JPS6227055B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to acyl fluorides and/or chlorides, particularly those produced from carbon monoxide and anhydrous hydrogen fluoride or anhydrous hydrogen chloride and an olefin or ester having one or more double bonds. The present invention relates to the production of carboxylic acid esters by esterifying acyl fluorides and/or acyl chlorides.

Prior art, such as British Patent No. 942367, involves carbonylating a compound or ester with one or more double bonds and then further hydrolyzing the reaction product with excess water to form a carboxylic acid (or Emphasis is placed on aqueous acid catalyst systems for the production of carboxylic acids by subsequently esterifying the carboxylic acids. In these methods, the aqueous acid catalyst is corrosive and requires expensive equipment. These prior art problems are solved with the carboxylic ester production method described herein.

Carboxylic acid esters (e.g. methyl isobutyrate)
The acylium anion product (e.g., isobutyryl fluoride) is esterified with less than the total amount of alcohol required to react with all of the acylium anion product to form a carboxylic acid ester and an acid anhydride ( For example, it is produced by regenerating hydrogen fluoride or hydrogen chloride). The acyllium anion product is produced in any reaction, but preferably with carbon monoxide and an anhydrous acid (e.g., hydrogen fluoride) as described herein, which is capable of reacting with carbon monoxide and an acid anhydride. It is produced by reaction with an organic compound (eg propylene) under conditions that produce an acylium anion product (eg isobutyryl fluoride). In another embodiment of the invention, a portion or all of the carboxylic ester (e.g., methyl isobutyrate) is separated from the esterification mixture, and the esterification mixture after separation of the portion or all of the carboxylic ester The remainder (e.g., hydrogen fluoride, unreacted isobutyryl fluoride, unseparated methyl isobutyrate) is recycled to react with an organic compound (e.g., propylene) to generate further acylium anion products (e.g., isobutyryl fluoride). Circulate. In another embodiment of the invention, separation and esterification are carried out simultaneously so that side reactions are substantially minimized. The acylium anion product is esterified while the acid anhydride is separated and recovered. Lower alkyl propionates or isobutyrates (e.g. methyl isobutyrate) are oxydehydrogenated to form lower alkyl acrylates or methacrylates (e.g. methyl methacrylate).
can be generated.

A novel process for producing carboxylic acid esters from acyllium anion products comprises combining an acylium anion product (fluoride or chloride), such as isobutyryl fluoride, particularly carbon monoxide, with the acids described herein. and an organic compound as described herein, for esterifying all of the asyllium anion products in the mixture to a carboxylic acid ester (e.g., methyl isobutyrate). esterification with less than the total amount of alcohol required. This reaction is conducted under conditions that produce the carboxylic ester and regenerate the acid as described herein.

In another embodiment of the invention, the method of the invention comprises the steps of separating 1-100% of the acid from the esterification mixture, further separating 1-100% of the separated acid with carbon monoxide and It also includes a step or steps of recycling to react with the organic compounds described herein to produce a mixture comprising an acylium anion product and an acid anhydride.

In another embodiment of the present invention, the method of the present invention comprises: obtaining one of the carboxylic esters from the esterification mixture;
Step of separating ~100% of the esterified product mixture remaining after separation of the carboxylic esters
100% may be recycled for further reaction with carbon monoxide and an organic compound described herein to produce a mixture comprising an acyllium anion product.

In another embodiment, the carboxylic acid esters produced by the process of the invention, particularly the lower alkyl esters of propionic acid and/or isobutyric acid, such as methyl propionate and methyl isobutyrate, are prepared by methods known in the art. Direct oxydehydrogenation with
Suitable for forming lower alkyl unsaturated esters such as methyl acrylate and methyl methacrylate.

The acylium anion products described herein (e.g., isobutyryl fluoride) can be produced by any method, e.g., by reacting isobutyryl chloride or isobutyryl bromide with hydrogen fluoride to produce isobutyryl fluoride, and It can be produced by regenerating hydrogen oxide.

