JP2662683B2 - Solid catalyst for carbonylation reaction and method for producing acetic acid using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a solid catalyst for a carbonylation reaction and a method for producing acetic acid using the same.

[0002]

2. Description of the Related Art Conventionally, in order to produce acetic acid, a vinylpyridine resin having a porous crosslinked structure carrying a rhodium complex is used as a catalyst for a carbonylation reaction, and the reaction is carried out in a reaction solvent in the presence of an alkyl iodide. A method of reacting methanol with carbon monoxide is known (Japanese Patent Laid-Open No. 63-25 / 1988).
No. 3047). In this publication, the most preferred vinylpyridine resin is “Raylex 425” (trademark), which is commercially available from Reilly tarand chemical (Indianapolis, IN, USA). Have been described. This resin has a degree of crosslinking of 33.
% And a porous crosslinked structure having a pore volume of 0.71 cc / g. The carbonylation reaction catalyst obtained from this resin has high carbonylation reaction activity, but has poor durability and abrasion resistance. When a carbonylation reaction is carried out using this, a partial decomposition of the resin occurs, and the pyridine ring contained in the resin is gradually released. Includes the problem of producing fines. Removal of the pyridine ring from the resin destabilizes the catalyst activity and shortens the catalyst life.
On the other hand, the surface wear of the resin reduces the activity of the catalyst, and the catalyst fine powder generated by the surface wear of the catalyst is mixed into the reaction solution. give.

[0003]

DISCLOSURE OF THE INVENTION The present invention provides a solid catalyst for a carbonylation reaction having excellent carbonylation reaction activity, excellent durability and wear resistance, and a long catalyst life, and a process for producing acetic acid using the same. Is the task.

[0004]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have completed the present invention. That is, according to the present invention, in a solid catalyst for a carbonylation reaction comprising a vinylpyridine-based resin having a porous crosslinked structure supporting a rhodium complex, the vinylpyridine-based resin has a degree of crosslinking of 30 to 60%, .2
A solid catalyst for a carbonylation reaction is provided, which has a pore volume of 0.4 cc / g and an average pore diameter of 20 to 100 nm. Further, according to the present invention, using a solid catalyst for carbonylation reaction, in the presence of alkyl iodide,
In a method for producing acetic acid by reacting methanol with carbon monoxide in a reaction solvent, a method for producing acetic acid is provided, wherein the solid catalyst is used as the carbonylation reaction catalyst.

In the present invention, a vinylpyridine-based resin having a porous cross-linking structure (hereinafter simply referred to as a VP resin) used as a support for supporting a rhodium complex is 30 to 60.
%, Preferably 35-60%, 0.2-0.4%
It is characterized by having a pore volume of cc / g, preferably 0.3-0.4 cc / g and an average pore diameter of 20-100 nm, preferably 30-90 nm. Various VP resins are commercially available from Rayleigh Tar & Chemical Co., Ltd., but those having the characteristics specified in the present invention are not commercially available. The present invention provides a catalyst in which a rhodium complex is supported on a VP resin having the above-mentioned specific degree of crosslinking, pore volume and average pore diameter, has excellent durability and abrasion resistance, and its catalyst life is significantly extended, Moreover, it has been completed based on the finding that it has excellent carbonylation reaction activity.

In a catalyst in which a rhodium complex is supported on a VP resin, if the degree of crosslinking of the VP resin is smaller than the above range, problems such as an increase in the rate of depyridine and a decrease in abrasion resistance are undesirable. If it is larger than the above range, a problem of a decrease in the catalytic activity occurs, which is not preferable. Further, if the pore volume of the VP resin is smaller than the above range, a problem of a decrease in catalytic activity occurs, which is not preferable. On the other hand, if the pore volume is larger than the above range, a problem such as a decrease in abrasion resistance occurs. Further, if the average pore diameter of the VP resin is smaller than the above range, it is not preferable because a problem of a decrease in catalytic activity occurs, while if it is larger than the above range, a problem such as a decrease in abrasion resistance occurs.

