WO2004069777A1

WO2004069777A1 - Method for producing alkylene derivative and method for regenerating catalyst for producing alkylene derivative

Info

Publication number: WO2004069777A1
Application number: PCT/JP2004/001322
Authority: WO
Inventors: Masahiko Yamagishi; Kazuki Kawabe
Original assignee: Mitsubishi Chemical Corporation
Priority date: 2003-02-07
Filing date: 2004-02-09
Publication date: 2004-08-19
Also published as: WO2004069777A8; KR20050098900A; TW200422285A; KR100880135B1; TWI313260B

Abstract

A method for producing alkylene glycol or alkylene carbonate wherein alkylene oxide is reacted with water or carbon dioxide in the presence of carbon dioxide by the use of a quaternary phosphonium iodide or bromide catalyst, characterized in that the quaternary phosphonium iodide or bromide catalyst is recovered efficiently from the reaction system and is circulated for use, and in that quaternary phosphonium chloride formed in the reaction system is converted efficiently to quaternary phosphonium iodide or bromide, and the resultant iodide or bromide is recovered and circulated to the reaction system for use.

Description

Description Method for producing alkylene derivative and method for regenerating catalyst for producing alkylene derivative

The present invention relates to a method for producing an alkylene derivative such as alkylenedic alcohol or alkylenedalycol, and more specifically, an alkylene oxide such as ethylene oxide using a quaternary phosphonimoxide and / or bromide catalyst. Water, reacting in the presence of carbon dioxide to produce an alkylene glycol such as ethylene glycol, or a method of reacting an alkylene oxide with carbon dioxide to produce ethylene carbonate and the like, The present invention relates to a method for efficiently recovering a quaternary phosphonimoxide and a Z or promide catalyst from this reaction system and recycling the catalyst.

In the present invention, the alkylene glycol means an alkylene glycol having about 2 to about 10 carbon atoms such as ethylene glycol and propylene glycol, and the alkylene glycol is, for example, ethylene glycol and propylene glycol. It means an alkylene carbonate having about 2 to 10 carbon atoms such as a ponate. Background art

Ethylene glycol is produced on a large scale by hydrolyzing ethylene oxide (ethylene oxide) by directly reacting it with water. In this method, ethylene glycol is used in the hydrolysis. In order to suppress by-products such as ethylene glycol, a large excess of water over the stoichiometric amount of ethylene oxide must be used. For this reason, it is necessary to distill the generated aqueous solution of ethylene glycol to dehydrate a large excess of water, and there is a problem that a large amount of energy is required to obtain purified ethylene glycol.

As a method for solving this problem, there has been proposed a method for producing ethylene glycol by reacting water and ethylene oxide in the presence of carbon dioxide. This reaction is a two-stage reaction in which ethylene carbonate is generated by the reaction of ethylene oxide and carbon dioxide, and ethylene glycol is generated by hydrolysis of the ethylene carbonate. This two-stage reaction proceeds in the same reactor due to the presence of water in the reaction system, but an additional reactor may be provided in the subsequent stage to complete the second-stage reaction. In the hydrolysis of ethylene carbonate, diethylene glycol and triethylene dalicol are hardly produced as by-products, so that the hydrolysis can be carried out with a slight excess of water than the stoichiometric amount. Costs can be greatly reduced. In addition, since carbon dioxide is generated by hydrolysis of ethylene carbonate generated by the reaction between ethylene oxide and carbon dioxide, this carbon dioxide is recycled and reused.

In this method, it is also possible to suppress the production of ethylene glycol by lowering the reaction conditions and lowering the amount of raw water, thereby producing ethylene glycol. In this way, ethylene glycol can be produced from ethylene oxide. A variety of catalysts have been proposed for the production of Z- and Z- or ethylene-potionates. One of the preferred catalysts is an organic phosphonium salt, particularly preferably a quaternary phosphonium salt. Or bromide (Japanese Patent Publication No. 55-47673). Further, an alkali metal carbonate may be used in combination with such an organic phosphonium salt as a co-catalyst (Japanese Patent Application Laid-Open No. H12-128814).

By the way, the raw material ethylene oxide is produced by the oxidation of ethylene. At that time, in order to improve the selectivity of the oxidation reaction, chlorohydrocarbons such as ethyl chloride are used to control the selectivity of the reaction system. It is supplied as an agent (Japanese Patent Application Laid-Open No. 2-104579). The method of producing ethylene glycol or ethylene carbonate by reacting ethylene oxide with water or carbon dioxide in the presence of carbon dioxide is an industrially advantageous method having no problem of by-products as described above. However, there is a problem that the reaction efficiency is reduced by continuing the reaction.

The present inventors have studied the cause of the reduction in the reaction efficiency, and have found that the cause is that the quaternary phosphonimoxide or promide catalyst in the reaction system is converted into chloride having low catalytic activity. In fact, about 20% by weight of the quaternary phosphonimoxide or promide catalyst in the reaction system was converted to quaternary phosphonium chloride by operating the apparatus for about one year.

The reason that quaternary phosphonimoxide or promide is converted to quaternary phosphonium chloride is thought to be that chlorine compounds contained as impurities in the raw material ethylene oxide are introduced into the reaction system. Was done. That is, as described above, in the process of producing ethylene oxide, a hydrocarbon is supplied as a selectivity regulator to the reaction system in order to improve the selectivity of the reaction, but is included in the hydrocarbon. Chlorine remains in the product ethylene oxide as a chlorine compound even after passing through the purification system, and is contaminated in the production process of ethylene glycol or ethylene carbonate. The chlorine compound introduced into the product ethylene oxide

Although the details of the reaction mechanism are not clear, it is considered that quaternary phosphonimoxide or promide is converted to quaternary phosphonium chloride.

Therefore, in the process of producing ethylene glycol or ethylene glycol, the quaternary phosphonium chloride having low reaction activity derived from the catalyst is separated and removed from the reaction system, and the quaternary phosphonium chloride or promide having high activity is separated. Only need to leave. However, it has not been clarified conventionally that the decrease in reaction efficiency over time is due to the time-dependent conversion to chloride. Furthermore, regarding the method of separating quaternary phosphonimoxide or promide, which is a catalyst of the reaction system, from quaternary phosphonium chloride, quaternary phosphonium chloride is converted to quaternary phosphonimoxide or promide. There was no study on how to do it. Disclosure of the invention

The present invention solves the above-mentioned conventional problems, and reacts an alkylene oxide such as ethylene oxide with water or carbon dioxide in the presence of carbon dioxide using a quaternary phosphonimoxide and a Z or bromide catalyst. In the process for producing alkylene glycols such as ethylene glycol or alkylene derivatives such as alkylene forces such as ethylene carbonate, quaternary phosphonium chloride generated in the reaction system is efficiently removed. Or or by converting the quaternary phosphonium chloride to quaternary phosphonimoxide and / or promide and collecting and recycling it to the reaction system, It is an object of the present invention to provide a method for maintaining the catalyst activity in a reaction system at a high level and stably and efficiently performing a production reaction of an alkylene derivative for a long period of time.

The gist of the present invention is characterized by the following description.

(1) A method for producing an alkylene derivative, comprising a reaction step of reacting an alkylene oxide with water in the presence of carbon dioxide to produce an alkylene glycol using a quaternary phosphonimoxide or bromide catalyst,

The alkylene glycol is removed from at least a part of the reaction solution and Z or the catalyst solution so that the molar ratio of the alkylene glycol to the catalyst is 20 times or less, and then the catalyst is recovered by mixing with water. A method for producing an alkylene derivative.

(2) The production method according to the above (1), wherein the molar ratio of the alkylene glycol to the catalyst is twice or less.

(3) The method according to the above (1) or (2), wherein the operating temperature at the time of mixing with water to recover the catalyst is 30 ° C or less.

(4) The method according to any one of (1) to (3) above, wherein the amount of water to be mixed is at least 0.1 times the weight of the recovered catalyst.

(5) The method according to any one of the above (1) to (4), wherein after mixing with water, solid-liquid separation is performed to separate the catalyst into a solid, and then the mixture is circulated to the reaction step.

(6) The method according to (5), wherein the liquid separated by the solid-liquid separation is circulated and used as catalyst washing water.

(7) The method according to any one of the above (1) to (6), wherein the alkylene oxide is ethylene oxide.

(8) Using quaternary phosphonimoxide and Z or bromide as a catalyst, reacting alkylene oxide containing a chlorine compound as an impurity with water in the presence of carbon dioxide to form alkylene glycol. Mixing the quaternary phosphonium chloride obtained from the step and a mixture containing quaternary phosphonium chloride and Z or promide with iodide and Z or bromide to obtain the quaternary phosphonium chloride. A method for regenerating a catalyst, comprising converting into a phosphonimoxide and Z or promide to precipitate in water.