However, a more preferred method is via a carbonylation reaction between carbon monoxide, an acid anhydride as described herein, and an organic compound as described herein. Preferred carbonylation reactions for producing acyllium anion products are described below.

The reactants for producing the acyllium anion product may be from any source of reactants, but must be free of harmful substances that would interfere with the process of the present invention. The total amount of water in the reaction mixture to be esterified should be less than 0.01% by weight to prevent side reactions in which the acylium anion product forms undesirable ethers. Preferably, the reaction system is anhydrous.

The carbon monoxide may be from any carbon monoxide source, but is preferably substantially anhydrous to maintain substantially anhydrous reaction conditions. Carbon monoxide may be diluted with other substances that do not interfere with the reaction. For example, dry synthesis gas or coal combustion gas can be used. Preferably, dry carbon monoxide itself is used.

The organic compound is one that is capable of reacting with carbon monoxide and acid anhydride, i.e. capable of being carbonylated to form an acylium anion, such as an organic ester as described herein or carbonylated as described herein. An olefin having at least one double bond capable of producing the acyllium anion product described in the book.

The organic ester for the carbonylation reaction is represented by the general formula below.

In the above general formula, R is alkyl having up to 20 carbon atoms, such as methyl, ethyl, propyl, dodecyl, eicosanyl. Alkyl is preferably methyl or ethyl or propyl or isopropyl, with ethyl and isopropyl being most preferred. R′ is ethyl, propyl,
such as t-butyl, dodecyl, eicosanil,
Alkyl having 2 to 20 carbon atoms.
R' is preferably ethyl or isopropyl, and most preferably.

When using organic esters in the carbonylation methods described herein, any of the esters listed herein may be used. However, isopropyl isobutyrate (2-propanol 2-methylpropionate) or ethyl isobutyrate (ethanol 2-methylpropionate) or isopropyl propionate (2-propanolpropionate) or ethyl propionate (ethanol propionate) ), and it is particularly preferred to use isopropyl isobutyrate or ethyl propionate.

Examples of organic compounds having at least one double bond capable of forming an acylium anion product (carbonylating to form an acylium anion product) and which can be used in the method of the invention include:
Olefins having up to 20 carbon atoms, such as ethylene, propylene, butene, 1,3-butadiene, dodecene. The olefins may be substituted with alkyl or aryl or cycloalkyl or other substituents that do not interfere with the process of the invention. Furthermore, olefins, like 1,3-butadiene, can have multiple double bonds in the molecule that do not interfere with the method of the invention. Preferred olefins are ethylene, propylene, isobutene, 1-butene, 2-butene, 1,3-butadiene, with ethylene and propylene being highly preferred.

Although all of the organic compounds described herein can be used in the process of the invention, propylene is particularly preferred.

The acid used in the preferred method of making acylium anions described herein must be substantially water-free, ie, anhydrous. As used herein, the term "anhydrous" refers to an acid that is substantially free of water, e.g., less than 200 ppm water.
Alternatively, if water is present, it means an acid that does not interfere with the reaction for producing an acyllium anion or the reaction for producing a carboxylic acid ester from an acylium anion.

Anhydrous acids that can be used in the process of the invention are hydrogen fluoride (hydrofluoric acid) (HF) and hydrogen chloride (hydrochloric acid) (HCl). The most preferred acid anhydride for the process of the invention is hydrogen fluoride (hydrofluoric acid).

The alcohol used in the esterification method of the present invention can be a primary alcohol or a secondary alcohol that does not separate under the esterification and separation conditions and does not react with the regenerated acid to form an acid anhydride. Examples of such alcohols are alkanols having up to 20 carbon atoms. Preferred alkanols are those having up to 5 carbon atoms. Highly preferred alcohols are methanol, ethanol, propanol;
The most preferred alcohol is methanol.