[0007] In the present specification, the degree of cross-linking for the VP resin is defined as follows. The pore volume and surface area of the VP resin are measured as follows. Furthermore, the average pore diameter of the VP resin is calculated as follows. (Cross-linking degree) Cross-linking degree (%) = A / B × 100 A: Weight of crosslinking agent contained in resin B: Weight of vinylpyridine monomer contained in resin (Pore volume) Mercury Pressure Porosity It was measured by a method using a meter model 70 (manufactured by Carlo Elba, Milan, Italy) (a so-called mercury intrusion method). In this case, the surface tension of mercury is 474 at 25 ° C.
dyne / cm, the contact angle used was 140 degrees, and the absolute mercury pressure was varied from 1 to 200 kg / cm ² for measurement. (Surface area) E. FIG. It was measured by the T method. (Average pore diameter) Using the measured values of the pore volume and the surface area measured as described above, it was calculated by the following formula. Average pore diameter (nm) = 4 (C / D) × 10 ³ C: pore volume (cc / g) D: surface area (m ² / g)

The VP resin is composed of a vinylpyridine monomer and
It is produced by copolymerizing an aromatic compound having two vinyl groups as a crosslinking agent. The copolymerization method itself for obtaining the VP resin is a conventionally known method, and includes, for example, (1) a method of adding a precipitant, (2) a method of adding a linear polymer,
There are (3) a swelling agent / precipitating agent addition method, and (4) a diluent / linear polymer adding method. A preferred method for producing the VP resin used in the present invention is described in detail in JP-B-61-25731. That is, according to this method, the VP resin is
It is produced by subjecting a mixture of a vinylpyridine-based monomer, a crosslinking agent having two vinyl groups, and a vinyl monomer used as required to a polymerization reaction in the presence of a radical polymerization reaction catalyst. . In this case, an aqueous suspension polymerization using water as a medium is employed for the polymerization reaction. Further, a suspension stabilizer and a precipitant are added to the polymerization reaction system. Examples of the suspension stabilizer include polyvinyl alcohol, hydroxyethylcellulose, carboxymethylcellulose, polysodium methacrylate, sodium polyacrylate, starch, gelatin, water-soluble polymers such as ammonium salt of styrene / maleic anhydride copolymer, and calcium carbonate. And inorganic salts such as calcium sulfate, bentonite and magnesium silicate. Further, sodium chloride or sodium nitrite can be added to the reaction system. As a precipitant, an organic solvent that acts as a solvent for the monomer, but acts as a poor solvent for the resulting polymer, for example,
In addition to hydrocarbons having 5 to 10 carbon atoms such as isooctane, alcohols and esters are used. In such a method for producing a VP resin, the degree of crosslinking of the obtained VP resin can be controlled by the amount of the crosslinking agent added, and the pore volume and average pore diameter are determined by the type of the precipitant and the amount of the additive. Of the suspension stabilizer, and the amount and the amount of the suspension stabilizer, and the reaction temperature.

The vinylpyridine monomers used to obtain the VP resin include 4-vinylpyridine, 2-vinylpyridine, a 4-vinylpyridine derivative having a lower alkyl group such as a methyl group or an ethyl group on the pyridine ring, 2-vinylpyridine derivatives and the like. In addition, other vinyl monomers, for example, an aromatic vinyl monomer such as styrene and vinyltoluene can be mixed into the vinylpyridine monomer. The amount of these aromatic vinyl monomers mixed is 30 mol% or less, preferably 2 mol%, of all monomers.
The content is preferably 0 mol% or less. The crosslinking agent copolymerized with the vinylpyridine-based monomer is a compound having two vinyl groups. Examples of such compounds include aromatic compounds such as divinylbenzene and divinyltoluene, and aliphatic compounds such as butadiene. The amount of the crosslinking agent used is appropriately determined according to the desired degree of crosslinking of the VP resin.

The particle size of the VP resin is 0.01 to 4 mm, preferably 0.1 to 2 mm, more preferably 0.4 to 2 m.
m is used as a granular material, and its preferred shape is a spherical body.

In the present invention, the rhodium complex carried on the VP resin is represented by a rhodium complex ion in a supported form, for example, [Rh (CO) ₂ I ₂ ] ^- . As a method of supporting the rhodium complex on the VP resin, the following method is exemplified. (1) A method in which a rhodium ion is supported in an aqueous solution on a nitrogen atom of a pyridine ring of a VP resin, and then converted to a rhodium complex in an organic solvent in the presence of alkyl iodide and carbon monoxide. The reaction between the pyridine ring and rhodium in this method is represented by the following formula. Further, as the reaction conditions, generally, rhodium can be supported under normal temperature and normal pressure, and complexation of supported rhodium can be performed under the same conditions as the carbonylation conditions of methanol.

