JP2000159723A - Production of fumaric acid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a fumaric acid in a high yield by isomerizing maleic acid in the presence of a catalyst system comprising the combination of a bromine- donating compound with a specific oxidizing agent and further in the coexistence of a specific auxiliary catalyst. SOLUTION: This method for producing fumaric acid comprises isomerizing maleic acid in the presence of (A) a water-soluble bromine-donating compound (for example, lithium bromide or N-bromosuccinic acid imide), (B) a compound (oxidizing agent) having a standard electrode potential of >=1 V [for example, ammonium cerium (IV) nitrate] and (C) an auxiliary catalyst comprising a metal salt containing a heavy metal, for example, a metal salt containing iron, copper or zinc, (e.g. CuCl2), preferably at 40-100 deg.C at a pressure of 0.2-1 kg/cm2. By the method, the conversion and the reaction rate are improved, and, even when the mother solution is reused, the lowering in the conversion of the maleic acid can be stopped.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for producing fumaric acid. More specifically, the present invention relates to an improvement in a method for producing fumaric acid by isomerizing maleic acid in the presence of a specific catalyst. Fumaric acid is widely used as a raw material for producing polyester resins, malic acid, aspartic acid, and the like, as an intermediate raw material for surfactants, insecticides, and the like, and also for foods such as soft drinks and confectionery.

[0002]

2. Description of the Related Art Known maleic acid isomerization catalysts include, for example, thioureas (US Pat. No. 2,454,387) and thiocyanic acids (US Pat. No. 2,208,51).
No. 9), bromates (US Pat. No. 2,914,5)
No. 59), and a catalyst comprising a combination of a bromine donating compound and an oxidizing agent (Belgium Patent No. 604912) are known.

[0003]

According to the results of studies conducted by the inventors of the present invention, the conversion rate of the catalyst is still insufficient, and the conversion rate of the catalyst is not sufficient. It has been found that it is difficult to recycle the mother liquor due to a trace amount of reaction by-products, and it is difficult to maintain a sufficient conversion unless the oxidizing agent is added in a larger amount than the initial amount. An object of the present invention is to solve these problems and to provide a method for efficiently producing fumaric acid.

[0004]

Means for Solving the Problems The present inventors have conducted intensive studies in view of the above-mentioned circumstances, and as a result, isomerizing maleic acid using a catalyst system in which a bromine donor compound and a specific oxidizing agent are combined to convert fumaric acid. During the production, by further adding a specific co-catalyst, the conversion and the reaction rate are improved,
Further, they have found that the conversion rate of maleic acid does not decrease even when the mother liquor is reused, and have completed the present invention.

That is, the gist of the present invention is that the standard electrode potential is 1 V
In the coexistence of the above compound and a water-soluble bromine donating compound, when fumaric acid is produced by isomerizing maleic acid, a method for producing fumaric acid, comprising using a metal salt containing a heavy metal as a cocatalyst. .

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. In the method of the present invention, fumaric acid is obtained by isomerizing maleic acid in the presence of a compound having a standard electrode potential of 1 V or more (hereinafter sometimes referred to as an oxidizing agent), a water-soluble bromine donor compound and a metal salt containing a heavy metal. There is a way. Hereinafter, the oxidizing agent and the water-soluble bromine donating compound are referred to as an isomerization catalyst, and the metal salt may be referred to as a cocatalyst.

(Maleic acid) The maleic acid used in the present invention may be a purified or crude product of maleic acid or maleic anhydride. As a purified product, commercially available maleic acid or maleic anhydride can be used by dissolving it in water. In the case of maleic anhydride, it can be melted and supplied to the isomerization reaction. In this case, maleic acid is hydrated in the reaction system, and the reaction proceeds. In the case of a crudely purified product, a crude maleic acid aqueous solution obtained in an intermediate step of the maleic anhydride production process (for example, BC Trivedi)
and B. M. Culbertson "Malei
c Anhydride "(1982)) or a crude maleic acid aqueous solution (for example, JP-A-40-23784) which is recovered by bringing water into contact with exhaust gas from a phthalic anhydride production process can be used directly. These aqueous solutions usually contain about 20 to 60% of water.

Water is usually used as a solvent for the isomerization reaction, and the maleic acid concentration is 5 to 60% by weight, preferably 10 to 50% by weight of the charged amount of the reaction. When the concentration is lower than the above concentration, the amount of fumaric acid recovered as a solid is small, so that the economic efficiency is poor and thus impractical. It is not preferable because it becomes impossible.

