Concentration system for target material in solution

Abstract

A concentration system for a target material in a solution is provided. This concentration system is provided with: a separation device (1); a semi-permeable device (2); a concentrate discharge line (3); a dilution auxiliary liquid discharge line (4); a target liquid flow path; and an auxiliary liquid flow path (6), the concentration method being provided with: a separation step for separating the solution into a target liquid and a discharged liquid having a target material concentration lower than that of the target liquid and an osmotic pressure higher than or equal to that of the target liquid; and a semi-permeable step in which the target liquid is made to flow through one side of the semi-permeable membrane, an auxiliary liquid at least partially containing the discharged liquid is made to flow through the other side of the semi-permeable membrane, and the target liquid is concentrated to obtain a concentrated liquid, and when the osmotic pressure of the discharged liquid is higher than the osmotic pressure of the target liquid, mechanical pressure is applied or not applied in the semi-permeable step, and the osmotic pressure of the discharged liquid is lower than the osmotic pressure of the target liquid. When the osmotic pressure of the discharged liquid is equal to the osmotic pressure of the target liquid, the mechanical pressure is applied in the semi-permeation step.

Description

Technical Field

[0001] This utility model relates to a concentration system for a target material in a solution, belonging to the field of material concentration. Background Technology

[0002] Currently, the main methods for concentrating target materials in solutions include adsorption, nanofiltration, forward osmosis, reverse osmosis, osmotic pressure-assisted reverse osmosis, evaporation, electrodialysis, and combinations thereof. Among these, adsorption methods not only result in insufficient concentration but also generate additional waste during the adsorption and desorption processes. Nanofiltration suffers from high cost and clogging issues. Reverse osmosis has limited concentration, requires high-pressure-resistance equipment, and consumes a lot of energy. Evaporation is extremely energy-intensive and requires a large footprint. Electrodialysis has limited concentration, high energy consumption, and extremely high requirements for the pretreatment of the raw solution, limiting its applicability. These methods generally struggle to balance high concentration with low cost.

[0003] In recent years, an osmotic pressure-assisted reverse osmosis (RO) technology based on concentrate reflux has emerged. For example, CN201346446Y discloses a low-operating-pressure RO device, comprising a high-pressure pump and a reverse osmosis unit connected in sequence by pipelines. The reverse osmosis membrane modules in the reverse osmosis unit are arranged in a single-section parallel configuration. Simultaneously, a concentrate reflux pipe is connected from the concentrate discharge pipe of the reverse osmosis unit to the high-pressure pump, and a regulating valve is installed on the concentrate reflux pipe. This device effectively reduces the operating pressure of the RO unit by combining the single-section parallel arrangement of the reverse osmosis membrane modules with partial concentrate reflux.

[0004] When the aforementioned osmotic pressure-assisted reverse osmosis technology based on concentrate reflux is used to concentrate target materials in solution, it has the advantages of relatively high concentration and relatively low energy consumption. However, due to the use of a large amount of self-concentrated concentrate as reflux liquid, the membrane flux is low and the system efficiency is not high. Therefore, a large number of membrane elements are required, resulting in a large equipment investment cost. Utility Model Content

[0005] Problems to be solved by utility models

[0006] As mentioned above, existing technologies and methods for concentrating target materials in solutions generally suffer from the difficulty of simultaneously achieving high concentrations and low costs. Osmosis-assisted reverse osmosis (ROS) technology based on concentrate recirculation requires a large number of semi-permeable membrane elements to achieve relatively high concentrations, resulting in high equipment investment costs and large footprints. Furthermore, while this ROS-assisted RO technology reduces operating pressure compared to traditional RO technology without concentrate recirculation, the energy consumption required to apply pressure to these numerous semi-permeable membrane elements to achieve relatively high concentrations is difficult to significantly reduce, thus leaving room for improvement in operating costs.

[0007] In view of the above-mentioned problems of the prior art, the present invention provides a system and method for concentrating target materials in solution at low cost and high efficiency by reducing the number of semi-permeable membrane elements used.

[0008] Solution for solving the problem

[0009] In view of the above problems, in-depth research and repeated experiments were conducted. The results showed that by combining the separation device with the semi-permeable device, the solution used as the raw liquid is separated into a target liquid with a high concentration of the target material and a discharge liquid with a low concentration of the target material and an osmotic pressure higher than or equal to that of the target liquid. Under the condition of the presence or absence of mechanical pressure, the target liquid and the auxiliary liquid containing the discharge liquid are allowed to flow through the two sides of the semi-permeable membrane respectively, thereby concentrating the target liquid and solving the above problems.

[0010] [1] A concentration system for a target material in a solution, comprising:

[0011] A separation device is configured to separate the solution into a target liquid and a discharge liquid with a target material concentration lower than that of the target liquid and an osmotic pressure higher than or equal to that of the target liquid. The separation device includes a solution inlet pipe, a separation component, a target liquid outlet pipe, and a discharge liquid outlet pipe.

[0012] A semi-permeable device is configured to concentrate the target liquid and dilute at least a portion of the auxiliary liquid containing the drained liquid. The semi-permeable device includes a single-stage or multi-stage semi-permeable component, the semi-permeable component having a semi-permeable membrane and a container, the internal space of the container being divided into a first chamber and a second chamber by the semi-permeable membrane, the first chamber having a target liquid inlet and a target liquid outlet, and the second chamber having an auxiliary liquid inlet and an auxiliary liquid outlet.

[0013] Concentrate discharge pipeline;

[0014] Dilution auxiliary solution discharge pipeline;

[0015] The target liquid flow path connects the target liquid discharge line of the separation device, the first chamber of the semi-permeability component of each stage of the semi-permeability device, and the concentrate discharge line; and

[0016] An auxiliary liquid flow path connects the discharge pipe of the separation device, the second chamber of the semi-permeable component of each stage of the semi-permeable device, and the dilution auxiliary liquid discharge pipe.

[0017] in,

[0018] The target liquid flow path is configured such that the target liquid inlet of each semi-permeable component is connected to the target liquid discharge pipeline of the separation device, or to the target liquid outlet of other semi-permeable components, and that the target liquid inlet of at least any one semi-permeable component is connected to the target liquid discharge pipeline of the separation device, and the target liquid outlet of at least any one semi-permeable component is connected to the concentrate discharge pipeline.

[0019] The auxiliary liquid flow path is configured such that the auxiliary liquid inlet of each semi-permeable component is connected to the liquid discharge pipeline of the separation device or to the auxiliary liquid outlet of other semi-permeable components, and the auxiliary liquid inlet of at least any semi-permeable component is connected to the liquid discharge pipeline of the separation device, and the auxiliary liquid outlet of at least any semi-permeable component is connected to the dilution auxiliary liquid discharge pipeline.

[0020] [2] The concentration system for the target material in the solution according to [1] is characterized in that,

[0021] The semi-permeable device comprises a single-stage semi-permeable component.

[0022] The target liquid inlet of the semi-permeable component is connected to the target liquid outlet of the separation device, and the target liquid outlet of the semi-permeable component is connected to the concentrate outlet.

[0023] The auxiliary liquid inlet of the semi-permeable component is connected to the liquid discharge pipeline of the separation device, and the auxiliary liquid outlet of the semi-permeable component is connected to the dilution auxiliary liquid discharge pipeline.

[0024] [3] The concentration system for the target material in the solution according to [1] is characterized in that the semi-permeable device comprises multiple stages of semi-permeable components sequentially along the flow direction of the target liquid.

[0025] The target liquid inlet of the first-stage semi-permeable component is connected to the target liquid outlet pipeline of the separation device.

[0026] Except for the first-stage semi-permeable component, the target liquid inlet of each semi-permeable component is connected to the target liquid outlet of the previous stage semi-permeable component, or to the target liquid discharge pipeline of the separation device.

[0027] The target liquid outlet of the final semi-permeable component is connected to the concentrate discharge pipeline.

[0028] [4] The concentration system for the target material in the solution according to [3] is characterized in that,

[0029] The auxiliary liquid inlet of the first-stage semi-permeable component is connected to the liquid discharge pipeline of the separation device.

[0030] The auxiliary liquid inlet of each semi-permeable module, except for the first-stage semi-permeable module, is connected to the auxiliary liquid outlet of the previous-stage semi-permeable module, or to the discharge pipeline of the separation device.

[0031] The auxiliary liquid outlet of the final stage semi-permeable component is connected to the dilution auxiliary liquid discharge pipeline.

[0032] The auxiliary liquid outlet of each semi-permeable component, except for the last stage semi-permeable component, is connected to the auxiliary liquid inlet of the next stage semi-permeable component, or to the dilution auxiliary liquid discharge pipeline.

[0033] [5] The concentration system for the target material in the solution according to [3] is characterized in that the auxiliary liquid inlet of the first-stage semi-permeable component is connected to the liquid discharge pipeline of the separation device.

[0034] Except for the first-stage semi-permeable module, the auxiliary liquid inlet of each semi-permeable module is connected to the auxiliary liquid outlet of the previous stage semi-permeable module.

[0035] The auxiliary liquid outlet of the last stage semi-permeable component is connected to the dilution auxiliary liquid discharge pipeline.

[0036] [6] A concentration system for a target material in a solution according to any one of [1] to [5], characterized in that the separation component comprises at least one selected from the group consisting of an adsorbent, a solvent extractor, a molecular sieve, a nanofiltration membrane, and an ion exchange resin.

[0037] [7] A concentration system for the target material in a solution according to any one of [1] to [5], characterized in that the concentration system further comprises a pretreatment device,

[0038] The pretreatment device is located between the separation device and the semi-permeation device.

[0039] The pretreatment device includes at least one selected from the group consisting of microfiltration membranes and ultrafiltration membranes.

[0040] [8] A concentration system for a target material in a solution according to any one of [1] to [5], characterized in that the concentration system further comprises a pre-concentration device.

[0041] The pre-concentration unit is located between the separation unit and the semi-permeation unit.

[0042] The pre-concentration device includes a reverse osmosis membrane or an evaporation pond.

[0043] [9]. A concentration system for a target material in a solution according to any one of [1] to [5], characterized in that the semi-permeable membrane is a hollow fiber membrane.

[0044]

[10] A concentration system for the target material in a solution according to any one of [1] to [5], characterized in that the concentration system further comprises a pressurization device,

[0045] The pressurizing device is configured to apply mechanical pressure to at least any one of the semi-permeable components contained in the semi-permeable device.

[0046]

[11] A method for concentrating a target material in a solution, characterized by comprising the following steps:

[0047] The separation process separates the solution into a target liquid and a discharge liquid with a target material concentration lower than that of the target liquid and an osmotic pressure higher than or equal to that of the target liquid; and...

[0048] The semi-permeable process involves concentrating the target liquid by passing it through one side of a semi-permeable membrane and passing an auxiliary liquid, at least partially containing the drained liquid, through the other side of the semi-permeable membrane to obtain a concentrated solution.

[0049] When the osmotic pressure of the drained liquid is higher than the osmotic pressure of the target liquid, mechanical pressure may or may not be applied during the semi-permeation process.

[0050] When the osmotic pressure of the drained liquid is equal to the osmotic pressure of the target liquid, mechanical pressure is applied during the semi-permeation process.

[0051]

[12] The method for concentrating the target material in the solution according to

[11] is characterized in that,

[0052] The concentration method does not include: refluxing at least a portion of the concentrate obtained from the semi-permeation process back into the semi-permeation process as at least a portion of the auxiliary liquid.

