zinc solids about 48.1%, and from the galvanizing ash about 72% (30% metallic zinc).
[0007] Later, U.S. Patent No. 6,036,937 to Dunaway (also from the applicant) disclosed a method for producing ZnBr2 essentially by (a) dissolving bromine in an aqueous reaction solvent containing a metal halide salt, and (b) contacting metallic zinc with the resulting bromine solution to form a zinc bromide solution essentially free of bromine. Alternative production of zinc bromide has also been disclosed in other patents, such as U.S. Patent No. 8,992,882 to Sauer et al. Again, focusing on the need for zinc bromide only to meet purity standards for zinc-bromine batteries, Sauer proposed a simple method of combining elemental bromine with at least about a 1 percent molar excess to about a 10 percent molar excess of raw zinc metal. The zinc metal feedstock would contain metallic impurities that would include one or more of greater than 500 ppm Pb, at least 3 ppm Cu, and at least 1 ppm Fe, producing an isolable zinc bromide composition that includes less than 1 ppm Pb, less than 1 ppm Cu, and less than 1 ppm Fe. Again, this method left out another aspect truly related to the battery electrolyte (i.e., zinc chloride), primarily because the zinc chloride would be expected to be purchased separately from a third-party supplier. Furthermore, Sauer's process is costly, slow, appears to be performed only in batch mode, and also presents problems with removing heat.
[0008] Variations of the above general process, including the preparation of other halides, e.g., chlorides, and the use of other metals, e.g., zinc, can be found, for example, in U.S. Pat. No. 6,117,408, U.S. Pat. No. 7,087,209, and U.S. Pat. No. 9,685,543.
[0009] A key problem with zinc-bromine batteries is that they require a high purity zinc bromide solution to function properly. The use of low-cost ZnBr2 sources, particularly zinc sulfate and sodium bromide to generate zinc bromide solutions, can be problematic due to the presence of significant amounts of iron (Fe) impurities. During each charge and discharge cycle, the battery suffers from changes in its energy density, and the impurities in the electrolyte begin to show their strong non-conductive presence, thus significantly hindering the performance of the battery. This entails that those skilled in the art need to remove these impurities (i.e., Fe) if the ZnBr2 battery is expected to be able to operate for long periods of time. Previous literature shows how to achieve a certain purification of zinc brine by using different concentrations of hydrogen peroxide to prepare ZnBr2 solution instead of distilled water when dissolving zinc sulfate and sodium bromide salts (see Patil, Anil, and Pallavi Managave. “The Effect of Peroxide Concentration when Removing Iron from Brine: A Kinetic Study.” SPE Bergen One Day Seminar, Bergen, Norway, April 2014). This allows all Fe to be converted to Fe +3 oxidized to ZnO and precipitates out of solution. Nevertheless, even with this additional step, the separation between the electrodes is very large and the electrode area is low, so there are very substantial ohmic losses in this type of configuration. This means that charge / discharge cycle data is not useful. In fact, typical levels of trace metals observed in commercial battery electrolytes made from off-the-shelf zinc bromide and zinc chloride blends show that they contain at least 14 ppm of lead (Pb) and sodium (Na), at least 5 ppm of lithium (Li), at least 2 ppm of calcium (Ca) and boron (B), among other impurities that are not beneficial for proper battery performance. Their pH levels are typically in the range of 3.5-4.5, their density is 1.58-1.62, and their color is orange / yellow, mainly due to residual bromine.
[0010] 2. Pursuit of a manufacturing method for ultra-pure zinc compounds Despite the methods used throughout history, the ultimate goal of processes for producing electrolytic zinc compounds has always been to obtain the highest degree of purity in the zinc.
[0011] For example, the "roasting, leaching, and electrowinning" (RLE) process "roasts" zinc sulfide concentrate to produce impure zinc oxide (calcined body) and SO2 gas, which are then converted to sulfuric acid. The calcined body is then "leached" with sulfuric acid solution recycled from the "electrowinning" stage. Separation of the leach pulp produces an impure solution, which is then purified by cementation with zinc powder. The purified solution is sent to zinc electrowinning to produce zinc plates, which are then sent to the melting and casting stage. However, impurity concentration levels low enough to achieve extreme quality electrowinning were never achieved, and therefore ultra-pure zinc was not achieved, unless further processing was carried out, which requires a lot of time and financial investment.
[0012] Another common process uses the acid from the leaching step to dissolve the zinc and then selectively extracts the dissolved zinc with an organic acid solvent acting as an extractant, after which the zinc-loaded organic acid is treated to recover the zinc in the form of an aqueous solution and regenerate the organic solvent which is then recycled.
[0013] In typical electrolyte manufacturing, ZnBr2, bromine complex additive (BCA), and supporting electrolyte (KBr, ZnCl2) are purchased separately from manufacturers with different specifications and impurities. Therefore, it becomes difficult to obtain consistent results in battery manufacturing. This problem can be solved by making the battery large enough, but it still has to face other drawbacks such as: The need to short the terminals through a low impedance shunt every 1-4 cycles while the electrolyte pump is operating to completely remove zinc from the battery plates. Low areal power (less than 0.2W / cm2) during both charging and discharging, which translates into excessive power costs. · Low round-trip DC-DC efficiency of up to 80%, significantly lower than Li-ion batteries, which are typically 90% or higher. Low energy density (approximately 42Wh / kg). Complex structures with moving parts.
[0014] Most typically, zinc chloride suppliers obtain such products by mixing zinc and hydrogen chloride, offering purities up to 99%. This simplifies purification of the chloride, since zinc exists in only one oxidation state, 2+, but battery manufacturers still need to purify their purchased product, either by recrystallization from hot dioxane, or by sublimation in a stream of hydrogen chloride gas, followed by heating to 400 degrees Celsius in a stream of dry nitrogen gas. Until recently, only dilute ZnCl2 electrolytes were used, for example mixed with NH4Cl for optimal conductive properties, but ZnCl2 has long been used as an electrolyte for electrochemical devices.