(9) A quaternary phosphonium chloride and a quaternary obtained from a reaction step of reacting alkylene oxide with carbon dioxide to form an alkylene carbonate using a quaternary phosphonimoxide and Z or bromide as a catalyst. By mixing iodide and / or bromide with a mixture containing phosphonidomonodide and Z or promide, the quaternary phosphonidyl chloride and Z or promide are converted to quaternary phosphonidomonodide and Z or promide, and A method for regenerating a catalyst, comprising:

(10) A mixture containing a quaternary phosphonium chloride and a quaternary phosphonimoxide and / or bromide is a reaction solution extracted from the reaction step, or water or Z or The method according to the above (8) or (9), which is a residue after at least part of the alkylene derivative of the target product is distilled off.

(11) a mixture containing a quaternary phosphonium chloride and a quaternary phosphonimoxide and / or bromide, a reaction solution extracted from the reaction step, or Water and the residue obtained by distilling off at least a part of z or the alkylene derivative of the target product from the reaction solution are mixed with water to precipitate the catalyst as a solid. The method according to (8) or (9) above, wherein

(12) The method according to any one of the above (8) to (11), wherein the precipitated quaternary phosphonimide and / or promide are recovered and circulated to the reaction step.

(13) Using a quaternary phosphonimide and / or promide as a catalyst, reacting an alkylene oxide containing a chlorine compound as an impurity with water in the presence of carbon dioxide to produce an alkylene glycol. Iodide and Z or bromide are added to a mixture containing quaternary phosphonium chloride and quaternary phosphonium chloride and / or promide, and chlorine derived from quaternary phosphonium chloride is converted to an inorganic solvent as an inorganic chloride. A method for regenerating a catalyst, comprising recovering quaternary phosphonimide and / or promide by precipitating in a catalyst.

(14) A quaternary phosphonidium obtained from a reaction step of reacting an alkylene oxide with carbon dioxide to form an alkylene cation using a quaternary phosphonimoxide and Z or a promide as a catalyst. By adding iodide and Z or bromide to a mixture containing chloride and quaternary phosphonium chloride and Z or promide to precipitate chlorine derived from quaternary phosphonium chloride as inorganic chloride in an organic solvent. A method for regenerating a catalyst, comprising recovering quaternary phosphonimoxide and / or bromide.

(15) The above-mentioned (1), wherein the mixture containing a quaternary phosphonium chloride and a quaternary phosphonium chloride and / or a promide is any of the following (a) to (c): 13) or the method according to (14).

(a) a liquid or solid obtained by adding water to the reaction liquid extracted from the reaction step to precipitate the catalyst, and dehydrating an aqueous solution after separating the same,

(b) adding water to a residue obtained by distilling off water and at least a part of the alkylene derivative of the target product from water from the reaction solution extracted from the reaction step to precipitate the catalyst as a solid by adding water; A liquid or solid obtained by dehydrating the aqueous solution after separation,

(c) A liquid obtained by dissolving the liquid or solid obtained by dehydration in (a) or (b) in an organic solvent.

(16) The above (d) wherein the mixture containing a quaternary phosphonium chloride and a quaternary phosphonium chloride and Z or promide is any of the following (d) and (e): 13) or the method according to (14).

(d) a solution obtained by diluting the reaction solution extracted from the reaction step with an organic solvent,

(e) a residue obtained by distilling and removing at least a part of water and / or an alkylene derivative of a target product from the reaction solution extracted from the reaction step, or a residue obtained by dissolving the residue in an organic solvent Liquid,

(17) The method according to any one of the above (13) to (16), wherein the recovered quaternary phosphonimoxide and Z or promide are circulated to the reaction step. (18) Production of an alkylene derivative comprising a reaction step of reacting alkylene oxide with carbon dioxide using a quaternary phosphonimoxide and / or promide as a catalyst to generate an alkylene force component. In the method,

By adding iodide and Z or bromide to a mixture obtained from the reaction step and containing quaternary phosphonium chloride and quaternary phosphonium chloride and Z or promide, the quaternary phosphonium chloride is added. A process for producing an alkylene derivative, comprising converting muchloride into a quaternary phosphonimidyl monohydrate and Z or promide, precipitating and recovering in water, and circulating the reaction process.

(19) A method for producing an alkylene derivative comprising a reaction step of reacting an alkylene oxide with carbon dioxide to produce an alkylene carbonate, using a quaternary phosphonimoxide and / or a promide as a catalyst,

Iodide and / or bromide are added to a mixture containing quaternary phosphonium chloride and quaternary phosphonium chloride-dyd and Z or promide obtained from the reaction step, and the mixture is derived from quaternary phosphonium chloride. A quaternary phosphonimoxide and / or or promide by precipitating chlorine in an organic solvent as an inorganic chloride, and circulating the same in the reaction step. . In the present invention, when a reaction solution containing a catalyst at a high concentration and / or a catalyst solution are mixed with water, chlorine salts derived from the catalyst remain dissolved in the solution side, but iodine salts or bromide salts precipitate. Will come. In other words, iodine salts, bromine salts, and chloride salts are all soluble in alkylene glycol peralkylene carbonate, but iodide salts or bromine salts have low solubility in water, and chlorine salts have low solubility in water. high. By performing solid-liquid separation of the precipitated quaternary phosphonium hydroxide or promide, the catalyst can be easily separated and recovered.

In the present invention, for example, the catalyst can be precipitated as follows.

(1) Mix the reaction solution containing the catalyst and Z or the catalyst solution with water and then cool.

② After removing at least a part of alkylene glycol from the reaction solution and / or catalyst solution containing the catalyst, mix with water.

In this case, a cooling operation is not necessarily required. However, cooling is preferred to reduce the solubility of the catalyst.

In this way, the quaternary phosphonimoxide or promide thus recovered can be recycled to the reaction step.

On the other hand, the separated liquid after solid-liquid separation and recovery of the quaternary phosphonimide or promide contains the quaternary phosphonium chloride chloride, which is a quaternary phosphonium chloride. It can be recovered after being converted to quaternary phosphonimoxide or bumuide by ion exchange or the like, or can be recycled to the reaction process in a solution state.

Further, in the present invention, an alkylene glycol and an alkylene glycol are reacted with an alkylene oxide and water or carbon dioxide in the presence of carbon dioxide using a quaternary phosphonimoxide and / or bromide catalyst. Adding iodide and Z or bromide to a mixture containing quaternary phosphonium chloride and quaternary phosphonium iodide and / or promide obtained from the reaction step to be formed Thus, the quaternary phosphonium chloride in this mixture can be converted to a chloride and / or a promide. As a result, the quaternary phosphonimoxide and Z or promide, which are present in advance, and the quaternary phosphonimoxide and Z or bromide formed by the reaction of the quaternary phosphonium chloride with iodide and Z or bromide are converted into It can be precipitated in water and recovered as a precipitate.

In the following, iodide and / or bromide are added in order to convert quaternary phosphonium chloride into quaternary phosphonium chloride and Z or bromide.Quarterary phosphonium chloride and quaternary phosphonium chloride are added. And / or a mixture containing bromide may be referred to as a “mixture to be treated”. In the following, the liquid flowing out of the reactor or the liquid extracted from the reactor is simply referred to as "reaction liquid", and water, alkylene glycol and alkylene carbonate are separated from the reaction liquid by distillation to concentrate the catalyst. The resulting liquid may be simply referred to as “catalyst liquid”.

The present invention can be directly applied to the reaction mixture containing the catalyst extracted from the reaction step of alkylene glycol or alkylene carbonate as the mixture to be treated. After removing part or all of the alkylene glycol or alkylene carbonate as the solvent by evaporation, water is added to the liquid catalyst liquid or solid residue to precipitate and recover a part of the catalyst. (Hereinafter, the operation of adding water to this catalyst solution or solid residue to precipitate and recover a part of the catalyst may be referred to as “pre-recovery”. ). Through such a pre-recovery treatment, the concentration of the quaternary phosphonium chloride in the mixture to be treated can be increased, and the conversion to the quaternary phosphonimoxide and / or promide and the recovery rate can be increased. .

That is, since quaternary phosphonimoxide and Z or promide have lower solubility in water than quaternary phosphonium chloride, quaternary phosphonimoxide and / or bromide can be obtained by adding water in this manner. Most of the quaternary phosphonium chloride is dissolved in water. Through such a pre-recovery treatment, the concentration of the quaternary phosphonium chloride in the mixture to be treated can be increased, and its conversion to quaternary phosphonium chloride and / or bromide and the recovery rate can be increased. .

As a further alternative, in the above-mentioned pre-recovery, an aqueous solution in which iodide, Z, or odor is dissolved is used instead of water added to the catalyst solution or solid residue. As a result, the recovery of quaternary phosphonimoxide and Z or bromide can be improved.