The reaction of carbon monoxide with the organic compound described herein and the acid anhydride described herein is carried out between 0°C and 100°C.
The upper temperature limit is determined by the formation of by-products. For reactions between the preferred reactants described herein, the temperature can be between 40 and 80<0>C, but is preferably about 60<0>C. Carbon monoxide pressure from 1 bar (14.7 psia) to approximately 408
The pressure can range up to 6000 psia (6000 psia) or 10000 psia (680 psia), but is generally between 500 psia (500 psia) and 5000 psia (340 psia), preferably between 1500 psia (1500 psia) and 3000 psia (204 bar); is increased as necessary due to the solubility of carbon monoxide in the anhydrous acid and to increase reactor productivity.

The molar ratio of acid anhydride to organic compound described herein should be from 1:1 to 100:1, but generally
The ratio is between 10:1 and 20:1, preferably about 15:1. The molar ratio of carbon monoxide to the organic compound described herein is from 1:1 to 5:1 or more,
Preference is given to 1.5:1 to 1:1, the maximum corresponding to the saturation limit of carbon monoxide in the reaction mixture during and at the end of the reaction.

All of the carbon monoxide and anhydrous acids (e.g. anhydrous hydrogen fluoride) that should be reacted with the organic compound are
Organic compounds as described herein (e.g. propylene)
must be thoroughly mixed before contacting. Next, the organic compound is reacted while being mixed with the premixed carbon monoxide and acid. In general, the reaction depends on pressure and temperature, but
This occurs within minutes to form an acylium anion product (eg, isobutyryl fluoride). The organic compound itself can be diluted with carbon monoxide or an inert diluent (eg, methane, ethane, propane) before reacting with the acid anhydride.

Although the reaction can be carried out in a semi-batch reactor or a plug-flow reactor or back-mixing reactor (CSTR) or other reactors known to those skilled in the art, the preferred reactor is a plug-flow reactor.

The esterification reaction of the acyllium anion product (e.g. isobutyryl fluoride) with an alcohol, especially methanol, is carried out at a temperature of 20°C to 150°C and 1
Can occur at pressures between Bar (14.7 psia) and 340 Bar (5000 psia), but typically between 40°C and 70°C
occurs at a temperature of 3.3 bar (50 psia) and a pressure of 6.7 bar (100 psia). The temperature and pressure are
It is determined to avoid decomposition of the desired product and to facilitate separation of the product.

It is preferred to stir the reactants during esterification. In many cases, when rapid mixing is used, the esterification reaction can be completed within seconds to minutes, with simultaneous regeneration of the acid anhydride (eg, HF).

A critical feature of the esterification reaction is to maintain the molar ratio of alcohol (eg methanol) to acyllium anion product less than 1:1.
That is, the total amount of alcohol that reacts with the mixture containing the asyllium anion products must be less than the amount of alcohol required for all of the asyllium anion products to form carboxylic acid esters.

Although it is possible to inject the entire amount of alcohol into the mixture containing the acyllium anion product,
Preferably, the alcohol is added in portions into the mixture containing the acyllium anion product. Since the esterification step is an exothermic step, cooling may be required. The mixture may include carbon monoxide, unreacted organic compounds, acid anhydrides, and carboxylic esters. Preferably, the mixture comprises an acid anhydride, particularly preferred when the acylium anion product is isobutyryl fluoride. When esterifying acylium anion products such as isobutyryl fluoride, the ratio of the amounts of anhydrous acid (e.g., hydrogen fluoride) and isobutyryl fluoride is between 0.01 and 95.5 parts by weight of anhydrous hydrogen fluoride (AHF) to fluoride. The range is 99.09 to 4.5 parts by weight of isobutyryl (IBF), preferably 10.0 to 90.0 parts by weight of AHF to 90 to 10 parts by weight of IBF. The amount of acid anhydride (e.g., hydrogen fluoride) in the mixture is determined by the effective operation of the process as well as between the acylium anion products (e.g., isobutyryl fluoride) and the hydrogen fluoride, carbon monoxide, and alkyl isobutyrates such as methyl isobutyrate. and the ease of separation of the acid anhydride (e.g. hydrogen fluoride) from the product mixture containing.