[0053]

[13] The method for concentrating target material in solution according to

[11] is characterized in that the concentration system for target material in solution described in any one of [1] to

[10] is used.

[0054]

[14] The method for concentrating the target material in the solution according to

[11] is characterized in that it further comprises:

[0055] The pretreatment step, which occurs after the separation step and before the semi-permeation step, removes impurities from the target liquid.

[0056]

[15] The method for concentrating the target material in the solution according to

[11] is characterized in that it further comprises:

[0057] The pre-concentration step, which is performed after the separation step and before the semi-permeation step, involves pre-concentrating the target liquid in such a way that the osmotic pressure of the pre-concentrated target liquid is not higher than that of the drained liquid.

[0058] Effects of the utility model

[0059] According to the present invention, the concentration system and method for target materials in solution can efficiently concentrate target materials in solution by combining a separation device with a semi-permeable device, thereby significantly improving the concentration.

[0060] Furthermore, according to the present invention, the concentration system and method for the target material in the solution, by using the drain generated by the separation device as at least a part of the auxiliary liquid flowing on the side opposite to the target liquid separated by a semipermeable membrane, compared with the osmotic pressure-assisted reverse osmosis technology based on the return of the concentrate, a higher concentration can be achieved using fewer semipermeable membrane elements, thus significantly reducing the investment and operating costs of the equipment and achieving better economic benefits.

[0061] Furthermore, by utilizing the wastewater generated by the separation device that was previously discarded as an auxiliary liquid in the semi-permeable device, this invention can reduce or eliminate the use of additional auxiliary liquid, thus saving materials and equipment used for obtaining and regenerating the auxiliary liquid. Attached Figure Description

[0062] Figure 1 This is a schematic diagram of the concentration system of this utility model.

[0063] Figure 2 This is a schematic diagram of the concentration system of the present invention, which includes only a single-stage semi-permeable component.

[0064] Figure 3 This is a schematic diagram illustrating the concentration system of the present invention, which includes multi-stage semi-permeable components.

[0065] Figure 4 This is a schematic diagram illustrating one embodiment of the concentration system of this utility model.

[0066] Figure 5This is a schematic diagram illustrating one embodiment of the auxiliary liquid flow path of the concentration system of this utility model.

[0067] Figure 6 This is a schematic diagram illustrating another embodiment of the auxiliary liquid flow path of the concentration system of this utility model.

[0068] Figure 7 This is a schematic diagram illustrating another embodiment of the auxiliary liquid flow path of the concentration system of this utility model.

[0069] Figure 8 This is a schematic diagram illustrating another embodiment of the auxiliary liquid flow path of the concentration system of this utility model.

[0070] Figure 9 This is a schematic diagram illustrating another embodiment of the auxiliary liquid flow path of the concentration system of this utility model.

[0071] Figure 10 This is a schematic diagram illustrating another embodiment of the auxiliary liquid flow path of the concentration system of this utility model.

[0072] Figure 11 This is a schematic diagram illustrating another embodiment of the concentration system of this utility model.

[0073] Figure 12 This is a schematic diagram illustrating another embodiment of the concentration system of this utility model.

[0074] Figure 13 This is a schematic diagram illustrating another embodiment of the concentration system of this utility model.

[0075] Figure 14 This is a schematic diagram illustrating another embodiment of the concentration system of this utility model.

[0076] Figure 15 A schematic diagram of an osmotic pressure-assisted reverse osmosis concentration system based on concentrate reflux, as shown in a comparative example of the present invention.

[0077] Explanation of reference numerals in the attached figures

[0078] 1. Separation device

[0079] 11 Solution inlet tubing

[0080] 12 Separate components

[0081] 13. Object liquid discharge pipeline

[0082] 14 Drainage drain line

[0083] 2. Semi-permeable device

[0084] 20 Semi-permeable modules

[0085] 21 Semi-permeable membrane

[0086] 22 containers

[0087] Room 210, Room 1

[0088] 211 Target Liquid Inlet

[0089] 212 Target liquid outlet

[0090] Room 220

[0091] 221 Auxiliary fluid import

[0092] 222 Auxiliary fluid outlet

[0093] 3. Concentrate Discharge Pipeline

[0094] 4. Dilution auxiliary solution discharge pipeline

[0095] 5. Flow path of the object fluid

[0096] 6. Auxiliary fluid flow path

[0097] 7 pumps

[0098] 8. Pressurization device Detailed Implementation

[0099] Various exemplary embodiments, features, and aspects of the present invention will be described in detail below. The term "exemplary" as used herein means "serving as an example, embodiment, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as superior to or better than other embodiments.

[0100] Furthermore, to better illustrate this utility model, numerous specific details are provided in the following detailed embodiments. Those skilled in the art should understand that this utility model can be implemented without certain specific details. In other instances, methods, means, equipment, and steps well-known to those skilled in the art have not been described in detail, in order to highlight the main points of this utility model.

[0101] Unless otherwise stated, all units used in this specification are international standard units, and all numerical values ​​and ranges appearing in this utility model should be understood to include systematic errors that are unavoidable in industrial production.

[0102] In this specification, the word "may" has two meanings: to perform a certain process and not to perform a certain process.

[0103] In this specification, references to "some specific / preferred embodiments," "other specific / preferred embodiments," "implementation," etc., refer to specific elements (e.g., features, structures, properties, and / or characteristics) related to that embodiment, which are included in at least one of the embodiments described herein and may or may not be present in other embodiments. Furthermore, it should be understood that these elements may be combined in any suitable manner in various embodiments.

[0104] In this specification, the range of values ​​referred to as "value A to value B" refers to the range including the endpoint values ​​A and B.

[0105] [Concentration system for target material in solution]

[0106] One embodiment of this invention is a concentration system for a target material in a solution. In this invention, a solution refers to a solution containing at least one solvent, the target material, and at least one other solute besides the target material. The concentration system of this invention is preferably used to obtain a high-concentration concentrate of the target material from solutions containing many and / or high amounts of other solutes, and is particularly preferred for the recovery of high-value substances such as brine concentration, lithium extraction from salt lakes, seawater salt production, or precious metals.

[0107] Figure 1 The diagram schematically illustrates the concentration system for a target material in solution according to this invention. Wherein, Figure 1 The concentration system for the target material in the solution shown includes a separation device 1, a semi-permeable device 2, a concentrate discharge pipeline 3, a dilution auxiliary liquid discharge pipeline 4, a target liquid flow path 5, and an auxiliary liquid flow path 6. Each part is described below.

[0108] [Separation device]

[0109] The aforementioned separation device 1 is configured to separate the solution into a target liquid and a discharge liquid whose concentration is lower than that of the target liquid and whose osmotic pressure is higher than or equal to that of the target liquid. For example... Figure 1 As shown, the separation device 1 includes a solution inlet pipe 11, a separation component 12, a target liquid outlet pipe 13, and a drain pipe 14. Here, "osmotic pressure higher than the target liquid" means that the osmotic pressure of the drained liquid is greater than that of the target liquid, while "osmotic pressure equal to the target liquid" means that the osmotic pressure of the drained liquid is substantially equal to that of the target liquid. This includes not only the case where the osmotic pressure of the drained liquid is equal to that of the target liquid, but also the case where the osmotic pressure of the drained liquid is only less than 1 MPa lower than that of the target liquid, which is considered substantially equal in the art.

[0110] The aforementioned separation component 12 can be used without particular restriction as long as it can separate the solution, which is the raw liquid, into a enriched solution with a high concentration of the target material and a lean solution with a low concentration of the target material. Examples of separation components include adsorbents, solvent extraction, molecular sieves, nanofiltration membranes, ion exchange resins, and combinations thereof. From the viewpoint of low cost and high throughput, adsorbents are preferred. The method of separating the raw liquid using the separation component 12 can employ known operating procedures depending on the type of component used. For example, if the separation component 12 contains an adsorbent, the target material can be selectively adsorbed by contacting the raw liquid with the adsorbent, and then the target material adsorbed on the adsorbent can be eluted to obtain a enriched solution with a high concentration of the target material; while the raw liquid becomes a lean solution with a low concentration of the target material after the target material is adsorbed by the adsorbent.

[0111] The aforementioned enriched solution and lean solution can be used as the target solution and discharge solution obtained by the separation device 1, respectively, after the osmotic pressure is appropriately adjusted using known methods as needed. Typically, when the original solution contains a large amount of other solutes relative to the target material, for example, more than 100 times by weight, in a specific case, such as when the concentration system of this invention is used for lithium extraction from a preferred salt lake, the osmotic pressure of the enriched solution obtained by the separation component 12 is less than or equal to that of the lean solution. Therefore, the aforementioned enriched solution can be directly used as the target solution obtained by the separation device 1, and the aforementioned lean solution can be directly used as the discharge solution obtained by the separation device 1.

[0112] Thus, the aforementioned separation device 1 separates the original solution into a target liquid and a discharge liquid with a target material concentration lower than that of the target liquid and an osmotic pressure higher than or equal to that of the target liquid. In embodiments where the osmotic pressure of the discharge liquid is higher than that of the target liquid, from the viewpoint of further reducing equipment and energy consumption costs, a concentrated liquid with an osmotic pressure higher than the target concentration is preferred.

[0113] like Figure 1 As shown, the aforementioned target liquid discharge pipe 13 and drain liquid discharge pipe 14 are respectively connected to the semi-permeable device 2 and are configured to introduce the target liquid and drain liquid into the semi-permeable device 2, respectively. The target liquid is concentrated in the semi-permeable device 2, and the drain liquid, which constitutes at least a portion of the auxiliary liquid, is diluted in the semi-permeable device 2. The auxiliary liquid may partially contain the drain liquid or may consist solely of the drain liquid, as long as the osmotic pressure of the auxiliary liquid before it is introduced into the semi-permeable device 2 is higher than or equal to that of the target liquid.

[0114] In addition, pressurizing devices (not shown) may be provided in the target liquid discharge line 13 and the discharge line 14, respectively. The aforementioned pressurizing devices are used to apply mechanical pressure to the target liquid and / or discharge liquid to be introduced into the semi-permeable device 2.

[0115] [Semi-permeable device]

[0116] The aforementioned semi-permeable device 2 is configured to concentrate the target liquid and dilute the auxiliary liquid, which at least partially contains the aforementioned drained liquid. When the auxiliary liquid consists solely of the aforementioned drained liquid, the auxiliary liquid is the drained liquid, and therefore the osmotic pressure of the auxiliary liquid introduced into the semi-permeable device 2 is higher than or equal to that of the target liquid. When the auxiliary liquid also contains other components besides the aforementioned drained liquid, the type, amount, and introduction method of the other components are appropriately selected such that the osmotic pressure of the auxiliary liquid introduced into the semi-permeable device 2 is higher than or equal to that of the target liquid. From the viewpoint of saving material and equipment costs, it is preferable not to use these other components, i.e., to use only the aforementioned drained liquid as the auxiliary liquid.

[0117] like Figure 1 As shown, the aforementioned semi-permeable device 2 includes a semi-permeable component 20. The semi-permeable component 20 has a semi-permeable membrane 21 and a container 22. The internal space of the container 22 is divided by the semi-permeable membrane 21 into a first chamber 210 and a second chamber 220. The first chamber 210 has a target liquid inlet 211 and a target liquid outlet 212, and the second chamber 220 has an auxiliary liquid inlet 221 and an auxiliary liquid outlet 222. In the semi-permeable component 20, the solvent in the target liquid moves from the first chamber 210 through the semi-permeable membrane 21 to the second chamber 220 by the action of osmotic pressure difference and / or mechanical pressure, thereby concentrating the target liquid while simultaneously diluting the auxiliary liquid.

