Methods and systems for concentrating solutions with two-tier, ultrahigh pressure reverse osmosis

Abstract

Examples relate to systems and methods for concentrating solutions using two tier ultrahigh pressure ("UHP") reverse osmosis. The systems and methods disclosed herein utilize a first tier UHP reverse osmosis array to concentrate a solution and a second tier UHP low rejection reverse osmosis array to further concentrate the solution, producing a highly concentrated product and a permeate stream with an osmotic pressure that exceeds a hydrostatic pressure of one or both of the first or second UHP reverse osmosis array and the second permeate stream has an osmotic pressure that is greater than the difference of the osmotic pressure of the concentrated product and a hydrostatic pressure used in the second UHP low rejection reverse osmosis array.

Description

METHODS AND SYSTEMS FOR CONCENTRATING SOLUTIONS WITH TWO-TIER, ULTRAHIGH PRESSURE REVERSE OSMOSISCROSS REFERENCE TO RELATED APPLICATION(S)

[0001] This application claims priority to U.S. Provisional Application No. 63 / 637,340, filed April 22, 2024. The aforementioned application is incorporated herein by reference, in its entirety, for any purpose.BACKGROUND

[0002] Solutions have one or more dissolved solutes which may be removed from the solution using one or more techniques. Conversely, solvents may be removed from solutions using one or more techniques. Many of these techniques require specialized equipment and may not be cost efficient, energy efficient, or require use of greenhouse gasproducing fuels. For example, thermal concentration processes such as distillation are often utilized. However, such processes require combustion of heating fuel(s) which may lead to significant greenhouse gas emissions. Such processes also tend to be energy inefficient.

[0003] Accordingly, practitioners continue to search for effective means of concentrating solutions and separating solutes from solutions.SUMMARY

[0004] Embodiments of the invention relate to concentrating solutions having at least one solute using two tier ultrahigh pressure (“UHP”) reverse osmosis.

[0005] In an embodiment, a method for concentrating solutions with at least one permeable solute is disclosed. The method includes subjecting a feed stream including a solution having a solute therein to a first ultrahigh pressure reverse osmosis process to form a first concentrate stream and a first permeate stream. The method includes subjecting the first concentrate stream to a second ultrahigh pressure reverse osmosis process to form a second concentrate stream and a second permeate stream, wherein the second concentrate stream has an osmotic pressure that exceeds a hydrostatic pressure of the first ultrahigh pressure reverse osmosis process and the second permeate stream has an osmotic pressure that is greater than a difference of the osmotic pressure of the second concentrate stream and a hydrostatic pressure of the second ultrahigh pressure reverse osmosis process. The method includes combining the second permeate stream with a raw feed stream prior to the first ultrahigh reverse osmosis process to form the feed stream.

[0006] In an embodiment, a system for concentrating solutions is disclosed. The system includes a first ultrahigh pressure reverse osmosis membrane module array configured to receive a feed stream including a solution having a solute and to produce a first concentrate stream and a first permeate stream. The system includes a second ultrahigh pressure reverse osmosis membrane module array configured to receive the first concentrate stream and produce a second concentrate stream and a second permeate stream, wherein the second concentrate stream has an osmotic pressure that exceeds a hydrostatic pressure of the first ultrahigh pressure reverse osmosis membrane module array and the second permeate stream has an osmotic pressure that is greater than a difference of the osmotic pressure of the second concentrate stream and a hydrostatic pressure used in the second ultrahigh pressure reverse osmosis membrane module array. The system includes a recirculation loop operably connecting the second permeate stream with the feed stream.

[0007] Features from any of the disclosed embodiments may be used in combination with one another, without limitation. In addition, other features and advantages of the present disclosure will become apparent to those of ordinary skill in the art through consideration of the following detailed description and the accompanying drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0008] For better understanding, the like elements have been designated by like reference numbers throughout the various accompanying figures. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered to be limiting of its scope, the embodiments of the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:

[0009] FIG. 1 is a schematic of a two-tiered system for concentrating solutions, according to at least some embodiments.

[0010] FIG. 2 is a schematic of an ultrahigh pressure reverse osmosis membrane module array for concentrating solutions, according to at least some embodiments.

[0011] FIG. 3 is a schematic of an ultrahigh pressure low rejection membrane module array for concentrating solutions, according to at least some embodiments.

[0012] FIG. 4 is a flow chart of a method for concentrating a solution, according to at least some embodiments.DETAILED DESCRIPTION

[0013] Embodiments described herein relate to methods, devices, and systems that utilize ultrahigh pressure reverse osmosis followed by low rejection ultrahigh pressure reverse osmosis to concentrate solutions using two tiers of reverse osmosis membrane module arrays. Ultra high pressure reverse osmosis utilizes reverse osmosis membranes and modules configured to withstand and operate at “ultrahigh pressures’' between 1200 psi (8.3 MPa) and 2000 psi (13.8 MPa), such as at least 1700 psi (11.72 MPa) or at least 1750 psi (12.1 MPa). By utilizing a first ultrahigh pressure (UHP) reverse osmosis (RO) membrane module array and a second UHP low rejection (ER) membrane module array, which both have ultrahigh pressure membranes and operating at ultrahigh pressures, users can obtain a final concentrate stream having an osmotic pressure exceeding the ultrahigh hydrostatic pressure of the UHPRO and / or UHPLR processes (e.g., 1700 psi). The final concentrate stream include a selected solute (e.g., at least 30 wt%) content exhibiting at least 1700 psi osmotic pressure and a final permeate comprised of a solute exhibiting at least 340 psi osmotic pressure. Further, by using UHPLR processing after UHPRO processing, the osmotic pressure differential between the concentrate stream and the permeate stream does not overcome the ultrahigh hydrostatic pressure in the UHPLR modules and process due to the low rejection of the UHPLR membrane elements and combined pressure provided by the osmotic pressure of the (second) permeate stream and the hydrostatic pressure in the UHPLR process. Accordingly, a higher concentration concentrate product can be reached than if another UHPRO membrane module array and separation process was used after the first UHPRO membrane module array and separation process. Some solute is lost into the permeate stream of the UHPLR process, but this permeate stream is recycled back to the feed stream for reprocessing.

[0014] The systems and methods disclosed herein utilize a first ultrahigh pressure reverse osmosis (UHPRO) membrane module array followed by a second ultrahigh pressure reverse osmosis (UHPLR) membrane module array to concentrate solutions with energy7savings compared to thermal processing and in only two tiers of operation. The first ultrahigh pressure reverse osmosis membrane module array is configured to receive a feed stream including a solution having a solute and to produce a first concentrate stream and a first permeate stream via reverse osmosis. The second ultrahigh pressure reverse osmosis membrane module array configured to receive the first concentrate stream and produce a second concentrate stream and a second permeate stream via low rejection reverse osmosis, where the second permeate stream has a solute content providing an osmotic pressure (e.g., at least 340 psi) that is greater than a difference between the osmotic pressure of the secondconcentrate stream and the hydrostatic pressure used in the second ultrahigh pressure reverse osmosis membrane module array. Additionally, the systems disclosed herein include a recirculation loop operably connecting the second permeate stream with the feed stream.

[0015] FIG. 1 is a schematic of a two-tiered system 100 for concentrating solutions having one or more solutes therein, according to at least some embodiments. The system 100 depicted in FIG. 1 includes a first tier including a UHPRO membrane module array 120 and a second tier including a UHPLR membrane module array 140. The membrane module arrays disclosed herein are UHP membrane module arrays unless context dictates otherwise. As explained in greater detail below the UHP membrane modules in the respective arrays are constructed to function at, and withstand, ultrahigh pressure to separate solutes from a solution using reverse osmosis. For example, the RO membrane modules in the respective arrays include one or more UHPRO membrane elements 121 or UHPLR membrane elements 141 configured to function at, and withstand, ultrahigh pressures. The UHPLR membrane modules in the array 140 disclosed herein are UHPRO membrane modules that operate at a lower rejection rate (at ultrahigh pressures) than a UHPRO membrane modules in the array 120.

[0016] One or more streams of liquids in the system 100 are connected to the UHPRO and UHPLR membrane module arrays 120 and 140, such as via conduits connected thereto. For example, a raw feed stream 112 is connected to the UHPRO membrane module array 120, such as via the feed stream 1 14 (e.g., combined raw feed stream 1 12 and one or more of permeate stream 146 or concentrate stream 124). The UHPLR membrane module array 140 may be fluidly connected to the concentrate stream 124 rejected from the UHPRO membrane module array 120. The first permeate stream 126 may be disposed of outside of the system 100 via an outlet. The UHPLR membrane module array 140 is configured to produce a second concentrate stream 144 having a higher concentration of the solute than the first concentrate stream 124, via low rejection (e.g., 20% to 80% solute rejection) reverse osmosis. The UHPLR membrane module array 140 is configured to produce a second permeate stream 146 having an amount of the at least one solute that provides a greater osmotic pressure (e g., at least 340 psi osmotic pressure) than the pressure difference between the osmotic pressure of the second concentrate stream and the hydrostatic pressure used in the UHPLR membrane module array.

