Membrane hydrogen peroxide purification

Abstract

Hydrogen Peroxide Purification on a Membrane. The present invention relates to the use, for the purification of a hydrogen peroxide solution, of a reverse osmosis filtration membrane, said membrane comprising at least one active layer of a polyethersulfone polymer. The present invention also relates to the method of purifying a hydrogen peroxide solution by passing it through a reverse osmosis filtration membrane, said membrane comprising at least one active layer of a polyethersulfone polymer. Fig.: none

Description

Title of the invention: Purification of hydrogen peroxide on a membrane

[0001] The present invention relates to the field of the purification of hydrogen peroxide (H2O2) solutions and more particularly to the field of hydrogen peroxide purification on membrane, and more specifically to the field of hydrogen peroxide purification on membrane by reverse osmosis.

[0002] The purification of hydrogen peroxide by reverse osmosis has many advantages, among which we can mention the obtaining of hydrogen peroxide, and more specifically of aqueous solutions of hydrogen peroxide, of very high purity, and in particular of a degree of purity compatible with the technical and industrial fields which require hydrogen peroxide of very high purity and in particular the fields of electronics, pharmaceuticals, cosmetics but also the agri-food sector.

[0003] Reverse osmosis purification technology is described, for example, in document EP0930269, which deals with an industrial process for producing high-purity hydrogen peroxide by reverse osmosis using a membrane made of polyamides, polypiperazinamides, polyacrylonitril, or polysulfones. Documents EP1520839 and US4879043 also mention the use of such membranes for the reverse osmosis purification of hydrogen peroxide solutions.

[0004] However, it turns out that the membranes used for the production of high-purity hydrogen peroxide most often have relatively short lifespans, on the order of about thirty days, in continuous operation mode. This problem of very short lifespan is mainly observed when the membranes have a polyamide-based active layer.

[0005] The rapid degradation of polyamide membranes is now well known and is the subject of numerous studies and publications, such as the study conducted by R. Abejôn et al. (“Effective Lifetime Study of Commercial Reverse Osmosis Membranes for Optimal Hydrogen Peroxide Ultrapurification Processes”, Ind. Eng. Chem. Res., (2013),52, 17270-17284), where the various advantages and disadvantages of electronic-grade hydrogen peroxide preparation processes using polyamide (PA) or cellulose acetate (AC) based membranes are analyzed.

[0006] Current industrial reverse osmosis membranes are most often made of a thin layer of polyamide (generally less than 200 nm), deposited on a porous layer of polyethersulfone (PES) or polysulfone (PS) (approximately 50 µm thick), itself placed on top of a support sheet, for example, a non-woven fabric. The three-layer configuration provides the desired properties of high rejection of unwanted materials (such as salts), a high filtration rate, and good mechanical strength. The top polyamide layer is responsible for the high rejection rate and is chosen primarily for its water permeability and relative impermeability to various dissolved impurities, including salt ions and other small, unfilterable molecules.

[0007] This rapid degradation of membranes, and in particular of polyamide-based membranes, results from the rapid degradation of polymer membranes under the action of the very high oxidizing power of the hydrogen peroxide solutions to be purified.

[0008] In addition to the need for polymer membranes resistant to degradation by oxidation, inherent in hydrogen peroxide, the polymer membranes must also have a high rejection rate, in order to ensure optimal purification.

[0009] There therefore remains today a need for membranes intended for the purification of hydrogen peroxide solutions, whose lifespans remain compatible with efficient and cost-effective implementation at the industrial level.

[0010] An objective of the present invention is therefore the provision of polymer membranes enabling the preparation of very high purity hydrogen peroxide solutions by reverse osmosis purification, said membranes having an improved lifespan compared to the polyamide-based membranes used today.

[0011] In addition to the need for polymer membranes resistant to degradation by oxidation, inherent in hydrogen peroxide, the polymer membranes must also exhibit a high rejection rate to ensure optimal purification. Another objective of the present invention is therefore to provide polymer membranes for reverse osmosis purification of hydrogen peroxide, exhibiting improved long-term stability and high rejection rates.

[0012] Thus, another objective of the present invention is the provision of polymer membranes exhibiting both an improved lifespan and a high rejection rate for use in the preparation of high purity hydrogen peroxide solutions, usable in particular in the fields of cosmetics, pharmaceuticals, food processing and electronics, especially for the preparation of semiconductors and printed circuits.

[0013] Other objectives will become apparent in the following description of the present invention. The inventors have discovered that the aforementioned objectives can be achieved in whole or at least in part, by means of polymer membranes. specific ones particularly well suited for the purification of hydrogen peroxide solutions and the preparation of very high purity hydrogen peroxide solutions.