[0118] The aforementioned semi-permeable component 20 can be single-stage or multi-stage. From the viewpoint of increasing the concentration, multi-stage is preferred, more preferably three-stage or more, more preferably four-stage or more, and even more preferably five-stage or more.

[0119] In the semi-permeable device 2, the driving force for moving the solvent in the target liquid from the first chamber 210 through the semi-permeable membrane 21 to the second chamber 220 in the semi-permeable component 20 can be at least one of the osmotic pressure difference between the auxiliary liquid and the target liquid (also denoted as osmotic pressure difference) and mechanical pressure. It should be noted that in this invention, the osmotic pressure difference in the semi-permeable component 20 is the value obtained by subtracting the osmotic pressure of the target liquid from the osmotic pressure of the auxiliary liquid. Only when this osmotic pressure difference is positive can it function as the driving force for moving the solvent from the first chamber 210 to the second chamber 220. When the osmotic pressure difference is 0 or negative, mechanical pressure must be applied as the driving force.

[0120] In this invention, the mechanical pressure in the semi-permeable component 20 refers to the difference between the mechanical pressure applied to the target liquid and the mechanical pressure applied to the auxiliary liquid, i.e., the mechanical pressure applied to the target liquid minus the mechanical pressure applied to the auxiliary liquid. Therefore, this mechanical pressure is sometimes referred to as the mechanical pressure difference in the following text. Where no mechanical pressure is applied to the auxiliary liquid, the mechanical pressure difference is equal to the mechanical pressure applied to the target liquid. When the mechanical pressure difference is positive, it means that mechanical pressure exists as a driving force.

[0121] In this invention, the osmotic pressure of the auxiliary liquid introduced before the semi-permeable device 2 is higher than or equal to that of the target liquid. In the semi-permeable assembly 20, the target liquid is concentrated, resulting in a higher osmotic pressure, while the auxiliary liquid is diluted, resulting in a lower osmotic pressure. Therefore, in the semi-permeable assembly 20, especially in a multi-stage semi-permeable assembly 20, the relationship between the osmotic pressure of the target liquid and the osmotic pressure of the auxiliary liquid may differ from that before it is introduced into the semi-permeable device 2. Therefore, in each stage of the semi-permeable assembly 20, the osmotic pressure difference and the mechanical pressure can be independently positive, negative, or zero, and their individual values ​​are not particularly limited, as long as the sum of the osmotic pressure difference and the mechanical pressure is positive.

[0122] The aforementioned driving force can be expressed by the following formula.

[0123] Driving force Dp= P+ π>0

[0124] P = (P 对象液 -P 辅助液 )

[0125] π = (π) 辅助液 -π 对象液 )

[0126] π represents osmotic pressure, measured in MPa; P represents mechanical pressure, also measured in MPa. P is the mechanical pressure difference. π represents the osmotic pressure difference.

[0127] In this invention, as long as the osmotic pressure difference is used as the driving force in at least one stage of the semi-permeable component 20, it is considered that the osmotic pressure difference is used as the driving force in the semi-permeable device 2; similarly, as long as the mechanical pressure is used as the driving force in at least one stage of the semi-permeable component 20, it is considered that the mechanical pressure is used as the driving force in the semi-permeable device 2.

[0128] In this invention, any one of osmotic pressure difference and mechanical pressure can be used as the driving force in the semi-permeable device 2, and there are no particular restrictions on the composition of the driving force in each stage of the semi-permeable component 20. When the driving force in the semi-permeable device 2 is only osmotic pressure difference, it may include, but is not limited to, the following situations: no mechanical pressure is applied; the mechanical pressure applied to the target liquid is equal to the mechanical pressure applied to the auxiliary liquid, and there is no mechanical pressure difference across the semi-permeable membrane. When the driving force in the semi-permeable device 2 is only mechanical pressure, it may include, but is not limited to, the following situations: in each stage of the semi-permeable component 20 in the semi-permeable device 2, there is no osmotic pressure difference across the semi-permeable membrane, i.e., the osmotic pressure of the target liquid is kept equal to that of the auxiliary liquid; in a portion of the semi-permeable components 20 in the semi-permeable device 2, there is no osmotic pressure difference across the semi-permeable membrane, while in another portion of the semi-permeable components 20, there is a reverse osmotic pressure difference, i.e., the osmotic pressure of the target liquid is greater than that of the auxiliary liquid. When the driving force in the semi-permeable device 2 is osmotic pressure difference and mechanical pressure, it may include, but is not limited to, the following situations: osmotic pressure difference and mechanical pressure exist as driving forces in each stage of the semi-permeable module 20; both osmotic pressure difference and mechanical pressure exist in some of the semi-permeable modules 20, while only either osmotic pressure difference or mechanical pressure exists in other of the semi-permeable modules 20; only osmotic pressure difference exists in some of the semi-permeable modules 20, while only mechanical pressure exists in other of the semi-permeable modules.

[0129] For any stage of the semi-permeable module 20, when the osmotic pressure of the target liquid in the first chamber 210 is lower than the osmotic pressure of the auxiliary liquid in the second chamber 220, the aforementioned driving force may consist solely of the aforementioned osmotic pressure difference, or mechanical pressure may be further applied. For any stage of the semi-permeable module 20, when the osmotic pressure of the target liquid in the first chamber 210 is equal to the osmotic pressure of the auxiliary liquid in the second chamber 220, mechanical pressure must be applied as the driving force. For any stage of the semi-permeable module 20, when the osmotic pressure of the target liquid in the first chamber 210 is higher than the osmotic pressure of the auxiliary liquid in the second chamber 220, mechanical pressure must be applied, a portion of which is used to counteract the reverse osmotic pressure difference, and the remainder serves as the driving force.

[0130] In the concentration system of this invention, from the viewpoint of saving energy and equipment costs, it is preferable that the aforementioned osmotic pressure difference is positive in at least a portion of the semi-permeable components, and more preferably that the aforementioned osmotic pressure difference is positive in more than half of the semi-permeable components. In another preferred embodiment of the concentration system of this invention, from the viewpoint of balancing concentration efficiency and cost, the aforementioned mechanical pressure difference is positive in more than half of the semi-permeable components, and more preferably that the aforementioned mechanical pressure difference is positive in all the semi-permeable components.

[0131] In a preferred embodiment, the osmotic pressure of the auxiliary liquid introduced into the semi-permeable device 2 is much higher than that of the target liquid. Specifically, preferably, the osmotic pressure of the auxiliary liquid is higher than that of the concentrate of the target concentration, or the difference in osmotic pressure between the auxiliary liquid and the target liquid exceeds 20 MPa. In this case, there is a tendency to ensure that the difference in osmotic pressure in each stage of the semi-permeable component 20 is sufficient to drive the solvent from the first chamber 210 to the second chamber 220, thus reducing or eliminating the use of mechanical pressure as a driving force to further save energy and equipment costs.

[0132] In another preferred embodiment, the osmotic pressure of the auxiliary liquid introduced into the semi-permeable device 2 is equal to that of the target liquid, and the osmotic pressure difference in each stage of the semi-permeable component 20 is 0 or negative. In this case, a portion of the mechanical pressure applied to each stage of the semi-permeable component 20 offsets the negative osmotic pressure difference, and the remainder acts as a driving force. From the viewpoint of balancing concentration efficiency and low cost, it is preferable that the difference between the osmotic pressure of the target liquid in the first chamber 210 and the osmotic pressure of the auxiliary liquid in the second chamber 220 in each stage of the semi-permeable component 20 is less than 8 MPa, and more preferably less than 3 MPa.

[0133] The aforementioned mechanical pressure can be implemented using a pressurizing device (not shown) installed as needed between the separation unit and the semi-permeation unit, and / or between the semi-permeation components. From the viewpoint of balancing concentration efficiency and cost, it is preferable to install the pressurizing device between the separation unit and the semi-permeation unit. As a method of installing the pressurizing device between the separation unit and the semi-permeation unit, for example, the pressurizing device can be installed in one or both of the target liquid discharge line 13 and the discharge line 14. Preferably, the pressurizing device is installed near the target liquid inlet 211 in the first-stage semi-permeation component 20F, or pressurizing devices are installed near the target liquid inlet 211 and the auxiliary liquid inlet 221 in the first-stage semi-permeation component 20F, respectively. As the pressurizing device, there is no particular limitation as long as it can impart mechanical pressure to the target liquid and / or auxiliary liquid in the semi-permeation unit 2; a booster pump is typically used.

[0134] In the case of a multi-stage semi-permeable module, pressurization devices (not shown) can be provided between the semi-permeable modules as needed. When pressurization devices are provided between the multi-stage semi-permeable modules 20, the driving force between the target liquid and the auxiliary liquid in the semi-permeable module can be adjusted, which is preferable from the perspective of improving concentration efficiency. On the other hand, if the first-stage semi-permeable module 20F has a very large driving force, for example, exceeding 20 MPa, by providing a pressurization device between the separation unit and the semi-permeable unit, there is a tendency to ensure sufficient driving force in each stage of the semi-permeable module. Therefore, from the viewpoint of saving equipment and energy costs, it is preferable to provide pressurization devices only between the separation unit and the semi-permeable unit, and not to provide pressurization devices between the multi-stage semi-permeable modules 20 in the semi-permeable unit 21.

[0135] In the semi-permeable device 2 of this invention, each stage of the semi-permeable assembly 20 may also include multiple semi-permeable units. Each semi-permeable unit is a semi-permeable membrane element composed of a single semi-permeable membrane. When the semi-permeable assembly 20 includes multiple semi-permeable units, these units can be connected in series, in parallel, or a combination of series and parallel. From the perspective of equipment setup and process control operability, it is preferable that the multiple semi-permeable units in each stage of the semi-permeable assembly 20 are connected in parallel. In this case, each semi-permeable unit has a sub-semi-permeable membrane and a first sub-chamber and a second sub-chamber (not shown) separated by the sub-semi-permeable membrane. The sub-semi-permeable membranes of these semi-permeable units together constitute the semi-permeable membrane 21 of the semi-permeable assembly 20; the first sub-chambers of these semi-permeable units together constitute the first chamber 210 of the semi-permeable assembly 20; and the second sub-chambers of these semi-permeable units together constitute the second chamber 220 of the semi-permeable assembly 20.

[0136] The aforementioned semi-permeable membranes can be used without particular restrictions as long as they allow the solvent in the solution to pass through while intercepting the target material. Examples of semi-permeable membranes include those called forward osmosis membranes (FO membranes), reverse osmosis membranes (RO membranes), osmically assisted reverse osmosis membranes (OARO membranes), nanofiltration membranes (NF membranes), and ultrafiltration membranes (UF membranes). Forward osmosis membranes or osmically assisted reverse osmosis membranes are preferred. It should be noted that, when a forward osmosis membrane or a osmosis-assisted reverse osmosis membrane is used as a semi-permeable membrane, from the viewpoint of improving concentration efficiency, the osmotic pressure of the target liquid obtained by the separation device 1 is preferably 0 to 20 MPa, more preferably 0 to 10 MPa; the osmotic pressure of the auxiliary liquid containing the discharge obtained by the separation device 1 when it is about to be introduced into the semi-permeable device 2 is preferably 10 to 50 MPa, more preferably 20 to 40 MPa.