After the esterification reaction (depending on reaction conditions) is completed, 1 to 100 of the produced carboxylic ester
% is separated from the product mixture of the esterification reaction. Preferably 80-100 of the carboxylic acid ester
% and the remaining esterification product mixture,
It is recycled for further reaction with reactants to form an acylium anion product. This recycle stream contains carbon monoxide and/or acid anhydride and/or unreacted organic compounds and/or
Unesterified asylium anion products may be included.

In another embodiment of the invention, 1 to 100% (preferably 80 to 100%) of the acid anhydride is separated from the esterification product mixture to further produce an acylium anion product. Recirculate for reaction. This recycle stream contains a small amount of unseparated, unesterified acylium anion product and/or carboxylic acid ester and/or
It may contain unreacted organic compounds.

Separation can be carried out by any of the known separation methods such as distillation or solvent extraction. Preferably distillation is used.

A preferred embodiment for the preparation of the carboxylic acid esters described herein comprises esterifying the organic acylium anion products described herein with the alcohols described herein under substantially anhydrous conditions. and separating the carboxylic acid ester, unreacted alcohol, acid anhydride, and unreacted acylium anion product under conditions where esterification continues until substantial completion.

The process of the present invention involves separating 80-100% (preferably 90-100%) of the acid anhydride and esterifying the separated acid anhydride with recycling to further produce the acylium anion product. can also be included.

The method of the present invention preferably separates 90% to 100% of the carboxylic ester and 80 to 100% of the acid anhydride from the esterification mixture and further processes the separated acid anhydride to produce an acylium anion product. It can also include esterification with recycling.

Preferably, the esterification of the asyllium anion product continues to substantial completion, i.e. 80% to 100%, preferably 90 to 100%, of the asyllium anion product is esterified to the carboxylic ester. Separation occurs during esterification by distilling the esterification reaction mixture under conditions. Distillation conditions are such that the formation of by-products is substantially reduced. Distillation conditions are also such that halogen acids, particularly HF, are removed so as to substantially reduce the formation of halogenated by-products. Preferably, the esterification yield is
Substantially 80%-100%, with 90-100% highly preferred.

A schematic diagram of a preferred esterification and separation apparatus is shown in the accompanying drawings. Although this apparatus is adaptable to the esterification process of the present invention, it is particularly useful for esterifying isobutyryl fluoride with methanol to methyl isobutyrate. Asyllium anion product (e.g., isobutyryl fluoride source) 20 is added to line 30.
is fed through metering pump 32 via line 34, valve 36 and line 38 to esterification reactor 40 where alcohol (e.g. methanol) is
react with. Alcohol is supplied from alcohol source 42 through metering pump 44 to esterification reactor 40 via line 46, valve 48, and line 50. Feeds of acyllium anion product (e.g., isobutyryl fluoride) and alcohol (e.g., methanol) are fed to dispersion nozzles connected to lines 38 and 50, respectively.
(not shown) into the esterification reactor 40. The esterification reactor 40 includes:
Buffles or other means to ensure rapid mixing of the reactants can be installed. The reaction mixture from esterification reactor 40 is transferred to line 54
through the reflux inlet to the distillation column 52.
entry) at point 56 (above point 60) between point 58 and liquid phase removal point 60. Distillation column 52 removes unreacted organic carbon monoxide anions (e.g., isobutyryl fluoride), unreacted alcohol (e.g., methanol), and regenerated acid (e.g., hydrogen fluoride) and removes the ester started in esterification reactor 40. The distillation column 52 is operated so that the reaction is completed within the distillation column 52. The attached drawing shows the supply and discharge points.
This distillation column 52 is shown with
is particularly applicable to the esterification of isobutyryl fluoride with substantially anhydrous methanol. However, as known to those skilled in the art, the feed and discharge points can be easily modified to accommodate anhydrous esterification with other alcohols. For example, if the boiling point of the ester is lower than the boiling point of the acid anhydride, the ester will be discharged at the top and the anhydride will be discharged at the bottom.

