TW201605536A - Processing of deactivated ionic liquids - Google Patents

Abstract

The present disclosure relates to a process for separating the cationic and anionic components from deactivated ionic liquids. The process includes reacting the deactivated ionic liquid with 8-hydroxyquinoline to precipitate the anionic component, separating the precipitate followed by extracting the deactivating components from the cationic component. The anionic precipitate and the deactivating component free cationic component are subsequently recovered and reused for different applications. The ionic liquid can be reconstituted from the cationic component and another anionic component for use as a fresh ionic liquid.

Description

Treatment of deactivated ionic liquids

This invention relates to ionic liquids, and more particularly to the reconstitution of deactivated ionic liquids and the separation of their cationic and anionic components.

As the name suggests, ionic compounds are compounds that include cations and anions. Generally, they include salts having a melting point below 100 °C. It is well known that ionic liquids are used in various applications such as alkylation, polymerization, dimerization, oligomerization, acetylation, displacement, and copolymerization of catalysts, solvents, and electrolytes. For example, U.S. Patent No. 7,432,408 describes the use of 1-butyl-4-methyl-pyridine chloroaluminate (BMP), 1-butyl-pyridine chloroaluminate (BP), 1-butyl-3- A method of alkylating an isoparaffin and a C ₂ -C ₅ olefin by using a methyl-imidazolium chloroaluminate (BMIM) and a 1-H-pyridine chloroaluminate (HP) plasma as a catalyst. U.S. Patent No. 7,495,144 also describes a process for the alkylation of isoparaffins and C ₂ -C ₅ olefins using a complex ionic liquid catalyst wherein the ionic liquid is an acidic ionic liquid such as 1-butyl-4-methyl. -pyridine chloroaluminate (BMP), 1-butyl-pyridine chloroaluminate (BP), 1-butyl-3-methyl-imidazolium chloroaluminate (BMIM) and 1-H-pyridine chloroaluminum a mixture of an acid salt (HP) and a metal halide such as aluminum trichloride.

Ammonium, phosphorus, ruthenium, pyridine and imidazolium salts are some of the commonly used cations; and halose aluminates such as BF ₄ ^- , PF ₆ ^- , Al ₂ Cl ₇ ^- and Al ₂ Br ₇ ^- , [(CF ₃ SO ₂ ) 2N)] ^- , alkyl sulfate (RSO ₃ ^- ), carboxylate (RCO ₂ ^- ) are commonly used anions in some ionic liquids. However, when an ionic liquid containing a haloaluminate is used in any of the above reactions, it is deactivated due to the presence of various chemical entities such as hydrocarbons, bound polymers, and water in the reaction. Therefore, at the end of the reaction, the ionic liquid cannot be reused for other reactions because it is in an inactive state. It is necessary to replenish the raw materials, but the cost of the chemicals leads to an increase in the processing cost index. In addition, because the used ionic liquid must be discarded, a large amount of waste is generated, and valuable reagents are wasted.

Attempts have been made to reuse waste ionic liquids. U.S. Patent Application Serial No. 2,010,160,145 describes a process for decomposing an ionic liquid catalyst and employing a secondary alcohol for this purpose. WO2010062902 also describes a process for recovering ionic liquids. However, the process in WO2010062902 promotes the achievement of this purpose by removing aluminum trichloride in the ionic liquid by cooling or cooling and crystallization of the ionic liquid to precipitate precipitated aluminum trichloride.

However, these techniques that have been used to reuse ionic liquids have certain drawbacks, such as the use of expensive reagents and time consuming processing steps. Accordingly, the present invention provides a process for reconstituting an ionic liquid which is more cost effective than conventional processes and which produces certain reaction products that can be effectively utilized.

Purpose of the invention

In some objects of the invention, at least one embodiment is directed to the object set forth below: A first object of the invention is to provide a reconstitution process for a deactivated ionic liquid.

A second object of the present invention is to provide a process for separating the cationic and anionic components of the deactivated ionic liquid and reconstituting the new ionic liquid.

A third object of the invention is to provide a simple, economical process for reconstituting a new ionic liquid from a deactivated ionic liquid.

A fourth object of the present invention is to provide an environmentally friendly process for reconstituting a new ionic liquid.

A fifth object of the present invention is to provide a process for reconstitution of a deactivated ionic liquid which provides an industrially useful reaction product.