[0014] Thus, and according to a first object, the present invention relates to the use, for the purification of a hydrogen peroxide solution, of a reverse osmosis filtration membrane, said membrane comprising at least one active layer of a polyethersulfone (PES) type polymer.

[0015] It has indeed been observed that PES-based polymer membranes have a substantially longer lifespan than those observed with polyamide-based polymer membranes, while offering a rejection rate particularly suited to the industrial production of very high purity hydrogen peroxide solutions, and in particular electronic grade hydrogen peroxide solutions.

[0016] In the present invention, the term "hydrogen peroxide solution" refers to an aqueous solution of hydrogen peroxide. The concentration of hydrogen peroxide in the water can vary widely and is generally between 1% and 98%, preferably between 5% and 75%, for example between 10% and 70%, even better between 20% and 70%, advantageously between 30% and 70% by weight of hydrogen peroxide, relative to the total weight of the solution.

[0017] Polyethersulfone (PES) polymers are well known to those skilled in the art and comprise ether and sulfone groups. The polyethersulfones that have shown the best results in the application according to the present invention are PES containing aromatic groups, commonly identified under the generic term polyarylethersulfones (PAES). The aromatic groups present in PAES are typically phenyl groups. These can be substituted, for example, by one or more sulfonate, amino, halogen (and more particularly fluorine), alkyl, alkenyl, and other groups. In a particularly preferred embodiment, the PES polymer for use according to the present invention is a polyarylethersulfone comprising at least one sulfonate group.

[0018] Such PES-type polymers, particularly suitable for the purposes of the present invention, are polyarylethersulfones comprising at least one sulfonate group, as described, for example, in US patent application 20200362107 AL

[0019] It has indeed been discovered that reverse osmosis membranes comprising at least one active layer with respect to the filtration of a PES-type polymer, as defined above, confer very good membrane stability over time, and particularly when used for the purification of concentrated solutions, typically exceeding 20% ​​by weight and more specifically greater than 30% by weight of hydrogen peroxide, while ensuring a high rejection rate, to ensure their purification, up to high quality grades, up to electronic grade.

[0020] According to a particularly preferred aspect of the present invention, the polyethersulfone (PES) active layer gives the reverse osmosis membrane a salt rejection rate greater than 90%, preferably greater than 95%, preferably even greater than 97%, better still greater than 98%, advantageously greater than 99%. The rejection rate is measured on an aqueous solution of 2000 mg per liter of sodium chloride, at 25°C, under a pressure of 15.5 bar (1.55 MPa), at pH 7, for 20 minutes, with a conversion rate of 15%, where the conversion rate is equal to the ratio of permeate flow rate to feed flow rate.

[0021] Examples of membranes particularly suitable for use according to the present invention include, by way of non-limiting example, homogeneous, symmetrical, asymmetrical, and composite membranes. Composite membranes, and in particular so-called TFC (Thin Film Composite) membranes, form a particularly preferred subset of PES-based polymer membranes.

[0022] As previously stated, the membranes used in the application according to the present invention comprise at least one active layer for filtering a polyethersulfone (PES) polymer, preferably a polyarylethersulfone (PAES) polymer, and particularly a polyarylethersulfone (PAES) polymer bearing a sulfonate group. Homogeneous membranes are preferred among these membranes. Another preferred group of membranes includes composite membranes, for example, of the TFC type, comprising at least one active layer for filtering a polyethersulfone (PES) polymer, in association with one or more other polymer layers, for example, polyamide, polypiperazinamide, polyacrylonitrile, polysulfone, polyester (typically cellulose acetate), and others well known to those skilled in the art.However, for the reasons mentioned above, it is preferable to use reverse osmosis membranes that do not have a polyamide layer.

[0023] Examples of TFC membranes usable in the present invention include membranes comprising two support layers of polyester and polysulfone. Membranes particularly well suited for use according to the present invention are membranes whose active layer is a polyethersulfone type polymer, as previously stated, said active layer being associated with one or two polymer support layers selected from polyester and polysulfone.

[0024] Such membranes have the advantages described above of being more stable over time than the membranes currently used for the purification of hydrogen peroxide solutions, and in particular for the purification of concentrated hydrogen peroxide solutions.

[0025] The use according to the present invention of a membrane comprising at least one polyethersulfone polymer as an active layer makes it possible to obtain a good degree of purification of hydrogen peroxide solutions, while maintaining a good rejection rate. The use according to the present invention makes it possible to achieve high purity grades of hydrogen peroxide, in particular up to electronic grade. Those skilled in the art will be able to adapt, according to the desired grade and the nature of the stream to be purified, the type of reverse osmosis membrane comprising at least one polyethersulfone active layer, for example, a BW (Brackish Water) or SW (Sea Water) membrane.