[0137] The materials constituting the semipermeable membrane are not particularly limited, but examples include cellulose-based, polysulfone-based, and polyamide-based materials. The semipermeable membrane is preferably composed of a material containing at least one of cellulose-based and polysulfone-based materials. Cellulose-based materials are preferably cellulose acetate-based. Cellulose acetate-based materials are resistant to chlorine as a bactericide and have the characteristic of inhibiting the proliferation of microorganisms. Cellulose acetate-based materials are preferably cellulose acetate, and from the viewpoint of durability, cellulose triacetate is more preferred. Polysulfone-based materials are preferably polyethersulfone-based. Sulfonated polyethersulfone-based materials are particularly preferred.

[0138] It should be noted that, for simplicity, the semi-permeable membrane 21 is depicted as a flat membrane in the accompanying drawings, but the shape of the semi-permeable membrane is not particularly limited in this invention. The semi-permeable membrane 21 can be, for example, a flat membrane such as a spiral membrane (spiral semi-permeable membrane), or a hollow fiber membrane (hollow fiber semi-permeable membrane). Compared to a flat membrane, a hollow fiber membrane has a smaller membrane thickness and can increase the membrane area of ​​each component, making it preferred from the viewpoint of improving concentration efficiency. From the viewpoint of improving concentration efficiency, it is further preferred to use an externally pressurized hollow fiber membrane. This is because the pressure loss is small when external pressure is applied and the hollow fiber membrane needles are less likely to rupture due to pressure. In other words, when using a hollow fiber membrane as the semi-permeable membrane 21, it is preferable that the outer side of the hollow fiber membrane is the first chamber 210 and the inner side (hollow portion) of the hollow fiber membrane is the second chamber 220.

[0139] As a specific example of a hollow fiber membrane, a membrane with a monolayer structure composed entirely of cellulose can be cited. However, the monolayer structure referred to here does not need to be a membrane with a uniform overall thickness; for example, it can also be a membrane that is non-uniform in the thickness direction. Specifically, it can also be a membrane with a dense layer on the outer peripheral surface, which becomes a separation active layer that substantially defines the pore size of the hollow fiber membrane, and the density on the inner peripheral surface side is lower than that of the dense layer. Since the dense layer becomes a separation active layer that substantially defines the pore size of the hollow fiber membrane, when the solution outside the hollow fiber membrane is pressurized, the movement of molecules from the outside to the inside of the hollow fiber membrane can be accurately controlled.

[0140] Other examples of specific hollow fiber membranes include two-layer membranes having a dense layer of polyphenylene oxide (e.g., sulfonated polyethersulfone) on the outer peripheral surface of a support layer (e.g., a layer made of polyphenylene ether). Additionally, as another example, two-layer membranes having a dense layer of polyamide on the outer peripheral surface of a support layer (e.g., a layer made of polysulfone or polyethersulfone).

[0141] For semipermeable membrane elements based on hollow fiber membranes, there are no particular limitations; well-known and commonly used components or commercially available products can be used. Examples of commercially available products include, for instance, the Hollosop (registered trademark) series manufactured by TOYOBO MC Corporation.

[0142] [Concentrate Discharge Pipeline]

[0143] The aforementioned concentrate discharge pipe 3 is configured to extract the concentrate obtained by passing the target liquid through the aforementioned semi-permeation device 2 to the outside of the device. The concentrate obtained by the concentration system of this invention contains less solvent and has a high concentration of the target material, which is beneficial for better subsequent processing of the target material. From the viewpoint of improving concentration efficiency, the osmotic pressure of the concentrate is preferably not less than 7 MPa, and more preferably 15 MPa or more.

[0144] Unlike conventional osmotic pressure-assisted reverse osmosis technology based on concentrate reflux, this invention does not have a pipeline for refluxing at least a portion of the concentrate back to the second chamber 220 of any stage of the semi-permeable component 20 in the aforementioned semi-permeable device 2. In other words, in the concentration system of this invention, the auxiliary liquid in the semi-permeable device 2 does not contain the concentrate obtained from the semi-permeable device 2, thus achieving high concentration efficiency and reducing the number of semi-permeable membrane elements used.

[0145] Furthermore, in conventional osmotic-assisted reverse osmosis (ROS) technology based on concentrate recirculation, since the concentrate containing a large amount of the target material is recirculated to the dilution side, in order to recover the target material in the auxiliary liquid and improve the concentration efficiency, it is usually necessary to recirculate the auxiliary liquid diluted on the dilution side of the semi-permeable unit back to the concentration side of the semi-permeable unit, thus further increasing the number of semi-permeable membrane elements required. Compared with such osmotic-assisted RO technology based on concentrate recirculation, this invention uses the discharge from the separation device as the auxiliary liquid for the dilution side, instead of using the concentrate, thereby significantly reducing the number of semi-permeable membrane elements required while achieving high concentration.

[0146] [Dilution aid drain line]

[0147] The aforementioned dilution auxiliary liquid discharge pipe 4 is configured to discharge the auxiliary liquid diluted by the aforementioned semi-permeable device 2 to the outside of the device. This invention utilizes the wastewater previously discarded by the separation device as the auxiliary liquid in the semi-permeable device, which can reduce the number of semi-permeable membrane elements used and concentrate the target material in the solution at low cost and high efficiency. Furthermore, it can reduce or eliminate the use of additional auxiliary liquid, thus saving materials and equipment used for preparing and regenerating the auxiliary liquid. For example, the number of semi-permeable membrane elements used can be reduced by at least half, preferably to less than one-third, and more preferably to less than one-quarter.

[0148] [Object fluid flow path]

[0149] The aforementioned target liquid flow path 5 is connected to the target liquid discharge pipeline 13 of the separation device 1, the first chamber 210 of the semi-permeable component 20 of each stage of the semi-permeable device, and the concentrate discharge pipeline 3.

[0150] In the target liquid flow path 5, the target liquid inlet 211 of each stage of the semi-permeable component 20 is connected to the target liquid discharge line 13 of the separation device 1, or to the target liquid outlet 212 of other semi-permeable components 20. Furthermore, the target liquid inlet 211 of at least any stage of the semi-permeable component 20 is connected to the target liquid discharge line 13 of the separation device 1, and the target liquid outlet 212 of at least any stage of the semi-permeable component 20 is connected to the concentrate discharge line 3. Thus, the target liquid from the target liquid discharge line 13 flows through the first chamber 210 of each stage of the semi-permeable component 20 in the semi-permeable device 2 before flowing to the concentrate discharge line 3.

[0151] In the aforementioned semi-permeable device 2, as Figure 2In the case shown, which only includes a single-stage semi-permeable component 20, the target liquid inlet 211 of the semi-permeable component 20 is connected to the target liquid discharge pipeline 13 of the separation device 1, and the target liquid outlet 212 of the semi-permeable component 20 is connected to the concentrate discharge pipeline 3.

[0152] In the aforementioned semi-permeable device 2, as Figure 3 In the case of a multi-stage semi-permeable module 20 as shown, there are no particular restrictions on the connection method between the first chambers 210 of each stage of the semi-permeable module 20, as long as there are direct connections (such as...) in the first chamber 210 of each stage of the semi-permeable module 20. Figure 3 (as shown by the dashed line above) or indirectly (such as...) Figure 3 (As shown by the dotted line at the top) The object liquid from the object liquid discharge pipe 13 flows in from the object liquid inlet 211 and flows out from the object liquid outlet 212.

[0153] From the viewpoint of improving concentration efficiency, it is preferable that the semi-permeable device 2 includes multiple semi-permeable components 20 sequentially along the flow direction of the target liquid. The target liquid inlet 211 of the first-stage semi-permeable component 20F is connected to the target liquid discharge pipe 13 of the separation device 1. The target liquid inlet 211 of each semi-permeable component other than the first-stage semi-permeable component 20F is connected to the target liquid outlet 212 of the previous-stage semi-permeable component or to the target liquid discharge pipe 13 of the separation device 1. The target liquid outlet 212 of the last-stage semi-permeable component 20L is connected to the concentrate discharge pipe 3.

[0154] From the perspective of improving concentration efficiency, a further preferred option is, such as Figure 4 As shown, the semi-permeable device 2 includes multiple semi-permeable components 20 sequentially along the flow direction of the target liquid. The target liquid inlet 211 of the first-stage semi-permeable component 20F is connected to the target liquid discharge pipeline 13 of the separation device 1. The target liquid inlet 211 of each semi-permeable component except the first-stage semi-permeable component 20F is connected to the target liquid outlet 212 of the previous stage semi-permeable component. The target liquid outlet 212 of the last-stage semi-permeable component 20L is connected to the concentrate discharge pipeline 3.

[0155] A pressurizing device (not shown) can be installed in the aforementioned target liquid flow path 5 as needed. Typical locations for installing the pressurizing device include: between the separation device 1 and the semi-permeation device 2, for example, in the target liquid discharge line 13, or between the target liquid discharge line 13 and the target liquid inlet 211 of any stage of the semi-permeation assembly; between multiple stages of the semi-permeation assembly, for example, between the target liquid inlet 211 of any stage of the semi-permeation assembly and the target liquid outlet 212 of the previous stage of the semi-permeation assembly, or near the target liquid inlet 211 of any stage of the semi-permeation assembly other than the first stage of the semi-permeation assembly 20F. From the viewpoint of achieving a balance between energy saving and improving concentration efficiency, it is preferable to install a pressurizing device between the separation device 1 and the semi-permeation device 2, especially in the target liquid discharge line 13. There are no particular limitations on the pressurizing device; a booster pump can typically be used.

[0156] In addition, in order to monitor the state of the target liquid in the flow path, auxiliary devices such as flow meters, pressure gauges, and concentration meters can be installed at any position in the target liquid flow path 5 as needed (not shown).

[0157] [Auxiliary fluid flow path]

[0158] The aforementioned auxiliary liquid flow path 6 is connected to the discharge pipe 14 of the separation device 1, the second chamber 220 of the semi-permeable component 20 of each stage of the semi-permeable device 2, and the dilution auxiliary liquid discharge pipe 4.

[0159] In the auxiliary liquid flow path 6, the auxiliary liquid inlet 221 of each stage of the semi-permeable component 20 is connected to the discharge pipe 14 of the separation device 1, or to the auxiliary liquid outlet 222 of other semi-permeable components 20. Furthermore, the auxiliary liquid inlet 221 of at least any stage of the semi-permeable component 20 is connected to the discharge pipe 14 of the separation device 1, and the auxiliary liquid outlet 222 of at least any stage of the semi-permeable component 20 is connected to the dilution auxiliary liquid discharge pipe 4. Thus, the auxiliary liquid, containing the discharge from the discharge pipe 14, flows through the second chamber 220 of each stage of the semi-permeable component 20 in the semi-permeable device 2 before flowing to the dilution auxiliary liquid discharge pipe 4.

[0160] In the aforementioned semi-permeable device, such as Figure 2 In the case where only a single-stage semi-permeable component 20 is included as shown, the auxiliary liquid inlet 221 of the semi-permeable component 20 is connected to the liquid discharge pipeline 14 of the separation device 1, and the auxiliary liquid outlet 222 of the semi-permeable component 20 is connected to the dilution auxiliary liquid discharge pipeline 4.