(Water-soluble bromine-donating compound) A water-soluble bromine-donating compound is a bromine compound having a solubility in water of 0.1 g / 100 g water or more, such as lithium bromide, sodium bromide, potassium bromide, ammonium bromide, Magnesium bromide, calcium bromide, iron bromide, copper bromide, zinc bromide, alcohol bromide, tetrabutylammonium bromide (bromine valence: -1), bromine (bromine valence: 0), N -Bromosuccinimide, sodium hypobromide (the valence of bromine: +1) and the like, preferably those having a bromine valence of -1 and those having a bromine valence of 0. It is also possible to use two or more of these compounds in combination. The amount of the water-soluble bromine donating compound used in the isomerization reaction is, for example, in the case of ammonium bromide, usually 1 × 10 ⁻³ to 4 mol%, preferably 1 × 10 ⁻³ mol%, based on the charged maleic acid.
^{-2 to} 3 mol%.

(Compound having a standard electrode potential of 1 V or more)
For the absolute value of the standard electrode potential, for example,
s Handbook of Chemistry 13
th Section 6. Standard electrode
As a compound having a potential of 1 V or more, tetravalent cerium
Compounds containing ions, compounds containing persulfate ions or
Hydrogen oxide. Containing tetravalent cerium ion
Examples of the compound include cerium ammonium nitrate (I
V): Ce (NH_Four)_Two(NO_Three)₆, Cerium sulfate
(IV): Ce (SO_Four)_TwoCerium (IV) sulfate
Ammonium: Ce (NH_Four)_Four(SO_Four) _FourEtc., persulfuric acid
Compounds containing ions include sodium persulfate: Na
_TwoS_TwoO₈, Potassium persulfate: K_TwoS_TwoO₈, Persulfate
Ammonium: (NH_Four)_TwoS_TwoO₈Etc. are preferred.
Or cerium (IV) ammonium nitrate,
(IV), cerium (IV) ammonium persulfate
Sodium, potassium, and ammonium persulfate
is there. These compounds may be used in combination of two or more.
It is also possible.

The amount of the compound having a standard electrode potential of 1 V or more used in the reaction is usually 0.005 to the charged amount of maleic acid in the case of ammonium persulfate.
10 to 10% by weight, preferably 0.01 to 5% by weight.
The water-soluble bromine donating compound and the compound having a standard electrode potential of 1 V or more, which are isomerization catalysts, are each used alone, and the water-soluble bromine donating compound has no isomerization catalyzing ability.
Compounds having a standard electrode potential of 1 V or more have only a weak isomerization catalytic activity, but act as an isomerization catalyst by combining them.

(Metal salt containing heavy metal (co-catalyst)) The present invention
Heavy metal elements that make up metal salts containing heavy metals used for
Is a metal element having a specific gravity of 4 or more, and preferably has a long period
Element belonging to Group 7A, 8 or 1B in the Periodic Table
Or zinc. For the elements shown in the periodic table,
For example, Iwanami Physical and Chemical Dictionary (4th edition, 580 pages and Appendix 2)
It is described in. Elements belonging to Group 7A include man
Gun (specific gravity 7.21-7.44), technetium (specific gravity
11.5) and rhenium (specific gravity 21.4)
However, a typical metal salt is a manganese metal salt (sulfuric acid).
Manganese (MnSO_Four), Manganese chloride (MnC)
l_Two), Manganese carbonate (MnCO_Three), Manganese nitrate
(Mn (NO_Three)_TwoEtc.) are exemplified. A member of the 8th family
The elements are iron (specific gravity 7.86) and cobalt (specific gravity 8.86).
9), nickel (specific gravity 8.85), ruthenium (specific gravity 1
2.0), rhodium (specific gravity 12.41), palladium
(Specific gravity 12.03), osmium (specific gravity 22.48),
Iridium (specific gravity 22.65), platinum (specific gravity 21.4)
Typical metal salts include iron metal salts.
(Iron sulfate (Fe_Two(SO_Four) _Three, FeSO_Four), Iron chloride
(FeCl_Two, FeCl_Three), Iron bromide (FeBr)_Three),
Iron nitrate (Fe (NO_Three)_Three), Iron perchlorate (Fe (Cl
O_Three)_Two, Fe (ClO_Three)_ThreeEtc.), nickel metal salts
(Nickel sulfate (NiSO_Four), Nickel bromide (NiB
r_Two), Nickel chloride (NiCl_Two), Nickel carbonate
(NiCO_Three), Nickel acetate (Ni (CH_ThreeCOO)
_Two) Etc. are exemplified. The elements belonging to group 1B include:
Copper (specific gravity 8.92), silver (specific gravity 10.49), gold (specific gravity)
19.3), and typical metal salts include
Copper (I, II) metal salts (copper chloride (CuCl_Two, CuC
l), copper sulfate (CuSO_Four), Copper acetate (Cu (CH_ThreeC
OO) _Two, Copper bromide (CuBr, CuBr_Two), Cyanation
Copper (CuCN), copper nitrate (Cu (NO_Three)_Two) Etc.), silver
Metal salts (silver chloride (AgCl), silver bromide (AgBr),
Silver carbonate (Ag_Two(CO_Three)), Silver nitrate (AgNO_Three),
Silver sulfate (Ag_TwoSO_Four) Etc. are exemplified. Zinc (specific gravity
Examples of metal salts containing (7.14) include (zinc chloride (ZnCl
_Two), Zinc sulfate (ZnSO_Four), Zinc bromide (ZnB)
r_Two), Zinc nitrate (Zn (NO_Three)_Two) Etc.)
You. Preferred metal salts are manganese, iron, nickel, copper,
It is a metal salt of silver and zinc. More preferred metal salts are Ni
It is a metal salt of kel, copper and iron. Particularly preferred metal salts are
It is a metal salt of copper. In addition, two or more of these compounds may be used together.
It is also possible to use it.