A liquid phase containing unreacted alcohol (methanol) and/or acylium anion addition products (e.g. isobutyryl fluoride) and/or hydrogen fluoride and/or esters (e.g. methyl isobutyrate) is discharged from discharge point 60. discharged, line 6
2 into heat exchanger 64 where it is cooled if necessary, passed through line 66 into metering pump 68, and passed through line 70 into esterification reactor 40. The acyllium anion product (e.g. isobutyryl fluoride) is supplied at feed point 56.
During the stripping operation, which occurs between the stripping point 60 and the liquid stream discharge point 60, the alcohol (e.g., methanol) is reacted and combined and substantially converted to an ester (e.g., methyl isobutyrate), which flows down through the stripping section. , exits outlet 72 of distillation column 52 and passes through line 74 into storage 76 . The slip of crude product passing through line 74 can be reintroduced into distillation column 52 from line 78 through heat exchanger 80 and through line 82 from 84 . The acid anhydride (e.g., hydrogen fluoride) regenerated by the esterification reaction rises through the distillation column 52, exits at the top outlet 86, and is passed through line 88 into the heat exchanger 90 where it is It is partially or completely condensed and sent through line 92 into separation column 94 . The anhydrous acid (eg, hydrogen fluoride) is sent via line 96 into a storage device 98 or 102 for reuse to produce further acylium anion product.
Separator bottoms are discharged from the separator bottom through line 96 and all or a portion thereof is sent back to the distillation column from point 58 through line 98 for reflux. Condenser and separation column operations shall be specified by those skilled in the art to facilitate the removal of impurities and/or byproducts that are either more or less volatile than hydrogen fluoride (HF). I can do it.

In another embodiment of the invention, a second solvent is added as a stripping agent through line 104 to remove the acylium anion adduct (e.g., isobutyryl fluoride) from the ester (e.g., methyl isobutyrate). can be increased, thereby eliminating heat exchanger 64 and placing the full energy load on heat exchanger 90.

In another embodiment of the invention, the level at point 60 can be chosen to remove heat exchanger 64 and place the full energy load on heat exchanger 90.

In another embodiment of the invention, the solvent and alcohol are combined to aid dilution and mixing of the alcohol (e.g., methanol) in the reaction mixture and to enhance stripping of the regenerated acid anhydride (e.g., HF). Co-currently added into esterification reactor 40 and removed through purge 102. The solvent used is inert towards the reactants under the reaction and separation conditions and does not azeotrope with the ester (e.g. methyl isobutyrate) or the acid anhydride (hydrogen fluoride) and with the anhydride (e.g. HF). and esters (eg, methyl isobutyrate) to enhance separation, and the solvent preferably has a low heat of vaporization. Useful solvents for the esterification and for the separation of isobutyryl fluoride esterified with methanol are hydrofluoroalkanes having up to 20 carbon atoms, but preferably hydrofluoroalkanes having up to 5 carbon atoms. It is a fluoroalkane.

The present invention will be explained below with reference to Examples.

The following method was used to study the esterification of isobutyryl fluoride under semi-adiabatic conditions with less methanol than required to esterify all of the isobutyryl fluoride to methyl isobutyrate.