[0017] In operation, the feed solution (e.g., glycerol solution) entering the UHPRO membrane module array 120 may be concentrated to produce a first concentrate stream 124and a first permeate stream 126. The concentrate stream 124 from the UHPRO membrane module array 120 is further processed in the UHPLR membrane module array 140 to further concentrate the solution (first concentrate or reject stream) to provide a second concentrate stream 144 and a second permeate stream 146 with a selected concentration of the solute therein. The second permeate stream 146 is combined with the incoming raw feed stream 112 to provide a selected concentration of the solute in the feed stream 114. By selectively controlling the solute content in the second permeate stream 146 to have an amount of solute that provides (e.g., is at least 340 psi, at least 500 psi, at least 1000 psi, or at least 1200 psi) osmotic pressure that is greater than the pressure difference between the osmotic pressure of the second concentrate stream 144 and the hydrostatic pressure of the feed stream 114 and / or first concentrate stream 124, the system 100 provides efficient concentration of a solution while recycling permeate(s) of the system 100 for further processing.

[0018] One or more streams of liquids in the system 100 are connected to the UHPRO and UHPLR membrane module arrays 120 and 140, such as via conduits (e.g. , tubes, pipes, hoses, etc.) connected thereto. For example, a raw feed stream 112 from a feed source 110 (e.g. feed solution supply) is fluidly connected to the UHPRO membrane module array 120, such as via the feed stream 114 (e.g., combined raw feed stream 112 and one or more of second permeate stream 146, first concentrate stream 124, or first permeate stream 126). The feed source 110 may include one or more of a filter apparatus, a forward osmosis module, a still, a holding tank, a supply line, or the like.

[0019] Each membrane module array may include one or more reverse osmosis membrane modules. Each reverse osmosis membrane module includes a pressure vessel or housing containing one or more membrane elements therein. The pressure vessel for a UHPRO or UHPLR membrane module may include one or more membrane elements (e.g., spiral wound element) therein. For example, a pressure vessel may include 1 to 25 UHPRO or UHPLR membrane elements arranged in parallel or in series, respectively. Each of the UHPRO or UHPLR membrane module arrays 120 or 140 may independently include one or more UHPRO or UHPLR membrane modules arranged in series or in parallel, such as 1 to 20, 2 to 15, 2 to 10, 2 to 5, 10 to 20, less than 25, less than 15, less than 10, less than 5, or at least 2 membrane modules.

[0020] Each of the UHPRO or UHPLR membrane module arrays 120 or 140 may independently include one or more UHPRO or UHPLR membrane elements 121 or 141 arranged in series or in parallel, such as 1 to 35, 2 to 35, 5 to 25, 2 to 5, 2 to 10, 5 to 15, 10to 20. 15 to 25, less than 25, less than 15, or at least 2 membrane elements. Such UHPRO or UHPLR membrane elements 121 or 141 may be disposed in multiple UHPRO or UHPLR membrane modules, such as at least 2 membrane elements per membrane module (e.g., per pressure vessel), 2 to 10, 2 to 5, 5 to 10, 10 to 15, 2 to 10, less than 15, less than 10, or less than 5 membrane elements per membrane module. In some examples, a membrane module array may include membrane modules containing different numbers of membrane elements in at least some of the membrane modules. For example, the first ultrahigh pressure reverse osmosis membrane module array may include 2 to 35 ultrahigh pressure high rejection reverse osmosis elements and the second ultrahigh pressure reverse osmosis (e.g., UHPLR) membrane module array includes 2 to 25 ultrahigh pressure low rejection reverse osmosis elements, wherein the first membrane module array and the second membrane module array have a different number of UHP membrane module elements therein, respectively.

[0021] FIG. 2 is a schematic of a UHPRO membrane module array 120, according to an embodiment. The UHPRO membrane modules 120a-120n include UHPRO membrane elements 121 having a UHPRO membrane capable of withstanding hydrostatic pressure in excess of 1200 psi (8.3 MPa), such as between 1200 psi (8.3 MPa) and 2000 psi (13.8 MPa), 1500 psi (10.3 MPa) to 1750 psi (12. 1 MPa), 1750 psi (12. 1 MPa) to 2000 psi (13.8 MPa), at least 1500 psi (10.3 MPa), or at least 1700 psi (11.72 MPa). Suitable UHPRO membranes include DuPont™ Specialty Membrane XUS 180808. XUS 180804. and XUS 180802, and HYDRANUATICS (Nitto Group Company) PRO-XR, PRO-LF, PRO-XP, PRO-XPS, and PRO-XT, Porifera PUHPRO-4040-HR1, Mann+Hummel TRISEP® UPR 4040-RO-31- FG. TRISEP® UPR 8040-RO-31-FG, TRISEP® UPR 8040-RO-46-FG reverse osmosis membranes. The UHPRO membrane is configured to have a rejection rate of at least 98% of solutes, at least 99% of solutes, or at least 99.5% of solutes at ultrahigh pressures. The UHPRO membrane separates a feed and reject (e.g., concentrate) side from a permeate side in a respective UHPRO membrane element and module.

[0022] The UHPRO membrane modules 120a-120n include a pressure vessel (e.g., fluid tight housing) capable of withstanding ultrahigh pressures without leaking, a feed inlet, an RO permeate outlet, and an RO concentrate (e.g., reject) outlet. The pressure vessel(s) or housing(s) may include one or more UHPRO membrane elements therein, such as a plurality of UHPRO membrane elements in series or parallel. The total membrane area of the UHPRO membrane modules 120a-120n and / or array 120 may be selected to provide different flux rates in the respective membrane modules. For example, the UHPROmembrane modules and arrays receiving solutions with greater concentrations of solutes in the feed stream or solution may have relatively larger membrane areas than UHPRO membrane modules and arrays receiving streams with relatively lower concentrations of the solute.

[0023] The UHPLR modules in the UHPLR membrane module array 140 may be similar or identical to the UHPRO modules in the UHPRO membrane module array 120 in one or more aspects. FIG. 3 is a schematic of a UHPLR membrane module array 140. according to an embodiment. The UHPLR membrane modules 140a-140n include UHPLR membrane elements 141 having UHPLR membranes (e.g., low rejection reverse osmosis membranes) capable of withstanding hydrostatic pressure in excess of 1200 psi, such as between 1200 psi and 2000 psi, 1500 psi to 1750 psi, 1750 psi to 2000 psi, at least 1500 psi, or at least 1700 psi. Suitable UHPLR membranes include HYDRANUATICS (Nitto Group Company) PRO-XS and NF86 Sea, Toray MNF-0001 and UTK-NE40, DuPont™ Filmtec NF270, Applied Membrane NFK and NFE, Mann+Hummel TRISEP® UPR 8040- TS80-31-FG. TRISEP® UPR 8040-TS50-31-FG, TRISEP® UPR 8040-TS40-31-FG,TRISEP® UPR 8040-XN45-31-FG, TRISEP® UPR 8040-UA60-31-FG, TRISEP® UPR 8040-NP030-31-FG, TRISEP® UPR 8040-NP010-31-FG, TRISEP® UPR 8040-HF5-31- FG, TRISEP® UPR 8040-UF10-31-FG, TRISEP® UPR 8040-UE50-31-FG, TRISEP® UPR 8040-SB90-31-FG. The UHPLR membrane is configured to have a rejection rate of 20% to 80% of the amount solutes in a solution, such as 30% to 50%, 50% to 70%, less than 70%, or less than 60% at ultrahigh pressures. The inventors have found that a UHPLR membrane with a rejection rate of at least 20% provides for concentration of the solution that does not require excess amounts of membrane elements (and associated operating costs) in order to reach the same concentration as would lower rejection membrane elements. Additionally, the UHPLR membranes with less than 80% rejection rates provide for greater concentration of the solution than higher rejection membranes due to high rejection membranes producing an osmotic pressure differential (at a lower concentration) in the concentrate stream that exceeds the hydrostatic pressure differential, which prevents migration of solvent through the membrane(s). The UHPLR membrane separates a feed and reject (e.g., concentrate) side from a permeate side in a respective UHPLR membrane element and module.