[0012]

Embedded image In the above formula, R represents a lower alkyl group.

(2) A method in which a VP resin is brought into contact with a rhodium salt in a solvent containing an alkyl iodide under a pressure of carbon monoxide. In the case of this method, generally, the rhodium salt may be brought into contact with the VP resin under methanol carbonylation reaction conditions. In the catalyst thus obtained, the pyridine ring contained in the VP resin is quaternized by alkyl iodide to form a pyridinium salt, which is formed by the reaction of a rhodium salt, an alkyl iodide and carbon monoxide. Rhodium carbonyl complex [Rh (CO) ₂ I ₂ ] ^-
Has an ionically bonded structure.

Examples of the rhodium salt include rhodium chloride and rhodium halides such as rhodium bromide and rhodium iodide. Examples of the alkyl iodide include those having a lower alkyl group having 1 to 6 carbon atoms, such as methyl iodide, ethyl iodide, and propyl iodide.
Particularly, use of methyl iodide is preferred. The use ratio of the alkyl iodide to the rhodium salt is 2 to 2000 mol, preferably 50 mol of the alkyl iodide per mol of the rhodium salt.
５００500 mol. The carbon monoxide pressure when the rhodium salt is brought into contact with the alkyl iodide is 7 to 30 k.
g / cm ² G, preferably 10 to 20 kg / cm ² G.

In the catalyst of the present invention, the supported amount of the rhodium complex is expressed in terms of metal rhodium with respect to the VP resin.
It is good to specify in the range of 0.2 to 2% by weight, preferably 0.5 to 1.0% by weight. When the supported amount of the rhodium complex is larger than the above range, the catalytic activity per 1 mol of rhodium metal decreases, the product yield per mol of rhodium metal (mol / molRh · hr) decreases, and when the catalyst is used, This is not preferred because the amount of dissociation of the rhodium complex from the compound increases. In the case of the catalyst of the present invention, in which the supported amount of rhodium complex is constant, the concentration of rhodium present in the reaction solution after dissociating from the catalyst does not change much even when the amount of the catalyst used is increased. Therefore, in order to use rhodium effectively, it is preferable to reduce the amount of supported rhodium and increase the amount of catalyst used.However, if the amount of supported rhodium complex is too low, the amount of catalyst used to obtain a desired reaction rate is reduced. It is not preferable because the amount becomes too large and stirring in the reactor becomes difficult and the surface of the catalyst is apt to be worn. From this point, the lower limit of the supported amount of the rhodium complex is 0.2
% By weight.

The catalyst for the carbonylation reaction of the present invention is advantageously used as a catalyst for the production of acetic acid by carbonylation of methanol, but can generally be used as a catalyst for the carbonylation reaction of lower alcohols. The production of acetic acid by the carbonylation reaction of methanol using the catalyst of the present invention is carried out by allowing the catalyst of the present invention and an alkyl iodide to be present in a reaction solvent, introducing methanol and carbon monoxide into the reaction solvent, and causing the reaction. Is done. The carbonylation reaction of methanol using the catalyst of the present invention can be carried out using various reactors. Examples of the type of such a reactor include a fixed bed, a mixing tank, and an expansion bed. The amount of catalyst charged in the reactor is generally 2 to 40% by weight based on the solution in the reactor. However, in the case of a mixing tank reactor, it is preferable to select 2 to 25% by weight. Further, in a fixed bed reactor, 20 to 40% by weight, and in an expanded bed reactor, 2 to 2% by weight.
It is better to select 5 wt%.

As the reaction solvent, various conventionally known solvents are used, and generally, a solvent containing a carbonyl group-containing organic solvent having 2 or more carbon atoms is used. Examples of such a reaction solvent include carboxylic acids and carboxylic esters such as acetic acid and methyl acetate. Further, the reaction solvent can contain water. In this case, the content of water in the reaction solvent is 0.05 to 50 wt%, preferably 0.1 to 20 wt%. As the alkyl iodide,
Alkyl iodide having 1 to 6 carbon atoms is used.
The use of methyl iodide is preferred.