[0026] It has also been observed that membranes comprising at least one active layer of a PES-type polymer are much more resistant to oxidative attack from hydrogen peroxide solutions than membranes with a polyamide active layer. This results in a very significant increase in the lifespan of said PES-based membranes.

[0027] This increase in the lifespan of purification membranes, which, it should be noted, is currently only a few days to a few weeks, leads to a significant reduction in waste as well as in the operating costs associated with membrane replacements. The use, according to the invention, of membranes comprising at least one active layer of PES-type polymer therefore allows for a significant improvement in the productivity of the high-purity hydrogen peroxide solution production system, both in terms of cost and in terms of volumes processed.

[0028] According to a second aspect, the present invention relates to an industrial process for preparing high purity hydrogen peroxide solutions, and in particular very high purity solutions, and especially electronic grade hydrogen peroxide solutions, that is to say, solutions whose very low level of impurities they contain makes them compatible with the purity criteria required for use in the electronic industry.

[0029] The solutions purified by the process of the invention are aqueous solutions of hydrogen peroxide generally having a concentration between 1% and 98%, preferably between 5% and 75%, for example between 10% and 70%, better still between 20% and 70%, and more generally between 30% and 70% by weight of hydrogen peroxide, relative to the total weight of the solution.

[0030] According to one embodiment, high-purity hydrogen peroxide solutions are obtained from hydrogen peroxide, or even from stabilized hydrogen peroxide, such as is commercially available. Commercial hydrogen peroxide is subjected to well-known purification processes designed to eliminate impurities unacceptable for so-called high-purity grades used particularly in the cosmetics, pharmaceutical, food, and especially electronics industries. The process of the invention is also suitable for purifying concentrated hydrogen peroxide solutions, for example, solutions obtained directly from the process of preparing said hydrogen peroxide.

[0031] Suitable purification processes well known to those skilled in the art include at least one reverse osmosis purification step. According to the invention, the purification process includes at least one reverse osmosis purification step on a membrane comprising at least one layer of polyethersulfone-type polymer, as previously discussed.

[0032] In addition to this reverse osmosis purification step, the process of the invention may include one or more other purification steps selected from distillation, ion exchange resin treatment, adsorption resin treatment, liquid-liquid extraction, electrodeionization (EDI) treatment, ultrafiltration, microfiltration, nanofiltration, and other purification techniques well known to those skilled in the art.

[0033] Generally, to obtain very high degrees of purity, it is advantageous to combine one or more of the treatments indicated above. According to one embodiment of the invention, the process thus comprises at least one reverse osmosis treatment with a membrane comprising at least one active layer of the PES type as defined above, one ion exchange resin treatment, and optionally one EDI treatment.

[0034] It has thus been discovered that the process of the present invention, through the use of PES type active layer membrane, makes it possible to obtain high purity hydrogen peroxide solutions, even of electronic grade, in a completely viable and profitable industrial manner in terms of economic and commercial profitability.

[0035] More particularly, the process of the present invention is an industrial process for the purification and more particularly for the production of high-purity, or even very high-purity, hydrogen peroxide solutions, ranging from technical grade to electronic grade, said process comprising at least the steps of: a) supplying a crude hydrogen peroxide solution to be purified, b) treating said crude solution in a reverse osmosis membrane purification unit, said membrane comprising at least one active layer of polyethersulfone type polymer, c) recovering a permeate of purified hydrogen peroxide solution.

[0036] In step a), the term "crude hydrogen peroxide solution to be purified" refers more specifically to a hydrogen peroxide solution whose purity is to be increased. The hydrogen peroxide solutions to be purified can be of any type, whether commercial solutions whose purity is to be increased at varying concentrations, as defined previously, or hydrogen peroxide solutions obtained from the synthesis process.

[0037] The synthesis processes, for example industrial synthesis, of hydrogen peroxide solutions are well known to those skilled in the art or readily available in the literature and on the Internet. One particularly common process used today is the so-called anthraquinone process. The hydrogen peroxide solutions thus obtained and used in the process of the present invention are generally and most commonly aqueous solutions of hydrogen peroxide with a concentration of approximately 60% to 70% by weight. These solutions may or may not contain stabilizers, which are also well known to those skilled in the art.

[0038] Step b) of purification by reverse osmosis can itself be carried out once or several times, in series or in parallel, with or without direct recycling of the concentrated permeate. It is thus possible to carry out one, two, or more membrane purification steps by reverse osmosis, for example by reprocessing the permeate and then performing another purification step on said membrane. According to one embodiment, the process can thus comprise from 1 to 5, preferably from 1 to 4, preferably again 1, 2, or 3, advantageously 1 or 2 membrane purification steps.