[0015] Dilute ZnCl2 electrolyte may show interesting results compared to other diluted Zn electrolytes. C.Wang, Z.Pei, Q.Meng et al., Toward flexible zinc-ion hybrid capacitors with superhigh energy density and ultralong cycling life: the pivotal role of ZnCl2salt-based electrolytes, Angew.Chem.,133(2021),pp.1003-1010, reports that 2m of ZnCl2 is equivalent to 100% of the electrolyte in aqueous Zn 2+ It has been reported that ZnO is the optimal electrolyte for Zn-based electric double layer capacitors (EDLCs). In particular, here density functional theory (DFT) studies have shown that the desolvation energy is reduced by ZnO from the electrolyte. 2+The results suggest that the charge carrier potential of [ZnCl]+ is much lower than that of ZnCl+, which is specific to ZnCl2. The concept of [ZnCl]+ as a cationic charge carrier is intriguing, as it 2 The present study seeks to answer the question of whether [ZnCl]+ or [ZnCl]+ is the de facto charge carrier for the operation of the cathode material in aqueous batteries with ZnCl2, including its water-in-salt electrolyte as the electrolyte. Further investigation into this question is warranted.
[0016] Further increase in ZnCl2 concentration increases the viscosity of the electrolyte, thereby decreasing ionic conductivity. However, the advantages of higher concentration (i.e., less "dilute" ZnCl2) could potentially outweigh the disadvantage of decreased conductivity by evoking intriguing properties. This does not provide certainty to battery manufacturers due to the varying electrochemical performance in addition to purity issues in ZnCl2.
[0017] 3. Cost-effective battery system It has been known in the art since 1926 that bromine and zinc do not react directly with each other, but require the formation of the intermediates ZnO and HBr.
[0018] As can be seen from the above discussion, zinc-bromine flow, and to some extent non-flow batteries, are considered to represent a promising next-generation battery technology due to their low cost, high energy density, and abundance of constituent materials. See Li, XJ, Li, TY, Xu, PC, Xie, CX, Zhang, YH, Li, XF, A Complexing Agent to Enable a Wide-Temperature Range Bromine-Based Flow Battery for Stationary Energy Storage. Adv. Funct. Mater. 2021, 31, 2100133. However, zinc-bromine batteries suffer from severe gassing issues, which deteriorate electrochemical cycling performance and limit their design in view of the expensive electrolyte flow systems required. The accumulation of these gases in the cell is prevented by the electrolyte flow system, which makes the importance of minimizing gassing reactions rarely addressed. However, to provide flexibility in cell design and achieve widespread acceptance of cost-effective ZnBr2 chemistry in consumer applications such as pouch formats, new strategies to prevent gassing need to be developed. I would like to enter the world of deep eutectic solvent (DES) mixtures.
[0019] DES are eutectic mixtures of Lewis or Brönsted acids and bases that are widely used in various fields (e.g., separation, synthesis, and electromechanical processes) due to their simplicity in preparation, low cost, low toxicity, and tunable chemical properties. DES can also be used as electrolytes for batteries, as exemplified by DES-based lithium and zinc organic batteries. See J. Song, Y. Si, W. Guo, D. Wang, Y. Fu, Angew. Organosulfide-Based Deep Eutectic Electrolyte for Lithium Batteries. Chem. Int. Ed. 2021, 60, 9881. The ionic liquid-like ion-conducting properties of DES make them a possible electrolyte material choice, however, the technology of DES-based batteries is still in its infancy. Regarding the possible use of DES in battery applications, halide-based DESs for zinc bromide-based batteries have been of particular interest, given their potential to provide Br conductivity, high solubility of Br2, and Br2 scavenging capacity.
[0020] In Heo, J., Shin, K., Kim, H.-T., A Zinc-Bromine Battery with Deep Eutectic Electrolytes. Adv. Sci. 2022, 9, 2204908, a DES electrolyte was designed by simply mixing ZnBr2, ZnCl2, and MEPBr. Each DES was prepared by simply mixing the required amount of ZnBr2, ZnCl2, and MEPBr at 115 °C without any further processing. To completely dissolve the parent salt, the DES was placed in an oven for more than 3 days before use. The final product was in the form of a clear brown liquid. Due to the anhydrous character of the electrolyte and the excellent Br2 adsorption capacity, the zinc bromide battery using this DES could be operated in a closed coin-shaped configuration without any gas generation. Experimental and computational analysis elucidated the reconstruction of MEPBr and the formation of Zn-halide complex anions. By including Cl-, not only the ion mobility was affected, but also the cycle stability and reaction rate were improved, resulting in better cycle performance of DES zinc bromide battery with Cl-. By utilizing the non-gassing feature of BCM DES, a flexible pouch-type DES zinc bromide battery was successfully demonstrated. However, in this process, the solvent extraction does not include a purification step, and as a result, the organic solvent cannot produce high purity zinc bromide and zinc chloride without additional MEPBr. Moreover, the raw materials supplied are very specific, which ultimately makes this process impossible to mass-produce.
[0021] We would like to enter the world of carbon-zinc batteries, specifically zinc chloride batteries. Introduced around the 1900s, carbon-zinc batteries with a slightly acidic electrolyte consisting mainly of zinc chloride in water were found to provide an economical source of power for devices requiring light to moderate drain due to the use of inexpensive materials and their proven construction. At the time, they were used mainly in flashlights due to their low capacity. As technology advanced, the service capacity of zinc chloride batteries increased due to the use of purer grades of manganese dioxide, the addition of graphite powder to the manganese dioxide to lower the internal resistance, better sealing, and purer zinc for the negative electrode. Their service capacity was not a fixed number of ampere hours since the battery performed at different efficiencies depending on the conditions imposed on it. Service varied with current drain, operating schedule, and cut-off voltage. However, these batteries were also affected by operating temperature and storage conditions.
[0022] Today, side reactions between impurities in the zinc chloride anode and the ammonium chloride electrolyte have been shown to increase the self-discharge rate and promote cell corrosion. Previously, zinc was coated with mercury (Hg) to form an amalgam to protect it. Considering this is environmentally harmful, current production batteries no longer use mercury and manufacturers now need to use more highly purified zinc to prevent localized action and self-discharge. Still, the quest to obtain such a pure zinc chloride product does not appear to be successful, and thus the combined use of zinc bromide and zinc chloride in the battery electrolyte has not been sufficient to realize all of the benefits associated with zinc chloride batteries (e.g., continuous use in high drain applications).