[0161] In the aforementioned semi-permeable device 2, as Figure 3In the case of a multi-stage semi-permeable module 20 as shown, there are no particular restrictions on the interconnection of the second chambers 220 of each stage of the semi-permeable module 20, as long as each stage of the semi-permeable module 20 has a direct connection (such as...). Figure 3 (as shown by the dashed line below) or indirectly (such as...) Figure 3 (As shown by the dotted line at the bottom) The auxiliary liquid from the drainage pipe 14 flows in from the auxiliary liquid inlet 221 and flows out from the auxiliary liquid outlet 222.

[0162] From the viewpoint of improving concentration efficiency, it is preferable that the semi-permeable device 2 sequentially includes multiple semi-permeable components 20 along the flow direction of the target liquid. The auxiliary liquid inlet 221 of the first-stage semi-permeable component 20F is connected to the discharge pipe 14 of the separation device 1. The auxiliary liquid inlet 221 of each semi-permeable component other than the first-stage semi-permeable component 20F is connected to the auxiliary liquid outlet 222 of the previous-stage semi-permeable component or to the discharge pipe 14 of the separation device 1. The auxiliary liquid outlet 222 of the last-stage semi-permeable component 20L is connected to the dilution auxiliary liquid discharge pipe 4. The auxiliary liquid outlet 222 of each semi-permeable component other than the last-stage semi-permeable component 20L is connected to the auxiliary liquid inlet 221 of the next-stage semi-permeable component or to the dilution auxiliary liquid discharge pipe 4.

[0163] exist Figures 5-10 The document also shows some examples of specific connection methods for auxiliary fluid flow paths, but is not limited to these. It should be noted that... Figures 5-10 Although pump 7 is shown, it is not mandatory and can be included or omitted as needed. It should be noted that in this utility model, the term "pump" is not limited to "booster pump" but can also include pumps that do not intentionally apply pressure, such as infusion pumps and flow pumps.

[0164] From the perspective of achieving high concentration efficiency at a lower cost, and in order to use little or no auxiliary liquid other than the liquid discharged from the separation unit, it is further preferred that, such as Figure 4 As shown, the semi-permeable device 2 includes multiple semi-permeable components 20 sequentially along the flow direction of the target liquid. The auxiliary liquid inlet 221 of the first-stage semi-permeable component 20F is connected to the liquid discharge pipeline 14 of the separation device 1. The auxiliary liquid inlet 221 of each semi-permeable component 21 except the first-stage semi-permeable component 20F is connected to the auxiliary liquid outlet 222 of the previous stage semi-permeable component 21. The auxiliary liquid outlet 222 of the last-stage semi-permeable component 20L is connected to the dilution auxiliary liquid discharge pipeline 4.

[0165] Alternatively, one can also adopt Figure 11 or Figure 12The auxiliary liquid flow path shown in another embodiment of the concentration system of this utility model is as follows: the semi-permeable device 2 includes multiple semi-permeable components 20 in sequence along the flow direction of the target liquid. The auxiliary liquid inlet 221 of the first-stage semi-permeable component 20F is connected to the liquid discharge pipe 14 of the separation device 1. The auxiliary liquid inlet 221 of each semi-permeable component except the first-stage semi-permeable component 20F is connected to the liquid discharge pipe 14 of the separation device 1. The auxiliary liquid outlet 222 of each semi-permeable component 20 is connected to the dilution auxiliary liquid discharge pipe 4.

[0166] A pressurizing device can be installed in the aforementioned auxiliary liquid flow path 6 as needed. Typical locations for installing the pressurizing device include: between the separation device 1 and the semi-permeable device 2, for example, in the drain line 14, or between the drain line 14 and the auxiliary liquid inlet 221 of any stage of the semi-permeable module; between multiple stages of semi-permeable modules, for example, between the auxiliary liquid inlet 221 of any stage of the semi-permeable module and the auxiliary liquid outlet 222 of the previous stage of the semi-permeable module, or near the auxiliary liquid inlet 221 of any stage of the semi-permeable module other than the first stage of the semi-permeable module 20F. From the viewpoint of improving concentration efficiency, it is preferable to install pressurizing devices between multiple stages of semi-permeable modules to compensate for the pressure loss generated by the auxiliary liquid passing through the second chamber 220 of the semi-permeable module 20. There are no particular limitations on the pressurizing device; a booster pump can typically be used. As a representative example, Figure 13 , Figure 14 Another embodiment of the concentration system of this invention is shown, wherein a pressurizing device 8 is provided between the semi-permeable components. The number and position of the pressurizing devices 8 are not limited to those shown in the figures.

[0167] In addition, in order to monitor the state of the auxiliary liquid in the flow path, auxiliary devices such as flow meters, pressure gauges, and concentration meters can be installed at any position in the auxiliary liquid flow path 6 as needed (not shown).

[0168] In addition, the system of this utility model may also have the following parts.

[0169] [Pretreatment device]

[0170] The concentration system of this invention may also include a pretreatment device (not shown). The pretreatment device can be installed in a desired location as needed, without particular limitation. For example, the pretreatment device can be installed between the separation device and the semi-permeation device to remove impurities therein before the target liquid and / or auxiliary liquid are introduced into the semi-permeation device. From the viewpoint of stable operation of the semi-permeation device, it is preferable to install the pretreatment device between the separation device and the semi-permeation device to remove impurities from the target liquid.

[0171] The aforementioned impurities refer to substances that can cause instability in subsequent process operations. Typically, these may include solids or colloids that easily clog membrane modules, substances that easily corrode modules, and substances that easily cause scaling in the flow path.

[0172] The pretreatment device is not particularly limited as long as it can remove the aforementioned impurities. Examples include multi-media filtration, cartridge filtration coagulation, centrifugation, microfiltration (MF), ultrafiltration (UF), nanofiltration (NF), and any combination thereof. One type of pretreatment device can be used, or two or more can be used in combination. From the viewpoint of removing impurities at low cost and high efficiency, microfiltration membranes or ultrafiltration membranes are preferred.

[0173] [Pre-concentration unit]

[0174] In the concentration system of this invention, a pre-concentration device (not shown) may be added as needed. The pre-concentration device can be positioned at a desired location depending on the object to be pre-concentrated, without particular limitation. For example, a pre-concentration device can be placed between the separation device and the semi-permeation device to pre-concentrate the target liquid obtained from the separation device. The pre-concentration of the target liquid is subject to the following limitation: the osmotic pressure of the pre-concentrated target liquid is not higher than that of the discharge liquid obtained from the separation device, or the auxiliary liquid containing the discharge liquid.

[0175] When using a pre-concentration unit that includes a reverse osmosis membrane, from the viewpoint of protecting the reverse osmosis membrane, it is preferable to provide the aforementioned pretreatment unit before the pre-concentration unit; in other words, the pre-concentration unit is located between the aforementioned pretreatment unit and the separation unit.

[0176] Furthermore, when a pre-concentration system is provided between the separation device and the semi-permeation device, from an economic point of view, it is preferable to place the pre-concentration system in the target liquid flow path to pre-concentrate the target liquid before it enters the semi-permeation device. Examples of suitable locations include, for instance, the target liquid discharge line 13, or near the target liquid inlet 211 in the first-stage semi-permeation assembly 20F.

[0177] When a pre-concentration unit is installed between the separation unit and the semi-permeation unit, there is no particular limitation on the type of pre-concentration unit; for example, reverse osmosis membranes and evaporation ponds are preferred. When using a pre-concentration unit that includes a reverse osmosis membrane, from the viewpoint of protecting the reverse osmosis membrane, it is preferable to install the aforementioned pretreatment unit before the pre-concentration unit; in other words, the pretreatment unit and the pre-concentration unit are sequentially installed in the target liquid flow path between the separation unit and the semi-permeation unit.

[0178] [Add auxiliary fluid flow path]

[0179] The concentration system of this invention utilizes the discharge from the separation device as at least a portion of the auxiliary liquid. However, the auxiliary liquid does not necessarily have to be solely the discharge from the separation device; it can also partially utilize other components besides the discharge from the separation device. In this invention, such other components are referred to as added auxiliary liquid. Therefore, the concentration system of this invention may, as needed, have an added auxiliary liquid flow path (not shown), which is configured to supply the added auxiliary liquid to the semi-permeable device. The aforementioned added auxiliary liquid flow path can be configured to allow the added auxiliary liquid to flow into the second chamber of at least any stage of the semi-permeable component from the auxiliary liquid inlet and out from the auxiliary liquid outlet of the semi-permeable component as needed. From the perspective of equipment setup and process control operability, it is preferable that the added auxiliary liquid flow path is connected to the discharge pipe 14, so that the added auxiliary liquid and the discharge are combined in the discharge pipe 14 and then introduced together into the semi-permeable device 2.

[0180] It should be noted that "partial use of auxiliary liquid other than the discharge from the separation unit" means that it includes not only the case where the auxiliary liquid, which is a mixture of the auxiliary liquid and the discharge from the separation unit, flows through each stage of the semi-permeable module, but also the case where the auxiliary liquid, which consists only of the discharge from the separation unit, flows through a portion of the semi-permeable modules, and the case where the auxiliary liquid, which consists only of the auxiliary liquid or is a mixture of the auxiliary liquid and the discharge from the separation unit, flows through another portion of the semi-permeable modules.

[0181] As for the aforementioned auxiliary liquid, there are no particular restrictions on its composition as long as the osmotic pressure of the auxiliary liquid is higher than or equal to that of the target liquid. For example, a solution containing a solute of appropriate concentration and the same solvent as the original liquid can be used. Furthermore, since the concentration system of this invention does not have a pipeline for the return of the concentrate, the aforementioned auxiliary liquid does not contain the concentrate obtained from the semi-permeable device.

[0182] From the viewpoint of saving costs associated with purchasing or preparing auxiliary additives, it is preferable to use the concentrate as the auxiliary additive. However, if the concentrate diluted by the semi-permeation unit is discharged together with the dilution auxiliary additive when using the concentrate as the auxiliary additive, the target material will be lost. Therefore, it is preferable to set up a concentrate recycling path, which is configured to circulate the diluted concentrate discharged from the semi-permeation unit 2 to the separation unit 1 or its upstream stage. In this case, the diluted concentrate circulated by the concentrate recycling path is introduced into the separation unit 1 as a solution, either alone or together with the concentrate. Using the concentrate as the auxiliary additive is sometimes also preferable in terms of improving concentration efficiency. On the other hand, from the viewpoint of avoiding loss of the target material and saving equipment costs, it is preferable to use only the discharge from the separation unit as the auxiliary additive.

[0183] [Methods for concentrating target materials in solution]

[0184] Another embodiment of this utility model is a method for concentrating a target material in a solution. The concentration method of this utility model includes the following steps:

[0185] The separation process separates the solution into a target liquid and a discharge liquid with a target material concentration lower than that of the target liquid and an osmotic pressure higher than or equal to that of the target liquid; and...

[0186] The semi-permeable process involves concentrating the target liquid by passing it through one side of a semi-permeable membrane and passing an auxiliary liquid, at least partially containing the drained liquid, through the other side of the semi-permeable membrane to obtain a concentrated solution.

[0187] When the osmotic pressure of the drained liquid is higher than the osmotic pressure of the target liquid, mechanical pressure may or may not be applied during the semi-permeation process.

[0188] When the osmotic pressure of the drained liquid is equal to the osmotic pressure of the target liquid, mechanical pressure is applied during the semi-permeation process.

[0189] There are no particular limitations on the equipment used in this concentration method; any known equipment capable of implementing the various steps of the method can be used. As a preferred embodiment, the concentration method of this invention can utilize the concentration system for the target material in the solution described above.

[0190] The following describes each step of the method of this utility model.