A sixth object of the invention is to improve one or more of the problems of the conventional process, or at least to provide a useful alternative.

The following description will further clarify other objects and advantages of the present invention, but is not intended to be limiting The scope of the invention.

The present invention provides a process for separating the cationic and anionic components of a deactivated ionic liquid, the process comprising the steps of: a. mixing the deactivated ionic liquid with a first solvent and heating it to a temperature of 60 to 80 °C Range, obtaining a first blend; b. mixing 8-hydroxyquinoline with a second solvent and heating it to a temperature range of 60 to 80 ° C to obtain a second blend; c. Mixing the first admixture with the second admixture to obtain a dispersion system, using at least one pH adjuster to maintain the pH in the range of 4 to 7; d. cooling the dispersion system And to a temperature below 60 ° C, and then filtered to obtain: i. a residue comprising a precipitate of the anion component and 8-hydroxyquinoline; ii. a filtrate comprising the cationic component, an inactive component of the ionic liquid And the second solvent; e. washing the residue with the second solvent, and then drying to obtain a pure precipitate; f. distilling the filtrate to remove the second solvent, and obtaining the cation a mixture of components and said inactive components; An extracting agent extracts the deactivated component in the mixture to obtain a cationic component free of the inactive component; h. crystallizing the cationic component with at least one crystallization agent to recover the Cationic component.

Typically, the cationic component is selected from the group consisting of 1-butyl-3-methylimidazolium bromide, 1-butyl-3-methylimidazolium chloride, 1-butyl-4-methylpyridinium pyridine, and 1-butyl -4-methylbromide pyridine; the anion component is aluminum chloride, and the inactive component is at least one of a polymer, a tar, a hydrocarbon, and moisture. Precipitate A tris(8-hydroxyquinoline)aluminum (III) complex characterized by being used as a fluorescent material in an organic light-emitting diode.

The invention will now be described in connection with the accompanying embodiments, which are not intended to limit the scope of the invention. It is described by way of example only and by way of illustration.

Embodiments herein, as well as various features and detailed advantages thereof, are described in accordance with the following non-limiting embodiments. Descriptions of well-known components and processing techniques are omitted so as not to unnecessarily obscure the embodiments herein. The examples used herein are merely for the purpose of facilitating the understanding of the possible embodiments of the embodiments and the embodiments of the invention. Therefore, the examples are not to be construed as limiting the scope of the embodiments herein.

The description of the specific embodiments is a comprehensive description of the general nature of the embodiments herein, and other embodiments can be modified and/or adapted to various uses at any time by applying the prior art without departing from the ordinary concepts. Accordingly, such adaptations and modifications are intended to be more commensurate in the context of the meaning and scope of the disclosed embodiments. It is not difficult to understand that the phrase or terminology used herein is for the purpose of description and not limitation. Therefore, the embodiments herein are described in the preferred embodiments, and those skilled in the art will recognize that the embodiments described herein may be modified within the spirit and scope of the embodiments described herein.

Ionic liquids are used as catalysts, solvents and electrolytes in various reactions such as polymerization and alkylation. In these reactions, the ionic liquid is deactivated by contamination by different chemical entities such as polymers and hydrocarbons. The present invention provides a process for recovering a composite form of an anionic component and a cationic component in an inactivated ionic liquid, wherein the ionic liquid can be recovered and reused for different uses. The ionic liquid can be reconstituted through the cationic component and the new anionic component and used as a new ionic liquid.

The process of the present invention achieves the reconstitution of the ionic liquid by separating the inactive components The cationic and anionic components, the resulting cationic component is combined with the new anionic component to reconstitute the ionic liquid, thereby providing a reconstituted new ionic liquid.

Typically, the cationic component of the present invention is selected from the group consisting of 1-butyl-3-methylimidazolium bromide, 1-butyl-3-methylimidazolium chloride, 1-butyl-4-methylpyridinium chloride, and 1 - butyl-4-methylbromide pyridine. The anionic component is a metal chloride, especially aluminum chloride. The deactivating component of the present invention is selected from the group consisting of polymers, tars, hydrocarbons, and moisture.