[0039] According to one embodiment, the process of the present invention may also further comprise one or more additional purification steps, according to other techniques well known to those skilled in the art and which may, for example, and without limitation, be chosen from distillation, ion exchange resin treatment, adsorption resin treatment, liquid-liquid extraction, electrodeionization (EDI) treatment, ultrafiltration, microfiltration, nanofiltration, and others, as indicated above. Among these additional techniques, EDI purification techniques and ion exchange resin purification techniques are preferred.

[0040] It should be understood that one or more of these complementary purification techniques can be implemented before and / or after reverse osmosis purification using the membrane according to the present invention. Thus, according to one embodiment of the process of the invention, it comprises at least one reverse osmosis purification step using a membrane as defined above, with a polyethersulfone polymer active layer, and at least one purification step by passing through an ion-exchange resin. According to another embodiment of In implementation, the purification process of the invention comprises at least one reverse osmosis purification step using a membrane as previously defined, with a polymer active layer of the polyethersulfone type, at least one purification step by passing through an ion exchange resin, and at least one purification step using the EDI technique.

[0041] The ion exchange resin purification step generally allows for even higher degrees of purity. If desired, this ion exchange resin treatment can be carried out in one or more stages, in series or in parallel.

[0042] The ion exchange resins that can be used are well known to those skilled in the art and can, for example, be chosen from those of the so-called strong cation type, and for example, and without limitation, from the Amberlite™ 200C and Amberjet™ 1500H resins from Rohm & Haas.

[0043] If desirable, the purification process of the present invention may also include one or more nanofiltration and / or microfiltration and / or ultrafiltration steps, which are well known to those skilled in the art. Microfiltration and / or nanofiltration and / or ultrafiltration can, where necessary, remove any particles that may be present in the hydrogen peroxide solutions. These additional purification operations by ultrafiltration and / or nanofiltration and / or microfiltration are themselves well known to those skilled in the art and can be carried out in one or more stages, in series or in parallel, before and / or after the reverse osmosis membrane purification step(s) described above.

[0044] Thus, the process of the invention, which incorporates at least one purification step using a membrane comprising at least one active polymer layer of the polyethersulfone type, as defined above, is particularly effective for obtaining very high-purity hydrogen peroxide solutions, and especially for purifying concentrated solutions, on the order of 60% to 70% by weight. The process of the invention is particularly well-suited for industrial production of electronic-grade hydrogen peroxide. Furthermore, the process is particularly easy to implement and cost-effective due to the high resistance of reverse osmosis membranes, unlike the membranes commonly used in this application.

Claims

Demands

1. Use, for the purification of a hydrogen peroxide solution, of a reverse osmosis filtration membrane, said membrane comprising at least one active layer with respect to the filtration of a polyethersulfone (PES) type polymer, in association with one or more other polymer layers, selected from polyamide, polypiperazinamide, polyacrylonitrile, polysulfone, and polyester, preferably from polysulfone and polyester.

2. Use according to claim 1, wherein the polyethersulfone type polymer is a polyarylethersulfone type polymer, preferably comprising at least one sulfonate group.

3. Use according to claim 1 or claim 2, wherein the membrane has a salt rejection rate greater than 90%, preferably greater than 95%, preferably still greater than 97%, better still greater than 98%, advantageously greater than 99%, said rejection rate being measured on an aqueous solution of 2000 mg per liter of sodium chloride, at 25°C, under a pressure of 1.55 MPa, at pH 7, for 20 minutes, with a conversion rate of 15%, where the conversion rate is equal to the ratio permeate flow rate / feed flow rate.

4. Use according to any one of the preceding claims, wherein the membrane is a membrane selected from homogeneous, symmetric, asymmetric, and composite membranes, preferably from composite membranes and even more preferably from TFC composite membranes.

5. A method for purifying a hydrogen peroxide solution, and in particular an electronic grade hydrogen peroxide solution, comprising at least one reverse osmosis membrane filtration step comprising at least one polymer active layer of the polyethersulfone type according to any one of claims 1 to 4.

6. A method according to claim 5, comprising at least the steps of: a) supplying a crude hydrogen peroxide solution to be purified, b) treatment of said crude solution in a reverse osmosis membrane purification unit, said membrane comprising at least one active layer of polyethersulfone type polymer according to any one of claims 1 to 4, c) recovery of a purified hydrogen peroxide solution permeate.

7. A method according to claim 6, wherein step b) of purification by reverse osmosis is carried out once or several times, in series or in parallel, with or without direct recycling of the concentrated permeate.

8. A process according to any one of claims 5 to 7, further comprising one or more additional purification steps, selected from distillation, ion exchange resin treatment, adsorption resin treatment, liquid-liquid extraction, electrodeionization (EDI) treatment, ultrafiltration, microfiltration, nanofiltration, and others, and preferably from electrodeionization treatment techniques and ion exchange resin purification techniques.