[0024] The UHPLR membrane modules 140a-140n include a pressure vessel (e.g., fluid tight housing) capable of withstanding ultrahigh pressures without leaking, a feed inlet, a permeate outlet, and a concentrate (e.g., reject) outlet. The pressure vessel(s) ofhousings may include one or more UHPRO membrane elements therein, such as a plurality of UHPRO membrane elements in series or parallel. The total membrane area of the UHPRO membrane modules 120a-120n and / or array 120 may be selected to provide different flux rates in the respective membrane modules and total array. For example, the UHPRO membrane modules and arrays receiving solutions with greater concentrations of solutes in the feed stream or solution may have relatively larger membrane areas than UHPRO membrane modules and arrays receiving streams with relatively lower concentrations of the solute.

[0025] During use, the raw feed stream 112 including a solution having a first concentration of one or more solutes (e.g., acetic acid, vinegar, glucose, sucrose, glycerol) may be introduced into the system 100 at a first mass flow rate (e.g.. at least 3.2 gallons per minute). The solution may include solutes and mainly water (e.g., at a concentration range of 5-30 wt% glycerol) and does not include significant amounts of dissolved or suspended solids. Significant amounts (e.g, more than trace amounts) of dissolved or suspended solids, other than the solute(s) or volatile organic chemicals, may reduce or even halt the performance of the process by changing the flow conditions for the process stream or by fouling the membranes. Accordingly, the system 100 may include a pretreatment apparatus such as at feed source 110. The pretreatment apparatus may include one or more of a forward osmosis module, a filter, a still, or the like to remove suspended solids or selected dissolved solids.

[0026] The raw feed stream 1 12 may be combined with other streams prior to introduction into the UHPRO membrane module array 120. For example, raw feed stream 112 may be combined with second permeate stream 146 composed of permeate from the UHPLR membrane module array 140 fluidly connected thereto to form the feed stream 114. Accordingly, the system 100 may include a recirculation loop operably connecting the second permeate stream 146 with the feed stream 114 and raw feed stream 112. The second permeate stream 146 may include a concentration of the solute(s) have an amount of solute that is at least 1213 psi osmotic pressure of glycerol (23.8 wt%).

[0027] The feed, permeate, and concentrate streams may be temperature controlled, for example by a heat exchanger, to a temperature of between 2°C and 30°C, 5°C and 20°C, or 15°C. For example, the system may include a temperature control device prior to or after the first UHPRO membrane module array 120.

[0028] The UHPRO membrane module array 120 may operate between 25% and 75% recovery by mass, for example 31% recovery by mass, rejecting 99% of the solute(s),producing concentrate stream 124 (e.g, reject or concentrate stream of the first UHPRO module array 120) including a higher concentration solution than the feed stream 114 (e.g, at least 28 wt%, 1500 psi). The mass flow rate of the first concentrated stream 124 may be at least of 4.7 gallons per minute. The first RO membrane module array (UHPRO membrane module array 120) produces the first permeate stream 126, which may include a lower concentration of the solutes than the first concentrate stream 124 (e.g., less than 0.1 wt%. 4 psi). The mass flow rate of the first permeate stream 126 may be greater than the mass flow rate of the first concentrate stream 124. The first permeate stream 126 may be output from the system 100 to be sold, consumed, or further processed.

[0029] The first concentrate stream 124 may be temperature controlled, for example by a heat exchanger not shown), to a temperature of between 2°C and 30°C, 5°C and 20°C, or about 15°C. The first concentrate stream 124 may be pressurized to an ultrahigh pressure, between 1200 psi (8.3 MPa) and 2000 psi (13.8 MPa), for example 1750 psi (12.1 MPa), and delivered to the second UHP module array, UHPLR membrane module array 140.

[0030] The UHPLR membrane module array 140 may operate between 20% and 80% recovery by mass, for example 75% recovery by mass, rejecting at least 31% of the solute(s), producing the second (e.g., product or final) concentrate stream 144 having the highest concentration of solute(s) and highest osmotic pressure in the system 100 of FIG. 1 (e.g, such as at least 41 wt%, 2500 psi). For example, the second concentrate has a solute(s) content that provides an osmotic pressure that is greater than the hydrostatic pressure of one or both of the first reverse osmosis process (e.g., UHPRO) or the second reverse osmosis process (e.g., UHPLR) at least 1700 psi, such as 1700 psi to 2500 psi, 1700 psi to 1900 psi, 1900 psi to 2200 psi, 2200 psi to 2500 psi, at least 2000 psi, or at least 2200 psi. The second concentrate stream 144 may be produced at a mass flow rate of at least 1.2 gallons per minute. The second concentrate stream 144 is now at a final concentration and leaves the system 100 of FIG. 1 to be collected, such as through a product line (e.g., pipe, conduit) or product vessel (e.g., tank) fluidly connected to the second concentrate stream 144. The UHPLR membrane module array 140 (e.g., second RO membrane module array) produces the second permeate stream 146 which has an amount (e.g., concentration) of solutes that provide an osmotic pressure that is greater than the difference between the osmotic pressure of the second concentrate stream 144 and the hydrostatic pressure used in the UHPLR membrane module array 140, such as at least 340 psi (e.g., 24 wt%, 1213 psi). The second permeate stream 146 may be recycled back to the UHPRO membrane module array 120 (e.g., first RO membrane module array), such as being a portion of the feed stream114. The relatively high osmotic pressure of the second permeate stream 146 ensures the effective osmotic pressure differential does not exceed the operating hydrostatic pressure differential of the second module array.

[0031] While the pressure in each of the UHPRO and UHPLR membrane module arrays is in the ultrahigh range (e.g, 1200 psi (8.3 MPa) to 2000 psi (13.8 MPa), 1200 psi (8.3 MPa) to 1500 psi (10.3 MPa), 1500 psi (10.3 MPa) to 1750 psi (12.1 MPa), 1500 psi (10.3 MPa) to 2000 psi (13.8 MPa). 1750 psi (12.1 MPa) to 2000 psi (13.8 MPa), at least 1500 psi (10.3 MPa), or at least 1750 psi (12.1 MPa)), the pressure in the UHPLR membrane module array 140 may be the lowest of the two tiers (arrays). In some examples, the UPHLR membrane module array 140 may be operated with the higher pressure of the two tiers.

[0032] In examples, various alterations may be made to the system 100 of FIG. 1. For example, one or more pumps may be located at one or more points in the system 100 to control the pressures in the various streams. In some examples, one or more high pressure pumps may be disposed prior to the UHPRO membrane module array 120 to boost the pressure of the feed stream 114 to ultrahigh pressures. One or more high pressure booster pumps may be disposed between the UHPRO membrane module array 120 and the UHPLR membrane module array 140, such as on the first concentrate stream 124. One or more high pressure booster pumps may be disposed between the UHPLR membrane module array 140 and the UHPRO membrane module array 120. such as on the second permeate stream 146.

[0033] The system 100 is particularly efficient at processing incoming feed streams with solute (e.g., glycerol, glucose, sodium chloride, potassium citrate) concentrations with osmotic pressures between 300 psi to 1200 psi. However, the system 100 may be reconfigured to accommodate the different solute(s) concentration(s). For example, if solute content in the incoming feed stream were relatively high (e.g., 1200 psi to 2200 psi osmotic pressure), the system 100 may include a bypass to direct the feed stream directly into the UHPLR (e.g., second UHPRO) membrane module array 140. In some examples, at least a portion the first permeate stream 126 may be combined with the feed stream 114 to selectively lower the solute(s) concentration of the feed stream. In such examples, the remainder of the system 100 may be substantially identical. The bypass may be located prior to or after the point at which the feed stream 114 and the second permeate stream 146 combine. Such bypasses may include conduits and valves to selectively control the direction of flow of the feed stream 114.

[0034] Various concentrations of solutes (e.g., sodium chloride, glucose, dextrose, glycerol) in feed streams may be concentrated utilizing the system 100 of FIG. 1. For example, with the glycerol rejection values in the 30-70% range with the UHPLR membrane module array 140 in the system 100, concentration of glycerol solutions can be performed in two stages to achieve concentrations exceeding 1700 psi. Due to the recirculation effect of the recirculation loop containing the second permeate stream 146 into the feed stream 114. the UHPRO (including UHPLR) processes and systems disclosed herein can achieve at least double the concentration of 800 psi (17 wt%) reverse osmosis and 1500 psi (28 wt%) with single stage ultrahigh pressure reverse osmosis process.