A 2-Hastelloy C pal was equipped with a methanol introduction device (using 34 bar (500 psia) of nitrogen), a generator couple connected to a continuous temperature recorder, an air motor, and a stirrer adjusted to 1000 rpm.
A reactor (C Parr) was charged with metered amounts of the reactants, anhydrous hydrogen fluoride (if used) and isobutyryl fluoride (maintained at dry ice-acetone temperature). After charging, the reactants and reactor are brought to the desired temperature and the temperature recorder is started. A metered amount of methanol (less than the amount required for reaction with all of the isobutyryl fluoride) is then injected into the reactor. The initial temperature of methanol was room temperature.
After the esterification was completed, the mixture was analyzed by gas chromatography (GC). From the temperature-time records, an increase in temperature was observed. Generally, the first temperature increase was due to the heat of mixing and the second temperature increase was due to the esterification reaction.

Example 1 Isobutyryl fluoride, IBF (419.3 g, 4.66
mol) was esterified by injection of 131.2 g of methanol (21°C). The reaction mixture temperature initially dropped and then rose to 64.6°C over the next 5.25 minutes. The reaction was complete, and GC analysis showed that the reaction was complete.
Only anhydrous hydrogen fluoride (182 g, 4.1 mol) and methyl isobutyrate (418.2 g, 4.1 mol) were produced, 50.3 g
(0.56 mol) of isobutyryl fluoride was found to be unreacted.

Example 2 A mixture of 46.6 g (10 wt. %) of anhydrous hydrogen fluoride and 422.6 g (90 wt. %) of anhydrous hydrogen fluoride at 29.3° C. was esterified with 133 g of methanol at 21° C. (methanol was added in one step). ). After a temperature increase of 20.7°C was observed, the temperature increased to 128°C over the next 38.4 seconds. The reaction was complete, and as a result of GC analysis, methyl isobutyrate (416.0 g), anhydrous HF (134.3
g) was found to be unreacted isobutyryl fluoride (51.8 g).

Example 3 A mixture of 540.4 g of anhydrous hydrogen fluoride and 59.9 g of isobutyryl fluoride at 30°C was mixed with methanol (22°C).
Esterification was carried out by adding 18.6 g at once. Under these conditions, the temperature increased continuously from 30°C to 49.5°C after 1.5 seconds. The reaction was complete, and analysis revealed that 58.2 g of methyl isobutyrate had been produced. The amount of anhydrous HF is 552.7
g, and the amount of unreacted isobutyryl fluoride was 8.0 g.

Example 4 To produce methyl isobutyrate by the method of the invention, the following continuous process can be carried out.

A plug flow reactor is used for the production of isobutyric acid from propane. The plug flow reactor has an inner diameter of approximately 12.7 mm with a premix section of approximately 5 feet.
It consists of approximately 40 feet (1/2 inch) of tubing with injection points and heaters spaced approximately 5 feet apart. The carbonylation reaction was carried out at 50°C, approximately 190 bar (2800 psia), and 1.0:14:
The molar ratio of propane, anhydrous hydrogen fluoride, and carbon monoxide is 1.3, and the flow rate is approximately 1.52 kg/hr (3.2 lbs/hr).
Anhydrous hydrogen fluoride and carbon monoxide are injected into a premix section where they are thoroughly mixed, and approximately 50% of propane is added to the anhydrous hydrogen fluoride and carbon monoxide mixture.
Injections are made at 5 ft. intervals, with the final addition of propane approximately 30 ft. from the beginning of the reactor. After the reaction is completed, approximately 10.675 m (35
ft) methanol into the reactor at the injection point,
Esterification is preferably injected at a rate at which esterification occurs and methyl isobutyrate is produced. The amount of methanol injected is less than the amount of isobutyryl fluoride produced. This part of the reactor where esterification takes place is maintained at about 40° C. and a pressure of about 6.8 bar (100 psia). Methyl isobutyrate is separated from the final product mixture by simple distillation, and the remaining isobutyryl fluoride, carbon monoxide, and anhydrous hydrogen fluoride are combined with carbon monoxide and anhydrous hydrogen fluoride, which are injected into the premix section of the reactor. It is recycled together with anhydrous hydrogen fluoride.