[0191] [Pretreatment process]

[0192] The concentration method of this invention can include a pretreatment step as needed. For example, a pretreatment step can be included after the separation step and before the semi-permeation step.

[0193] The aforementioned pretreatment step can remove impurities from the target liquid and / or auxiliary liquid after the separation step and before the semi-permeation step. From the viewpoint of stable operation of the semi-permeation apparatus, it is preferable to perform the aforementioned pretreatment step after the separation step and before the semi-permeation step to remove impurities from the target liquid.

[0194] The impurities refer to substances that can cause instability in subsequent process operations. Typically, they may include solids or colloids that easily clog membrane modules, substances that easily corrode modules, and substances that easily cause scaling in the flow path.

[0195] The pretreatment process preferably uses at least one of the following selected from the group consisting of microfiltration membranes and ultrafiltration membranes to remove the aforementioned impurities.

[0196] As the apparatus used in the pretreatment process, the pretreatment apparatus included in the concentration system described above may be used as needed.

[0197] [Pre-concentration process]

[0198] The concentration method of this invention can include a pre-concentration step as needed. For example, a pre-concentration step can be included after the separation step and before the semi-permeation step. The aforementioned pre-concentration step can pre-concentrate the target liquid after the separation step and before the semi-permeation step. When the target liquid is pre-concentrated, the osmotic pressure of the pre-concentrated target liquid is not higher than that of the discharge obtained from the separation device or the auxiliary liquid containing the discharge.

[0199] As the apparatus used in the pre-concentration process, the pre-concentration apparatus included in the concentration system described above may be used as needed.

[0200] From an economic perspective, it is preferable to have a pre-concentration step after the separation step and before the semi-permeation step. More preferably, the pre-concentration step pre-concentrates the target liquid through reverse osmosis. In this case, from the viewpoint of protecting the reverse osmosis membrane, it is even more preferable to perform the pre-concentration step after the pretreatment step and before the semi-permeation step. In this case, from the viewpoint of further improving economic efficiency, the osmotic pressure of the target liquid after the pre-concentration step is preferably not less than 2 MPa, and more preferably 3.5 MPa or more.

[0201] [Separation Process]

[0202] In the separation step of the concentration method of this invention, the solution used as the raw liquid is separated into a target liquid and a discharge liquid with a target material concentration lower than that of the target liquid and an osmotic pressure higher than or equal to that of the target liquid. From the viewpoint of improving concentration efficiency, the concentration of the target material in the target liquid is preferably 20 times or more, more preferably 100 times or more, and even more preferably 200 times or more than the concentration of the target material in the discharge liquid. From the viewpoint of improving concentration efficiency, the osmotic pressure of the target liquid is preferably 0.2~10MPa, even more preferably 0.5~8MPa; the osmotic pressure of the discharge liquid or the auxiliary liquid containing the discharge liquid is preferably 10~50MPa, more preferably 25~40MPa. Taking the application scenario of lithium extraction from salt lakes using the concentration method of this invention as an example, preferably, the concentration of the target material in the target liquid is 0.8~10g / L, the TDS of the target liquid is 2~70g / L, the concentration of the target material in the auxiliary liquid is 0~0.5g / L, and the TDS of the auxiliary liquid is 150~500g / L. As a concentration target, the concentration of the target material in the aforementioned concentrate can be, for example, 4 to 10 times the concentration of the target material in the target liquid, preferably 10 to 30 g / L.

[0203] From the viewpoint of improving the concentration efficiency in each stage of the semi-permeable module, especially the last stage, it is preferable that the osmotic pressure difference between the auxiliary liquid (including the drain provided by the separation process) and the target liquid exceeds 10 MPa, and more preferably exceeds 20 MPa. When the aforementioned osmotic pressure difference between the auxiliary liquid and the target liquid is less than 10 MPa, from the viewpoint of improving the concentration efficiency in each stage of the semi-permeable module, especially the last stage, it is preferable to use a pressurizing device to provide mechanical pressure as part of the driving force. More preferably, in the first stage semi-permeable module, the sum of the osmotic pressure difference between the auxiliary liquid and the target liquid and the mechanical pressure exceeds 10 MPa, and more preferably exceeds 20 MPa. The aforementioned mechanical pressure can be appropriately selected according to the semi-permeable membrane used, without particular limitation. It is typically 16 MPa or less, and from the viewpoint of cost and safety, it is preferably 12 MPa or less, more preferably 10 MPa or less, and even more preferably 8 MPa or less.

[0204] As the apparatus used in the separation process, the separation apparatus in the concentration system described above can be used, and preferably a separation apparatus containing an adsorbent can be used.

[0205] The separation process includes separating the original solution into a concentrated solution with a high concentration of the target material and a lean solution with a low concentration of the target material. When using a separation apparatus containing an adsorbent, the separation process includes: an adsorption step, in which the target material is adsorbed by contacting the solution with the adsorbent; and an elution step, in which the target material adsorbed on the adsorbent is eluted using an elution solution. In this case, the eluent obtained in the elution step is the aforementioned concentrated solution, and the original solution in the adsorption step becomes the aforementioned lean solution after the target material is adsorbed by the adsorbent. If the osmotic pressure of the aforementioned concentrated solution is less than or equal to that of the lean solution, the aforementioned concentrated solution can be directly used as the target solution obtained from the separation process, and the aforementioned lean solution can be directly used as the discharge solution obtained from the separation process.

[0206] The aforementioned separation process may be further equipped with an osmotic pressure adjustment step, which appropriately adjusts the osmotic pressure of the enriched solution and / or lean solution using known methods. The enriched solution and lean solution, after osmotic pressure adjustment as needed, become the target solution and the discharge solution, respectively, with a target material concentration lower than that of the target solution and an osmotic pressure higher than or equal to that of the target solution. Thus, the aforementioned separation process separates the original solution into the target solution and the discharge solution, with a target material concentration lower than that of the target solution and an osmotic pressure higher than or equal to that of the target solution.

[0207] [Semi-permeation process]

[0208] In the semi-permeable process of the concentration method of this utility model, the target liquid is concentrated by allowing the target liquid to flow through one side of the semi-permeable membrane and the auxiliary liquid containing at least part of the drained liquid to flow through the other side of the semi-permeable membrane, thereby obtaining a concentrated liquid.

[0209] In the semi-permeable process, the solvent moves from the target liquid through the semi-permeable membrane to the auxiliary liquid by the osmotic pressure difference and / or mechanical pressure between the auxiliary liquid and the target liquid, thereby concentrating the target liquid to obtain a concentrated liquid, while the auxiliary liquid is diluted to become a diluted auxiliary liquid.

[0210] As the apparatus used in the semi-permeation process, the semi-permeation apparatus in the concentration system described above can be used, preferably a semi-permeation apparatus including a hollow fiber membrane, and more preferably a semi-permeation apparatus including an externally pressurized hollow fiber membrane. There are no particular limitations on the number and connection method of the semi-permeation components in the semi-permeation apparatus; the semi-permeation components can be single-stage or multi-stage. In the case of multiple stages, they can be connected in series, in parallel, or any combination of both. For example, one could use... Figure 2 A semi-permeable device with only one stage of semi-permeable components, as shown, can also be used. Figure 4 A semi-permeable device composed of multi-stage semi-permeable components connected in series, as shown, can also be used... Figure 11 or Figure 12 The diagram illustrates a semi-permeable device constructed by connecting the first chamber in series and the second chamber in parallel within a multi-stage semi-permeable assembly. Those skilled in the art can modify the connection method of the semi-permeable assembly shown in the diagram based on common sense and experience, and such modifications are also included within the scope of this invention.

[0211] In the semipermeable components of a semipermeable apparatus, at least one of the osmotic pressure difference between the auxiliary liquid and the target liquid, and mechanical pressure, provides the driving force for the solvent in the target liquid to move through the semipermeable membrane to the auxiliary liquid. Therefore, the sum of the osmotic pressure difference between the auxiliary liquid and the target liquid and the mechanical pressure difference must be positive. The target liquid provided by the separation process is gradually concentrated as it passes through each stage of the semipermeable component, while the auxiliary liquid, containing the drained liquid provided by the separation process, is gradually diluted as it passes through each stage of the semipermeable component. From the viewpoint of concentration efficiency, the osmotic pressure of the concentrate obtained from the semipermeable process should not be less than 5 MPa.

[0212] In the semi-permeation process, the driving force, namely the sum of the osmotic pressure difference between the auxiliary liquid and the target liquid and the mechanical pressure difference, only needs to be positive. The composition of the driving force can be appropriately selected based on actual equipment prices, power consumption, investment payback period, etc. Typically, it can be appropriately selected based on the relationship between the osmotic pressure of the auxiliary liquid introduced into the semi-permeation unit and the osmotic pressure of the target material concentrate of the required concentration.

[0213] In one possible implementation, the osmotic pressure of the auxiliary liquid introduced into the semi-permeable device is greater than the osmotic pressure of the target material concentrate of the desired concentration. In this case, the driving force can typically be provided by the osmotic pressure difference between the auxiliary liquid and the target liquid, as well as the mechanical pressure required.

[0214] In a more specific embodiment, when the osmotic pressure of the aforementioned auxiliary liquid is significantly greater than the osmotic pressure of the target material concentrate of the desired concentration, especially when the difference between the osmotic pressure of the aforementioned auxiliary liquid and the target material concentrate of the desired concentration preferably exceeds 10 MPa, from the viewpoint of avoiding increased energy consumption and increased costs due to pressure-resistant equipment, it is preferable not to use mechanical pressure in the semi-permeation process, but to provide driving force solely by the osmotic pressure difference between the auxiliary liquid and the target liquid.

[0215] In a more specific embodiment, when the osmotic pressure of the aforementioned auxiliary liquid is slightly greater than the osmotic pressure of the target material concentrate of the desired concentration, especially when the difference between the osmotic pressure of the aforementioned auxiliary liquid and the osmotic pressure of the target material concentrate of the desired concentration is less than 10 MPa, although concentration can be achieved solely by relying on the aforementioned osmotic pressure difference, there is a tendency to require more semipermeable membranes to obtain a high concentration, leading to increased costs. Therefore, from the viewpoint of equipment cost, it is preferable to use the aforementioned osmotic pressure difference and mechanical pressure to provide driving force in the semipermeation process.

[0216] In another possible implementation, the osmotic pressure of the auxiliary liquid introduced into the semi-permeable device is higher than that of the target liquid but lower than that of the target material concentrate of the required concentration. In this case, the auxiliary liquid is diluted by passing through each stage of the semi-permeable components, and the target liquid is concentrated by passing through each stage of the semi-permeable components. As a result, the osmotic pressure difference between the auxiliary liquid and the target liquid gradually decreases to the point that concentration cannot be achieved by relying solely on the osmotic pressure difference, or even becomes 0 or negative. Therefore, mechanical pressure must be used to compensate for the insufficient osmotic pressure difference or to counteract the reverse osmotic pressure difference.

[0217] In yet another possible implementation, the osmotic pressure of the auxiliary liquid introduced into the semi-permeable device is equal to the osmotic pressure of the target liquid. In this case, the auxiliary liquid is diluted by passing through each stage of the semi-permeable components in sequence, while the target liquid is concentrated by passing through each stage of the semi-permeable components in sequence. As a result, the osmotic pressure difference between the auxiliary liquid and the target liquid becomes negative in each stage of the semi-permeable components. Therefore, mechanical pressure must be used to counteract the reverse osmotic pressure difference and provide driving force.