The amount of the reaction solvent in the reactor is preferably set to 0.30 parts by weight or more based on 1 part by weight of methanol. The preferred amount of the reaction solvent is 2.40 parts by weight or more based on 1 part by weight of methanol. By maintaining the amount of the reaction solvent in the reaction solution within the above range, the reaction activity of the rhodium carbonyl complex, which is the active center of the catalyst, is enhanced, and the binding stability between the rhodium carbonyl complex and the pyridinium salt is also improved. The carbonylation reaction of methanol can proceed smoothly at a reaction rate and effectively preventing the dissociation of rhodium from the VP resin. More importantly, by keeping the amount of the reaction solvent in the reactor within the above range, the rhodium carbonyl complex can be stably present even under an extremely low CO partial pressure condition of 7 kg / cm ² , and a high reaction rate can be obtained. To allow the carbonylation reaction of methanol to proceed. This means that there is no need to use a special pressure vessel as a reactor, so that the cost of the reactor can be greatly reduced and a practical and economical acetic acid process can be obtained.

The partial pressure of CO (partial pressure of carbon monoxide) when performing the carbonylation reaction of methanol using the catalyst of the present invention is 7
kg / cm ² or more, preferably 10 kg / cm ²
cm ² or more. Even if the CO partial pressure is particularly increased, the reaction rate does not increase so much, and no particular advantage in reaction is obtained. From an economic viewpoint, the upper limit of the CO partial pressure is 30 kg / cm ^2.
It is better to be about. Therefore, the CO partial pressure is 7 to 30 k.
g / cm ² , preferably in the range of 10 to ²⁰ kg / cm ² . By maintaining the CO partial pressure in such a range, the total reaction pressure is reduced to an economical 15-60 kg / c.
The pressure can be maintained at a low pressure of m ² G, particularly 15 to 40 kg / cm ² G, and more preferably 15 to 30 kg / cm ² G or less.

The reaction temperature in the carbonylation reaction using the catalyst of the present invention is 140 to 250 ° C., preferably 160 to 250 ° C.
The upper limit is appropriately selected according to the heat resistance of the VP resin used. The amount of the alkyl iodide in the reaction system is 1 to 40% by weight, preferably 5 to 30% by weight in the solution in the reactor. Further, the rhodium concentration in the reaction system was 50 wt% in the solution in the reactor.
ppm or more, preferably 300 wtppm or more, more preferably 400 wtppm or more. Note that the rhodium concentration referred to here is wt% of the amount of rhodium metal with respect to the solution excluding the VP resin from the reactor.

The amount of the reaction solvent in the reactor is defined as follows according to the type of the reactor. In a batch reactor, the amount of the reaction solvent is based on methanol in the raw material liquid charged in the reactor. Since the methanol concentration decreases with the progress of the reaction, the concentration of the reaction solvent in the reactor becomes higher than the charged raw material. In a mixed tank flow reactor, the solution in the reactor is uniformly mixed and substantially equal to the composition of the reaction product liquid discharged from the reactor outlet. That is, in this case, the definition of the amount of the solvent in the reactor is substantially the amount of the reaction solvent with respect to methanol in the reaction product discharged from the reactor outlet. In a piston flow type reactor, the amount is defined as the amount of the reaction solvent with respect to methanol in the entire supply liquid supplied to the reactor. In this case, the concentration of methanol decreases and the amount of the reaction solvent increases as going from the inlet to the outlet of the reactor. Therefore, the amount of the reaction solvent with respect to methanol increases as going to the reactor outlet. Therefore, the amount of the reaction solvent is defined as the amount of the reaction solvent with respect to methanol in the entire supply liquid supplied to the reactor inlet.

In the carbonylation reaction of methanol, a side reaction represented by the following reaction formulas (2) and (3) occurs together with a main reaction represented by the following reaction formula (1). _{CH 3 OH + CO → CH 3} COOH (1) CH 3 COOH + CH 3 OH → CH 3 COOCH 3 + H 2 O (2) 2CH 3 OH → CH 3 OCH 3 + H 2 O (3)

In the present invention, in order to produce acetic acid in good yield, it is necessary to suppress the side reactions (2) and (3) and selectively proceed the carbonylation reaction (1) of methanol. For this purpose, it is effective to use a reaction solvent containing methyl acetate or water. In the case where methyl acetate is present in the reaction system to increase the acetic acid yield, it is preferable that methyl acetate is added to methanol in advance and supplied to the reaction system. Methyl acetate is methanol 1wt
It is preferable to add 1.5 parts by weight or more, preferably 3 parts by weight or more to the parts, whereby the by-product of methyl acetate can be suppressed and the acetic acid yield can be increased. Also,
When increasing the acetic acid yield by adding the added water to the reaction system, it is preferable to add the added water to methanol in advance and supply it to the reaction system. The added water is methanol 1wt
Parts, more than 0.3 wt parts, preferably 0.5 wt parts
It is preferable that the acetic acid is added in a proportion of at least one part, whereby by-products of methyl acetate and dimethyl ether can be suppressed and the acetic acid yield can be increased.