[0023] 4. Use of Zinc Bromide as a Catalyst Zinc bromide has proven to be a facile and efficient catalyst by stereoselective semipinacol rearrangement of α-hydroxyepoxides. Zinc bromide as catalyst for the stereoselective construction of quaternary carbon: improved synthesis of diastereomerically enriched spirocyclic diols; Yong Qiang Tu et al.; Journal of the Chemical Society, Perkin Transactions 1 Issue 22, 2000. The important attraction of this heterogeneous catalyst is mainly based on economic and environmental considerations (low toxicity), since it is generally cheap and easily available. Moreover, it can be easily handled and removed from the reaction mixture, thus simplifying the experimental procedure. In recent years, the application of ZnBr2 as a catalyst for the synthesis of organic compounds and heterocyclic molecules has been reported in the literature. Nevertheless, so far, the oil and gas industry has mainly used zinc bromide to replace oil well mud, while the electrical and metallurgical industries have used it in electrolysis and catalysis.
[0024] 5. Conclusion As can be seen, none of the references teach or suggest a method for producing zinc bromide and zinc chloride blends on a commercial scale on a large scale (continuous) and small scale (batch) with controlled purity for suitable battery manufacturing. Therefore, it would be desirable to produce zinc bromide and zinc chloride blends directly in a reactor from inexpensive raw materials. As a result, these would satisfy the need for an inexpensive and simple method for rapidly producing large quantities of zinc bromide and zinc chloride blends with controlled purity levels for consistent electrochemical performance. Summary of the Invention
[0025] The present invention seeks to address one or more of the above-mentioned needs by providing a cost-effective method for producing ultra-pure zinc bromide and zinc chloride blends that utilizes an aqueous solution of zinc bromide as a catalyst that may otherwise be inefficient to produce. This represents a significant step forward in accelerating market adoption of zinc batteries as more sustainable energy storage systems and reducing production costs, while providing longer service life and more stable voltage output to electrolyte batteries.
[0026] While others have failed to produce ultra-pure zinc bromide alone, the present disclosure achieves more by producing an ultra-pure zinc bromide and zinc chloride blend with reduced metal impurities for use in battery electrolyte blends by reacting chlorine with a mixture of zinc bromide and zinc. The method uses a heel of zinc bromide along with zinc shot and chlorine. The zinc bromide acts as a catalyst in a reaction where the true catalyst is bromine, which is converted to bromide and then back to bromine again. The ratio of zinc bromide to zinc chloride is 5:1 to 15:1 ZnBr2:ZnCl2. An aqueous solution of zinc bromide is added to pure zinc metal, and then chlorine gas is bubbled through the reaction mixture. The Cl2 reacts with the bromide ions (Br-) in the solution to create chloride ions (i.e., ZnCl2) and bromine. The bromine then reacts with the Zn metal to create more ZnBr2. This cycle continues until all the Cl2 is used up. Typical direct reaction of Cl2 with zinc in a ZnCl2 solution is very slow, so in the present invention, Cl2 reacts first with Br- to create bromine which reacts quickly with Zn in a solution of ZnBr2.
[0027] Overall, at the end of the reaction, there is a mixture of zinc bromide and zinc chloride, which is controlled by the exact amount of Cl2 charged to the reactor. In practice, such a level of control can be implemented that the percentage of ultra-pure zinc bromide to zinc chloride can be adjusted from 5 to 95 percent, depending on the utility required for the battery. The zinc bromide heel acts as a heat sink for this exothermic reaction. The temperature is typically kept around 60 to 80 degrees Celsius. The trace metal content in parts per million (ppm) for this ultra-pure zinc bromide and zinc chloride blend is less than 1 ppm of trace metals selected from the group consisting of Ag, Al, As, B, Ba, Be, Cd, Co, Cr, Cu, Fe, Li, Mn, Mo, Nb, Ni, P, Pb, Sb, Se, Si, Sn, Sr, Ti, and V, and less than 10 ppm of metals selected from the group consisting of Ca, K, Na, and Mg. The color is nearly colorless and transparent, less than 11 on the American Public Health Association (APHA) color standard.
[0028] This unique battery blend benefits from the use of an ultra-pure zinc bromide and zinc chloride "water-in-salt" electrolyte blend that minimizes Fe dissolution (which is key to the battery), which increases the cation insertion potential at the cathode and suppresses the anion insertion potential at the anode, thus spreading the total cell voltage with a dilute ZnCl2 electrolyte.
[0029] The teachings of the present invention can be readily understood by considering the following detailed description in conjunction with the accompanying drawings. [Brief description of the drawings]
[0030] [Figure 1] FIG. 1 is a simplified flow chart diagram for the continuous production in a reactor system of ultra-pure zinc bromide and zinc chloride fluid blends with reduced metal impurities for use in battery electrolyte blends by reacting chlorine with a mixture of zinc bromide and zinc, according to one embodiment of the present disclosure. [Diagram 2]FIG. 1 illustrates a simplified flow chart diagram for the batch production in a reactor system of ultra-pure zinc bromide and zinc chloride fluid blends with reduced metal impurities for use in battery electrolyte blends by reacting chlorine with a mixture of zinc bromide and zinc, according to one embodiment of the present disclosure. [Diagram 3] FIG. 1 shows a simplified block diagram of a semi-closed loop continuously stirred reactor system for the continuous production of ultra-pure zinc bromide and zinc chloride fluid blends according to one embodiment of the present disclosure. [Figure 4] FIG. 1 shows a simplified block diagram of a semi-closed loop batch stirred reactor system for batch production of ultra-pure zinc bromide and zinc chloride fluid blends according to one embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0031] 1. Introduction Reference will now be made in detail to several embodiments of the present disclosure, examples of which are illustrated in the accompanying figures. It should be noted that wherever practicable, similar or similar reference symbols may be used in the figures and may indicate similar or similar functionality. The figures depict embodiments of the present disclosure for illustrative purposes only. Those skilled in the art will readily recognize from the following description that alternative embodiments of the structures, systems, and methods shown therein may be used without departing from the principles of the present disclosure described herein.
[0032] The subject matter which is believed to be the invention is particularly pointed out and distinctly claimed in the concluding portion of this specification, however, the invention, together with its objects, features, and advantages, both as to organization and method of operation, may best be understood by reference to the following detailed description when read in connection with the accompanying drawings.