The process first includes mixing the deactivated ionic liquid with a first solvent and heating it to a temperature range of 60 to 80 ° C to obtain a first blend. The first solvent of the present invention may be toluene. Then, 8-hydroxyquinoline is mixed with a second solvent and heated to a temperature range of 60 to 80 ° C to obtain a second blend. Typically, the second solvent is ethanol.

The first blend is then added dropwise to the second blend while maintaining its pH at 4 to 7, resulting in a dispersion. At least one pH adjuster is used to maintain the pH within the desired range. The pH adjusting agent is selected from the group consisting of sodium acetate, sodium hydroxide, and sodium carbonate.

The dispersion was then cooled to a temperature below 60 ° C and filtered to give a residue and a filtrate. The residue is a precipitate of aluminum ions and 8-hydroxyquinoline in the form of aluminum chloride, which is produced in the step of mixing the first blend and the second blend. Usually, the resulting precipitate is a complex of tris(8-hydroxyquinoline)aluminum (III). The residue is then washed with the second solvent and then dried to give a pure precipitate which can be used for different purposes.

The filtrate includes the cationic component, the deactivated component, and the second solvent. The second solvent is removed by distillation leaving a mixture comprising the cationic component and the deactivated component. The deactivated component in the mixture is then extracted to obtain a cationic component free of the deactivated component. The extracting agent of the present invention is at least one of ethylene glycol diacetate and toluene.

The cationic component not containing the deactivating agent is further crystallized through at least one crystallization agent to recover the cationic component. The crystallization agent of the present invention is at least one of acetonitrile and dichloromethane. Once the inactive component is separated, the cationic component can be combined with another anionic component to act as a new ionic liquid.

Therefore, this process reconstructs the deactivated ionic liquid and achieves the purpose of recycling. The anion component complex isolated according to the present process is fluorescent. It can be further used for different purposes, such as a fluorescent light source in an organic light-emitting diode. Thus, the process of the present invention effectively reuses the deactivated ionic liquid that has been previously discarded.

The invention is further described in conjunction with the experiments provided below, which are for illustrative purposes only and are not to be construed as limiting the scope of the invention. These laboratory-scale experiments can be scaled up to industrial/commercial scale.

Example 1: Process for separating and recovering cationic and anionic components from deactivated, new ionic liquids Preparation of a new ionic liquid catalyst (1-butyl-3-methylimidazolium bromide + aluminum chloride)

The apparatus used included a 5 liter three-neck round bottom (RB) flask equipped with an overhead stirrer placed in an ice bath at 0-5 °C. The flask was clamped to ensure agitation stability. The assembled device was placed under a nitrogen atmosphere. 680 g [BMIM]Br was weighed and carefully added to the flask through a funnel. Start low speed agitation. Then, 830 g of aluminum trichloride was weighed and slowly added to the flask. The operation of adding aluminum trichloride was completed within 1.5 hours, and then the mixture was stirred for 2 hours to thoroughly mix the reactants. Finally, the catalyst was sealed under nitrogen blanket conditions.

Separation and recovery of cationic and anionic components

0.264 g of the above novel ionic liquid catalyst was placed in a beaker, 5 ml of ethanol was added thereto, and it was heated to a temperature of 67 to 68 °C. To another Erlenmeyer flask was added 0.6 g of 8-hydroxyquinoline and 5 ml of ethanol, and it was heated to a temperature of 67-68 °C. The ionic liquid was slowly added to the 8-hydroxyquinoline solution while a saturated sodium acetate solution was added thereto to maintain the pH at 5-6. The pH was measured with a pH meter. The yellow solid tris-(8-hydroxyquinoline)aluminum (III) precipitated and the BMIMBr was dissolved in ethanol. The dispersion was cooled and the precipitate was filtered. The precipitate was further washed with ethanol to remove excess BMIMBr, and then dried to obtain 95% of fluorescent tris-(8-hydroxyquinoline)aluminum (III). The solvent phase of the dispersion was distilled to remove ethanol and toluene to separate the BMIMBr. The BMIMBr was further crystallized using acetonitrile to give a BMIMBr yield of 61%.

