MXPA98003866A - Procedure for purification of organic liquids cuasi-anhid - Google Patents

Abstract

To purify a quasi-anhydrous organic liquid, it is put in contact with one or several cation exchange resins, this resin or at least one of the resins is a sulphonic type resin in the form of -SO3H6-SO3NH4 with polystyrene-divinylbenzene copolymer base, wherein the proportion of divinylbenzene represents 50 to 60% by weight of the copolymer

Description

PROCEDURE FOR PURIFICATION OF ORGANIC LIQUIDS WHEN -ANHYDRATES FIELD OF THE INVENTION The present invention relates to the purification of quasi-anhydrous liquids constituted by one or several organic compounds and, more particularly, it relates to a method for eliminating the metallic impurities present in these liquids.

BACKGROUND OF THE INVENTION Most commercial organic liquids are commercially available with a very high purity, generally higher than 99%. However, as shown in the data in Table 1, metals in the form of traces are also found in these liquids that need additional purification to enable them to be used in industries such as electronics or pharmacy. In general, organic liquids containing less than 10 ppb of each metallic, alkaline and alkaline earth metal contaminant will be necessary for most uses in these technical fields (1 ppb = 1 part by weight per billion, ie 1 μg per kilogram).

P129S / 98 X TABLE 1 Therefore, it is desirable to have a purification process for commercial liquids containing one or more organic compounds already of good purity, but nevertheless with insufficient purity for certain applications, this process is mainly aimed at reducing the content of metallic traces. Ionic exchange resins are currently used today to deionize water. On the contrary, its use in the organic environment is much less known and studied. This lack of development is P1296 / 98 X originates in the particular properties of the water that ionizes the salts and completely separates the anions from the cations. Furthermore, according to the dielectric constant of the organic medium, the ions formed by ionization are more or less dissociated and more or less free to interchange with the functional groups of the resin. However, we find certain research works (CA Fleming and AJ Monhemus, Hydrometallurgy, 4, pp 159-167, 1979) whose objective is to improve, through a solvent effect, the exchange selectivity of some metals with cationic resins, the objective final is to determine the conditions that allow the separation of metals in preparative ion chromatography. These studies describe the exchange isotherms, that is, the laws that govern the balance between the metal ion in solution and the metal ion fixed in the resin. The normal conditions of these works are, therefore, very far from a method of deionization of organic medium. US Patent 4,795,565 describes the purification with ion exchange resin of an aqueous solution of ethanolamine. The purpose of this patent is the elimination of some salts produced during the ethanolamine extraction of carbon dioxide and hydrogen sulfide contained in the refinery gas. The solution P1296 / 98MX used ethanolamine containing between 80 and 50% water by weight, and was passed successively in a fixed bed of strong anionic resin, and then on a fixed bed of strong cationic resin. The patent US 5,162,084 refers to the same type of application but improves the efficiency of the purification using an association of two anionic resins and judiciously controlling the operation of the unit with the help of conductometric sensors. This patent does not describe the purification of ethanolamine based on the water content on the ion exchange resins. Patent GB 2,088,850 describes the purification of l-methyl-2-pyrrolidone (NMP) by its passage on an anionic resin that binds the chloride and carboxylate ions. This treatment is inserted in a procedure of selective extraction by the NMP, of the aromatic hydrocarbons contained in a mixture of paraffins. Although purification with cationic resins is not described in this patent. However, 10% of the water by weight is advantageously added to the NMP to improve the extraction selectivity. The patent RU 2,032,655 refers to the deionization of aliphatic alcohols or diols, in order to reduce their electrical conductivity. Therefore, the authors used a fixed bed of resin Anionic P129S / 98MX and cationic resin in equal proportions, these resins are previously saturated in water. In a later publication (Vysokochist, Veshchestva, 2, pp 71-75, 1992), A.G. Myakon'kii et al. they indicate that a minimum water content of 2.5% in the medium is needed to obtain a deionization with the help of a pair of dry resins. In another article entitled "novel ultrapurification