In either method, when iodide, Z or bromide is added to quaternary phosphonium chloride dissolved in water, quaternary phosphonium chloride precipitates as iodide and / or promide, and is contained in the solution. Chloride corresponding to the added compound remains dissolved. Therefore, quaternary phosphonium chloride can be easily separated and recovered as quaternary phosphonimoxide and Z or bromide by solid-liquid separation of the deposited precipitate.

The quaternary phosphonimoxide and Z or promide thus recovered can be recycled to the reaction step of alkylene glycol or alkylene carbonate. Furthermore, according to the present invention, a mixture containing a quaternary phosphonium chloride obtained from the reaction step or obtained from the above-mentioned recovery step, and a quaternary phosphonimoxide and Z or bromide is further provided. It is possible to recover quaternary phosphonimoxide and Z or promide by adding iodide and Z or bromide to the organic solvent and precipitating quaternary phosphonium chloride-derived chlorine as an inorganic chloride in an organic solvent. It is. That is, a reaction step of reacting an alkylene oxide with water or carbon dioxide in the presence of carbon dioxide using a quaternary phosphonimoxide and Z or a bromide catalyst to produce alkylene glycol or alkylene carbonate. By adding an iodide and / or a bromide to a mixture containing a quaternary phosphonium chloride and a quaternary phosphonimide and / or promide obtained from It is possible to convert quaternary phosphonium chloride to quaternary phosphonium chloride and Z or bromide. On the other hand, chlorine derived from quaternary phosphonium chloride is precipitated as an inorganic chloride having low solubility in an organic solvent in an organic solvent, and separated from the quaternary phosphonium chloride dissolved in the organic solvent. And Z or promide can be recovered.

In the following, as described above, an operation of precipitating chlorine derived from quaternary phosphonium chloride as an inorganic chloride in an organic solvent may be referred to as an “inorganic chloride precipitating operation”. In order to precipitate chlorine of quaternary phosphonium chloride as inorganic chloride, iodide and Z or bromide are added, and quaternary phosphonium chloride and quaternary phosphonium chloride and / or promide are added. Mixtures containing may also be referred to as “mixtures to be treated”.

The quaternary phosphonium chloride is converted to chloride or promide, and chloride derived from chloride is precipitated as an inorganic chloride in an organic solvent, and the separated liquid is separated into quaternary phosphonium chloride in an organic solvent. It is one in which nimoxide and / or promide are dissolved. Therefore, by removing the organic solvent from this separated solution by evaporation, quaternary phosphonodioxide and / or promide can be recovered as a solid. The recovered quaternary phosphonimoxide and Z or promide can be recycled as it is or after dissolving in an appropriate solvent after washing with water if necessary, to the alkylene glycol or alkylene carbonate reaction step. . BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the method for producing an alkylene glycol of the present invention will be described in detail. In the following, a case where the present invention is applied to a reaction for producing ethylene glycol from ethylenoxide using a quaternary phosphonimoxide catalyst will be mainly described, but the present invention is not limited thereto. For example, the present invention can be suitably applied to the production of various alkylene glycols such as the production of propylene glycol from propylene oxide.

The same applies to the case where quaternary phosphonium bromide is used as a catalyst, or the case where quaternary phosphonimoxide and quaternary phosphonium bromide are used in combination as catalysts.

Furthermore, as described above, the present invention provides a method similar to the method for producing an alkylene glycol, in which the reaction conditions are changed, the reaction temperature is lowered, and the amount of alkylene glycol, such as ethylene glycol, is suppressed. Alkylene carbonates such as ethylene carbonate The present invention can also be applied to a reaction for producing a unit, and also to a reaction in which both an alkylene glycol and an alkylene glycol are used as target products. In the following, a method of adding iodide to the mixture to be treated, converting quaternary phosphonium chloride to quaternary phosphonium iodide and recovering the same will be exemplified. Bromide may be added in place of iodide to convert quaternary phosphonium chloride to quaternary phosphonium bromide, and the iodine and bromide may be added in combination to add quaternary phosphonium chloride. It may be converted into quaternary phosphonimoxide and quaternary phosphonium bromide and recovered.

Further, in the following, a method of adding quaternary phosphonium chloride to a quaternary phosphonium chloride by adding inorganic iodide to the mixture to be treated and a method of precipitating chlorine derived from quaternary phosphonium chloride as inorganic chloride are exemplified. I do. Bromide may be added in place of iodide to convert quaternary phosphonium chloride to quaternary phosphonium promide and to precipitate chlorine derived from quaternary phosphonium chloride as inorganic chloride. Chloride and bromide to convert quaternary phosphonium chloride into quaternary phosphonimoxide and quaternary phosphonium bromide, and to precipitate chlorine derived from quaternary phosphonium chloride as inorganic chloride. Good.

As the quaternary phosphonimoxide catalyst applicable to the present invention, there are compounds described in Japanese Patent Publication No. 58-22448. Representative examples include triphenylmethyl phosphonimoxide, triphenyl propyl phosphonimoxide, triphenylbenzyl phosphonimoxide, tributyl methyl phosphonimoxide and the like. . It is preferable that such a quaternary phosphonimoxide catalyst be supplied to the reaction system in a molar amount of 0.01 to 0.05 times the molar amount of ethylene oxide. When a quaternary phosphonium bromide catalyst is used, a promide catalyst corresponding to the above-mentioned quaternary phosphonimudide catalyst can be used, and the preferable usage thereof is the same as that of the quaternary phosphonimudide catalyst.

In the present invention, an alkali metal carbonate may coexist as a co-catalyst in the reaction system, whereby the production efficiency of ethylene glycol can be increased. Alkali metal carbonate can coexist in the reaction system by adding a hydroxide, carbonate or bicarbonate of an alkali metal such as sodium or potassium, preferably potassium. Even when the compounds are added, they exist as carbonates in the reaction system. In this case, it is preferable that the alkali metal carbonate, preferably potassium carbonate, is present in a molar ratio of 0.01 to 1 with respect to the quaternary phosphonium iodide.

The amount of water relative to ethylene oxide can be reduced to the stoichiometric amount, and may be less depending on the type of reaction, but it is usually 1.0 to 10.0 times the molar amount of ethylene oxide. It is preferable to use it. In addition, carbon dioxide has a sufficient effect in an amount of not more than equimolar to ethylene oxide, and is used in an amount of about 0.1 to 5.0 mol per mol of ethylene oxide under ordinary conditions. However, there is no strict limit on the ratio of these quantities.

The reaction temperature varies depending on the type of alkylene oxide, the type of catalyst, the composition of the reaction solution at the beginning of the reaction, and the like, but is generally in the range of 50 to 180 ° C. The pressure is the amount of carbon dioxide, The temperature varies depending on the reaction temperature and the like, and also varies with the progress of the reaction, but is generally in the range of 0.5 to OMPa.

The type of the reactor is not particularly limited as long as the gas-liquid reaction can be smoothly performed. The number of reactors and the residence time are also selected so that the desired conversion can be achieved. When producing ethylene glycol, a reactor is added as necessary to hydrolyze ethylene glycol in the reaction solution.

From the reaction solution discharged from the reactor, most of water and ethylene glycol are separated by distillation. The liquid containing the remaining catalyst (catalyst liquid) is circulated to the reactor so that the catalyst can be used for the reaction again. A mode in which a quaternary phosphonimoxide or promide catalyst is efficiently recovered from the reaction system and used in a cyclic manner.When the catalyst is recovered from the reaction solution after leaving the reactor, the catalyst concentration is low and the catalyst precipitates as it is. Therefore, it is preferable to once remove the water and ethylene glycol contained in the reaction solution to increase the catalyst concentration (the catalyst after removing the ethylene glycol), and then mix it with water again.

When using a catalyst solution to recover the catalyst, it is possible to recover the catalyst by mixing water as it is.However, to increase the recovery rate of the catalyst, the ethylene glycol contained was further removed by distillation. It is preferable to recover the catalyst by mixing with water later.

That is, in this reaction, at least a part of the reaction solution or the catalyst solution is extracted from such a reaction step, and when the molar ratio of the alkylene glycol to the catalyst contained in the solution is higher than 20 times, the reaction solution or catalyst solution is 20 times. Thereafter, water and alkylenedalycol or alkylenedalycol are removed so as to be preferably twice or less, and then mixed with water again.

When the molar ratio between the alkylene glycol and the catalyst contained in the liquid is lower than the 20-fold molar ratio, the catalyst is precipitated and recovered by simply mixing water.

When mixing the liquid extracted from the reaction step with water, it may be necessary to cool down to precipitate quaternary phosphonimoxide. That is, the solubility of quaternary phosphonimide in water or ethylene glycol decreases as the temperature decreases.

Generally, the temperature of the reaction solution extracted from the reaction step is about 100 to 180 ° C. It is preferable to cool the temperature of the liquid after mixing the reaction liquid and water to 30 or less, preferably about 0 to 20 ° C., thereby precipitating quaternary phosphonimoxide in a more efficient manner. be able to. The necessity of this cooling is determined by the temperature of the reaction solution, the temperature of the water to be mixed, and the mixing amount.