[0218] In the semi-permeation process, there is no particular limitation on the method of applying mechanical pressure. For example, the aforementioned mechanical pressure can be applied using a pressurizing device installed between the separation device and the semi-permeation device, and / or between the semi-permeation components. From the viewpoint of balancing cost reduction and concentration efficiency, it is preferable to use a pressurizing device such as a booster pump installed in the target liquid flow path between the separation device and the semi-permeation device to apply mechanical pressure to the target liquid introduced into the semi-permeation device; or, a pressurizing device such as a booster pump installed near the semi-permeation component where the osmotic pressure difference becomes too low to achieve concentration can be used to apply mechanical pressure to the target liquid introduced into the semi-permeation component.

[0219] Furthermore, the auxiliary liquid introduced into the semi-permeation unit during the semi-permeation process includes the auxiliary liquid obtained through the separation process and additional auxiliary liquid used as needed. From the viewpoint of balancing cost and concentration efficiency, it is preferable to use the original liquid as the additional auxiliary liquid when using it, and more preferably to use only the discharge obtained through the separation process as the auxiliary liquid.

[0220] [Other processes]

[0221] The concentration method of this invention does not include: recirculating at least a portion of the concentrate obtained from the aforementioned semi-permeation process back to at least a portion of the concentrate used as an auxiliary solution in the aforementioned semi-permeation process. Unlike conventional osmotic pressure-assisted reverse osmosis technology based on concentrate recirculation, this invention does not have a concentrate recirculation process, thereby reducing the number of semi-permeable membrane elements required to achieve high concentrations. For example, compared to conventional osmotic pressure-assisted reverse osmosis methods based on concentrate recirculation, the number of semi-permeable membrane elements used can be reduced by at least half, preferably to less than one-third, and more preferably to less than one-quarter, while achieving the same concentration ratio.

[0222] The concentration method of this invention may include a dilution auxiliary liquid discharge step as needed, in which the dilution auxiliary liquid obtained from the semi-permeation process is discharged directly or after treatment in accordance with environmental protection requirements. Alternatively, the concentration method of this invention may include a dilution auxiliary liquid circulation step as needed, in which the dilution auxiliary liquid obtained from the semi-permeation process is evaporated or a driving agent is added to increase its osmotic pressure, and then circulated back to the auxiliary liquid flow path. From the viewpoint of saving circulation equipment and improving economic efficiency, it is preferable to include the dilution auxiliary liquid discharge step, but not the dilution auxiliary liquid circulation step.

[0223] The concentration method of this invention can include a target material recovery step as needed. The concentrate obtained from the semi-permeation process contains the target material at a high concentration, with very few types and amounts of impurities, which is beneficial for the recovery, further concentration or purification, or direct use of the target material.

[0224] Example

[0225] The embodiments of the present invention will be described in detail below with reference to the examples. However, those skilled in the art will understand that the following examples are only used to illustrate the present invention and should not be regarded as limiting the scope of the present invention.

[0226] Example 1

[0227] Building such Figure 10 The concentration system shown uses commercially available lithium adsorbent in the separation unit, and the semi-permeation unit comprises a 3-stage semi-permeation module. Figure 10 The diagram shows four stages for illustrative purposes, but the device in this example uses three stages. A total of 77 cellulose triacetate hollow fiber membranes (Hollosep series semi-permeable membranes manufactured by TOYOBO MC) are used. In the concentration system of this embodiment, the target liquid flow path is sequentially connected from the separation device to the pre-concentration system (not shown), the first chamber of the first semi-permeable component, the first chamber of the second semi-permeable component, and the first chamber of the third semi-permeable component; the auxiliary liquid flow path is sequentially connected from the separation device to the second chamber of the third semi-permeable component, the second chamber of the second semi-permeable component, and the second chamber of the first semi-permeable component.

[0228] This system was used to concentrate lithium in brine (TDS 220 g / L, osmotic pressure 24 MPa, lithium ion concentration 120 mg / L).

[0229] The brine was separated into a high osmotic pressure drain (osmotic pressure 24 MPa; TDS 220 g / L) with almost no lithium and a mixed solution of lithium chloride and sodium chloride (lithium-rich eluent) with TDS 18.5 g / L using a lithium adsorbent-based separation device.

[0230] The lithium-rich eluent was pre-concentrated to an osmotic pressure of 6.1 MPa and a TDS of 46.3 g / L by passing it through a pre-concentration system, i.e., a reverse osmosis membrane system, at a pressure of 6.5 MPa.

[0231] The pre-concentrated lithium-rich eluent is introduced into the first chamber of the first semi-permeable module at a pressure of 5-8 MPa and a flow rate of 834 L / min, and the drain is introduced into the second chamber of the third semi-permeable module at a pressure of 0.5-1.5 MPa and a flow rate of 204 L / min.

[0232] The drained liquid is diluted by sequentially flowing through the second chamber of each semi-permeable membrane module, and the diluted tailwater is discharged as waste liquid. The aforementioned pre-concentrated lithium-rich eluent is concentrated by sequentially flowing through the first chamber of each permeable membrane module to obtain a concentrated solution. The lithium ion concentration in this concentrated solution is 20 g / L, which meets the required concentration of 20 g / L or higher for the addition of sodium carbonate to precipitate lithium carbonate. The power consumption of this semi-permeable concentration system is 2.0~3.0 kWh / m³. 3 (Calculated based on the inlet flow rate of lithium-rich eluent).

[0233] Example 2

[0234] Building such Figure 10 The concentration system shown is a series of semi-permeable modules, in which commercially available lithium adsorbent is used in the separation unit, and the semi-permeable unit comprises 5 stages of semi-permeable modules ( Figure 10 The diagram shows four stages for illustrative purposes, but the device in this example has five stages. A total of 164 cellulose triacetate hollow fiber membranes (Hollosep series semi-permeable membranes manufactured by TOYOBO MC) are used. In the concentration system of this embodiment, the target liquid flow path is connected sequentially from the separation device to the pre-concentration system (not shown), the first chamber of the first semi-permeable module, the first chamber of the second semi-permeable module, the first chamber of the third semi-permeable module, the first chamber of the fourth semi-permeable module, and the first chamber of the fifth semi-permeable module; the auxiliary liquid flow path is connected sequentially from the separation device to the second chamber of the fifth semi-permeable module, the second chamber of the fourth semi-permeable module, the second chamber of the third semi-permeable module, the second chamber of the second semi-permeable module, and the second chamber of the first semi-permeable module.

[0235] This system was used to concentrate lithium in brine (TDS 220 g / L, osmotic pressure 24 MPa, lithium ion concentration 120 mg / L).

[0236] The brine was separated into a high osmotic pressure drain (osmotic pressure 24 MPa; TDS 220 g / L) with almost no lithium and a mixed solution of lithium chloride and sodium chloride (lithium-rich eluent) with TDS 18.5 g / L using a lithium adsorbent-based separation device.

[0237] The lithium-rich eluent was pre-concentrated to an osmotic pressure of 6.1 MPa and a TDS of 46.3 g / L by passing it through a pre-concentration system, i.e., a reverse osmosis membrane system, at a pressure of 6.5 MPa.

[0238] The pre-concentrated lithium-rich eluent is introduced into the first chamber of the first semi-permeable module at a pressure of 0-1 MPa and a flow rate of 834 L / min, and the drain is introduced into the second chamber of the fifth semi-permeable module at a pressure of 0-1 MPa and a flow rate of 145 L / min.

[0239] The drained solution is diluted by sequentially flowing through the second chamber of each semi-permeable membrane module, and the diluted drained solution is discharged as waste liquid. The aforementioned pre-concentrated lithium-rich eluent is concentrated by sequentially flowing through the first chamber of each permeable membrane module to obtain a concentrated solution. The lithium ion concentration in this concentrated solution is 20 g / L, which meets the required concentration of 20 g / L or higher for the addition of sodium carbonate to precipitate lithium carbonate. The power consumption of this semi-permeable concentration system is 0.2~0.5 kWh / m³. 3 (Calculated based on the inlet flow rate of lithium-rich eluent).

[0240] Example 3

[0241] Building such Figure 9 The concentration system shown is a series-connected semi-permeable module system. The separation unit uses commercially available lithium adsorbent, and the semi-permeable unit comprises four stages of semi-permeable modules, using a total of 99 cellulose triacetate hollow fiber membranes (TOYOBOMC Holloosep series semi-permeable membranes). In this embodiment, the target liquid flow path, starting from the separation unit, is sequentially connected to the pre-concentration system (not shown), the first chamber of the first semi-permeable module, the first chamber of the second semi-permeable module, the first chamber of the third semi-permeable module, and the first chamber of the fourth semi-permeable module. The auxiliary liquid flow path, starting from the separation unit, splits into two paths: one path sequentially connects to the second chamber of the fourth semi-permeable module and the second chamber of the third semi-permeable module, and the other path sequentially connects to the second chamber of the second semi-permeable module and the second chamber of the first semi-permeable module.

[0242] This system was used to concentrate lithium in brine (TDS 220 g / L, osmotic pressure 24 MPa, lithium ion concentration 120 mg / L).

[0243] The brine was separated into a high osmotic pressure drain (osmotic pressure 24 MPa; TDS 220 g / L) with almost no lithium and a mixed solution of lithium chloride and sodium chloride (lithium-rich eluent) with TDS 18.5 g / L using a lithium adsorbent-based separation device.

[0244] The lithium-rich eluent was pre-concentrated to an osmotic pressure of 6.1 MPa and a TDS of 46.3 g / L by passing it through a pre-concentration system, i.e., a reverse osmosis membrane system, at a pressure of 6.5 MPa.

[0245] The pre-concentrated lithium-rich eluent is introduced into the first chamber of the first semi-permeable module at a pressure of 0-1 MPa and a flow rate of 834 L / min. The first drain stream is introduced into the second chamber of the fourth semi-permeable module at a pressure of 0.5-1.5 MPa and a flow rate of 70 L / min. The second drain stream is introduced into the second chamber of the second semi-permeable module at a pressure of 0-1 MPa and a flow rate of 175 L / min. After exiting the first chamber of the second semi-permeable module, the lithium-rich eluent is introduced into a high-pressure pump (not shown) between the first chamber of the second and third semi-permeable membranes. After being pressurized to 5-8 MPa by the high-pressure pump, it is introduced into the first chamber of the third semi-permeable module.

[0246] The two streams of wastewater flow sequentially through the second chambers of the fourth and third semi-permeable membrane modules, and the second chambers of the second and first semi-permeable membrane modules, respectively, where they are diluted. The diluted wastewater is then discharged as waste liquid. The pre-concentrated lithium-rich eluent flows sequentially through the first chamber of each membrane module to be concentrated, yielding a concentrated solution. The lithium ion concentration in this concentrated solution is 20 g / L, which meets the requirement of adding sodium carbonate to precipitate lithium carbonate (above 20 g / L). The power consumption of this concentration system is 0.5~1.5 kWh / m³.3 (Calculated based on the inlet flow rate of lithium-rich eluent).

[0247] Comparative Example 1

[0248] Building such Figure 15 The concentration system shown is a series-connected semi-permeable components with a concentrate return line, wherein a commercially available lithium adsorbent is used in the separation unit, and the semi-permeable unit comprises 5 stages of semi-permeable components ( Figure 15 The diagram shows only two stages for illustrative purposes, but the device in this example has five stages. A total of 245 cellulose triacetate hollow fiber membranes (Hollosep series semi-permeable membranes manufactured by TOYOBOMC) were used.