[0033] 2. Figure a. Continuously Stirred Tank Reactor (CSTR) This disclosure describes a method for producing ultra-pure zinc bromide and zinc chloride fluid blends with reduced metal impurities for use in battery electrolyte blends by reacting chlorine with a mixture of ZnBr2 and zinc in a reactor system. The method 101 begins in FIG. 1 by determining at 102 whether the requirement is for continuous or batch processing. A continuous stirred tank reactor (CSTR), also known as a vat- or backmix reactor, as shown in FIG. 3, is a common ideal reactor type in chemical engineering. CSTR often refers to a model used to estimate key unit operating variables when using a continuous stirred tank reactor to reach a specified output. The mathematical model (4) works for all fluids: liquids, gases, and slurries. CSTRs are known to be one of the systems that exhibit complex behaviors such as stationary multiplicity, limit cycles, and chaos.
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[0034] This initial step is important to the present embodiment since it is used to determine the sequence of specifications for the reactor system 301. Then, at 103, at least 2100 kilograms of zinc are added into the reactor 302 using a solids feeder 308 connected to the reactor 302, and at 104, at least 400 kilograms of an aqueous solution of zinc bromide is added to the reactor using an inlet feed 305 connected to a piping system 306 which in turn is connected to the reactor 302. The zinc added at 103 typically contains at least 99.99 wt.% zinc, less than 0.0001 wt.% Al and Cd, at least 0.0002 wt.% Fe, and at least 0.0017 wt.% Pb. Aqueous zinc bromide fluids typically consist of less than 1 part per million (ppm) of Pb, Cd, As, Cr, Co, Fe, Ni, Nb, Cu, Rh, Pd, Ag, Mg, B, and Al; less than 3 ppm of Hg, V, Mo, and Ru; less than 6 ppm of Li; and less than 8 ppm of Ca. Additionally, aqueous zinc bromide fluids typically have a pH level of 5.5-5.6 and an APHA color value of less than 11.
[0035] A piping system 306 and a centrifugal recirculation pump 307 are used to mix 105 the added zinc 103 with the aqueous solution of added zinc bromide 104 in the reactor 102 at a rate of 75-150 liters per minute. Such mixing step is circulated through a heat exchanger 309 which obtains water from a reservoir or city connection 310. The heat exchanger 309 is used to regulate the temperature of the reactor between 20 degrees Celsius and 80 degrees Celsius. The cooling of the water in the heat exchanger 309 needs to occur at a rate of at least 350 liters per minute so that the solution (and future reactions) in the reactor 302 can occur. Thus, the cooling capacity of the heat exchanger 309 is about 70 kW. The mixing 105 of the aqueous fluid solution of added zinc bromide with the added zinc occurs at a flow rate of between 75-150 liters per minute (LPM) by the centrifugal recirculation pump 307.
[0036] After mixing of the added zinc with the aqueous solution of added zinc bromide at 105, and when the temperature within the reactor is at least 20 degrees Celsius, a step 106 of generating a reaction is performed by adding at least 4 kilograms per minute of chlorine to the reactor using a piping system when the temperature within the reactor is at least 20 degrees Celsius. Chlorine (which can be in either liquid or gas form) is added at 106 to the reactor 302 at a rate of at least 4 kilograms per minute (kg / min) through inlet supply 305, which, after constant mixing through centrifugal recirculation pump 307, generates a reaction as represented by the following equations (5) and (6): [ka]
[0037] Once the resulting reaction 106 proves stable, embodiments of the present disclosure allow the addition of chlorine 106 to be increased to 45 kilograms per hour. The reaction 106 is then heated at 107 to less than 80 degrees Celsius by continuously adding chlorine at a rate of at least 4 kilograms per minute and mixing the added zinc with an aqueous fluid solution of zinc bromide. A heat exchanger 309 maintains the temperature between the ranges, but when the temperature indicator 311 of the reactor 102 reaches 79 degrees Celsius, the chlorine feed 312 is stopped at 108. The chlorine feed 106 is stopped at 108, but a solid feeder connected to the reactor is used to add zinc to the reactor at a rate of at least 40 kilograms per hour at 109 to help reduce and maintain the temperature of the reactor 302 below 80 degrees Celsius. At that point, a solution indicator sensor in the reactor 302 determines whether a minimum of 16.4% by weight zinc chloride has been obtained. Reaching such a level indicates that the process of the present invention has already produced an ultra-pure zinc bromide and zinc chloride fluid blend within the reactor at 110.Thereafter, if the solution indicator determines that such minimum weight percent zinc chloride is not achieved, then the disclosed embodiment of the present invention, at 111, includes the steps of: (i) adding at least 2100 kilograms of zinc to the reactor using a solids feeder connected to the reactor; (ii) adding at least 400 kilograms of an aqueous solution of zinc bromide to the reactor using an inlet feed connected to a piping system and then connected to the reactor; (iii) mixing the added aqueous solution of zinc bromide with the added zinc in the reactor at a flow rate of 75 to 150 liters per minute using a centrifugal recirculation pump connected to the piping system; and (iv) adding at least 4 kilograms per minute of chlorine to the reactor using the piping system while the temperature in the reactor is at least 20 degrees Celsius. (v) heating the reaction to less than 80 degrees Celsius by continuously adding chlorine at a rate of at least 4 kilograms per minute and mixing the added zinc with an aqueous solution of added zinc bromide; (vi) stopping the addition of chlorine to the reactor at a rate of at least 4 pounds per minute using the piping system when the temperature in the reactor reaches 79 degrees Celsius; (vii) adding zinc to the reactor at a rate of at least 40 kilograms per hour using a solids feeder connected to the reactor; and (viii) producing an ultra-pure zinc bromide and zinc chloride fluid blend in the reactor until the ratio of produced ultra-pure zinc bromide and zinc chloride fluid blend in the reactor reaches a minimum of 16.4 weight percent zinc chloride in the decant tank.
[0038] Once the solution indicator within reactor 302 determines that a minimum of 16.4 wt. % zinc chloride has been achieved, system 301 begins decanting 112 using decant valve 313 connected to reactor 302, and the resulting ultra-pure zinc bromide and zinc chloride fluid blend is sent to decant tank 314 at a maximum rate of 550 kilograms per hour.