In another embodiment of the continuous reaction, prior to esterification, the product mixture containing the acylium anion product (isobutyryl fluoride) is sent to a separator where excess carbon monoxide and excess anhydrous 10 to 90% of the hydrogen fluoride is removed and recycled, while the remaining product mixture, preferably having 10 parts by weight of anhydrous hydrogen fluoride and 90 parts by weight of isobutyryl fluoride, is purified as described above. After esterification, the methyl isobutyrate is separated and the remaining product mixture with unreacted isobutyryl fluoride and anhydrous hydrogen fluoride is recycled.

Preparation of Methyl Acrylate or Methyl Methacrylate Methyl esters of carboxylic acids such as propionic acid or isobutyric acid made from acylium anion products (e.g. propionyl fluoride or isobutyryl fluoride) as described herein. teeth,
After esterification, U.S. Patent No. 3585248;
No. 3585249, No. 3585250, No. 3634494, No. 3652654, No. 3660514, No. 3766191,
Same No. 3781336, Same No. 3784483, Same No. 3855279
No. 3917673, No. 3948959, No. 3948959, No.
Oxydehydrogenation can be carried out by the method described in No. 3968149, No. 3975301, No. 4029695, No. 4061673, No. 4081465, No. 4088602, and British Patent No. 1447593.

Preferably, the catalyst has _the empirical formula _FeP
~3.5 atoms, where z indicates the number of oxygen atoms required to satisfy the valence requirements of the catalyst] is a catalyst containing iron, phosphorus, and oxygen. A more preferred catalyst is U.S. Pat. No. 3,948,959.
Me _y (where Me
are promoters Li, Na, K, Rb, Ce, Mg,
Indicates Ca, Sr, Br, and mixtures thereof, y
represents the number of promoter atoms per iron atom, 0.02
~2.0). The resulting methyl acrylate or methacrylate is then separated by methods known in the art, such as distillation or extraction in the presence of a polymerization inhibitor.

While the invention has been described in particular details of several illustrative embodiments, the present invention has been described with reference to specific details of several illustrative embodiments, except where these details appear in the claims.
The invention is not limited to such details.

[Brief explanation of the drawing]

The attached drawings show 1 of the esterification-separation method of the present invention.
FIG. 2 is a diagram showing two embodiments. Explanation of drawing numbers, 20... Acylium anion product (isobutyryl fluoride source), 40... Esterification reactor, 42... Alcohol supply source, 52...
... Distillation column, 64,90 ... Heat exchanger, 76 ... Storage device, 94 ... Separation column, 98,102 ... Storage device.

Claims (1)