system based on resins for IPA reprocessing in the semiconductor industry" (Ind. Eng. Che. Res. 1996, 35, 3149-3154), P.V. Buragohain et. to the. predict the use of cation exchange resins (Amberlite® IR 120, Dowex® M31 and lonac® CFP 110) to purify isopropyl alcohol (IPA). In these cationic resins based on polystyrene and divinylbenzene copolymer, the proportion of divinylbenzene in the copolymer does not exceed 20%. The use of an ion exchange resin of the sulfonic type, which has its active groups in the acid form of HSO 3 for the purification of dimethylsulfoxide (DMSO), was the subject of the patent application WO 97/19057 published on May 29, 1997. However, today it has been found that the use of a cationic resin of sulfonic type, based on polystyrene and divinylbenzene copolymer P1296 / 98MX has a very high proportion of divinylbenzene, allows that in a quasi-anhydrous organic liquid, all the Mn + cations are retained and exchanged (n has a value of 1 to 4) by n protons H + or by n NH4 + ions, of a resin in protonic or ammonium form. The object of the present invention is a method for purifying a quasi-anhydrous organic liquid, different from DMSO alone, to reduce the content of metal, alkali and alkaline earth cations, characterized in that it consists essentially of putting the organic liquid in contact with one or more cation exchange resins, and then remove from the resin (s) the purified organic liquid with very low contents of metal, alkali and alkaline earth cations, said resin or the at least one of these resins is a sulphonic resin in form of -SO3H or -SO3NH4 based on a copolymer of polystyrene and divinylbenzene, wherein the proportion of divinylbenzene represents 50 to 60% by weight of the copolymer, taking into account the sulfonic groups. By organic quasi-anhydrous liquid is meant here an organic liquid having a water content less than or equal to 1% by weight, preferably less than or equal to 0.15% by weight. The method according to the invention can P1296 / 98MX applied to purify all liquid organic compound having a dielectric constant e having from 5 to 50 and a pKa greater than 2. As non-exclusive examples of these compounds, one can more particularly cite 1-methyl-2-pyrrolidone (NMP), isopropyl alcohol (IPA), benzyl alcohol (ABY) and dimethylacetamide (DMAC), monoethanolamine (MEA), ethyl acetate, butyl acetate, ethyl lactate, butyl lactate, tetrahydrothiophene-1,1-dioxide (Sulfolane), glycerol, acetic acid, acetone and propylene glycol monoethyl ether acetate (PGMEA). The process is also used for the purification of mixtures of these compounds with each other or with DMSO in very variable proportions. Non-exclusive examples of these mixtures can be mentioned, more particularly the mixtures DMSO / MEA, NMP / MEA, DMSO / ABY and DMSO / ABY / MEA. The cationic resins used to carry out the process of the invention are well known and commercially available products, mainly under the designation Amberlyst® and XN 1010 (commercially available from the Rohm &Haas Company), Hypersol Macronet® (which commercializes the Purolite Company) and Relite® (marketed by the Mitsubishi Company). At least one of the resins used according to the invention is a sulphonic resin based on P1296 / 98MX a copolymer of polystyrene and divinylbenzene where the proportion of divinylbenzene represents 50 to 60% by weight and that of polystyrene of 50 to 40% by weight, based on the total weight of the copolymer, without taking into account the sulfonic groups. This proportion of divinylbenzene ensures a good kinetic activity of the exchange of Mn + cations by protons n.H + or n.NH4 + cations. When more resins are used, at least one of the resins is like the one defined above, the other (or the others) may be of the chelating type. The organic liquid to be purified can be contacted with a mixture of different resins or successively with each of the different resins. By contacting the organic liquid to be purified with the resin or resins (preferably in the form of H +), it is carried out at a temperature between the melting point of the liquid to be purified up to 120 ° C (limit temperature). of the thermal stability of the resins). This temperature is advantageously between 19 and 80 ° C, preferably between 20 to 50 ° C. The operation can be carried out discontinuously (batchwise) or continuously, under the conditions and with the apparatuses known to the expert in this field. The separation of the purified liquid from the resin (s) can be done by any means P1296 / 98MX known suitable, namely by filtration, percolation or centrifugation. The invention will be better understood with the help of the experimental part described below, with exemplary embodiments of the present invention.