In the present invention, even when an acetic acid solvent containing neither methyl acetate nor water is used as the reaction solvent, the carbonylation of methanol is carried out until the conversion of methanol becomes 96% or more, preferably 99% or more. , Methyl acetate and dimethyl ether can be suppressed to increase the acetic acid yield. In this case, the methanol concentration in the reaction product solution is 0.3 wt% or less, preferably 0.2 wt%.
%, The methanol conversion is preferably adjusted.

The carbonylation reaction of methanol using the catalyst of the present invention is advantageously carried out using a flow reactor. The flow reactor includes a mixed tank flow reactor and a piston flow reactor. Hereinafter, examples of acetic acid production by carbonylation of methanol using these reactors will be described in detail. FIG. 1 shows an example of a flow sheet for a method for producing acetic acid using a mixed tank flow reactor. In FIG. 1, R
-1 is a mixing tank flow type reactor, 7 is a cooler, and S is a separation system.

The reactor R-1 is filled with acetic acid as a reaction solvent, a VP resin carrying a rhodium complex as a catalyst, and methyl iodide as a reaction accelerator, and these fillers are charged in the reactor. The mixture is uniformly stirred and mixed by a stirrer attached to. Methanol containing methyl iodide was introduced into the reactor R-1 from the bottom via lines 1 and 2, and carbon monoxide was introduced from line 3 via a gas disperser attached to the reactor. To introduce. In this case, water or methyl acetate can be added to methanol as required. The methanol and carbon monoxide introduced into the reactor R-1 react here in the presence of the rhodium complex-supported VP resin and methyl iodide to produce acetic acid. The reaction product liquid containing acetic acid generated by this reaction is withdrawn through line 4, a part of which is introduced into separation system S through line 5, and another part is cooled through line 6. After passing through a vessel 7 where it is cooled, it is circulated through line 2 to reactor R-1. By circulating a part of the reaction product liquid to the reactor through the cooler in this way, the reaction heat generated in the reactor can be removed. Gaseous material containing unreacted carbon monoxide is withdrawn through line 8 and discharged through flow valve 9 and line 10. From this gaseous substance, low-boiling substances such as methyl iodide contained therein are separated and circulated to the reactor.

The reaction product liquid containing acetic acid introduced into the separation system S is subjected to a separation treatment including distillation here, acetic acid is recovered through the line 11, and the secondary liquid after the acetic acid is separated from the reaction product liquid. The residual liquid of the reaction product solution containing organisms is supplied to lines 12 and 13
To the methanol line 1 and circulated through line 2 to the reactor R-1. Part of the residual liquid is discharged to the outside of the system through the line 14 as necessary. This circulating liquid contains by-products such as methyl iodide, water, hydrogen iodide, methyl acetate and dimethyl ether, as well as unreacted methanol, methyl acetate and the like. Further, a part of the separated acetic acid can be mixed into the circulating liquid.

In the carbonylation reaction of methanol using the mixing tank flow reactor, the ratio of the reaction solvent to methanol is maintained at a high value of 50 parts by weight or more, preferably 150 to 1000 parts by weight, based on 1 part by weight of methanol. Since it is easy, the carbonylation reaction of methanol can be rapidly performed while keeping the catalyst stable and highly active.

When the carbonylation reaction of methanol is carried out as described above, the amounts of methanol and circulating liquid supplied to the reactor R-1 are adjusted to adjust the composition of the solution in the reactor to the above-mentioned specific range. It is preferable to maintain the carbon monoxide partial pressure at 7 to 30 kg / cm ² and the reaction temperature at 140 to 250 ° C. while maintaining the temperature. By performing the carbonylation reaction of methanol under such conditions, the reaction pressure is 15 to
60kg / cm ² G, it is possible to quickly perform the carbonylation reaction of methanol with particular 15~40kg / cm ² G the lowered pressure of.