[0039] Thereafter, or in continuous operation with the process cycle described above, to maintain the achieved minimum 16.4 wt.% zinc chloride, the system 301 begins, at 113, adding an aqueous solution of zinc bromide to the reactor 302 at a rate of at least 400 kilograms per hour using a piping system 306 connected to the reactor. Similarly, in continuous operation, the system begins, at 114, decanting the produced ultra-pure zinc bromide and zinc chloride fluid blend from the decant tank 314 to a storage tank 316 at a flow rate of 75-150 liters per minute using a clear and colorless fluid pump 315 connected to the decant tank 302. The storage tank is made of building materials typically in the form of epoxy vinyl ester resins with an optimized epoxy backbone and lower styrene content resins that provide superior thermal and corrosion resistance performance. These resins typically provide superior stability compared to conventional vinyl ester resins, thus providing fabricators with additional flexibility in storage and handling. The storage tank is then used to meet demand for the produced ultra-pure zinc bromide and zinc chloride fluid blend of the present invention and its level is monitored using a submersible level transmitter or sensor with an auto-calibration algorithm that provides an accurate level reading of the stored ultra-pure zinc bromide and zinc chloride fluid blend. This level monitoring system uses a wireless ultrasonic sensor, thereby calculating the level of the ultra-pure zinc bromide and zinc chloride fluid blend by measuring the distance between the sensor and the surface of the fluid.
[0040] According to one embodiment of the present disclosure, the production of ultra-pure zinc bromide and zinc chloride fluid blend at 110 is carried out in a continuous stirred tank reactor (CSTR) system 301, where traces of unreacted zinc metal remain at the bottom of the reactor 302. Therefore, in order to operate the system 301 continuously while maintaining the quality of the produced ultra-pure zinc bromide and zinc chloride fluid blend, it is necessary to remove traces of unreacted zinc from the reactor 302 through a filter at 115. The filter characteristics include a micron rating of 5 μm, an initial efficiency of at least 97%, and a media type of polypropylene microfiber material. The polypropylene microfiber comprises a usable filter of about 3.5 to 5.5 square meters and also helps to absorb unwanted traces of oil that may leak from multiple devices used in the present disclosure, thereby ensuring the following ultra-pure zinc bromide and zinc chloride fluid blend characteristics: 5 to 95 weight percent zinc bromide, 5 to 95 percent by weight zinc chloride, 2.55 to 48.5 weight percent chloride, 3.55 to 67.45 weight percent bromide; 22.4 to 35.6 percent by weight zinc, Less than 1 ppm of trace metals selected from the group consisting of Ag, Al, As, B, Ba, Be, Cd, Co, Cr, Cu, Fe, Li, Mn, Mo, Nb, Ni, P, Pb, Sb, Se, Si, Sn, Sr, Ti, and V; less than 10 ppm of metals selected from the group consisting of Ca, K, Na, and Mg; Density of 16-21 ppg measured at 20 degrees Celsius; -pH level of 1.7 to 2.0, APHA colors below 11, as well as Less than 40 ppm free bromine.
[0041] Finally, to maintain the ratio of the produced ultra-pure zinc bromide and zinc chloride fluid blend in the reactor at a minimum of 16.4 percent zinc chloride in the decanting tank, the continuous stirred tank reactor (CSTR) process then includes the steps of: (i) adding at least 2,100 kilograms of zinc to the reactor using a solids feeder connected to the reactor; (ii) adding at least 400 kilograms of an aqueous solution of zinc bromide to the reactor using an inlet feed connected to a piping system and then connected to the reactor; and (iii) adding at least 2,100 kilograms of an aqueous solution of zinc bromide to the reactor using an inlet feed connected to a piping system and then connected to the reactor. (iv) using a piping system to generate a reaction by adding at least 4 kilograms per minute of chlorine to the reactor while the temperature in the reactor is at least 20 degrees Celsius; and (v) heating the reaction to less than 80 degrees Celsius by continuously adding chlorine at a rate of at least 4 kilograms per minute and mixing the aqueous solution of added zinc bromide with the added zinc. (vi) stopping the addition of chlorine to the reactor at a rate of at least 4 pounds per minute using the piping system when the temperature in the reactor reaches 79 degrees Celsius; (vii) adding zinc to the reactor at a rate of at least 40 kilograms per hour using a solids feeder connected to the reactor; (viii) producing an ultra-pure zinc bromide and zinc chloride fluid blend in the reactor; and (x) decant the produced ultra-pure zinc bromide and zinc chloride fluid blend at a rate of up to 550 kilograms per hour using a decanting valve connected to the reactor. (xi) adding an aqueous solution of zinc bromide to the reactor at a rate of at least 400 kilograms per hour using a piping system connected to the reactor; (xii) decanting the produced ultra-pure zinc bromide and zinc chloride fluid blend from the decant tank to a storage tank at a flow rate of 75 to 150 liters per minute using a water-clear fluid pump connected to the decant tank; and (xiii) removing traces of unreacted zinc from the reactor through a filter.
[0042] B.Batch Turning now to Figure 2, which shows as 201 a simplified flow chart diagram of a method for producing an ultra-pure zinc bromide and zinc chloride fluid blend in a batch reactor system 401 of Figure 4 by reacting chlorine with a mixture of zinc bromide and zinc. The produced ultra-pure zinc bromide and zinc chloride fluid blend has reduced metal impurities for use in battery electrolyte blends.
[0043] Chemical manufacturing companies have long sought better approaches to material processing. One of the main topics of discussion is batch processing versus continuous flow. Although these two types of processing may appear different in different industries, for example, the production of medicines in the pharmaceutical industry and the processing of liquid waste in mining, they share more similarities than differences, regardless of the application. In particular, according to the disclosure of the present invention, batch processing involves the processing of bulk material in groups through each step of the disclosed method. Under batch processing, the processing of subsequent batches must wait until the current one is finished. Nevertheless, when demand is low, batch processing or production offers the advantage of lower initial set-up costs and the ability to adjust bulk material to supply the demand on its own. Nevertheless, problems with catalyzing the reaction still exist, and thus, to date, no technical solution has been introduced to produce ultra-pure zinc bromide and zinc chloride fluid blends. The foregoing has been solved by the specific disclosure of the present invention.