Experimental Part I. Methodology The metallic traces are in the form of Mn +. By contacting the liquid to be purified with the cation exchange resin (s), these in the form of H + or H4 +, the Mn + ions are replaced in solution by H + protons or by H4 + ions. In a first time, batch tests are carried out to treat different organic compounds, pure or in mixture. In a second moment, some media are purified continuously, passing the liquid over a fixed bed of ion exchange resin. This technique is effectively more satisfactory and representative of a real production of the purified liquid.

II. Method of Analysis The method of analysis of metal traces in the organic medium is I.C.P. (emission spectrometry P1296 / 98 Atomic X - plasma torch): the sample is introduced into a plasma torch or the different elements are excited and photons are emitted whose energy is characteristic of the element, since it is defined by the electronic structure of the element under consideration. A routine was used in a Perkin Elmer apparatus (Optima 3000 DV model). This technique allows the content of several metals to be analyzed simultaneously. In order to provide clarity to the results, it was chosen not to indicate more than the content of iron and sodium, trace elements representative of the set of metallic impurities present. Sodium is translated into atmospheric and accidental pollution (dust) and the iron is characterized by a contamination emitted from manufacturing or conditioning procedures (liquid contact with steel). The limits of detection of this analysis technique depend on the metal considered. For sodium, the limit of detection is 2 ppb (parts per billion) and for iron 1 ppb. III. Batch test III.1 Experimental preparation To 100 grams of an organic liquid were added between 100 and 1000 ppb (parts per billion) of sodium and iron, then this solution was put in contact with a P1296 / 98MX continuous amount of resin (between 2 and 10 g) in the form of H +. Samples of liquids were taken in the course of time in order to follow the evolution of iron and sodium concentrations. The resin used (Hypersol Macronet® MN 500 of the Purolite Company) is a sulphonic resin with a styrene / divinylbenzene structure that has a divinylbenzene content of 60%; it is provided in H + form. This was previously dried by suspending it in methanol and subjecting it to evaporation under vacuum in the rotary evaporator (90 ° C, 2000 Pa) until the observation of a constant weight. III.2 Reduction of the concentration of cation (other than H +) of the NMP: Example 1. The efficiency of the MN 500 resin was tested in the purification of the NMP, using 10 g of the resin per 100 g of NMP. Table 2 shows the evolution of iron and sodium content over time.

TABLE 2 (EXAMPLE 1) P1296 / 98MX III.3 Reduction of the content of cations (other than H +) of different pure organic media or in mixture: Examples 2 to 12. The efficiency of the ion exchange between a resin and an organic medium depends on the nature of the resin but also of the considered medium. In Examples 2 to 9, the activity of sulphonic resin MN 500 from the company Purolite was tested in parallel with the cations contained in various pure organic media or in a mixture of organic compounds. Table 3 (Example 2) indicates the evolution over time of the iron and sodium concentration in the benzyl alcohol treated with 2% by weight of resin MN 500.

TABLE 3 (EXAMPLE 2) Table 4 (Examples 3 to 7) gathers the results that refer to the exchange kinetics of iron and sodium in five other organic components: alcohol Isopropyl P129S / 98MX (IPA), N, -thylacetamide (DMAC), monoethanolamine (MEA), propylene glycol monomethyl ether acetate (PGMEA) and acetic acid (AcOH).

TABLE 4 EXAMPLES 3 TO 7 Ejettplo No. 3 4 5 6 7 Liquid IPA DMAC MEA PGMEA Organic AcOH Quantity 5 5 5 10 10 Resin (% W / W) Time [Na] [Fe] [Na] [Na] [Fe] [Na] [Fe] [Na] [Fe] [Na] [Faith] (hours) (ppb) (ppb) (ppb) (ppb) (ppb) (ppb) (ppb) (ppb) (ppb) (ppb) 0 250 240 530 570 100 100 30 40 420 100 1 5 36 5 70 20 3 22 20 30 6 2 3 6 2 30 12 2 20 12 19 3 4 2 5 < 2 15 10 < 2 19 9 15 2 6 3 6 2 13 8 2 - - 8 2 7 < 2 10 3 2 10 * 7 10 3 24 -. 24 - - - - - - 9 6 7 2 Table 5 lists the exchange kinetics of sodium and iron in the binary mixtures of organic compounds. The same resin that was used before is used.