[Claims] 1. A mixture containing an acylium anion product,
esterifying the carboxylic ester under anhydrous conditions with an amount of alcohol less than that required to esterify all of the acyllium anions in the mixture to produce the carboxylic ester and regenerating the acid from the anion; the alcohol is selected from the group consisting of primary alcohols having up to 20 carbon atoms and secondary alcohols having up to 20 carbon atoms; and the acyllium anion product is carbon monoxide;
produced from the reaction of an anhydrous acid selected from the group consisting of hydrogen fluoride (HF) and hydrogen chloride (HCl) and an organic compound capable of reacting with carbon monoxide and the acid anhydride; , (a) General formula (In the above general formula, R is an alkyl having up to 20 carbon atoms, and R' is an alkyl having from 2 to 20 carbon atoms.) and (b)acyllium anion products. an olefin having at least one double bond and up to 20 carbon atoms capable of producing carried out in the presence of the acid anhydride at a pressure of 1 bar (14.7 psia) to 340 bar (5000 psia), and the initial amount of the acid anhydride to acyllium anion product is 0.01 to 95.5 parts by weight of the acid anhydride to acylium. A process for producing a carboxylic acid ester from an acyllium anion product, characterized in that the process comprises ranging from 99.09 to 4.5 parts by weight of the anion product. 2. The method according to claim 1, wherein the organic compound is an ester selected from the group consisting of isopropyl isotorate, ethyl isobutyrate, isopropyl propionate, and ethyl propionate. 3. Claim 1, characterized in that the organic compound is an olefin having at least one double bond capable of forming an acylium anion product and having up to 20 carbon atoms. Method described. 4. The method according to claim 1, wherein the olefin is ethylene. 5. The method according to claim 1, wherein the olefin is propylene. 6. The method according to any one of claims 1 to 5, wherein the alcohol is methanol. 7 Separating 1% to 100% of the amount of acid anhydride from the esterification product mixture containing the generated carboxylic acid ester, and reacting the separated acid anhydride with carbon monoxide and an organic compound to further generate acylium anions. 7. The method of claim 6, further comprising the step of recycling to produce a product. 8 Separating 1% to 100% of the amount of carboxylic acid ester from the esterification product mixture and further separating 1% to 100% of the amount of the esterification product mixture remaining after separation of the carboxylic ester to form an acylium anion product. 7. The method of claim 6, further comprising the step of recycling to produce . 9. The method according to claim 6, wherein the acid anhydride is hydrogen fluoride. 10 The initial amount of anhydrous hydrogen fluoride to acyl anion product (acyl fluoride) is between 10 and 90 anhydrous hydrogen fluoride.
10. A process according to claim 9, characterized in that the ratio is between 90 and 10 parts by weight of the acylium anion product (acyl fluoride). 11. The method according to claim 7, wherein the acid anhydride is hydrogen fluoride. 12. The method according to claim 8, wherein the acid anhydride is hydrogen fluoride. 13. The mixture comprises carbon monoxide, anhydrous hydrogen fluoride and isobutyryl fluoride, the alcohol is methanol, the amount of methanol added initially is 70 to 99% of the amount of isobutyryl fluoride, and the mixture Claim 1, characterized in that the amount of anhydrous hydrogen fluoride in the isobutyryl fluoride is substantially within the range of 10 to 20 moles of anhydrous hydrogen fluoride per mole of isobutyryl fluoride.
The method described in section. 14. The esterification according to claim 13, characterized in that the esterification is carried out substantially within the pressure range of 3.3 bar (50 psia) to 6.7 bar (100 psia) and within the temperature range of 40 °C to 70 °C. Method. 15. Claim 14, characterized in that it also includes a distillation step for separating 80% to 100% of the produced isobutyric acid from the esterification product mixture.
The method described in section. 16. The method according to claim 15, characterized in that the distillation step and the esterification step occur simultaneously. 17. Process according to claim 16, characterized in that from 90 to 100% of the methyl isobutyrate is separated from the esterification product mixture. 18 an amount of methanol less than the amount required to esterify the mixture containing the asyllium anion product under anhydrous conditions to the corresponding ester selected from the group consisting of methyl propionate and methyl isobutyrate. esterification, thereby producing a carboxylic ester and regenerating the acid from the anion; separating the ester;
oxydehydrogenation of the corresponding unsaturated carboxylic acid ester, methyl acrylate or methyl methacrylate, and the acyl anion product is carbon monoxide, an olefin selected from the group consisting of ethylene and propylene, and hydrogen fluoride. with an anhydride selected from the group consisting of (HF) and hydrogen chloride (HCl) under conditions that produce an acylium anion product. and methyl methacrylate. 19. The method according to claim 18, wherein the acid anhydride is hydrogen fluoride. 20. The method according to claim 19, wherein the olefin is propylene. 21 The oxydehydrogenation process is carried out using the empirical formula FeP _x O _z (in the above experimental formula, for Fe1 atom, x is P atom 0.25
~3.5, where z indicates the number of oxygen atoms required to satisfy the valence requirements of the catalyst), and is characterized by the use of a catalyst containing iron, phosphorus, and oxygen. , a method according to any one of claims 18 or 19 or 20.