In addition, not only cooling to ensure the precipitation, but also the addition of a seed crystal or pre-existing seed crystal has a large effect of stabilizing crystallization.

Ethylene glycol (water may be contained at least partially, preferably most, for example, from the liquid extracted from the reaction step so that a certain concentration becomes 40% by weight or more. If water is mixed with the liquid after the removal of), quaternary phosphonimide can be precipitated without the need for cooling. Can be well precipitated. The amount of water varies depending on the amount of quaternary phosphonimoxide in the reaction solution, the amount of ethylene glycol, the amount of chlorine salt, the presence or absence of cooling, the desired recovery efficiency of quaternary phosphonimoxide, and the like. It tends to be difficult to filter, and the efficiency of dissolving the quaternary phosphonium chloride tends to decrease. On the other hand, if the amount is too large, the amount of quaternary phosphonimides contained in the liquid phase after separation of quaternary phosphonimides will increase. In general, the amount of water added in one treatment is appropriately determined within a range of 0.1 or more, preferably in a range of 0.1 to 5 times by weight of the liquid to be treated.

The liquid phase separated from the solid can be used again as a reaction solution, a catalyst solution, or washing water for the catalyst from which ethylene dalicol has been separated. In this case, if used repeatedly as washing water, the concentration of quaternary phosphonium chloride contained in the quaternary phosphonium chloride recovered will increase due to an increase in the concentration of quaternary phosphonium chloride contained in the washing water. To increase the volume, replace it with fresh water after using it 1 to 5 times.

A method in which the reaction solution is washed several times and gradually replaced with washing water having a low quaternary phosphonium chloride concentration can be implemented without any problem.

As a specific embodiment of this operation, cooled water or a slurry of quaternary phosphonium dihydrate is pre-existing in a vessel, and the reaction solution or catalyst solution and water are supplied continuously or batchwise, and the obtained mixture is continuously or It is also possible to extract in batches and collect the precipitate contained in this by filtration.

In order to separate ethylene glycol from the reaction solution, for example, an operation of distilling and separating ethylene glycol under reduced pressure may be performed. Water is also separated with the ethylenedalicol.

The precipitate obtained by mixing the reaction solution and water as described above is usually a highly active quaternary phosphonimoxide catalyst having an iodine salt content of 90% by weight or more and a chloride salt content of 10% by weight or less. And can be effectively recycled to the reaction process.

The separated solution after separating the precipitate of quaternary phosphonium dihydrate contains chlorinated quaternary phosphonium chloride. This quaternary phosphonium chloride is obtained by subjecting the separated solution to dehalogenation treatment with an OH-type anion exchange resin and neutralizing it with hydrogen iodide or directly converting chlorine ion to iodine ion with an ion exchange resin substituted with iodine. It is converted to quaternary phosphonimoxide by a method such as exchange. Thus, the catalyst can be regenerated, and the obtained regenerated catalyst can also be effectively recycled to the reaction step.

In the application of the present invention, a part of the reaction solution is continuously or intermittently withdrawn from the continuously operating reactor to recover the quaternary phosphonimoxide catalyst, and the recovered quaternary phosphonide is recovered. The mouldide catalyst may be circulated through the reactor. In this case, there is no particular limitation on the amount of the reaction solution and the amount of Z or the catalyst solution withdrawn to recover the quaternary phosphodiester catalyst, but chloride salts are removed within a range that does not excessively increase the cost of recovering the catalyst. When the weight ratio of chloride to iodine in the reactor is in the range of 0.01 to 1.0, the reaction solution is continuously or intermittently withdrawn to keep the reaction efficiency high. Processing is preferred. The amount of withdrawal is not particularly limited, but is preferably about 0.1 to 100% by weight with respect to the amount of the reaction solution or the amount of the catalyst solution, respectively. An embodiment in which the quaternary phosphonium chloride in the reaction system is converted to quaternary phosphonimoxide and / or promide, recovered, and recycled to the reaction system. According to the present invention, the ratio and composition of quaternary phosphonium chloride and chloride contained in the mixture to be treated containing quaternary phosphonium chloride and chloride are the same as those of chlorine in the ethylene glycol production process. Varies depending on the iodine ratio, bleeding location, and subsequent processing (pre-recovery operation, etc.) shown below. The abundance ratio and concentration of quaternary phosphonium chloride and chloride in the mixture to be treated are not particularly limited, but the higher the ratio of chloride to chloride and the higher the concentration of chloride, the higher the efficiency of the recovery operation. Desirably, preferably, the molar ratio of quaternary phosphonium chloride to quaternary phosphonium chloride in the mixture to be treated is 1/20 or more, and more preferably 1 Z 10 or more. The concentration of quaternary phosphonium chloride in the mixture is preferably at least 0.1% by weight, particularly preferably at least 1% by weight.

Specific examples to which the present invention is applied include the following methods depending on the method of obtaining the mixture to be treated and the method of adding iodide. These will be described in order, but the present invention is not limited to the following method.

[Application Example I]

Part of the liquid in the ethylene glycol production process is withdrawn as a liquid containing the catalyst. The extraction location is not particularly limited as long as the solution contains a catalyst present in the process. As described above, in the production reaction of ethylene glycol from ethylene oxide, ethylene carbonate is produced by the reaction of ethylene oxide and carbon dioxide, and ethylene glycol is produced by the hydrolysis of ethylene carbonate. It is a two-stage reaction. Therefore, when the liquid is withdrawn from this production process, if this reaction is carried out in two reactors provided in series, it may be withdrawn from either reactor or withdrawn from both reactors.

When extracting the liquid at the outlet of the reactor, the concentration of quaternary phosphonium chloride and chloride in the mixture to be treated must be increased in order to increase the recovery of quaternary phosphonium chloride in the subsequent process. In this case, it is preferable to concentrate by distilling off the solvent water, ethylene glycol or ethylene glycol. The distillation method can be carried out in a distillation tower, but a simple evaporator may be used. Preferably, the mixture is concentrated until the concentration of the quaternary phosphonimoxide in the mixture to be treated becomes 1Z20 mol times or more of the solvent. Considering the heat resistance of the quaternary phosphonium salt, this concentration operation by distillation is carried out under reduced pressure, preferably at 4 OO torr (53.2 Pa) or less, preferably at a temperature of 60 to 210. It is preferred to carry out.

The high-concentration catalyst solution obtained by distilling and concentrating the reaction solution contains quaternary phosphonimoxide and quaternary phosphonimoxide formed by chlorination of quaternary phosphonimoxide in the ethylene glycol production process. Contains muchloride. The catalyst solution may be a solution obtained by taking the reaction solution out of the process and concentrating the catalyst solution, and the catalyst extracted from the distillation column that separates the catalyst solution from water, ethylene glycol, and ethylene carbonate in the process. It may be a liquid.

As the iodide used for recovering the quaternary phosphonimoxide, any ionic compound that can be ion-exchanged with quaternary phosphonium chloride and that dissociates in water can be used. It may be selected as appropriate, but alkali metal salts such as sodium salt and potassium salt, or hydrogen acid and the like are preferable in terms of solubility, toxicity, price and the like. As the inorganic iodide, any ionic compound that can dissociate in water and that can be ion-exchanged with quaternary borophorum chloride can be used. However, from the viewpoints of solubility, toxicity, and price, sodium salts, potassium salts, etc. Are preferred.

The added amount of iodide may be equal to or more than the equivalent of the quaternary phosphonium chloride present in the mixture to be treated. A suitable range is 0.5 to 10 moles, preferably 1 to 5 moles, per 1 mole of the quaternary phosphonium chloride present in the mixture to be treated. Adding more iodide than necessary increases recovery, but excess iodide is lost.

Addition of iodide can be carried out in the form of a solid or organic solvent solution or an aqueous solution.However, in the case of industrial implementation, liquid is more convenient to handle, so add it as an organic solvent solution or as an aqueous solution Is preferred.

In the case of an aqueous solution, the amount of water may be sufficient to dissolve iodide, and the amount depends on the iodide used. For example, when potassium iodide is used, its saturation solubility in water is 60%, so it may be added so that the concentration of potassium iodide in the treated product is lower than this. Usually, it is preferably added as an aqueous solution of about 1 to 60% by weight.

The apparatus for adding iodide to the mixture to be treated can be carried out in any type of vessel, but is preferably carried out in a vessel equipped with a stirrer to promote the ion exchange reaction.

By this operation, the quaternary phosphonium chloride present in the mixture to be treated is converted into quaternary phosphonium chloride, and is precipitated in water together with the quaternary phosphonium chloride already present in the mixture to be treated. The lower the temperature for the precipitation, the less the quaternary phosphonimidide remains in the water. Preferably, it is performed at 0 to 30.