Preparation of a deactivated ionic liquid catalyst (alkylation using the ionic liquid catalyst prepared above)

9.2 liter of 10-15% C ₁₀ -C ₁₄ olefins and paraffins stream of benzene was added 3.6 liters of a 25 l round-bottomed reactor, the reactor is positioned inside a heating mantle. Start the stirrer and turn on the heating coil. When the mixture reached a temperature of 45 ° C, 0.13 kg of the new catalyst prepared above was added and stirred for 10 minutes. After standing for 10 minutes, the hydrocarbon layer and the catalyst layer were separated, and the bottom catalyst layer was recovered with the same amount of fresh olefin stream and benzene.

Separation and recovery of cationic and anionic components

0.264 g of the above-mentioned deactivated ionic liquid catalyst was placed in a beaker, 15 ml of toluene was added thereto, and it was heated to a temperature of 67 to 68 °C. To another Erlenmeyer flask was added 0.6 g of 8-hydroxyquinoline and 10 ml of ethanol, and it was heated to a temperature of 67-68 °C. The deactivated ionic liquid catalyst solution prepared above was slowly added to the 8-hydroxyquinoline solution while a saturated sodium acetate solution was added thereto to maintain the pH at 5-6. The pH was measured with a pH meter. The yellow solid tris-(8-hydroxyquinoline)aluminum (III) precipitated and the BMIMBr was dissolved in ethanol. The dispersion was cooled and the precipitate was filtered. The precipitate was further washed with ethanol to remove excess BMIMBr, and then dried to obtain 96% of fluorescent tris-(8-hydroxyquinoline)aluminum (III). The solvent phase of the dispersion is distilled to remove ethanol and toluene leaving a slurry containing BMIMBr and bound polymer. These bound polymers were removed by extraction with ethyl acetate, and BMIMBr was further crystallized using acetonitrile to give a BMIMBr yield of 58%.

in conclusion:

The process of separating the cationic and anionic components of the ionic liquid in the present invention can be successfully applied to new and deactivated ionic liquids.

Example 2: Process for separating and recovering cationic and anionic components from inactivated ionic liquids Preparation of a new ionic liquid catalyst (1-butyl-3-methylimidazolium chloride + aluminum chloride)

The apparatus used included a 5 liter three-neck round bottom (RB) flask equipped with an overhead stirrer placed in an ice bath at 0-5 °C. The flask was clamped to ensure agitation stability. The assembled device was placed under a nitrogen atmosphere. Weigh 542 grams [BMIM]Cl and carefully through a funnel It was added to the flask. Start low speed agitation. Then, 830 g of aluminum trichloride was weighed and slowly added to the flask. The operation of adding aluminum trichloride was completed within 1.5 hours, and then the mixture was stirred for 2 hours to thoroughly mix the raw materials. Finally, the catalyst was sealed under nitrogen blanket conditions.

Preparation of a deactivated ionic liquid catalyst (alkylation using the ionic liquid catalyst prepared above)

9.2 liter of 10-15% C ₁₀ -C ₁₄ olefins and paraffins stream of benzene was added 3.6 liters of a 25 l round-bottomed reactor, the reactor is positioned inside a heating mantle. Start the stirrer and turn on the heating coil. When the mixture reached a temperature of 45 ° C, 0.13 kg of the catalyst prepared above was added and stirred for 10 minutes. After standing for 10 minutes, the hydrocarbon layer and the catalyst layer were separated, and the bottom catalyst layer was recovered with the same amount of fresh olefin stream and benzene.

Separation and recovery of cationic and anionic components

0.264 g of the deactivated ionic liquid was placed in a beaker, 15 ml of toluene was added thereto, and it was heated to a temperature of 67 to 68 °C. To another Erlenmeyer flask was added 0.6 g of 8-hydroxyquinoline and 10 ml of ethanol, and it was heated to a temperature of 67-68 °C. The deactivated ionic liquid catalyst solution prepared above was slowly added to the 8-hydroxyquinoline solution while a saturated sodium acetate solution was added thereto to maintain the pH at 5-6. The pH was measured with a pH meter. The yellow solid tris-(8-hydroxyquinoline)aluminum (III) precipitated and the BMIMCl was dissolved in ethanol. The dispersion was cooled and the precipitate was filtered. The precipitate was further washed with ethanol to remove excess BMIMCl, and then dried to obtain 95% of fluorescent tris-(8-hydroxyquinoline)aluminum (III). The solvent phase of the dispersion is distilled to remove the ethanol leaving a slurry containing BMIClCl and the bound polymer. These bound polymers were removed by extraction with ethyl acetate, and BMIMCl was further crystallized using acetonitrile to give a yield of 62-78% of BMIMCl.

in conclusion:

The process of separating the cationic and anionic components of the ionic liquid in the present invention can be successfully applied to the deactivated ionic liquid.