[0035] Both the rejection and flux of the RO membranes is dependent on temperature and solute(s) concentration. As temperature increases, the flux increases and the rejection decreases. This effect is more extreme than in typical RO applications at lower pressures such as below 1200 psi. For this reason, temperature control may be utilized in the system 100 during operation. Such temperature control may be a determining factor in both the amount of required membrane area for a given flow rate, and the final concentrations achievable in both the second concentrate stream 144 and second permeate stream 146. The use of heat exchangers and temperature control systems may be used to control temperature within the system 100. For example, one or more heat exchangers may be positioned in the system 100 prior to the UHPRO membrane module array 120, prior to the UHPLR membrane module array 140, or in the recirculation loop of formed by the second permeate stream 146, such as fluidly connected to conduits containing the feed stream, first concentrate stream, first permeate stream, second concentrate stream, or the second permeate stream.

[0036] The system includes one or more pumps operably coupled to one or more of the feed stream, the first concentrate stream, or the first permeate stream, wherein the one or more pumps are configured to pressurize a fluid stream to any of the ultrahigh pressures disclosed herein.

[0037] In some examples, the systems disclosed herein may include plumbing and components to allow cleaning, testing, and recirculation of the various membrane module arrays.

[0038] Portions of the systems disclosed herein may be constructed of a corrosion resistant material such as stainless steel, nylon, polytetrafluoroethylene, a zirconium coated metal, or the like. For example, the conduits connecting the various streams to the UHPRO and UHPLR membrane module arrays. The pumps, heat exchangers, housing of themembrane modules, or other components in the systems may be constructed of one or more corrosion resistant materials.

[0039] The systems disclosed herein may be used to process glycerol solutions to provide glycerol concentrate having relatively high concentration of glycerol (e.g., at least 40 wt% glycerol) and a (first) permeate of relatively pure water (e.g., less than 1 wt% glycerol in water).

[0040] FIG. 4 is a flow diagram of a method 400 for concentrating glycerol solutions, according to an embodiment. The method 400 includes block 410 of subjecting a feed stream including a solution having a solute therein to a first ultrahigh pressure reverse osmosis process to form a first concentrate stream and a first permeate stream, a block 420 of subjecting the first concentrate stream to a second ultrahigh pressure reverse osmosis process to form a second concentrate stream and a second permeate stream, wherein the second concentrate stream has an osmotic pressure that exceeds a hydrostatic pressure of the first ultrahigh pressure reverse osmosis process and the second permeate stream has an osmotic pressure that is greater than a difference of the osmotic pressure of the second concentrate stream and a hydrostatic pressure of the second ultrahigh pressure reverse osmosis process, and a block 430 of combining the second permeate stream with a raw feed stream prior to the first ultrahigh reverse osmosis process to form the feed stream. In some embodiments, the method 400 may include more or fewer blocks than the blocks 410, 420, or 430. For example, some of the blocks 410. 420, or 430 may be combined into a single block. Additional blocks may be added in some embodiments. Fewer blocks may be used in some examples, such as omitting the block 430. The method 400 may be implemented utilizing any of the systems or components thereof disclosed herein or according to any of the flow diagrams of the systems disclosed herein.

[0041] The block 410 of subjecting a feed stream including a solution having a solute therein to a first ultrahigh pressure reverse osmosis process to form a first concentrate stream and a first permeate stream may include circulating the feed stream through a first UHPRO membrane module array at the ultrahigh pressure. For example, subjecting a feed stream including a solution having a solute therein to a first ultrahigh pressure reverse osmosis process to form a first concentrate stream and a first permeate stream may include circulating the feed stream through the first UHPRO module array at a pressure of at least 1200 psi, such as 1200 psi to 2000 psi, 1200 psi to 1500 psi, 1500 psi to 2000 psi, at least 1500 psi. at least 1700 psi. or at least 1750 psi.

[0042] The first UHPRO process separating one or more solutes from one or more solvents in the feed stream includes using a first array of reverse osmosis modules (and reverse osmosis elements) including ultrahigh pressure high rejection reverse osmosis membranes configured to provide a high rejection rate of the solute(s), such as at least 98% (e.g., at least 99%), at ultrahigh pressure. The first UHPRO membrane module array may include one or more UHPRO modules having one or more UHPRO membrane elements therein. The one or more UHPRO membrane modules may include any of the UHPRO membrane module arrays or modules disclosed herein, such as the UHPRO membrane module array 120 (FIG. 1). For example, the first array of (UHP) reverse osmosis elements in the first UHPRO membrane module array includes 2 to 35 ultrahigh pressure high rejection reverse osmosis elements. The first array of osmosis elements may be contained within one or more first UHPRO membrane modules, such as in 1-10 membrane modules, 2-20 membrane modules, or less than 20 membrane modules. The one or more UHPRO membrane modules may be arranged in parallel or in series. The first array of reverse osmosis membrane elements may be disposed in the UHPRO membrane modules in series, in parallel, or both, within each module.

[0043] The feed stream may include a raw feed stream as disclosed herein. The feed stream may include at least a portion of the second permeate stream, or both. The feed stream may include at least 5 w t% of one or more solutes, such as 5 wt% to 30 w t%, 5 w t% to 20 wt%, 15 wt% to 30 wt%. 7 wt% to 17 wt%, at least 7 wt%, or at least 10 wt% of one or more solutes. The solutes in the feed stream may include one or more of a salt (e.g., NaCl, sodium citrate, potassium citrate, CaCCh), a sugar (e.g., sucrose, dextrose, glucose), an acid (e.g.. citric acid), a sugar alcohol (e g., glycerol), dissolved salts of any of the foregoing, or the like. For example, the feed stream may include a glycerol solution. The feed stream may include a sugar or sugar-containing solution, such as a juice. The feed stream does not include significant amounts of dissolved or suspended solids. The feed stream may include one or more solvents such as water, one or more alcohols, or the like.

[0044] In some examples, at least a portion of the feed stream may be recirculated through the first UHPRO membrane module array, such as to selectively control the flow rate and / or concentration of the feed stream. For example, at least a portion of the first permeate stream or the first concentrate stream may be recirculated back to form a portion of the feed stream.

[0045] The first concentrate stream may have a solute concentration that provides and osmotic pressure that is at least 1400 psi, such as 1500 psi, or 1600 psi. For example, thefirst concentrate stream may include 24 wt% solute(s) or more, such as 28 wt% solute(s). In some examples, at least a portion of the first concentrate stream may be output from the first UHPRO membrane module array to the second (UHPLR) membrane module array.

[0046] The first permeate stream may have a solute concentration that is at least 95% smaller than the concentration of the feed stream, such as 98%, 99% smaller, 99.9% smaller than the solute concentration of the feed stream. For example, the first permeate stream may include 1 wt% solute(s) or less, such as 0. 1 wt% solute(s) or less. In some examples, at least a portion of the first permeate stream may be output from the first UHPRO membrane module array, such as to a storage vessel, system output, wastewater outlet, or the like.

[0047] The block 420 of subjecting the first concentrate stream to a second ultrahigh pressure reverse osmosis process to form a second concentrate stream and a second permeate stream, wherein the second concentrate stream has an osmotic pressure that exceeds a hydrostatic pressure of the first ultrahigh pressure reverse osmosis process and the second permeate stream has an osmotic pressure that is greater than a difference of the osmotic pressure of the second concentrate stream and a hydrostatic pressure of the second ultrahigh pressure reverse osmosis process may include producing a permeate stream with an osmotic pressure at least 340 psi. Subjecting the first concentrate stream to a second ultrahigh pressure reverse osmosis process may include circulating the first concentrate stream through a UHPLR membrane module array at an ultrahigh pressure. For example, subjecting the first concentrate stream to a second UHP reverse osmosis process may include circulating the first concentrate stream through the UHPLR membrane module array at a pressure of at least 1200 psi, such as 1200 psi to 2000 psi, 1200 psi to 1500 psi, 1500 psi to 2000 psi. at least 1500 psi. at least 1700 psi, or at least 1750 psi.

[0048] The second UHPRO process separating one or more solutes from one or more solvents in the feed stream includes using a second array of reverse osmosis modules (and reverse osmosis elements) including ultrahigh pressure low rejection reverse osmosis membranes configured to provide a low rejection rate of the solute(s). such as 20% to 80% rejection (e.g., 30% to 70%). at ultrahigh pressure. The ultrahigh pressure reverse osmosis membrane module array may include one or more ultrahigh pressure low rejection (UHPLR) membrane modules having one or more UHPLR membrane elements therein. The one or more UHPLR membrane modules may include any of the UHPLR membrane module arrays or modules disclosed herein, such as the UHPLR membrane module array 140 (FIG. 1). For example, the array of reverse osmosis elements in the UHPLR membranemodule array may include 2 to 35 ultrahigh pressure low rejection reverse osmosis elements. The array of UHPLR membrane elements may be contained within one or more UHPLR membrane modules, such as in 1-10 membrane modules, 2-20 membrane modules, or less than 20 membrane modules. The one or more UHPLR membrane modules may be arranged in parallel or in series. The array of UHPLR membrane elements may be disposed in the UHPLR membrane modules in series, in parallel, or both, within each module.