The precipitated quaternary phosphonimoxide is collected by filtration. There is no particular limitation on the filtration method, and centrifugation or the like can be applied in addition to filtration using a normal filter.

The quaternary phosphonium chloride recovered as a solid may contain about 10% by weight of quaternary phosphonium chloride and added iodide. Even with this concentration, it is possible to circulate it in the ethylene glycol reaction step as it is, but if necessary, wash it with water to increase the purity of the quaternary phosphonimoxide and then recycle it. Since the water used for washing contains quaternary phosphonimoxide, it can be used for the next washing or reused as water for dissolving the iodide added to the mixture to be treated as described above. It is.

The recovered quaternary phosphonimoxide can be, for example, dissolved in ethylene glycol and circulated to the reaction system.

As described above, the embodiment in which the quaternary phosphonium chloride is converted to the quaternary phosphonium chloride and recovered is described. This operation can be performed in an organic solvent. Hereinafter, an embodiment in which quaternary phosphonium chloride is converted to quaternary phosphonium monodide by performing an operation of precipitating an inorganic chloride in an organic solvent and then recovered will be described.

Since the obtained high-concentration catalyst solution contains ethylene glycol and Z or ethylene carbonate as a solvent, the inorganic chloride precipitation operation of the present invention is performed on this catalyst solution. Although it is possible to apply, it is also preferable to add another organic solvent having a low ability to dissolve inorganic chloride generated when iodide is added. Further, when ethylene glycol and / or ethylene carbonate in the high-concentration catalyst solution is further removed to obtain a substantially solvent-free solid, which is redissolved in another organic solvent, the solubility of inorganic chloride is reduced. Is further reduced, and the deposition efficiency is improved.

As the organic solvent used here, those having a low ability to dissolve inorganic chloride and a high ability to dissolve quaternary phosphonium salts are desirable. Suitable solvents include aliphatic halogenated hydrocarbons, ketones, alcohols, nitriles, amides, urea compounds, carbonates.

Of these, examples of alcohol include ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl-1-propanol, 1,1-dimethylethanol, and 1-pentanol. 2-pentanol, 3-pentanol, 3-methyl_1-butanol, 2-methyl-1-butanol, 1,1-dimethyl-1-propanol, 1-hexanol, 2- Hexanol, 3-Hexanol, 2-Methyl-1-pentanol, 4-Methyl-2-pentanol, 1-Heptanol, 2-Heptanol, 3-Hepanol, 4-Hepanol, 4-Hepanol 1-octanol, 2-octanol, 2-ethyl-1 hexanol, 1-nonanol, 2-nonanol, 1-decanol, 1-decanol, 1-dodecanol, 1,6-hexanediol, Ropen evening Nord, cyclohexane hexanol, benzyl alcohol, full energy chill alcohol.

Examples of the aliphatic halogenated hydrocarbon include methylene chloride, chloroform, 1,2-dichloroethane, 1,1,1-trichloroethane, 1,1,2-trichloroethane, and 1,2-dichloropropane. , 1,3-dichloropropane, 1,2,3-trichloropropane, 1,4-dichlorobutane, 1,6-dichlorohexane and the like.

Examples of nitriles include acetonitrile, propionitrile, ptyronitrile, adiponitrile, benzonitrile and the like. Examples of the amide include dimethylformamide and dimethylacetamide. Examples of the urea compound include tetramethyl perylene, 1,3-dimethylimidazolidin-2-one, and the like. Examples of ketones include acetone, methyl ethyl ketone, and methyl isopropyl ketone. Examples of the carbonate include ethylene carbonate, propylene carbonate, and butyl carbonate.

One of these organic solvents may be used alone, or two or more thereof may be used in combination. The amount of the organic solvent to be added is not particularly limited, but is usually 1 to 10 times by weight of the total of quaternary phosphonium chloride and chloride in the mixture to be treated.

For example, sodium fluoride is a suitable combination because it dissolves well in acetone. In addition, potassium iodide dissolves in ethylene glycol, and such a combination is also suitable. However, complete dissolution of iodide in organic solvents is not always necessary. Even if the iodide has a small amount of saturated dissolution, iodide is added to the mixture to be treated and then consumed by reacting with quaternary phosphonium chloride. Progresses. As a result, an amount exceeding the solubility can react to form an inorganic salt. The selection of iodide and the organic solvent requires iodide and the inorganic salt formed by the reaction of this iodide with quaternary phosphonium chloride. And the solubility in organic solvents. Examples of such a combination include butanol and ethylene glycol with respect to potassium iodide.

As a result of this operation, the quaternary phosphonium in the quaternary phosphonium chloride present in the mixture to be treated becomes quaternary phosphonium oxide, while chlorine precipitates as an inorganic chloride. The precipitation temperature is not particularly limited, and is determined in consideration of the dissolution temperature dependency of the inorganic chloride, the boiling point and viscosity of the organic solvent used, and the solubility of the quaternary phosphonium salt. Usually, it is performed at a normal temperature of 0 to 50 ° C. The reaction between iodide and quaternary phosphonium chloride proceeds rapidly when the viscosity of the solvent is low. However, when the solvent is a high-viscosity solvent or the solubility of iodide is low, it is desirable to increase the mixing time. The reaction is preferably completed in about 1 minute to 3 hours. By this operation, the quaternary phosphonium chloride of the quaternary phosphonium chloride in the organic solvent is converted to chloride at a conversion of 90% or more, and the inorganic chloride precipitates.

The precipitated inorganic chloride is removed by filtration. The method of filtration is not particularly limited, and besides ordinary filtration by filtration, centrifugation or the like can be applied.

Since the quaternary phosphonimoxide, which is a catalyst, is dissolved in the filtrate after the inorganic chloride is separated by filtration, the quaternary phosphonimoxide and the quaternary phosphonimoxide are removed by evaporating the organic solvent from the filtrate. If added in excess, iodide is recovered as a solid. The removal of the organic solvent can be performed with a usual evaporator. As described above, the evaporation of the organic solvent is performed at a temperature of 200 ° C or less by reducing the pressure as necessary in consideration of the heat resistance of the recovered quaternary phosphonimoxide. It is desirable to do.

The purity of the quaternary phosphonium iodide recovered in this way is 90% or more, excluding the iodide added in an excessive amount and the remaining solvent, so that it can be used directly or in a suitable solvent such as ethylene glycol. The solid can be dissolved in water and recycled to the reaction step. Preferably, the recovered solid is washed with water to remove the remaining iodide and the solvent before the solid is recycled to the reaction step. In the water washing, the recovered solid may be added with washing water to form a slurry, which may be filtered or centrifuged. In this case, the amount of washing water to be added is preferably not more than 2 times the weight of the recovered solid in consideration of the loss of dissolution in the washing water.

As another method of removing inorganic chloride in the above method, the solvent is removed by the same operation without filtering the inorganic chloride, and then the above-mentioned washing is performed to dissolve and remove the inorganic compound in water. It is also possible.

As another embodiment of the present invention, there is the following method.

[Application Example II]

In Application Example I, the concentration of the quaternary phosphonimoxide is 1 Z 20 mol times or more of ethylene glycol, or water is added to the high concentration catalyst solution concentrated to such a concentration. After mixing, the mixture is cooled and quaternary phosphonimoxide is selectively precipitated and recovered before recovery. Here, the amount of water to be added is arbitrary, but if it is too small, a sufficient precipitation effect cannot be obtained, so that at least the water is dissolved. It is necessary to add 0.1 weight times or more of the class phosphonimoxide. The upper limit of the amount of water to be added is not particularly limited, but is preferably about 5 times by weight or less with respect to the dissolved quaternary phosphonido monodide so as not to excessively increase the treatment capacity. It is preferable that the temperature at the time of the precipitation operation be lower, since the amount of quaternary phosphonimoxide remaining in water is small. It is preferably carried out at 0 to 30 ° C.

The remaining aqueous solution from which the precipitated quaternary phosphonium chloride was recovered contains the quaternary phosphonium chloride and quaternary phosphonium chloride which did not precipitate. The remaining aqueous solution obtained by collecting the above quaternary phosphonimoxide is treated as a mixture to be treated, concentrated if necessary, and then added with iodide to form a quaternary phosphonimoxide of quaternary phosphonium chloride. Conversion and precipitation can be performed. The concentration is performed so that the concentration of the quaternary phosphonium chloride in the mixture to be treated before adding iodide becomes 1% by weight or more, and the conversion efficiency of the quaternary phosphonium chloride and the quaternary phosphonium chloride are increased. It is preferable from the viewpoint of the recovery efficiency of moodide.

The type of iodide to be added, the concentration and method of addition, the method of filtering off the precipitate, the subsequent treatment, and the like are the same as those in Application Example I described above.

However, in this case, since water already exists in the system, iodide can be added as a solid, and as a result, the amount of water used is reduced, so that iodine is discharged. The dissolution opening of quaternary phosphonimoxide can be reduced.