The word "comprising" is used throughout the specification and is to be understood as meaning that An integer or step, or a set of elements, integers, or steps, but does not exclude any other elements, integers, or steps, or a set of elements, integers, or steps.

The use of the terms "at least" or "at least one of," or "an" or "an" or "an"

Any discussion of documents, acts, materials, devices, articles, etc. that have been included in this specification is for the purpose of providing information disclosure only and is not intended to admit that any or all of these matters form part of the basis of the prior art or General knowledge related to the invention, as these matters exist anywhere before the priority date of this application.

The values of the various physical parameters, dimensions or quantities mentioned are only approximations. It is to be understood that values that are higher/lower than the values assigned to the parameters, dimensions or quantities are also within the scope of the invention unless specifically stated to the contrary.

While the present invention has been described with respect to the preferred embodiments of the present invention, it is to be understood that various modifications may be made in the preferred embodiments. These and other modifications of the preferred embodiments of the invention, as well as other embodiments, can be readily made by those skilled in the art. Therefore, the above description is merely illustrative of the invention, but the invention is not limited thereto.

Technical advantage and economic significance

- The process of the invention can recover used deactivated ionic liquids which can then be used further for different purposes.

- The process of the present invention reduces unnecessary waste of valuable chemicals, thereby reducing environmental hazards.

- Reduced the cost of purchasing new ionic liquid catalysts for a variety of single uses.

- The anionic component complex obtained in the process of the present invention can be further used in an organic light-emitting diode.

Claims (14)

A process for separating a cationic and an anionic component of a deactivated ionic liquid; the process comprising the steps of: a. mixing the deactivated ionic liquid with a first solvent and heating it to a temperature range of 60 to 80 ° C to obtain a a first blend; b. mixing 8-hydroxyquinoline with a second solvent and heating it to a temperature range of 60 to 80 ° C to obtain a second blend; c. mixing the mixture in a dropping manner a first blend and the second blend, to obtain a dispersion system, using at least one pH adjuster to maintain the pH at 4-7; d. cooling the dispersion to a temperature below 60 ° C, And then filtered to obtain: i. a residue comprising a precipitate of the anion component and 8-hydroxyquinoline; ii. a filtrate comprising the cationic component, a deactivated component of the ionic liquid, and the first and second a solvent; e. washing the residue with the second solvent, and then drying to obtain a pure precipitate; f. distilling the filtrate to remove the first and second solvents, and obtaining the cationic component and a mixture of the inactive components; g. with at least one extractant The inactive component of the mixture is taken to obtain a cationic component free of the deactivated component; h. the cationic component is crystallized with at least one crystallization agent to recover the cationic component. The process of claim 1, wherein the cationic component is selected from the group consisting of 1-butyl-3-methylimidazolium bromide, 1-butyl-3-methylimidazolium chloride, 1-butyl-4-methyl Pyridine chloride and 1-butyl-4-methylbromide pyridine. The process of claim 1 wherein the anionic component is a metal chloride. The process of claim 3 wherein the anionic component is aluminum chloride. The process of claim 1 wherein the inactive component is at least one of a polymer, a tar, a hydrocarbon, and moisture. The process of claim 1 wherein the first solvent is toluene. The process of claim 1 wherein the second solvent is ethanol. The process of claim 1, wherein the step of preparing the dispersion is performed by adding the first blend to the second blend. The process of claim 1, wherein the step of preparing the dispersion is performed by adding the second blend to the first blend. The process of claim 1, wherein the pH adjusting agent is at least one selected from the group consisting of sodium acetate, sodium hydroxide, and sodium carbonate. The process of claim 1, wherein the precipitate is a tris(8-hydroxyquinoline)aluminum (III) complex. The process of claim 1, wherein the extracting agent is at least one of ethylene glycol diacetate and toluene. The process of claim 1, wherein the crystallization agent is at least one of acetonitrile and dichloromethane. The process of claim 1, wherein the precipitate is characterized by being used as a fluorescent material in the organic light-emitting diode.