[0249] This system was used to concentrate lithium in brine (TDS 220 g / L, osmotic pressure 24 MPa, lithium ion concentration 120 mg / L).

[0250] The brine was separated into a high osmotic pressure drain (osmotic pressure 24 MPa; TDS 220 g / L) with almost no lithium and a mixed solution of lithium chloride and sodium chloride (lithium-rich eluent) with TDS 18.5 g / L using a lithium adsorbent-based separation device.

[0251] The effluent obtained from the separation device is directly discharged as waste liquid.

[0252] The lithium-rich eluent was pre-concentrated to an osmotic pressure of 6.1 MPa and a TDS of 46.3 g / L by passing it through a pre-concentration system, i.e., a reverse osmosis membrane system, at a pressure of 6.5 MPa.

[0253] The pre-concentrated lithium-rich eluent is introduced into the first chamber of the first semi-permeable membrane module at a pressure of 6-8 MPa and a flow rate of 834 L / min. The aforementioned pre-concentrated lithium-rich eluent flows sequentially through the first chamber of each permeable membrane module and is concentrated to obtain a concentrated solution.

[0254] A portion of the concentrate is used as an auxiliary solution and introduced into the second chamber of the fifth semi-permeable module at a pressure of 0-1.5 MPa and a flow rate of 117 L / min. This auxiliary solution is then diluted as it flows sequentially through the second chambers of each permeable membrane module. The diluted auxiliary solution is then circulated to the pre-concentration unit, where it is combined with the lithium-rich eluent before pre-concentration and concentrated. Finally, it is introduced into the first chamber of the first semi-permeable module at a pressure of 6-8 MPa and a total flow rate of 1475 L / min.

[0255] The portion of the aforementioned concentrate, excluding the auxiliary liquid refluxed to the semi-permeation unit, is removed to obtain the concentrated product. This concentrate has a lithium ion concentration of 20 g / L, which meets the requirement of 20 g / L or higher for the addition of sodium carbonate to precipitate lithium carbonate. The power consumption of this concentration system is 2.0~3.0 kWh / m³. 3(Calculated based on the inlet flow rate of lithium-rich eluent).

[0256] Comparative Example 2

[0257] Building such Figure 15 The concentration system shown is a series-connected semi-permeable components with a concentrate return line, wherein a commercially available lithium adsorbent is used in the separation unit, and the semi-permeable unit comprises three stages of semi-permeable components ( Figure 15 The diagram shows only stage 2 for illustrative purposes, but the device in this example is stage 3. A total of 77 cellulose triacetate hollow fiber membranes (Hollosep series semi-permeable membranes manufactured by TOYOBO MC) were used.

[0258] This system was used to concentrate lithium in brine (TDS 220 g / L, osmotic pressure 24 MPa, lithium ion concentration 120 mg / L).

[0259] The brine was separated into a high osmotic pressure drain (osmotic pressure 24 MPa; TDS 220 g / L) with almost no lithium and a mixed solution of lithium chloride and sodium chloride (lithium-rich eluent) with TDS 18.5 g / L using a lithium adsorbent-based separation device.

[0260] The effluent obtained from the separation device is directly discharged as waste liquid.

[0261] The lithium-rich eluent was pre-concentrated to an osmotic pressure of 6.1 MPa and a TDS of 46.3 g / L by passing it through a pre-concentration system, i.e., a reverse osmosis membrane system, at a pressure of 6.5 MPa.

[0262] The pre-concentrated lithium-rich eluent is introduced into the first chamber of the first semi-permeable membrane module at a pressure of 6-8 MPa and a flow rate of 834 L / min. The aforementioned pre-concentrated lithium-rich eluent flows sequentially through the first chamber of each permeable membrane module and is concentrated to obtain a concentrated solution.

[0263] A portion of the concentrate is used as an auxiliary solution and introduced into the second chamber of the third semi-permeable module at a pressure of 0-1.5 MPa and a flow rate of 216 L / min. This auxiliary solution is then diluted as it flows sequentially through the second chambers of each permeable membrane module. The diluted auxiliary solution is then circulated to the pre-concentration unit, where it is combined with the lithium-rich eluent before pre-concentration and concentrated. Finally, it is introduced into the first chamber of the first semi-permeable module at a pressure of 6-8 MPa and a total flow rate of 1475 L / min.

[0264] The portion of the aforementioned concentrate, excluding the auxiliary liquid refluxed to the semi-permeation unit, is removed to obtain the concentrated product. The lithium ion concentration in this concentrate is 10.4 g / L, far below 20 g / L, and does not meet the concentration required for adding sodium carbonate to precipitate lithium carbonate. The power consumption of this concentration system is 2.0~3.0 kWh / m³. 3(Calculated based on the inlet flow rate of lithium-rich eluent).

[0265] Hereinafter, a summary of each embodiment and comparative example is shown in Table 1.

[0266] Table 1

[0267]

[0268] As can be seen from the above embodiments and comparative examples, the concentration apparatus and method of this utility model use the discharge of the separation device as the auxiliary liquid, thereby greatly reducing the number of semi-permeable membrane elements required to obtain a high concentration compared with the conventional osmotic pressure-assisted reverse osmosis technology based on concentrate reflux, resulting in lower investment costs and lower operating costs.

[0269] It should be noted that although the technical solution of this utility model has been described with specific examples, those skilled in the art will understand that this utility model should not be limited thereto.

[0270] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical applications, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

[0271] Industrial availability

[0272] This invention discloses a concentration system and method for target materials in solution. By combining a separation device with a semi-permeable device, and using the effluent from the separation device as at least a portion of the auxiliary liquid for the semi-permeable device, the system reduces the number of semi-permeable membrane elements required, concentrates the target material in solution at low cost and high efficiency, significantly reduces the investment and operating costs of the concentration process, and achieves better economic benefits. Therefore, this invention's concentration system and method for target materials in solution is suitable for industrial applications, especially for applications such as lithium extraction from salt lake brine where energy and resources are limited due to remote geographical locations.

Claims

1. A concentration system for a target material in a solution, characterized in that, have: A separation device is configured to separate the solution into a target liquid and a discharge liquid with a target material concentration lower than that of the target liquid and an osmotic pressure higher than or equal to that of the target liquid. The separation device includes a solution inlet pipe, a separation component, a target liquid outlet pipe, and a discharge liquid outlet pipe. A semi-permeable device is configured to concentrate the target liquid and dilute at least a portion of the auxiliary liquid containing the drained liquid. The semi-permeable device includes a single-stage or multi-stage semi-permeable component, the semi-permeable component having a semi-permeable membrane and a container, the internal space of the container being divided into a first chamber and a second chamber by the semi-permeable membrane, the first chamber having a target liquid inlet and a target liquid outlet, and the second chamber having an auxiliary liquid inlet and an auxiliary liquid outlet. Concentrate discharge pipeline; Dilution auxiliary solution discharge pipeline; The target liquid flow path connects the target liquid discharge line of the separation device, the first chamber of the semi-permeable component of each stage of the semi-permeable device, and the concentrate discharge line. as well as An auxiliary liquid flow path connects the discharge pipe of the separation device, the second chamber of the semi-permeable component of each stage of the semi-permeable device, and the dilution auxiliary liquid discharge pipe. in, The target liquid flow path is configured such that the target liquid inlet of each semi-permeable component is connected to the target liquid discharge pipeline of the separation device, or to the target liquid outlet of other semi-permeable components, and that the target liquid inlet of at least any one semi-permeable component is connected to the target liquid discharge pipeline of the separation device, and the target liquid outlet of at least any one semi-permeable component is connected to the concentrate discharge pipeline. The auxiliary liquid flow path is configured such that the auxiliary liquid inlet of each semi-permeable component is connected to the liquid discharge pipeline of the separation device or to the auxiliary liquid outlet of other semi-permeable components, and the auxiliary liquid inlet of at least any semi-permeable component is connected to the liquid discharge pipeline of the separation device, and the auxiliary liquid outlet of at least any semi-permeable component is connected to the dilution auxiliary liquid discharge pipeline.

2. The concentration system for the target material in solution according to claim 1, characterized in that, The semi-permeable device comprises a single-stage semi-permeable component. The target liquid inlet of the semi-permeable component is connected to the target liquid outlet of the separation device, and the target liquid outlet of the semi-permeable component is connected to the concentrate outlet. The auxiliary liquid inlet of the semi-permeable component is connected to the liquid discharge pipeline of the separation device, and the auxiliary liquid outlet of the semi-permeable component is connected to the dilution auxiliary liquid discharge pipeline.

3. The concentration system for the target material in solution according to claim 1, characterized in that, The semi-permeable device comprises multiple stages of semi-permeable components sequentially along the flow direction of the target liquid. The target liquid inlet of the first-stage semi-permeable component is connected to the target liquid outlet pipeline of the separation device. Except for the first-stage semi-permeable component, the target liquid inlet of each semi-permeable component is connected to the target liquid outlet of the previous stage semi-permeable component, or to the target liquid discharge pipeline of the separation device. The target liquid outlet of the final semi-permeable component is connected to the concentrate discharge pipeline.

4. The concentration system for the target material in solution according to claim 3, characterized in that, The auxiliary liquid inlet of the first-stage semi-permeable component is connected to the liquid discharge pipeline of the separation device. The auxiliary liquid inlet of each semi-permeable module, except for the first-stage semi-permeable module, is connected to the auxiliary liquid outlet of the previous-stage semi-permeable module, or to the discharge pipeline of the separation device. The auxiliary liquid outlet of the final stage semi-permeable component is connected to the dilution auxiliary liquid discharge pipeline. The auxiliary liquid outlet of each semi-permeable component, except for the last stage semi-permeable component, is connected to the auxiliary liquid inlet of the next stage semi-permeable component, or to the dilution auxiliary liquid discharge pipeline.

5. The concentration system for the target material in solution according to claim 3, characterized in that, The auxiliary liquid inlet of the first-stage semi-permeable component is connected to the liquid discharge pipeline of the separation device. Except for the first-stage semi-permeable module, the auxiliary liquid inlet of each semi-permeable module is connected to the auxiliary liquid outlet of the previous stage semi-permeable module. The auxiliary liquid outlet of the last stage semi-permeable component is connected to the dilution auxiliary liquid discharge pipeline.

6. The concentration system for the target material in the solution according to any one of claims 1 to 5, characterized in that, The separation component comprises at least one selected from the group consisting of adsorbents, solvent extraction, molecular sieves, nanofiltration membranes, and ion exchange resins.

7. The concentration system for the target material in the solution according to any one of claims 1 to 5, characterized in that, The concentration system also includes a pretreatment device. The pretreatment device is located between the separation device and the semi-permeation device. The pretreatment device includes at least one selected from the group consisting of microfiltration membranes and ultrafiltration membranes.

8. The concentration system for the target material in the solution according to any one of claims 1 to 5, characterized in that, The concentration system also includes a pre-concentration device. The pre-concentration unit is located between the separation unit and the semi-permeation unit. The pre-concentration device includes a reverse osmosis membrane or an evaporation pond.

9. The concentration system for the target material in the solution according to any one of claims 1 to 5, characterized in that, The semi-permeable membrane is a hollow fiber membrane.

10. The concentration system for the target material in the solution according to any one of claims 1 to 5, characterized in that, The concentration system also includes a pressurization device. The pressurizing device is configured to apply mechanical pressure to at least any one of the semi-permeable components contained in the semi-permeable device.

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