[0049] The first concentrate stream entering the second ultrahigh pressure reverse osmosis process (e.g., UHPLR process) may include a higher concentration of solutes than the feed stream. The UHPLR process produces a second concentrate stream and a second permeate stream. The second concentrate stream may have a solute concentration that is at least 25% larger than the concentration of the second permeate stream, such as 30%, 35%, or at least 40% larger than the solute concentration of the second permeate stream. The second concentrate stream may have a solute concentration that is at least 100% larger than the concentration of the feed stream. The second concentrate stream may have a solute concentration that provides an osmotic pressure that is larger than the hydrostatic pressure in one or both of the first UHP process (UHPRO) or the second UHP process (e.g., UHPLR). For example, the second concentrate stream may include at least 1700 psi osmotic pressure of solute(s), such as at least 2000 psi osmotic pressure of solute(s). In some examples, the second concentrate stream includes at least 2000 psi osmotic pressure solute content. In some examples, at least a portion of the second concentrate stream may be output from the second UHPRO membrane module array (e.g., the UHPLR membrane module array) to a system output, a storage vessel, or the like, as a product.

[0050] The second permeate stream may have a solute amount (e.g., concentration) that provides an osmotic pressure that is greater than a difference of the osmotic pressure of the second concentrate stream and a hydrostatic pressure of the second ultrahigh pressure reverse osmosis process, such as at least 340 psi osmotic pressure, 340 psi to 1500 psi, 340 psi to 700 psi, 700 psi to 1000 psi, 900 psi to 1200 psi, or 1000 psi to 1500 psi. In such examples, the amount of the solute(s) in the second permeate stream may be within 15 wt% of the amount of solutes (0.1 wt% to 5 wt%, 5 wt% to 10 wt%, or 10 wt% to 15 wt%) in the feed stream. In some examples, the second permeate stream may include 23-25 wt% solute(s) or less (e.g., 1200 psi to 1300 psi osmotic pressure) while the feed stream (e.g., glycerol solution) includes 14-21 wt% (640 psi to 1000 psi osmotic pressure) of solutes(s). In some examples, at least a portion of the first permeate stream may be output from thefirst UHPRO membrane module array, such as to a storage vessel, system output, wastewater outlet, or the like.

[0051] In some examples, at least a portion of the feed stream may be recirculated through the first UHPRO membrane module array, such as to selectively control the flow rate and / or concentration of the feed stream. For example, at least a portion of the first permeate stream or the first concentrate stream may be recirculated back to form a portion of the feed stream.

[0052] In some examples, the feed stream includes 300 psi osmotic pressure to 1400 psi osmotic pressure of the solute(s), the second permeate stream includes 300 psi osmotic pressure to 1400 psi osmotic pressure, and the second permeate stream has a similar concentration of the solute(s) to the feed stream.

[0053] In some examples, the second concentrate stream includes an amount of solute(s) that provides at least 1800 psi osmotic pressure, such as at least 2000 psi or at least 2200 psi. Water may be the majority of the remainder of the second concentrate stream. The second concentrate stream may be a product, which may be directed to a collection vessel (e.g., stainless steel tank, zirconium coated tank, polymer tank, or the like) for transport or storage. For example, the method 400 may include outputting at least a portion of the second concentrate stream to a system output, a storage vessel, or the like, as a product.

[0054] Likewise, the method 400 may include outputting at least a portion of the second permeate stream to a wastewater outlet or a storage vessel.

[0055] The first ultrahigh pressure reverse osmosis process and the second ultrahigh pressure reverse osmosis process are the only reverse osmosis processes used to concentrate the solution. Likewise, a single UHPRO membrane module array followed by a single UHPLR membrane module array may be the only reverse osmosis membrane module arrays used to concentrate the solution.

[0056] The block 430 of combining the second permeate stream with a raw feed stream prior to the first ultrahigh reverse osmosis process to form the feed stream may include recirculating the second permeate stream to the UHPRO membrane module array to perform the first UHPRO process via a recirculation loop operably connecting the second permeate stream with the feed stream. Combining the second permeate stream with a raw feed stream prior to the first ultrahigh reverse osmosis process to form the feed stream may include recirculating only a portion of the second permeate stream to the UHPRO membrane module array to form a selected solute amount in the feed stream.

[0057] The method may further include controlling the temperature of one or more of the feed stream, the first concentrate stream, the first permeate stream, the second concentrate stream, the second concentrate stream, the third concentrate stream, or the third permeate stream. Controlling the temperature may include circulating the respective stream(s) through one or more heat exchangers. The temperature of the respective streams may be controlled to a temperature of between 2 °C and 30 °C. such as between 5 °C and 20 °C, 5 °C and 20 °C. 7 °C and 17 °C, less than 25 °C. or less than 20 °C.

[0058] While FIG. l is a schematic of a two-tiered system for concentrating solutions, FIG. 1 also represents a flow chart for methods of concentrating solutions, such as described with respect to FIG. 4. Specific examples of methods of concentrating glycerol solutions are disclosed in more detail below.PROPHETIC EXAMPLES

[0059] Example processes through systems were modeled according to the following examples.

[0060] Example 1: Raw feed at 15.6 wt% glycerol solution producing a concentrate at41 wt% glycerol content.

[0061] With reference to FIG. 1, a raw feed stream 112 composed of 725 psi osmotic pressure (15.6 wt%) glycerol is introduced into the system 100 at a mass flow rate of 3.2 GPM (12.11 kg per minute). The raw feed stream 112 is combined with second permeate stream 146 composed of 1213 psi osmotic pressure (23.8 wt%) glycerol at a mass flow rate of 3.5 GPM (13.25 kg per minute) to form the feed stream 1 14 having a glycerol concentration of 972 psi osmotic pressure (19.9 wt%) at a mass flow rate of 6.8 GPM (25.74 kg per minute). The feed stream is pressurized to an ultrahigh pressure, betw een 1200 psi and 2000 psi. for example 1750 psi, and delivered to the UHPRO membrane module array 120 having 10 UHPRO membrane elements therein (FILMTEC™ SW30-4040 membranes) providing 74 m2of membrane area, w hich may operate at flux betw een 5 LMH and 18 LMH, for example 13.5 LMH to 7.7 LMH as the feed solution advances through the UHPRO membrane module array 120. The UHPRO membrane module array included 4 modules (e.g., pressure vessels) with the first including 3 UHPRO membrane elements. the second including 3 UHPRO membrane elements, the third including 2 UHPRO membrane elements, and the fourth including 2 UHPRO membrane elements.

[0062] The feed stream 114 is feed into the UHPRO membrane module array 120 where it is separated into the first concentrate 124 having a glycerol content of 1500 psi osmotic pressure (28. 1 wt%) at a mass flow rate of 4.7 GPM (17.79 kg per minute) and thefirst permeate 126 having a glycerol content of 4 psi osmotic pressure (0. 1 wt%) and a mass flow rate of 2.1 GPM (7.95 kg per minute). The UHPRO membrane module array 120 operates with a 99.3% rejection rate, an average flux of 6.36 LMH, and a recovery rate of 30.7%. The UHPRO membrane module array 120 may be configured to operate between 25% and 65% recovery by mass. The first permeate is output from the system and the first concentrate is directed to the UHPLR membrane module array 140.

[0063] The first concentrate stream 124 composed of 1500 psi osmotic pressure (28.1 wt%) glycerol is introduced into the UHPLR membrane module array 140 at a mass flow rate of 4.7 GPM at the ultrahigh pressure. The UHPLR membrane module array 140 includes 10 UHPLR membrane elements therein (TRISEP® UPR 4040-SB90-31-FG) providing 74. 15 m2of membrane area, to operate at flux between 1 LMH and 15 LMH. for example 14 LMH to 1.9 LMH as the first concentrate progressed through the UHPLR membrane module array 140. The UHPLR membrane module array included 10 modules (e.g., pressure vessels) each with a UHPLR membrane elements.

[0064] The first concentrate steam 124 is feed into the UHPLR membrane module array140 where it is separated into the second concentrate stream 144 having a glycerol content of 2476 psi osmotic pressure (41 wt%) at a mass flow rate of 1.2 GPM (4.54 kg per minute) and the second permeate stream 146 having a glycerol content of 1213 psi osmotic pressure (23.8 wt%) and a mass flow rate of 3.5 GPM (13.25 kg per minute). The UHPLR membrane module array 140 operates with a 31% rejection rate (e.g., average rejection rate of membranes therein), an average flux of 10.8 LMH, and a recovery rate of 74.6%. The UHPLR membrane module array 140 may be configured to operate between 40% and 85% recovery by mass.