The carbonylation reaction of methanol is an exothermic reaction, and it is necessary to remove the heat of reaction in order to maintain the reaction temperature at a predetermined temperature. As a typical method for removing the reaction heat, as shown in FIG. 1, a method of extracting a part of the solution in the reactor to the outside, indirectly cooling the solution with a cooler, and then returning the solution to the reactor. Can be shown. In addition to such a method, various methods are available for removing the heat of reaction. For example, the solution in the reactor may be introduced into a flasher to vaporize a part of the solution, adiabatically cool the solution, and circulate the cooled solution to the reactor.

The solution in the reactor R-1 can be stirred by a method other than the stirrer. For example, the solution in the reactor is fluidized and stirred by carbon monoxide gas introduced into the reactor. Alternatively, fluid stirring can be performed using a circulating liquid flow into the reactor.

Next, a method for producing acetic acid by a carbonylation reaction of methanol using a piston flow reactor will be described. FIG. 2 shows an example of a flow sheet of a method for producing acetic acid using a piston flow reactor. In FIG. 2, R-2 indicates a piston flow type reactor, 21 indicates a gas-liquid separator, and S indicates a separation system.

The piston flow type reactor R-2 has a structure in which a plurality of catalyst tubes are provided upright. The catalyst tube in this case has a rhodium complex-supported VP inside as a catalyst.
It may be of a fixed-bed type having a resin-filled structure and filled so that the catalyst does not flow, or may be of an expanded-bed type in which the catalyst flows.

The catalyst tube in the reactor R-2 is cooled by bringing a coolant into contact with the outer surface thereof. Steam is preferably used as the refrigerant. The steam is extracted from the reactor and used as a heat source for the distillation column. The raw material methanol containing methyl iodide is introduced into the reactor R-2 through the line 1 together with the circulating liquid circulated from the line 13 and the carbon monoxide supplied through the line 3 through the line 2. In this case, methyl acetate or water can be added to methanol as required. The gas-liquid mixture consisting of carbon monoxide introduced into the bottom of the inlet of the reactor R-2 and a liquid containing methanol and acetic acid is sufficiently dispersed in gas at the inlet of the reactor, and is supplied to a plurality of catalyst tubes. Liquid and gas are supplied uniformly.

In the catalyst tube, methanol and carbon monoxide react in acetic acid as a reaction solvent in the presence of a catalyst and methyl iodide to be converted to acetic acid. The reaction product liquid containing acetic acid is withdrawn through a line 20 and introduced into a gas-liquid separator 22, where gaseous matter containing unreacted carbon monoxide is withdrawn through a line 23, a flow valve 24 and a flow valve 24. Discharged through line 25. Low-boiling substances such as methyl iodide are separated from this gaseous substance and circulated to the reactor R-2. After the gaseous matter containing unreacted carbon monoxide is separated, the reaction product liquid is introduced into the separation system S through a line 22, where acetic acid is separated, and the separated acetic acid passes through a line 26. Collected.

In the separation system S, the residual liquid after the acetic acid is separated from the reaction product liquid is introduced into the methanol line 1 through the lines 12 and 13, and is passed through the line 2 to the reactor R-
Cycled to 2. Part of the circulating residual liquid is discharged out of the system through the line 14 as necessary. This circulating fluid
Contains by-products such as methyl iodide, hydrogen iodide and water, methyl acetate and dimethyl ether, and unreacted methanol and methyl acetate. Further, one part of the separated acetic acid can be mixed therein.

When the carbonylation reaction of methanol is carried out as described above, the amounts of methanol, acetic acid and circulating liquid supplied to the reactor R-2 are adjusted, and the composition of the solution in the reactor is specified as described above. While keeping the carbon monoxide partial pressure at 7-30 kg / cm ² and the reaction temperature at 140-2.
Preferably, the temperature is maintained at 50 ° C. By carrying out the carbonylation reaction of methanol under such conditions, the reaction pressure is increased to 15 to 60 kg / cm ² G, particularly 15 to 40 kg / cm ^2.
At a reduced pressure of cm ² G, the carbonylation reaction of methanol can be carried out rapidly.

[0038]

Industrial Applicability The solid catalyst for carbonylation reaction of the present invention is obtained by supporting a rhodium complex on a VP resin having a specified degree of cross-linking, pore volume and average pore diameter within a specific range. The catalyst life is remarkably prolonged and the carbonylation reactivity is high.
When a carbonylation reaction is performed using the catalyst of the present invention, the VP resin has high durability and abrasion resistance, so that elimination of a pyridine ring from the resin is effectively prevented, and Generation of fine powder due to surface wear is also effectively prevented, and the carbonylation reaction can be smoothly carried out for a long time.