[0044] When producing ultra-pure zinc bromide and zinc chloride fluid blends in a batch production mode, as indicated by 102, the process begins by adding at 202 an aqueous solution of at least 1500 grams of zinc bromide to a reactor 402, and then adding at least 68.1 grams of zinc to the reactor in 203. This solution typically contains 1,500 grams of an aqueous solution of zinc bromide, but less than 2,500 grams of an aqueous solution of zinc bromide. Thereafter, mixing of the added at least 1500 grams of aqueous solution of zinc bromide and at least 68.1 grams of zinc occurs in 204 using a stirrer. Mixing 204 is typically performed with a stirrer agitator arrangement 403 centrally mounted on a drive shaft 404 having an overhead drive unit 405. Impeller blades 406 are mounted on the shaft 404. Mixing 204 occurs at a speed of 270 to 350 revolutions per minute. A wide variety of blade designs are used, typically the blades cover about two-thirds of the diameter of the reactor 407. The reaction is then generated 205 using a stirrer agitator arrangement 403 by adding chlorine at a rate of less than 5 grams per minute when the temperature of the reactor reaches 20 degrees Celsius. At least 80.1 grams of chlorine (either in liquid or gas form) is added 205 through an inlet tube 410 at a rate of 5 grams (gr) per minute (min) over a period of 30 minutes (to avoid a sudden increase in temperature) when the temperature of the reactor 402 reaches 20 degrees Celsius. The reaction is generated 205 by said addition 205 of less than 80.1 grams of chlorine at a rate of less than 5 grams per minute when the temperature of the reactor reaches 20 degrees Fahrenheit. This occurs by continuously adding chlorine at a rate of less than 5 grams per minute when continuously mixed 204, and the generated reaction is heated 206 to less than 80 degrees Celsius. To keep the temperature within range and avoid reaching the boiling point of any of the elements in the reactor 402, a combination of coiled condensers 408 is used to insert cooler air while a circulator 409 extracts and dissipates any hot air around the reactor 402. An outlet tube 411 connected to the reactor 402 serves to dissipate or remove any accumulated gases inside.
[0045] Once the temperature of the thermocouple 407 detects that the reaction temperature has reached 79 degrees Celsius, cessation of the addition of chlorine at a rate of less than 5 grams per minute occurs at 207 when the temperature in the reactor reaches 79 degrees Celsius at 208 for up to 14 hours. Thereafter, cessation of the aqueous solution of zinc bromide and mixing of the zinc with the added chlorine occurs at 209 for 18 hours. An ultra-pure zinc bromide and zinc chloride fluid blend in the reactor 402 is produced at 210, and removal of traces of unreacted zinc metal from the reactor 402 occurs at 211 through a glass microfiber filter using a Buchner funnel under vacuum. The filter has a filtration rate of 41 seconds, 2.6 seconds / 100 ml / in 2 Air flow rate, basis weight 121g / m 2 , maximum operating temperature 550°C, particle retention in liquid of 2.7 μm, thickness of 675 μm, water flow rate of 681 ml / min, and diameter of at least 7 mm. In batch processing, this provides the following ultra pure zinc bromide and zinc chloride fluid blend properties: 5 to 95 weight percent zinc bromide, 5 to 95 percent by weight zinc chloride, 2.55 to 48.5 weight percent chloride, 3.55 to 67.45 weight percent bromide; 22.4 to 35.6 percent by weight zinc, Less than 1 ppm of trace metals selected from the group consisting of Ag, Al, As, B, Ba, Be, Cd, Co, Cr, Cu, Fe, Li, Mn, Mo, Nb, Ni, P, Pb, Sb, Se, Si, Sn, Sr, Ti, and V; less than 10 ppm of metals selected from the group consisting of Ca, K, Na, and Mg; Density of 16-21 ppg measured at 20 degrees Celsius; -pH level of 1.7 to 2.0, APHA colors below 11, as well as Less than 40 ppm free bromine.
[0046] 4.Example of test results To compare this disclosure, a baseline was established using off-the-shelf commercial zinc chloride from companies such as Spectrum Mfg. A 75.5 wt% zinc bromide aqueous solution from Company A was used and mixed using the apparatus of FIG. 4 in the same manner as described in this disclosure, specifically FIG. 2. The resulting zinc bromide and zinc chloride fluid blend had fluid properties of 4.04 wt% Cl, 48 wt% Br, 23 wt% Zn, pH of -0.56, and 0 ppm Br2. The ICP metal ppms were mostly below 1, except for Ca, K, Na, and Si, which were at 1-4 ppm.
[0047] After the same batch processing, at least four different examples were carried away, considering that the main chemical reactions expected were (5) and (6).
[0048] The charge, molar, and weight ranges used are given in the table below, as well as the final solution mass, unreacted zinc, and filtrate weight ranges. [Table 1]
[0049] The resulting properties of ultra-pure zinc bromide and zinc chloride fluid blends for four examples using the method of the present disclosure were as shown in the table below: [Table 2]
[0050] Finally, a comparative example was carried out showing the case where no aqueous solution of zinc bromide was present in the reactor. The reaction system was thoroughly washed prior to the reaction to remove any bromine / bromide species involved in any previous reaction. For this experiment, the zinc chloride feed was prepared by dissolving 1,020 grams of zinc chloride in 1,020 grams of water, so the feed had a concentration of 50.0% (by weight). In practice, 100 grams of chlorine was injected into the mixture of zinc shot and zinc chloride over a period of 42 minutes (2.38 g / min) with stirring at approximately 350 rpm and a coolant circulation of 52 degrees Celsius. The temperature rose 4.3 degrees Celsius at the end of the chlorine injection and then dropped. The color of the reaction changed from clear to colorless to pale yellow during the course of the chlorine injection and became clear and colorless again after 85 minutes of stirring. The reaction mixture was cooled to room temperature and allowed to stand overnight, then the zinc shot was collected and weighed, and a liquid sample was submitted for analysis. At the end of the process of this example, the theoretical analysis provides the following: Based on the weight of zinc reacted, it should be as follows: (276.33~254.98) / 65.38=0.327 moles (7) The ZnCl2 formed should be: 0.327 moles × 136.29 g / mol = 44.50 g (8) The actual Cl2 consumed should be: 0.327 moles × 70.91 g / mol = 23.15 g (9) The escaped Cl2 should be as follows: 100.0-23.15=76.85g (10) Therefore, the sum of all ingredients in grams should be: [Table 3]
[0051] Nevertheless, the recovered mass after workup was a total of 2265.98 grams divided into 2011 filtrate and 254.98 dry Zn. The total loss is therefore equal to 105.35 grams (2265.98 - 2416.33).
[0052] Since 21.35 grams of zinc were consumed, the newly formed zinc chloride should be 44.50 grams, which should result in a zinc chloride concentration after the reaction of (44.50 + 1,020) / (44.50 + 2,040) = 51.07%.