P1296 / 98MX TABLE 5 EXAMPLES 8 TO 12 IV. Continuous tests IV.1 Experimental preparation From the results of the batches, several continuous tests were carried out according to the rules commonly followed by those skilled in the art regarding column diameter / grain size relationships. , height of the column / diameter of the column and linear speed so as not to have difunctional limitations. The previously dried resin, as indicated above, is suspended in 90 ml of liquid in a beaker and stirred slightly (to eliminate air bubbles). This suspension is introduced in a Teflon column, in vertical position and whose lower part is P1296 / 98MX equipped with a polyethylene frit of 70 μm porosity. The beaker is rinsed with 10 ml of liquid. Under the frit, the column is equipped with a Teflon tap. This key closes during the filling operation. Once the resin is deposited and tamped in the column, the key is opened and the column is fed continuously with the medium to be purified, thanks to the use of a pump equipped with a Teflon head. Samples are taken at regular intervals. All tubes and connections are Teflon. The bottles are made of high density polyethylene.

IV.2 Reduction of the cation content (different from H +) of different media constituted by one or more organic products: Examples 13 to 16 Resin MN 500 Volume of dry resin: 35 cm- ^ (except for Example 16: 88 cm ^ ). Grain size: 0.3 to 1.2 mm The results appear in the following Table 6. The equivalent volume that translates the evolution of the test is the ratio between the volume of liquid (in liters) and the volume of resin (in me).

P129S / 98MX TABLE 6 EXAMPLES 13 TO 16 P1296 / 98MX

Claims (8)

1. NOVELTY OF THE INVENTION Having described the present invention, it is considered as a novelty and, therefore, the content of the following CLAIMS is claimed as property: 1. Procedure for purification of a quasi-anhydrous organic liquid, different from solid dimethyl sulfoxide, to decrease the content of metal cations, either alkaline or alkaline earth, characterized in that it consists essentially of contacting the organic liquid to be purified with one or more cation exchange resins in the form of acid or ammonium, subsequently separating it from the (or the) resin (s) to the purified organic liquid, said resin or the at least one of said resins is a sulfonic resin based on polystyrene and divinylbenzene copolymer, wherein the proportion of divinylbenzene represents 50 to 60% by weight of the copolymer, not taking into account the sulfonic groups.
2. 2. The process according to claim 1, characterized in that the water content of the organic liquid is less than or equal to 1% by weight, preferably less than or equal to 0.15% by weight.
3. 3. The process according to claim 1 or 2, characterized in that the liquid to be purified is P1296 / 98 X an organic compound having a dielectric constant e between 5 to 50 and a pKa greater than 2, or a mixture of these compounds with each other and / or with dimethylsulfoxide (DMSO).
4. 4. The process according to claim 3, characterized in that the liquid to be purified is selected from l-methyl-2-pyrrolidone (NMP), isopropyl alcohol, benzyl alcohol (ABY), dimethylacetamide, monoethanolamine (MEA), ethyl, butyl acetate, ethyl lactate, butyl lactate, tetrahydrothiophene-1,1-dioxide, glycerol, acetic acid, acetone, propylene glycol monomethyl ether acetate and mixtures of DMSO / MEA, NMP / MEA, DMSO / ABY and DMSO / ABY / MEA.
5. Method according to one of claims 1 to 4, characterized in that at least two resins are used, at least one of them is a sulphonic resin such as that defined in claim 1, and the other (or the others) They can be chelating.
6. 6. Process according to any of claims 1 to 5, characterized in that the resin or resins are in the form of H + acid. Method according to one of claims 1 to 6, characterized in that the contact of the liquid to be purified with the exchange resin (s) is carried out at a temperature of P1296 / 98MX between 19 to 80 ° C. Method according to claim 7, characterized in that the temperature is between 20 and 50 ° C. P1296 / 98 X