[0039]

Next, the present invention will be described in more detail with reference to Examples.

Example 1 (1) Preparation of Catalyst and Test of Catalytic Activity 6.7 g of vinylpyridine resin (dry weight) and 0.15 g of rhodium chloride were mixed with 62.3 g of methanol and acetic acid 6
The mixture was added to a mixture consisting of 5.2 g and 11.1 g of methyl iodide, and charged into an autoclave equipped with a stirrer.
C. and pressurized the inside of the autoclave with carbon monoxide until the total pressure became 50 kg / cm ^2. Under this condition, the contents of the autoclave were stirred at 600 rpm for 3 hours.
Stirred for 0 minutes. Thereafter, the contents were taken out of the autoclave and washed with methanol to obtain a catalyst comprising a vinylpyridine-based resin carrying a rhodium complex. next,
The catalyst obtained as described above was placed in an autoclave as it was, and further, 65.2 g of acetic acid and 62.2 g of methanol.
A mixed solution consisting of 3 g and 11.1 g of methyl iodide was charged, heated to 190 ° C., and then pressurized with carbon monoxide until the total pressure in the autoclave became 50 kg / cm ² , and stirred at 600 rpm. The reaction was performed for 1 hour. Next, the composition of the reaction solution obtained by the above reaction was analyzed,
The amount of CO involved in the reaction was measured, and the amount of reaction per liter per hour (Space Time Yield =
STY) was calculated.

(2) Abrasion Resistance Test of VP Resin 500 g of acetic acid and 25 g (dry weight) of vinylpyridine resin were placed in a 1-liter glass container, and 3.2 cm wide and 1.2 cm high stainless steel stirring blades were used. 1000 rpm
The suspension was stirred at room temperature for 1000 hours. After the stirring was stopped, fine particles of about 10 μm or less suspended in the liquid were filtered through a filter having a pore size of 0.2 μm, and the weight A of the fine particles collected by the filter was measured. From the fine particle weight A, the fine particle weight B similarly measured before the start of the test was subtracted, and the value was defined as the amount of fine particles generated by the test. The pulverization rate of the resin was calculated from the amount of the fine particles.

(3) Depyridine ring test A vinylpyridine resin was added to a solution of 90% acetic acid / 10% water in a boiling state at 110 ° C., and after 140 hours, the nitrogen concentration in the solution was measured to remove the resin from the resin. It was converted to the pyridine ring velocity.

Table 1 shows the characteristics of the vinylpyridine resin used in the test, and Table 2 shows the test results.

The specific contents of the vinylpyridine resin indicated by the reference numerals in Tables 1 and 2 are as follows. (Reilex 402) A commercially available product from Reilly Ter and Chemical Company, trade name "Reillex
x) 402 ", average particle size: 0.2 mm or less (powder) (Raylex 425) Commercial product from Rayleigh Tar & Chemical Company, trade name" Raylex 425 ", average particle size: 0.55 mm (KEX316 ) A commercial product from Koei Chemical Co., trade name "K
EX316 ", average particle size: 0.65 mm (KEX212) Commercial product from Koei Chemical Co., trade name" K
EX212 ", average particle size: 0.1 mm (VP resin A) 77 parts by weight of vinylpyridine and 38 parts by weight of divinylbenzene (containing 40 wt% of ethylvinylbenzene) were added by a precipitant addition method (Japanese Patent Publication No. 61-25731).
No.), average particle size:
0.5 mm (VP resin B) 72 parts by weight of vinylpyridine and 47 parts by weight of divinylbenzene (containing 40% by weight of ethylvinylbenzene) were added by a precipitant addition method (Japanese Patent Publication No. 61-25731).
No.), average particle size:
0.50 mm (VP resin C) 67 parts by weight of vinylpyridine and 56 parts by weight of divinylbenzene (containing 40 wt% of ethylvinylbenzene) were added by a precipitant addition method (Japanese Patent Publication No. 61-25731).
No.), average particle size:
0.60 mm (VP resin D) 63 parts by weight of vinylpyridine and 63 parts by weight of divinylbenzene (containing 40% by weight of ethylvinylbenzene) were mixed with a precipitant adding method (Japanese Patent Publication No. 61-25731).
No.), average particle size:
0.70 mm (VP resin E) 60 parts by weight of vinylpyridine and 67 parts by weight of divinylbenzene (containing 40% by weight of ethylvinylbenzene) were added by a precipitant addition method (Japanese Patent Publication No. 61-25731).
No.), average particle size:
0.65mm

[0045]

[Table 1]

[0046]

[Table 2]

Example 2 In the preparation of catalyst and the catalyst activity test in Example 1, catalysts in which various amounts of rhodium complex were supported on VP resin B were prepared, and these catalysts were similarly treated. The catalytic activity and the concentration of Rh desorbed in the reaction solution were examined. Table 3 shows the results.