In addition, after the pre-recovery is performed, preferably 90% or more, more preferably 99% or more of the water of the aqueous solution containing quaternary phosphonium chloride and chloride is removed by evaporation to obtain the mixture to be treated. An inorganic chloride precipitation operation can be performed. That is, the mixture to be treated is dissolved in an organic solvent in an amount of 1 to 10 times by weight the total of the quaternary phosphonium chloride and iodide in the mixture to be treated, and iodide is added thereto. I do.

In this method, it is also possible to add an aqueous iodide solution in place of the water added to precipitate the quaternary phosphonimoxide in the high-concentration catalyst solution, and in this case, the iodide in the latter stage is used. Is unnecessary.

In each case, the quaternary phosphonimide monodide can be further recovered by removing the organic solvent from the organic solvent solution after solid-liquid separation of the inorganic chloride precipitate, and can be recovered earlier. It can be reused with grade phosphonimide. As yet another embodiment, there is the following method.

[Application example III]

In Application Example I, the concentration of the quaternary phosphonimide is 120 times or more higher than that of ethylenedalicol, or the concentrated catalyst solution concentrated to such a concentration is further concentrated to 90% of the solvent. The above is distilled off. In this case, the residue (distillation residue) solidifies with cooling. By washing the solidified residue with an appropriate amount of water, the quaternary phosphonium chloride in the residue can be eluted to the water side and removed. In this case, too, the temperature of the water to be washed is preferably low, because the amount of quaternary phosphonimoxide dissolved in the washing water is small. It is preferably carried out at 0 to 30 ° C.

The amount of water used for washing is not particularly limited, but in consideration of washing efficiency and the loss of quaternary phosphonium moxide to wastewater, it is 0.5 to 10 times by weight of the solid residue to be washed. Desirably. The water used for cleaning does not need to be pure water, and the recycled water in the process can be used. It can also be used repeatedly. In particular, an aqueous solution containing a quaternary phosphonimoxide is preferable since the dissolution loss of the quaternary phosphonimoxide in water can be reduced.

The washed water contains the quaternary phosphonium chloride eluted and the quaternary phosphonium chloride dissolved slightly.

As a mixture to be treated, as described above, after concentrating the mixture as necessary, an oxide can be added to convert and precipitate quaternary phosphonium chloride into quaternary phosphonium chloride. . Also in this case, the concentration of the quaternary phosphonium chloride in the mixture to be treated before adding iodide is preferably 1% by weight or more.

The type of iodide added, the concentration and method of addition, the method of separating the precipitate by filtration, the subsequent treatment, and the like are the same as those in Application Example I described above.

In this case, too, water is already present in the system, so iodide can be added as a solid. Dissolution loss of phosphonimoxide can be reduced.

Further, in the method of adding iodide as a mixture to be treated by performing the above-mentioned washing operation and adding water after washing, as an embodiment of shortening the process, an aqueous iodide solution may be used as washing water. it can. In this case, the concentration of the iodide aqueous solution to be used may be such that the iodide concentration in the water after washing is the concentration in the state of the above-mentioned added and mixed state.

The aqueous solution containing the quaternary phosphonium chloride and chloride is preferably removed by evaporating water, preferably 90% or more, more preferably 99% or more, as the mixture to be treated, as inorganic chloride. A precipitation operation can be performed. That is, the mixture to be treated is

The quaternary phosphonium chloride and iodide in the mixture to be treated are dissolved in an organic solvent in an amount of 1 to 10 times by weight based on the total weight of the mixture, and iodide is added thereto. The type of iodide to be added, the concentration and method of addition, the method of filtering off the precipitate, the subsequent treatment, and the like are the same as those in Application Example I described above.

In this method, it is also possible to use an aqueous iodide solution instead of the washing water, and in this case, it is not necessary to add the iodide in the latter stage.

In each case, the quaternary phosphonimide monodide can be further recovered by removing the organic solvent from the organic solvent solution after solid-liquid separation of the inorganic chloride precipitate, and can be recovered earlier. It can be reused with grade phosphonimoxide. In addition, the concentration of the quaternary phosphonimoxide is 1 Z 20 times or more of ethylene glycol, or the concentrated catalyst solution thus concentrated is further concentrated, and 90% or more of the solvent is distilled. Since the liquid state can be maintained by maintaining the temperature at 90 ° C or higher after removing, quaternary phosphonimide is precipitated by adding water and then cooling to 0 to 40 ° C. It is also possible. Alternatively, the concentrated residue can be crystallized by supplying the concentrated residue alone or continuously with water to cold water or slurry already existing. Also in this case, the remaining aqueous solution obtained by separating and recovering the precipitated quaternary phosphonimoxide contains quaternary phosphonimoxide and chloride which did not precipitate. As a mixture to be treated, as described above, after concentrating the mixture as necessary, an iodide can be added to convert and precipitate quaternary phosphonium chloride into quaternary phosphonium chloride. . Also in this case, the quaternary phosphonium chloride concentration of the mixture to be treated before adding the iodide is preferably 1% by weight or more, and the kind of the added iodide, the added concentration and the adding method, the method of filtering the precipitate, and The processing and the like are the same as in the method of Application Example I described above.

However, even in this case, since water is already present in the system, it is possible to add iodide as a solid, and as a result, the amount of water used is reduced. The dissolution loss of quaternary phosphonimoxide in water can be reduced.

Further, as an embodiment for shortening the above steps, an aqueous iodide solution can be used by heating instead of water.

In this method, it is also possible to use an iodide aqueous solution instead of the water, and in this case, it is not necessary to add the iodide in the latter stage.

Throughout all embodiments, the present invention is applied to quaternary phosphonium chloride and chloride which still remain in the separated liquid after iodide is added to precipitate inorganic chloride, which is subjected to solid-liquid separation. It is also possible. That is, it is possible to repeatedly add iodide and remove inorganic chloride until the desired recovery rate is reached.

In the application of the present invention, at least a part of the reaction solution and / or the catalyst solution is continuously or intermittently extracted from the continuously operating reaction process, and concentrated and Z or pre-recovered as necessary. After that, the quaternary phosphonium chloride is converted into quaternary phosphonium chloride and the quaternary phosphonium chloride is recovered, and the recovered quaternary phosphonium chloride catalyst may be circulated through the reactor. In this case, there is no particular limitation on the amount of the reaction solution and / or the catalyst solution to be withdrawn to recover the quaternary phosphonium dihydrate catalyst, but the quaternary phosphonium chloride may be used within a range not excessively increasing the catalyst recovery cost. When the weight ratio of quaternary phosphonium chloride to iodide in the reactor is in the range of 0.01 to 1.0, the reaction solution and Z It is preferable that the liquid is continuously or intermittently withdrawn and processed. The amount to be withdrawn is not particularly limited, but is preferably about 0.1 to about 100% by weight of the reaction solution or the catalyst solution in the system. Example

Hereinafter, the present invention will be described more specifically with reference to examples. Of course, the present invention should not be construed as being limited to such embodiments. Example 11

Carbon dioxide 2. OMPa pressurized residence time lHr, 100 ° C in the first reactor, tributylmethylphosphonumodide 5 parts by weight ZHr as a catalyst, carbon dioxide 0.8 parts by weight / Hr, raw material ethylene oxide aqueous solution (60% by weight) 78 parts by weight

A reaction solution containing (EG) was obtained. This was transferred to a second reactor with a total residence time of 2 hours, a pressure of 0.5 MPa, and a temperature of 150 ° C to hydrolyze the ethylene carbonate contained therein, and an aqueous solution of ethylene dalicol containing a catalyst66. 5 parts by weight / hr were obtained. The obtained reaction solution was distilled by a vacuum distillation column at 140 ° C. and 11 kPa (8 OmmHg) to obtain a dehydrated liquid from the column bottom. Most of the ethylene glycol was evaporated by a reduced-pressure evaporator operated at (60 mmHg), and 13 parts by weight of Hr was recovered from the bottom of the evaporator in the concentrated catalyst solution. It was circulated to one reactor and the composition of the catalyst solution after one year of continuous operation was as follows.

[Catalyst liquid composition]

Ethylene glycol: about 59% by weight

Iodine salt (quaternary phosphonimoxide): about 33% by weight

Chlorine salt (quaternary phosphonium chloride): about 6% by weight

Potassium carbonate: about 2% by weight After reaching the above composition, the operation was changed to an operation in which part of this catalyst solution was withdrawn at 0.02 parts by weight ZHr. The extracted catalyst liquid (hereinafter referred to as “extracted liquid A”) is supplied to the flash vessel, and the ethylene glycol contained in the liquid is obtained under the conditions of 3 torr (4 O OP a), 128%%%% Was removed by about 93% by weight.