[0065] The second concentrate stream 144 is output from the system 100 as a product and has an osmotic pressure of roughly 2500 psi. The second permeate stream 146 is recycled to form part of the feed stream 114 (along with the raw feed stream 112) through a recirculation loop.

[0066] At any point in the process, one or more of the various streams may be temperature controlled, for example by a heat exchanger, to a temperature of between 5°C and 30° C (e.g., 15 °C).

[0067] Example 2: Raw feed at 15.0 wt% glucose solution producing a concentrate at 55.6 wt% glucose content.

[0068] With reference to FIG. 1, a raw feed stream 112 composed of 360 psi osmotic pressure (15.0 wt%) glucose solution is introduced into the system 100 at a mass flow rateof 8.0 GPM. The raw feed stream 112 is combined with second permeate stream 146 composed of 564 psi osmotic pressure (21.3 wt%) glucose at a mass flow rate of 1.84 GPM to form the feed stream 1 14 having a glucose concentration providing 403 psi osmotic pressure (16.4 wt%) at a mass flow rate of 9.8 GPM. The feed stream is pressurized to an ultrahigh pressure, between 1200 psi and 2000 psi, for example 1374 psi, and delivered to the UHPRO membrane module array 120 having 10 UHPRO membrane elements therein (FILMTEC™ SW30-4040 membranes) providing 66.6 m2of membrane area, which may operate at flux between 5 LMH and 25 LMH, for example 15 LMH to 25 LMH as the feed solution advances through the UHPRO membrane module array 120. The UHPRO membrane module array included three modules (e.g., pressure vessels) with the first including 3 UHPRO membrane elements, the second including 3 UHPRO membrane elements, the third including 3 UHPRO membrane elements.

[0069] The feed stream 114 is feed into the UHPRO membrane module array 120 where it is separated into the first concentrate 124 having a glucose content of 1374 psi osmotic pressure (40.4 wt%) at a mass flow rate of 4.0 GPM and the first permeate 126 having a glucose content of 5 psi osmotic pressure (0.25 wt%) and a mass flow rate of 5.9 GPM. The UHPRO membrane module array 120 operates with a 99.0% rejection rate, an average flux of 20.4 LMH, and a recovery' rate of 60.2%. The UHPRO membrane module array 120 may be configured to operate between 25% and 65% recovery by mass. The first permeate is output from the system and the first concentrate is directed to the UHPLR membrane module array 140.

[0070] The first concentrate stream 124 composed of 1374 psi osmotic pressure (28.1 wt%) glucose is introduced into the UHPLR membrane module array 140 at a mass flow rate of 5.9 GPM at the ultrahigh pressure. The UHPLR membrane module array 140 includes 10 UHPLR membrane elements therein (TRISEP® UPR 4040-UE50-31-FG) providing 66.6 m2of membrane area, to operate at flux between 1 LMH and 15 LMH, for example 14 LMH to 1.9 LMH as the first concentrate progressed through the UHPLR membrane module array 140. The UHPLR membrane module array included three modules (e.g., pressure vessels) each with three UHPLR membrane elements.

[0071] The first concentrate steam 124 is feed into the UHPLR membrane module array140 where it is separated into the second concentrate stream 144 having a glucose content of 2222 psi osmotic pressure (55.6 wt%) at a mass flow rate of 2. 1 GPM and the second permeate stream 146 having a glucose content of 564 psi osmotic pressure (21.3 wt%) and a mass flow rate of 1.84 GPM. The UHPLR membrane module array 140 operates with a50% rejection rate, an average flux of 6.4 LMH, and a recover}' rate of 46.3%. The UHPLR membrane module array 140 may be configured to operate between 30% and 75% recovery by mass.

[0072] The second concentrate stream 144 is output from the system 100 as a product and has an osmotic pressure of roughly 2222 psi. The second permeate stream 146 is recycled to form part of the feed stream 114 (along with the raw feed stream 112) through a recirculation loop.

[0073] At any point in the process, one or more of the various streams may be temperature controlled, for example by a heat exchanger, to a temperature of between 5°C and 30°C (e.g., 15 °C).

[0074] Example 3: Raw feed at 17 wt% potassium citrate solution producing a concentrate at 36.85 wt% potassium citrate content.

[0075] With reference to FIG. 1, a raw feed stream 112 composed of 803 psi osmotic pressure (17 wt%) potassium citrate solution is introduced into the system 100 at a mass flow rate of 8 GPM. The raw feed stream 112 is combined with second permeate stream 146 composed of 362 psi osmotic pressure (8.5 wt%) potassium citrate at a mass flow rate of 1.3 GPM to form the feed stream 114 having a potassium citrate concentration providing 735 psi osmotic pressure (15.8 wt%) at a mass flow rate of 9.3 GPM. The feed stream is pressurized to an ultrahigh pressure, between 1200 psi and 2000 psi, for example 1575 psi, and delivered to the UHPRO membrane module array 120 having 9 UHPRO membrane elements therein (FILMTEC™ SW30-4040 membranes) providing 66.6 m2of membrane area, which may operate at flux between 5 LMH and 25 LMH, for example 15 LMH to 25 LMH as the feed solution advances through the UHPRO membrane module array 120. The UHPRO membrane module array included 3 modules (e.g., pressure vessels) with the first including 3 UHPRO membrane elements, the second including 3 UHPRO membrane elements, the third including 3 UHPRO membrane elements.

[0076] The feed stream 114 is feed into the UHPRO membrane module array 120 where it is separated into the first concentrate 124 having a potassium citrate content of 1575 psi osmotic pressure (29.2 wt%) at a mass flow rate of 5.0 GPM and the first permeate 126 having a potassium citrate content of 8 psi osmotic pressure (0.21 wt%) and a mass flow rate of 4.3 GPM. The UHPRO membrane module array 120 operates with a 99% rejection rate, an average flux of 14.8 LMH, and a recovery rate of 46.3%. The UHPRO membrane module array 120 may be configured to operate between 25% and 65% recoveryby mass. The first permeate is output from the system and the first concentrate is directed to the UHPLR membrane module array 140.

[0077] The first concentrate stream 124 composed of 1575 psi osmotic pressure (29.2 wt%) potassium citrate is introduced into the UHPLR membrane module array 140 at a mass flow rate of 9.3 GPM at the ultrahigh pressure. The UHPLR membrane module array 140 includes 9 UHPLR membrane elements therein (TRISEP® UPR 4040-UA60-31-FG) providing 66.6 m2of membrane area, to operate at flux between 1 LMH and 15 LMH. for example 14 LMH to 1.9 LMH as the first concentrate progressed through the UHPLR membrane module array 140. The UHPLR membrane module array included 3 modules (e.g., pressure vessels) each with three UHPLR membrane elements.

[0078] The first concentrate steam 124 is feed into the UHPLR membrane module array 140 where it is separated into the second concentrate stream 144 having a potassium citrate content of 2142 psi osmotic pressure (36.85 wt%) at a mass flow rate of 5 GPM and the second permeate stream 146 having a potassium citrate content of 362 psi osmotic pressure (8.5 wt%) and a mass flow rate of 1.3 GPM. The UHPLR membrane module array 140 operates with a 77.6% rejection rate, an average flux of 4.6 LMH, and a recovery rate of 26%. The UHPLR membrane module array 140 may be configured to operate between 20% and 60% recovery by mass.

[0079] The second concentrate stream 144 is output from the system 100 as a product and has an osmotic pressure of roughly 2142 psi. The second permeate stream 146 is recycled to form part of the feed stream 1 14 (along with the raw feed stream 1 12) through a recirculation loop.

[0080] At any point in the process, one or more of the various streams may be temperature controlled, for example by a heat exchanger, to a temperature of between 5°C and 30°C (e.g., 15 °C).

[0081] Example 4: Raw feed at 5 wt% sodium chloride solution producing a concentrate at 18.6 wt% sodium chloride content.

[0082] With reference to FIG. 1, a raw feed stream 112 composed of 581 psi osmotic pressure (5 wt%) sodium chloride solution is introduced into the system 100 at a mass flow rate of 8 GPM. The raw feed stream 112 is combined with second permeate stream 146 composed of 923 psi osmotic pressure (7.8 wt%) sodium chloride at a mass flow rate of 3.3 GPM to form the feed stream 114 having a sodium chloride concentration providing 677 psi osmotic pressure (5.8 wt%) at a mass flow rate of 11.3 GPM. The feed stream is pressurized to an ultrahigh pressure, between 1200 psi and 2000 psi, for example 1476 psi,and delivered to the UHPRO membrane module array 120 having 9 UHPRO membrane elements therein (FILMTEC™ SW30-4040 membranes) providing 66.6 m2of membrane area, which may operate at flux between 5 LMH and 25 LMH, for example 15 LMH to 25 LMH as the feed solution advances through the UHPRO membrane module array 120. The UHPRO membrane module array included 3 modules (e.g., pressure vessels) with the first including 3 UHPRO membrane elements, the second including 3 UHPRO membrane elements, the third including 2 UHPRO membrane elements.