[0048]

[Table 3]

Example 3 In the catalyst activity test in Example 1, the catalyst No. 2 shown in Example 2 was used as a catalyst. 2, No. The experiment was carried out in the same manner except that the catalyst No. 4 was used and the amount used was changed variously. Table 4 shows the STY in this case and the concentration of Rh desorbed in the reaction solution in relation to the amount of catalyst used. The amount of the catalyst used is wt% with respect to the raw material mixture liquid charged in the autoclave.

[0050]

[Table 4]

From the results shown in Table 4, it can be seen that the concentration of Rh desorbed into the reaction solution depends on the amount of Rh supported, but not on the amount of catalyst used.

Example 4 Using the apparatus shown in FIG. 1, a carbonylation reaction of methanol was continuously performed. The reaction conditions in this case were as follows. The catalyst used was a VP resin of B in which 0.8% by weight of a rhodium complex was supported as metal Rh in the same manner as in Example 1. In this carbonylation reaction of methanol, even if the reaction was continuously performed for 4000 hours, the life of the catalyst was hardly observed. (1) Line 2 (component composition) Methanol: 40 wt% Methyl iodide: 10 wt% (flow rate) 200 parts by weight / hr (2) Line 3 (component composition) CO: 100 mol% (flow rate) 16 parts by weight / hr ( 3) Reaction conditions Temperature: 190 ° C. CO pressure: 15 kg / cm ² Total pressure: 45 kg / cm ² Catalyst loading: 10% by weight / reaction liquid Rhodium concentration: 800 wtppm / reaction liquid Stirring speed: 300 rpm (4) From line 4 Reaction liquid (component composition) Methanol: 0.5 wt% Acetic acid: 65 wt% Methyl iodide: 10 wt% Others: 24.5 wt% (Flow rate) 225 parts by weight / hr

[Brief description of the drawings]

FIG. 1 shows an example of a flow sheet of a method for producing acetic acid using a mixed tank flow type reactor.

FIG. 2 shows an example of a flow sheet of a method for producing acetic acid using a piston flow reactor.

[Explanation of symbols]

 R-1 Mixing tank flow type reactor R-2 Piston flow type reactor S Separation system

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yoshimi Shirato 2-1-1, Tsurumichuo, Tsurumi-ku, Yokohama-shi, Kanagawa Prefecture Inside Chiyoda Kako Construction Co., Ltd. (72) Inventor Noriyuki Yoneda Tsurumi-chuo, Tsurumi-ku, Yokohama, Kanagawa Prefecture No. 12-1, Chiyoda Kako Construction Co., Ltd. (56) References JP-A-63-253407 (JP, A) JP-A-6-315636 (JP, A) JP-A-8-501017 (JP, A)

Claims (5)

(57) [Claims] 1. A solid catalyst for a carbonylation reaction comprising a vinylpyridine resin having a porous crosslinked structure carrying a rhodium complex, wherein the vinylpyridine resin comprises:
A solid catalyst for a carbonylation reaction, having a degree of crosslinking of 30 to 60%, a pore volume of 0.2 to 0.4 cc / g, and an average pore diameter of 20 to 100 nm. 2. The solid catalyst according to claim 1, wherein the vinylpyridine resin contains styrene as a monomer component. 3. The solid catalyst according to claim 1, wherein the vinylpyridine resin contains divinylbenzene as a crosslinking agent component. 4. The solid catalyst according to claim 1, wherein the supported amount of the rhodium complex is 0.2 to 2% by weight in terms of metal rhodium based on the vinylpyridine resin. 5. A method for producing acetic acid by reacting methanol with carbon monoxide in a reaction solvent in the presence of an alkyl iodide using a solid catalyst for a carbonylation reaction. A method for producing acetic acid, comprising using the solid catalyst according to any one of 1 to 4.