While keeping the liquid after removing the ethylene glycol (hereinafter referred to as “concentrated liquid A”) at 95 T :, add a 3% by weight aqueous solution of potassium iodide and cool to 20 ° C with stirring and mixing for 1 hour. It was left still. The potassium iodide added here was equimolar to the chloride salt in concentrate A, and the amount of water used was equal to the weight of concentrate A.

The precipitate was analyzed by solid-liquid separation with a suction filter and analyzed. The composition of the precipitate was as follows. It was found that 90% by weight of the iodine salt and the chlorine salt in the extracted liquid A was 90% by weight. This corresponds to efficient separation as a quaternary phosphonimoxide catalyst.

[Precipitate composition]

About 18 water

Ethylene glycol About double 重

Iodine salt (quaternary phosphonimoxide) Approx.

Chlorine salt (quaternary phosphonium chloride) About

Potassium carbonate 1% by weight or less This precipitate was dissolved in ethylene dalicol and circulated to the reactor.

When the operation was continued while recovering and circulating the catalyst in this way, efficient operation could be continued in the production process of ethylene glycol without a reduction in reaction efficiency. Example 11 Example 11 In Example 11, to the concentrated solution A after separation and removal of ethylene dalicol, an equivalent amount of distilled water was added to the concentrated solution A in place of the aqueous solution of iodide, and the same operation was performed to precipitate a solid. I let it.

When the precipitate was analyzed by solid-liquid separation, the precipitate contained 94% by weight of the iodine salt and about 13% by weight of the chloride salt in the above extracted liquid A. The quaternary phosphonide iodide catalyst was used. It was confirmed that the salt could be efficiently separated from the chloride salt. About 6% by weight of the iodine salt and about 87% by weight of the chlorine salt in the withdrawn liquid A were also dissolved in the liquid from which the precipitate was separated (hereinafter referred to as “separated liquid A”). To this separated solution A, 1.2 mol times of potassium iodide with respect to the chlorine salt in the solution was added as a 50% by weight aqueous solution, and the mixture was allowed to stand at 20 ° C for 1 hour. The precipitate was subjected to solid-liquid separation and analyzed. In this precipitate, 50% by weight of the chlorine salt in the above extracted liquid A could be efficiently separated as a quaternary phosphonimide monodide catalyst. It was confirmed that. Example 11

Separation liquid A obtained in Example 12 was distilled, and water in separation liquid A was concentrated by distilling off 50% by weight of water. To this concentrated solution, potassium iodide was added as a 50% by weight aqueous solution in an amount of 1.2 mol times the chlorine salt in the solution, and the mixture was allowed to stand at 20 for 1 hour. When the precipitate was analyzed by solid-liquid separation, about 75% by weight of the chlorine salt in the above extracted liquid A could be efficiently separated as a quaternary phosphonimoxide catalyst in the precipitate. It was confirmed that. '' Example 2-1

Carbon dioxide 2. OMPa pressurized residence time lHr, 1st reactor at 100 ° C, tributyl methyl phosphonimoxide as catalyst 5 parts by weight / Hr, carbon dioxide rim 0.8 parts by weight ZHr A raw material ethylene oxide aqueous solution (60% by weight) was supplied with 78 parts by weight of ZHr to obtain a reaction solution containing ethylene carbonate and ethylene glycol (EG). This was transferred to a second reactor having a total residence time of 2 hours, a pressure of 0.5 MPa, and a temperature of 150 ° C, and the contained ethylene ponionate was hydrolyzed to produce ethylene dalicol containing a catalyst. An aqueous solution of 66.5 parts by weight / Hr was obtained.

The obtained reaction solution was distilled by a reduced-pressure distillation column having a bottom of 140 ° C and 11 kPa (8 OmmHg) to obtain a dehydrated liquid from the bottom of the column. Most of the ethylene glycol was evaporated by a reduced pressure evaporator operated at 60 mmHg), and 13 parts by weight of a catalyst solution enriched in the catalyst was recovered from the bottom of the evaporator. The recovered catalyst solution was recycled to the first reactor as a catalyst. The composition of the catalyst liquid after one year of continuous operation was as follows.

[Catalyst liquid composition]

About 59% by weight of ethylene glycol

Iodine salt (quaternary phosphonimoxide) 33% by weight

Chlorine salt (quaternary phosphonium chloride) About 6% by weight

Potassium carbonate Approximately 2% by weight After reaching the above composition, the operation was changed to withdrawing a part of this catalyst solution at 0.02 weight: part ZHr. Flash the extracted catalyst solution (hereinafter referred to as “extracted solution A”). The solution was supplied to the vessel to remove about 93% by weight of ethylene glycol contained in the solution under the conditions of 3 torr (4O OPa) and 128 ° C. Liquid after removing ethylene glycol

(Hereinafter referred to as “concentrate A”). While maintaining the temperature at 95 ° C., water of the same weight as the concentrate A was added, and the mixture was cooled to 20 while stirring and mixing, and then allowed to stand for 1 hour.

The precipitate (hereinafter, referred to as “precipitate A”) was subjected to solid-liquid separation with a suction filter, and the obtained filtrate (hereinafter, referred to as “filtrate A”) was analyzed. It was as follows, and contained about 80% by weight of the chlorine salt in the extracted liquid A.

[Filtrate A composition]

Water: about 78% by weight

Ethylene glycol: about 7% by weight

Iodine salt (quaternary HOUSHONOMUYUDIDE): about 1% by weight

Chlorine salt (quaternary phosphonium chloride): about 10% by weight

Potassium carbonate: 4% by weight On the other hand, when the precipitate A was analyzed, the composition of the precipitate A was as follows, which contained about 98% by weight of the iodine salt in the extracted liquid A. It was a thing.

[Precipitate A composition]

Water: about 16% by weight

Ethylene glycol: about 1% by weight

Iodine salt (4th grade HOUSHONOMUMO I-Dide): about 80% by weight

Chlorine salt (quaternary phosphonium chloride): about 2% by weight

Potassium carbonate: 1% by weight or less Water and ethylene glycol contained in filtrate A were removed using an evaporator operated at 140 ° C. The pressure was reduced as water and ethylene glycol were removed, and the pressure was finally maintained at 5 torr (660 Pa) for 30 minutes. By this operation, the amounts of water and ethylene glycol contained in the distillation residue became 10% by weight or less. An equal weight of acetone was added to the residue after removing water and ethylene glycol in this manner. Next, the obtained liquid was transferred to a storage tank with a stirrer, and 1.2 mol times of sodium iodide with respect to the contained chlorine salt was added as a solid, followed by stirring at room temperature for 1 hour.

The precipitate deposited by this inorganic chloride precipitation operation was subjected to solid-liquid separation with a suction filter and analyzed. The precipitate contained sodium chloride equivalent to 98% by weight or more of the chloride in filtrate A. Were present. On the other hand, the filtrate obtained by the solid-liquid separation (hereinafter referred to as “filtrate B”) is introduced into an evaporator operated at 110 torr (660 Pa) at 110, and the filtrate in the filtrate B is filtered.

After substantially the entire amount of seton and ethylene glycol was evaporated, the obtained solid was mixed with an equal weight of water, washed, and then subjected to solid-liquid separation with a suction filter. The obtained solid (hereinafter, referred to as “solid B”) was analyzed and found to have the following composition.

[Solid B composition]

Water: about 17% by weight

Ethylene glycol:: 1% by weight or less Iodine salt (quaternary phosporium moxide): about 81% by weight Chloride salt (quaternary phosphonium chloride): 1% by weight or less

Sodium iodide: about 1% by weight This solid B and the above-mentioned precipitate A are combined, and about 98% by weight of the iodine salt and the chlorine salt in the withdrawal liquid A is converted into a quaternary phosphonimoxide. These were dissolved in an equal weight of ethylene glycol and recycled to the reactor.

When the operation was continued while collecting and circulating the catalyst in this way, efficient operation could be continued without a problem of a reduction in reaction efficiency in the ethylene glycol production process. Example 2-2

In Example 2-1, an equal weight of normal butanol as an organic solvent was added to and dissolved in the concentrate A from which ethylene glycol was separated and removed. This solution was transferred to a storage tank equipped with a stirrer, solid potassium iodide in an equimolar amount to the chloride salt contained in the solution was added, and mixed at room temperature for 2 hours.

'When the precipitate was subjected to solid-liquid separation by a suction filter and analyzed, potassium chloride equivalent to 95% by weight or more of the chlorine salt contained in the concentrate A was present in the precipitate. On the other hand, the filtrate was introduced into an evaporator operated at 5 torr (660 Pa), 110, and substantially all of the solvent and ethylene glycol in the filtrate were evaporated to obtain a solid. Was mixed with an equal weight of water and washed, followed by solid-liquid separation with a suction filter. When the obtained solid was analyzed, it had the following composition and contained about 95% by weight of the iodine salt and the chloride salt in the withdrawn liquid A as quaternary phosphonimoxide.