[0053] In contrast, the Cl-% value of 26.2 obtained from the IC analysis indicates that the ZnCl2% should be 50.36%, which translates to 14.71 grams of zinc chloride being formed from the reaction of 7.06 g of zinc with 7.65 g of chlorine.
[0054] The Zn% value of 24.3 obtained from the ICP analysis indicates that the ZnCl2% should be 50.65%. The zinc may associate with other anions in the solution, some of which may come from chlorine, so the concentration of zinc chloride calculated from the zinc cations or zinc metal consumed may be higher than the actual zinc chloride formed. Therefore, the Cl-% value should be the most accurate data. Thus, the Cl-% obtained from the IC analysis indicates that the total zinc chloride concentration increased by 0.36% after the reaction. This translates to 14.71g of zinc chloride being formed from the reaction of 7.06g of zinc with 7.65g of chlorine. Compared to the total of 276g of zinc shot and 100g of chlorine added to the reactor, the extent of the reaction between zinc and chlorine was very small (7.65 / 100=7.65%). There may be side reactions, but the extent would be equally small.
[0055] The resulting properties of this example were as follows: [Table 4]
[0056] Mass balance calculation: 4. Abbreviations and definitions not defined elsewhere It should be noted here that, as used herein and in the appended claims, the singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise. Similarly, gerunds are derived from the word forms of their respective verbs, so they include references to those words, and verbs include their gerunds unless the context clearly dictates otherwise.
[0057] All percentages, pans, and ratios are based on the total weight of the compositions of the present invention unless otherwise specified. All such weights relating to listed ingredients are based on active levels and therefore do not include solvents or by-products that may be included in commercially available materials unless otherwise specified. The term "weight percent" may be expressed herein as "wt %". As used herein, all molecular weights are weight average molecular weights expressed in grams / mole unless otherwise specified.
[0058] As used herein, an "aqueous solution", "aqueous fluid solution", or "aqueous fluid" is a solution that generally consists of water and ions, atoms or molecules that have lost or gained electrons, and is electrically conductive. An "aqueous fluid of zinc bromide" contains at least 25% water (wt % zinc bromide), trace metals with a purity of less than 1 ppm selected from the group consisting of Ag, Al, As, B, Ba, Be, Cd, Co, Cr, Cu, Fe, Li, Mn, Mo, Nb, Ni, P, Pb, Sb, Se, Si, Sn, Sr, Ti, and V, and less than 10 ppm metals selected from the group consisting of Ca, K, Na, and Mg.
[0059] In the foregoing specification, the present disclosure has been described in connection with certain preferred embodiments, and numerous details have been set forth for purposes of illustration, but the present invention should not be unduly limited to the foregoing for purposes of illustration. To the contrary, a wide variety of modifications and alternative embodiments will be apparent to those skilled in the art without departing from the true scope of the present invention, as defined in the claims set forth below. Furthermore, it should be understood that structural features or method steps shown or described in any one embodiment herein may be used in other embodiments as well. When references throughout this specification discuss "one embodiment," "one embodiment," or "embodiment," they are intended to mean that the particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, although the phrase "in one embodiment" or "in one embodiment" may appear in various places throughout this specification, they do not necessarily all refer to the same embodiment.
[0060] As used herein, "and / or" placed between a first entity and a second entity means one of (a) the first entity, (b) the second entity, and (c) the first entity and the second entity. Multiple elements listed with "and / or" should be construed in the same manner, i.e., "one or more" of the elements so conjoined. Furthermore, as used in the claims and specification herein, the terms "comprising," "consisting," "including," and "having" shall be considered to indicate an open group that may include other elements not specified. The terms "a," "an," and singular words shall be understood to include the plural of the same word, such that the term means that one or more of something are provided. The terms "one" or "single" may be used to indicate that only one of something is intended. Similarly, other specific integer values, such as "two," may be used when a specific number of things is intended.
[0061] Unless otherwise indicated, when any type of range is disclosed or claimed, it is intended to separately disclose or claim each possible number that such range may reasonably encompass, including any subranges encompassed therein.
Claims
1. 1. A process for producing an ultra-pure zinc bromide and zinc chloride fluid blend having reduced metal impurities for use in battery electrolyte blends by reacting chlorine with a mixture of zinc bromide and zinc in a reactor system, the process comprising: (i) adding at least 2,100 kilograms of zinc to a reactor using a solids feeder connected to said reactor; (ii) adding at least 400 kilograms of an aqueous solution of zinc bromide to the reactor using an inlet supply connected to a piping system which is then connected to the reactor; (iii) mixing the added aqueous solution of zinc bromide with the added zinc in the reactor using a centrifugal recirculation pump connected to the piping system at a flow rate of 75 to 150 liters per minute; (iv) generating a reaction using the piping system by adding at least 4 kilograms per minute of chlorine to the reactor when the temperature within the reactor is at least 20 degrees Celsius; (v) continuously adding chlorine at a rate of at least 4 kilograms per minute and heating the reaction to less than 80 degrees Celsius by mixing the added zinc with an aqueous solution of the added zinc bromide; (vi) stopping the addition of chlorine to the reactor at a rate of at least 4 pounds per minute using the piping system when the temperature in the reactor reaches 79 degrees Celsius; (vii) adding zinc to said reactor at a rate of at least 40 kilograms per hour using said solids feeder connected to said reactor; (viii) producing an ultra-pure zinc bromide and zinc chloride fluid blend in said reactor; (ix) repeating steps (iii) through (viii) until the ratio of the ultra-pure zinc bromide and zinc chloride fluid blend produced in the reactor reaches a minimum of 16.4 percent zinc chloride in a decant tank; (x) decanting the produced ultra-pure zinc bromide and zinc chloride fluid blend into a decant tank at a maximum rate of 550 kilograms per hour using a decant valve connected to said reactor; (xi) adding the aqueous solution of zinc bromide to the reactor at a rate of at least 400 kilograms per hour using the piping system connected to the reactor; (xii) decanting the resulting ultra-pure zinc bromide and zinc chloride fluid blend from the decant tank to a storage tank at a flow rate of 75 to 150 liters per minute using a clear, colorless fluid pump connected to the decant tank; (xiii) removing traces of unreacted zinc from the reactor through a filter; (xiv) repeating steps (iii)-(viii) and (x)-(xiii) to maintain the ratio of the produced ultra-pure zinc bromide and zinc chloride fluid blend in the reactor at a minimum of 16.4 percent zinc chloride in the decant tank.