[0083] The feed stream 1 14 is feed into the UHPRO membrane module array 120 where it is separated into the first concentrate 124 having a sodium chloride content of 1476 psi osmotic pressure (12. 1 wt%) at a mass flow rate of 5.4 GPM and the first permeate 126 having a sodium chloride content of 12 psi osmotic pressure (0.1 wt%) and a mass flow rate of 5.9 GPM. The UHPRO membrane module array 120 operates with a 99% rejection rate, an average flux of 20.0 LMH, and a recovery' rate of 52.2%. The UHPRO membrane module array 120 may be configured to operate between 25% and 75% recovery by mass. The first permeate is output from the system and the first concentrate is directed to the UHPLR membrane module array 140.

[0084] The first concentrate stream 124 composed of 1476 psi osmotic pressure (12.1 wt%) sodium chloride is introduced into the UHPLR membrane module array 140 at a mass flow rate of 5.9 GPM at the ultrahigh pressure. The UHPLR membrane module array 140 includes 9 UHPLR membrane elements therein (Mann+Hummel TRISEP® UPR 4040-TS80-31-FG) providing 66.6 m2of membrane area, to operate at flux between 1 LMH and 15 LMH, for example 14 LMH to 1.9 LMH as the first concentrate progressed through the UHPLR membrane module array 140. The UHPLR membrane module array included three modules (e g., pressure vessels) each with three UHPLR membrane elements.

[0085] The first concentrate steam 124 is feed into the UHPLR membrane module array140 where it is separated into the second concentrate stream 144 having a sodium chloride content of 2374 psi osmotic pressure (18.6 wt%) at a mass flow rate of 2.1 GPM and the second permeate stream 146 having a sodium chloride content of 923 psi osmotic pressure (7.8 wt%) and a mass flow rate of 3.3 GPM. The UHPLR membrane module array 140 operates with a 43.7% rejection rate, an average flux of 1 1. 1 LMH, and a recovery' rate of 61.1%. The UHPLR membrane module array 140 may be configured to operate between 30% and 75% recovery' by mass.

[0086] The second concentrate stream 144 is output from the system 100 as a product and has an osmotic pressure of roughly 2374 psi. The second permeate stream 146 isrecycled to form part of the feed stream 114 (along with the raw feed stream 112) through a recirculation loop.

[0087] At any point in the process, one or more of the various streams may be temperature controlled, for example by a heat exchanger, to a temperature of between 5°C and 30°C (e.g., 15 °C).

[0088] The data from Examples 1-4 are provided below in Table 1.

[0089] TABLE 1

[0090] The two-tier methods and systems for concentrating solutions disclosed herein are not possible with typical RO membrane modules operating at “high pressure” between 500 psi (3.4 MPa) and 1200 psi (8.3 MPa). For example, the osmotic pressure of the concentrate is limited by the operating hydrostatic pressure ceiling of 1000 psi for reverse osmosis or 1700 psi for ultrahigh pressure reverse osmosis. Similar results are achieved with other solutes such as glycerol, glucose, or the like.COMPARATIVE EXAMPLES

[0091] Three comparative examples were calculated using the same starting raw' feed solution of 15 wt% dextrose to determine the effectiveness of various rejection rates of UHPLR membranes having a 50% rejection rate, 10% rejection rate, and 90% rejection rate, respectively.

[0092] Each comparative example was processed in a system like the system 100, where the only variation was the number of UHPRO membrane modules needed to produce a first permeate stream being less than 0.5 wt% dextrose and the number of and type of UHPLR membrane modules needed to reach the maximum dextrose content in the second concentrate stream. The models w ere calculated to maximize dextrose content in the second concentrate stream.

[0093] Example A: Effect of UHPLR membrane elements having 50% rejection on final concentration of second permeate stream.

[0094] The raw feed stream containing 360 psi osmotic pressure (15 wt%) dextrose at 8 GPM was combined with a second permeate stream being 564 psi osmotic pressure (21.2 wt%) dextrose provided at a rate of 1.84 GPM to form the feed stream being 403 psi osmotic pressure (16.44 wt%) dextrose at a rate of 9.84 GPM. The feed stream was pressurized to 1700 psi and circulated through the UHPRO membrane module array having 9 UHPRO membrane elements (Mann+Hummel TRISEP® UPR 4040-RO-31-FG) divided among 3 UHPRO membrane modules each having 3 UHPRO membrane elements therein. The UHPRO membrane elements at least a 99% rejection rate at base operating conditions. The first concentrate stream and first permeate stream were produced, with the first concentratestream being 1374 psi osmotic pressure (40.4 wt%) dextrose provided at a 3.97 GPM rate and the first permeate stream being 5 psi osmotic pressure (0.25 wt%) dextrose at 5.87 GPM rate.

[0095] The first concentrate stream was directed to the UHPLR membrane module array and circulated therethrough at the 1700 psi pressure. The UHPLR membrane module array included 9 UHPLR membrane elements (TRISEP® UPR 8040-UE50-31-FG) divided among 3 UHPLR membrane modules each having 3 UHPLR membrane elements therein. The UHPLR membrane elements had a 50% rejection rate at a base operation condition level. The UHPLR membrane module array produced the second concentrate stream being 2222 psi osmotic pressure (55.64 wt%) dextrose at a rate of 2.13 GPM and the second permeate stream being 564 psi osmotic pressure (21.29 wt%) dextrose at a rate of 1.84 GPM. The osmotic pressure differential between the second concentrate stream and the second permeate stream is 1658 psi which does not exceed the hydrostatic operating pressure of 1700 psi.

[0096] Example B: Effect of UHPLR membrane elements having 10% rejection on final concentration of second permeate stream.

[0097] The raw feed stream exhibiting 360 psi osmotic pressure (15 wt%) dextrose solution at 8 GPM was combined with a second permeate stream being 36.59 wt% dextrose provided at a rate of 14.77 GPM to form the feed stream being 29.01 wt% dextrose at a rate of 22.77 GPM. The feed stream was pressurized to 1700 psi hydrostatic pressure and circulated through the UHPRO membrane module array having 1 1 UHPRO membrane elements (Mann+Hummel TRISEP® UPR 4040-RO-31-FG) divided among 4 UHPRO membrane modules, with the first 3 modules having 3 UHPRO membrane elements therein and the final module having 2 UHPRO membrane elements therein. The UHPRO membrane elements at least a 99% rejection rate at the base operating conditions. The first concentrate stream and first permeate stream were produced, with the first concentrate stream being 38 wt% dextrose provided at a 17.31 GPM rate and the first permeate stream being 0.33 wt% dextrose at a 5.46 GPM rate.

[0098] The first concentrate stream was directed to the UHPLR membrane module array and circulated therethrough at the 1700 psi pressure. The UHPLR membrane module array included 45 UHPLR membrane elements (TRISEP® UPR 8040-UE50-31-FG) divided among 15 UHPLR membrane modules each having 3 UHPLR membrane elements therein. The UHPLR membrane elements had a 10% rejection rate at the base operation condition level. The UHPLR membrane module array produced the second permeatestream being 46. 1 wt% dextrose at a rate of 2.54 GPM and the second permeate stream being 36.59 wt% dextrose at a rate of 14.77 GPM.

[0099] Example C: Effect of UHPLR membrane elements having 90% rejection on final concentration of second permeate stream.

[0100] The raw feed stream containing 15 wt% dextrose at 8 GPM was combined with a second permeate stream being 3.66 wt% dextrose provided at a rate of 0.56 GPM to form the feed stream being 14.26 wt% dextrose at a rate of 8.56 GPM. The feed stream was pressurized to 1700 psi and circulated through the UHPRO membrane module array having 8 UHPRO membrane elements (Mann+Hummel TRISEP® UPR 4040-RO-31-FG) divided among 3 UHPRO membrane modules, with the first 2 modules having 3 UHPRO membrane elements therein and the final module having 2 UHPRO membrane elements therein. The UHPRO membrane elements at least a 99% rejection rate at the base operating conditions. The first concentrate stream and first permeate stream were produced, with the first concentrate stream being 40.19 wt% dextrose provided at a 3.01 GPM rate and the first permeate stream being 0.23 wt% dextrose at a 5.55 GPM rate.