[Solid component]

Water about 18% by weight

Ethylene glycol: 2% by weight

Iodine salt (quaternary HOUSHONOMUYUDIDE) About 80% by weight

Chlorine salt (quaternary phosphonium chloride) 1% by weight or less

Potassium iodide Approximately 1% by weight or less This solid was dissolved in an equal weight of ethylene glycol and circulated to the reactor. The operation was continued while recovering and circulating the catalyst in this way. Efficient operation was able to be continued without the problem of reduction in reaction efficiency in the manufacturing process. Comparative Example 1

In Example 11, 100 g of the dehydrated reaction solution was taken out from the bottom of the vacuum distillation column. The ratio of ethylene glycol to the catalyst contained therein was 87%. An equal weight of water was added thereto and the mixture was cooled to 0 ° C, but no precipitation occurred. Example 11 To the filtrate obtained in Example 12 was added a 50% by weight aqueous solution of iodinated rim with respect to the chlorate in the solution at a molar ratio of 1 mol, and the mixture was allowed to stand at 20 ° C. for 1 hour. The precipitate was analyzed by solid-liquid separation. As a result, it was confirmed that approximately 87% by weight of the chlorate in the filtrate was able to be efficiently separated as a quaternary phosphonimoxide catalyst in the precipitate. Industrial applicability

According to the present invention, an alkylene oxide such as ethylene oxide is reacted with water or carbon dioxide in the presence of carbon dioxide using a quaternary phosphonimoxide and Z or a promide catalyst to form an alkylene glycol such as ethylene glycol or In a method for producing an alkylene derivative such as an alkylene carbonate such as an ethylene carbonate, a quaternary phosphonimoxide or a promide catalyst is efficiently recovered from the reaction system and used in a circulating manner, or formed in the reaction system. The quaternary phosphonium chloride thus obtained can be efficiently converted to quaternary phosphonimoxide and Z or promide and recovered, and this can be recycled to the reaction system. Therefore, it is possible to prevent the accumulation of quaternary phosphonium chloride having low catalytic activity in the system and convert it to quaternary phosphonium chloride and Z or promide having high catalytic activity and to recycle them to reduce the catalytic activity in the system. It can be maintained at a high level, and the formation reaction of the alkylene derivative can be performed stably and efficiently over a long period of time. As the disclosure of the specification of the present invention, Japanese Patent Application No. 2003-003 3391 (filed on February 7, 2003), which is the basis of the priority claim of the present application, Japanese Patent Application No. 2 0 0 3 0 7 8 1 7 8 (filed on March 20, 2003) and Japanese Patent Application 2 0 3-0 8 8 2 8 1 (2 0 (Filed on March 27) is incorporated herein by reference.

Claims

The scope of the claims

I. A method for producing an alkylene derivative comprising a reaction step of reacting an alkylene oxide with water in the presence of carbon dioxide to produce an alkylene glycol using a quaternary phosphonimoxide or bromide catalyst,

From at least a part of the reaction solution and Z or the catalyst solution, remove the alkylene glycol so that the molar ratio of the alkylene glycol to the catalyst becomes 20 times or less, and then recover the catalyst by mixing with water. A method for producing an alkylene derivative.

2. The method according to claim 1, wherein the molar ratio of the alkylene glycol to the catalyst is set to twice or less.

3. The production method according to claim 1, wherein an operation temperature at the time of mixing with water to recover the catalyst is 30 ° C. or lower.

4. The method according to claim 1, wherein the amount of water to be mixed is at least 0.1 times the weight of the recovered catalyst.

5. The production method according to any one of claims 1 to 4, wherein after mixing with water, solid-liquid separation is performed to separate the catalyst as a solid, and then the mixture is recycled to the reaction step.

6. The production method according to claim 5, wherein the liquid separated by the solid-liquid separation is circulated and used as catalyst washing water.

7. The method according to any one of claims 1 to 6, wherein the alkylene oxide is ethylene oxide.

8. Reaction of alkylene oxide containing chlorine compound as impurity and water in the presence of carbon dioxide to form alkylene glycol using quaternary phosphonimoxide and Z or bromide as catalyst The quaternary phosphonium chloride is obtained by mixing a mixture containing the quaternary phosphonium chloride and the quaternary phosphonimoxide and Z or promide, obtained from the step, with iodide and Z or bromide. A method for regenerating a catalyst, comprising converting muchloride to quaternary phosphonimoxide and Z or promide to precipitate in water.

9. Using quaternary phosphonimoxide and / or bromide as a catalyst, alkylene oxide reacts with carbon dioxide to produce alkylene carbonate. By mixing a mixture containing quaternary phosphonimoxide and Z or promide with iodide and Z or bromide, the quaternary phosphonium chloride is converted to quaternary phosphonimoxide and / or promide in water. A method for regenerating a catalyst, which comprises precipitating.

10. A mixture containing a quaternary phosphonium chloride and a quaternary phosphonimoxide and Z or a promide may be a reaction solution extracted from the reaction step, or water and / or an objective solution from the reaction solution. 10. The method according to claim 8, wherein the residue is a residue obtained by distilling and removing at least a part of the product alkylene derivative.

II. A mixture containing a quaternary phosphonium chloride and a quaternary phosphonium amide and / or a promide is a reaction solution extracted from the reaction step, or water and Z or a target product from the reaction solution. Distill at least part of the alkylene derivative The method according to claim 8 or 9, wherein the catalyst is precipitated as a solid by mixing the residue after the removal with water, and the aqueous solution is separated.

12. The method according to any one of claims 8 to 11, wherein the precipitated quaternary phosphonimoxide and Z or promide are recovered and circulated to the reaction step.

13.4 Reaction of reacting alkylene oxide containing chlorine compound as an impurity with water in the presence of carbon dioxide using quaternary phosphonimoxide and / or bromide as a catalyst to form alkylene glycol Iodide and / or bromide are added to a mixture containing quaternary phosphonium chloride and quaternary phosphonium iodide and / or promide obtained from the step to remove chlorine derived from quaternary phosphonium chloride. A catalyst regeneration method comprising recovering quaternary phosphonimoxide and / or promide by precipitating them in an organic solvent as inorganic chlorides.

14. Using quaternary phosphonimoxide and / or bromide as a catalyst, quaternary phosphonium chloride obtained from the reaction step of reacting alkylene oxide with carbon dioxide to produce alkylene carbonate, By adding iodide and / or bromide to a mixture containing quaternary phosphonidomonodide and Z or promide to precipitate chlorine derived from quaternary phosphonium chloride as an inorganic chloride in an organic solvent. A catalyst regeneration method comprising recovering quaternary phosphonimoxide and Z or bromide.

15. The mixture containing a quaternary phosphonium chloride and a quaternary phosphonium chloride and / or a promide is any one of the following (a) to (c). The method described in 4.

(a) a liquid or solid obtained by adding water to the reaction liquid extracted from the reaction step to precipitate the catalyst, and dehydrating an aqueous solution after separating the catalyst,

(b) water is added to the residue obtained by distilling and removing water and at least a part of the alkylene derivative of the target product from water from the reaction solution extracted from the reaction step, and water is added to precipitate the catalyst as a solid; A liquid or solid obtained by dehydrating the aqueous solution after separation,

16. The mixture containing a quaternary phosphonium chloride and a quaternary phosphonium chloride and Z or a promide is one of the following (d) and (e): The method described in 14 above.

(e) a residue obtained by distilling and removing at least a portion of water and / or an alkylene derivative of a target product from the reaction solution extracted from the reaction step, or a residue obtained by dissolving the residue in an organic solvent Liquid,

17. The method according to any one of claims 13 to 16, wherein the recovered quaternary phosphonimoxide and / or promide is circulated to the reaction step.

18.8.4 A method for producing an alkylene derivative comprising a reaction step of reacting alkylene oxide with carbon dioxide by using quaternary phosphonimoxide and Z or bromide as a catalyst to produce an alkylene atom monoponate, By adding iodide and Z or bromide to a mixture obtained from the reaction step and containing a quaternary phosphonium chloride and a quaternary phosphonium chloride and / or promide, the quaternary phosphonium chloride is added. A process for producing an alkylene derivative, comprising converting muchloride into a quaternary phosphonimidyl monodide and / or promide, precipitating and collecting the same in water, and circulating the alkylene derivative in a reaction step.

9. A method for producing an alkylene derivative comprising a reaction step of reacting alkylene oxide with carbon dioxide using quaternary phosphonimoxide and Z or promide as a catalyst to generate an alkylene force component. ,

Iodide and Z or bromide are added to a mixture containing quaternary phosphonium chloride and quaternary phosphonium chloride and / or promide obtained from the reaction step, and the mixture is derived from quaternary phosphonium chloride. A method for producing an alkylene derivative, comprising recovering quaternary phosphonimoxide and Z or bromide by precipitating chlorine as an inorganic chloride in an organic solvent, and circulating the same in a reaction step.