2. The reactor system comprises: a heat exchanger connected to the reactor via the piping system and the pump, the reactor having the solid feeder for adding the zinc, the piping system for adding the aqueous solution of zinc bromide and the chlorine, and the pump for mixing the aqueous solution of zinc bromide; A decant valve and a decant tank connected to the reactor; a clear and colorless fluid pump connected to the decant tank and the storage tank; and 10. The method for producing an ultra-pure zinc bromide and zinc chloride fluid blend in a reactor system as described in claim 1, further comprising: a control system for carrying out the steps of adding, mixing, producing, heating, stopping, and removing.
3. 2. The method for producing an ultra-pure zinc bromide and zinc chloride fluid blend in a reactor system as described in claim 1, wherein said chlorine can be in either liquid or gaseous form in said step of producing a reaction by adding at least 4 kilograms per minute of chlorine to said reactor using said piping system when said temperature in said reactor is at least 20 degrees Celsius.
4. 2. The step of producing an ultra-pure zinc bromide and zinc chloride fluid blend in said reactor, said ultra-pure zinc bromide and zinc chloride fluid blend comprising: 5 to 95 percent zinc bromide; 5 to 95 percent zinc chloride; 2.55 to 48.5 weight percent chloride; 3.55 to 67.45 weight percent bromide; 22.4 to 35.6 weight percent zinc; Less than 1 ppm of trace metals selected from the group consisting of Ag, Al, As, B, Ba, Be, Cd, Co, Cr, Cu, Fe, Li, Mn, Mo, Nb, Ni, P, Pb, Sb, Se, Si, Sn, Sr, Ti, and V; less than 10 ppm of a metal selected from the group consisting of Ca, K, Na, and Mg; A density of 16-21 ppg measured at 70°F; pH level of -1.7 to 2.0; APHA color less than 11, and less than 40 ppm free bromine; 10. A process for producing an ultra-pure zinc bromide and zinc chloride fluid blend in a reactor system as recited in claim 1, further comprising:
5. The filter from the step of removing trace amounts of unreacted zinc from the reactor through a filter, Micron rating of 5 μm, An initial efficiency of at least 97%; and 10. A method for producing ultra-pure zinc bromide and zinc chloride fluid blends in a reactor system as recited in claim 1, further comprising a media-type polypropylene microfiber material.
6. 1. A process for producing an ultra-pure zinc bromide and zinc chloride fluid blend having reduced metal impurities for use in battery electrolyte blends by reacting chlorine with a mixture of zinc bromide and zinc in a reactor system, the process comprising: (i) adding at least 1500 grams of an aqueous solution of zinc bromide to a reactor; (ii) adding at least 68.1 grams of zinc to the reactor; (iii) mixing the added aqueous solution of at least 1500 grams of zinc bromide and the at least 68.1 grams of zinc using a stirrer; (iv) generating a reaction using the stirrer by adding chlorine at a rate of less than 5 grams per minute when the temperature of the reactor reaches at least 20 degrees Celsius; (v) heating the reaction mixture to less than 80 degrees Celsius by continuously adding chlorine at a rate of less than 5 grams per minute; (vi) stopping the addition of chlorine at a rate of less than 5 grams per minute when the temperature in the reactor reaches 79 degrees Celsius for up to 14 hours; (vii) stopping the mixing of the aqueous solution of zinc bromide and the zinc with the added chlorine at 18 hours; (viii) producing an ultra-pure zinc bromide and zinc chloride fluid blend in said reactor; (ix) removing traces of unreacted zinc metal from said reactor through a glass microfiber filter using a Buchner funnel under vacuum.
7. 7. The method for producing ultra-pure zinc bromide and zinc chloride fluid blends in a reactor system as described in claim 6, wherein said reactor system further comprises a coiled condenser for maintaining the temperature below 80 degrees Celsius, a thermocouple for measuring the temperature in said reactor, a circulator for exchanging air, an inlet tube for adding chlorine to said reactor, an outlet tube for removing accumulated gas in said reactor, and a control system for performing the adding, mixing, producing, heating, stopping, and removing steps.
8. 7. The method for producing an ultra-pure zinc bromide and zinc chloride fluid blend in a reactor system as described in claim 6, wherein said step of mixing said added at least 1500 grams of an aqueous solution of zinc bromide and said at least 68.1 grams of zinc using a stirrer is performed with said stirrer at a speed of 270 to 350 revolutions per minute.
9. 7. The method for producing ultra-pure zinc bromide and zinc chloride fluid blends in a reactor system as described in claim 6, wherein the step of generating a reaction using the stirrer by adding chlorine at a rate of less than 5 grams per minute is carried out for a period of less than 30 minutes when the temperature of the reactor reaches at least 20 degrees Celsius.
10. The ultra-pure zinc bromide and zinc chloride fluid blend in the step of producing the ultra-pure zinc bromide and zinc chloride fluid blend in the reactor comprises 5 to 95 percent zinc bromide; 5 to 95 percent zinc chloride; 2.55 to 48.5 weight percent chloride; 3.55 to 67.45 weight percent bromide; Less than 1 ppm of trace metals selected from the group consisting of Ag, Al, As, B, Ba, Be, Cd, Co, Cr, Cu, Fe, Li, Mn, Mo, Nb, Ni, P, Pb, Sb, Se, Si, Sn, Sr, Ti, and V; less than 10 ppm of a metal selected from the group consisting of Ca, K, Na, and Mg; A density of 16-21 ppg measured at 70°F; 22.4 to 35.6 weight percent zinc; pH level of -1.7 to 2.0; APHA color less than 11, and less than 40 ppm free bromine; 7. A process for producing an ultra-pure zinc bromide and zinc chloride fluid blend in a reactor system as recited in claim 6, further comprising:
11. the filter from the step of removing traces of unreacted zinc metal from the reactor through a glass microfiber filter using a Büchner funnel under vacuum; Filtration rate of 41 seconds; 2.6 seconds / 100ml / in ２ air flow velocity; Weight: 121 g / m ２ ; Maximum operating temperature 550℃; 2. Particle retention in 7 μm liquid; Thickness of 675 μm; A water flow rate of 681 ml / min; and 7. A method for producing an ultra-pure zinc bromide and zinc chloride fluid blend in a reactor system as recited in claim 6, further comprising a diameter of at least 7 mm.