[0101] The first concentrate stream was directed to the UHPLR membrane module array and circulated therethrough at the 1700 psi pressure. The UHPLR membrane module array included 9 UHPLR membrane elements (TRISEP® UPR 8040-UE50-31-FG) divided among 3 UHPLR membrane modules each having 3 UHPLR membrane elements therein. The UHPLR membrane elements had a 90% rejection rate at the base operation condition level. The UHPLR membrane module array produced the second permeate stream being 48.5 wt% dextrose at a rate of 2.45 GPM and the second permeate stream being 3.66 wt% dextrose at a rate of 0.56 GPM.

[0102] The comparative examples A-C demonstrate that UHPLR rejection elements having 10% rejection rate or a 90% rejection rate do not provide as high a concentration of dextrose in the second concentrate stream as the UHPLR rejection elements having the 50% rejection rate. The UHPLR rejection elements having 10% rejection rate require many more membrane elements to be used to reach the maximum concentration than the UHPLR rejection elements having 10% rejection rate or even the 90% rejection rate. UHPLR rejection elements having 30% to 70% rejection rate are most effective in the systems and methods disclosed herein.

[0103] The systems and methods disclosed herein allow solutions to be processed at two times the flux and two times the rejection of a high pressure system. The ultrahigh pressure osmosis systems and methods disclosed herein are capable of concentratingsolutes in a solution to at least 30 wt% (e.g., at least 40 wt% or at least 50 wt%) in only two tiers, a process that is commercially viable in capital and operational expenditure.

[0104] The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.

Claims

CLAIMSWhat is claimed is:

1. A method for concentrating a solution, the method comprising: subjecting a feed stream including a solution having a solute therein to a first ultrahigh pressure reverse osmosis process to form a first concentrate stream and a first permeate stream; and subjecting the first concentrate stream to a second ultrahigh pressure reverse osmosis process to form a second concentrate stream and a second permeate stream, wherein the second concentrate stream has an osmotic pressure that exceeds a hydrostatic pressure of the first ultrahigh pressure reverse osmosis process and the second permeate stream has an osmotic pressure that is greater than a difference of the osmotic pressure of the second concentrate stream and a hydrostatic pressure of the second ultrahigh pressure reverse osmosis process; and combining the second permeate stream with a raw feed stream prior to the first ultrahigh reverse osmosis process to form the feed stream.

2. The method of claim 1 wherein the feed stream includes solute content providing an osmotic pressure of 350 psi to 1000 psi, the second permeate stream includes a solute content providing an osmotic pressure of 350 psi to 1000 psi, and the second permeate stream has a greater osmotic pressure than the feed stream.

3. The method of any of claims 1-2 wherein the second concentrate stream includes an osmotic pressure of 2000 psi or more.

4. The method of any of claims 1-3 wherein: the first ultrahigh pressure reverse osmosis process includes using a first array of reverse osmosis modules including ultrahigh pressure high rejection reverse osmosis membranes configured to provide a rejection rate of the solute of at least 98% at ultrahigh pressure; and the second ultrahigh pressure reverse osmosis process includes using a second array of reverse osmosis modules including ultrahigh pressure low rejection reverse osmosis membranes configured to have a rejection rate of the solute of 30% to 70% at ultrahigh pressure.

5. The method of claim 4 wherein: the first array of reverse osmosis modules includes 2 to 35 ultrahigh pressure high rejection reverse osmosis elements; andthe second array of reverse osmosis modules includes 2 to 25 ultrahigh pressure low rejection reverse osmosis elements.

6. The method of any of claims 1-5 wherein the feed stream includes a sugar solution.

7. The method of any of claims 1-6 wherein the feed stream includes an acetic acid solution.

8. The method of any of claims 1-7 wherein subjecting a feed stream including a solution having a solute therein to a first ultrahigh pressure reverse osmosis process includes circulating the feed stream through a first ultrahigh pressure membrane module array at an ultrahigh pressure of at least 1200 psi.

9. The method of any of claims 1-8 wherein subjecting the first concentrate stream to a second ultrahigh pressure reverse osmosis process to form a second concentrate stream and a second permeate stream includes circulating the first concentrate stream through a second ultrahigh pressure membrane module array at an ultrahigh pressure of at least 1200 psi.

10. The method of any of claims 8 or 9 wherein the ultrahigh pressure is at least 1500 psi.

11. The method of any of claims 8 or 9 wherein the ultrahigh pressure is at least 1700 psi.

12. The method of any of claims 1-11, further comprising outputting the second concentrate stream to a storage vessel.

13. The method of any of claims 1-12, further comprising outputting at least a portion of the second permeate stream to a wastewater outlet or a storage vessel.

14. The method of any of claims 1-13 wherein the first ultrahigh pressure reverse osmosis process and the second ultrahigh pressure reverse osmosis process are the only reverse osmosis processes used to concentrate the solution.

15. A system for concentrating acetic acid solutions, the system comprising: a first ultrahigh pressure reverse osmosis membrane module array configured to receive a feed stream including a solution having a solute and to produce a first concentrate stream and a first permeate stream; a second ultrahigh pressure reverse osmosis membrane module array configured to receive the first concentrate stream and produce a second concentrate stream and a second permeate stream, wherein the second concentrate stream has an osmotic pressure that exceeds a hydrostatic pressure of the first ultrahigh pressure reverse osmosis membranemodule array and the second permeate stream has an osmotic pressure that is greater than a difference of the osmotic pressure of the second concentrate stream and a hydrostatic pressure used in the second ultrahigh pressure reverse osmosis membrane module array; and a recirculation loop operably connecting the second permeate stream with the feed stream.

16. The system of claim 15 wherein: the first ultrahigh pressure reverse osmosis membrane module array includes a first plurality of reverse osmosis elements including ultrahigh pressure high rejection reverse osmosis membranes configured to provide a rejection rate of the solute of at least 98% at ultrahigh pressure; and the second ultrahigh pressure reverse osmosis membrane module array includes a second plurality of reverse osmosis elements including ultrahigh pressure low rejection reverse osmosis membranes configured to have a rejection rate of the solute of 30% to 70% at ultrahigh pressure.

17. The system of any one of claims 15 or 16 wherein: the first ultrahigh pressure reverse osmosis membrane module array includes 2 to 35 ultrahigh pressure high rejection reverse osmosis elements; and the second ultrahigh pressure reverse osmosis membrane module array includes 2 to 25 ultrahigh pressure low rejection reverse osmosis elements.

18. The system of any one of claims 1 or 17 wherein the first plurality of reverse osmosis elements and second plurality of reverse osmosis elements are configured to operate at a pressure of 1500 psi or higher.

19. The system of any one of claims 16-18 wherein the first plurality of reverse osmosis elements and second plurality of reverse osmosis elements are configured to operate at a pressure of 1700 psi or higher.

20. The system of any one of claims 15-19 further comprising a feed solution supply fluidly connected to the first ultrahigh pressure reverse osmosis membrane module array.

21. The system of any of claims 15-20 wherein the feed stream includes vinegar, sugar, or a combination thereof.

22. The system of any of claims 15-21 wherein the second concentrate stream is fluidly connected to a product vessel.

23. The system of any of claims 15-22, further comprising one or more pumps operably coupled to one or more of the feed stream, the first concentrate stream, or the first permeate stream, wherein the one or more pumps are configured to pressurize a fluid stream to an ultrahigh pressure.

24. A method for concentrating solutions, the method comprising: circulating a feed stream including one or more solutes through a first ultrahigh pressure reverse osmosis membrane module array at a first pressure of at least 1500 psi to form a first concentrate stream and a first permeate stream; circulating the first concentrate stream through a second ultrahigh pressure reverse osmosis membrane module array at a second pressure of at least 1500 psi to form a second concentrate stream and a second permeate stream, wherein second concentrate stream has an osmotic pressure of at least 1700 psi and the second permeate stream has an osmotic pressure that is greater than a difference of the osmotic pressure of the second concentrate stream and a hydrostatic pressure used in the second ultrahigh pressure reverse osmosis membrane module array; and recirculating the second permeate stream to the feed stream prior to the first ultrahigh pressure reverse osmosis membrane module array.

25. The method of claim 24, wherein: the first ultrahigh pressure reverse osmosis membrane module array includes a first plurality of reverse osmosis elements including ultrahigh pressure high rejection reverse osmosis membranes configured to provide a rejection rate of the one or more solutes of at least 98% at ultrahigh pressure; and the second ultrahigh pressure reverse osmosis membrane module array includes a second plurality of reverse osmosis elements including ultrahigh pressure low rejection reverse osmosis membranes configured to have a rejection rate of the one or more solutes of 30% to 70% at ultrahigh pressure.

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