The amount of the metal salt used in the isomerization reaction needs to be such that the metal salt functions as a catalyst. However, the lower and upper limits of the amount used are different depending on the metal salt and cannot be specified uniformly. For example, in the case of copper chloride, the amount is usually 8 × 10 ^{−7 with} respect to the charged maleic acid.
２2 × 10 ^-1 mol%, preferably 8 × 10 ^-5 to 1 × 10
^-1 ppm.

(Isomerization Reaction) In the isomerization reaction in the method of the present invention, maleic acid is isomerized in the presence of an isomerization catalyst and a cocatalyst to obtain fumaric acid. This isomerization reaction may be performed as a batch reaction or a continuous reaction. In the case of a batch reaction, the order of addition and the method of addition of the raw material maleic acid, the isomerization catalyst and the cocatalyst are not particularly limited, but from the viewpoint of the yield, after mixing the water-soluble bromine donor compound and the cocatalyst with the raw material maleic acid. Or a method in which an oxidizing agent, a water-soluble bromine donating compound, and a cocatalyst are mixed at low temperature with maleic acid as a raw material, and the temperature is raised to carry out the reaction. In particular, since this reaction has a very large heat of reaction, it is important to carry out the reaction so that a rapid rise in temperature does not occur.

The isomerization catalyst and the cocatalyst may be added as a powder, but are preferably added as a slurry or an aqueous solution in terms of controlling the reaction temperature. For example, in the case of ammonium bromide, a concentration of 30% by weight or less dissolves in water at room temperature, so that it can be added as a uniform aqueous solution. The addition time is not particularly limited because it depends on the reaction scale or the heat removal capability of the reactor, but is not particularly limited, and when the reaction volume is 1 liter or more, for example, about 1 to 2 hours is required. It is preferable to add over. If the heat treatment is performed within the above-mentioned time, the amount of heat generated is large, so that it is generally difficult to remove heat when industrial scale-up is performed. In the case of a continuous reaction, the maleic acid, the isomerization catalyst and the co-catalyst may be continuously supplied while a fumaric acid crystal-containing slurry to be continuously produced may be continuously withdrawn. It is also possible to adopt an intermittent method.

The method of adding the catalyst can be divided and supplied in the case of a series multistage system, and the supply method is not particularly limited. This isomerization reaction occurs almost instantly by mixing maleic acid and the isomerization catalyst. However, when a continuous or intermittent method is used as the reaction type, the reaction is performed in terms of the conversion of maleic acid. It is preferable to carry out in a series multi-stage system of stages or more. The average residence time at that time is 5 minutes or more, preferably 20 to 300 minutes. If it is less than 5 minutes, the calorific value is large, so it is not preferable in terms of heat removal,
Further, if it exceeds 300 minutes, it is not preferable from an industrial point of view.

The reaction temperature is 40 to 100 ° C., preferably 45 to 90 ° C. When the temperature increases, the amount of malic acid generated increases, and the selectivity of the desired fumaric acid decreases, and when the temperature is low, the isomerization reaction is undesirably slow. The pressure is not particularly limited, but is reduced to normal pressure, for example, 0.2 to 1 k, from the viewpoint of heat removal.
g / cm ² is chosen. This isomerization reaction takes the form of a reaction crystallization in which fumaric acid crystals are precipitated due to the low solubility of fumaric acid as a reaction product. Therefore, this isomerization reaction is usually performed using a crystallization tank of a stirring tank type. As a result of the isomerization reaction, a slurry containing fumaric acid crystals is obtained.

The method for obtaining fumaric acid crystals from the slurry containing fumaric acid crystals from which the isomerization reaction is obtained is not particularly limited.
The solvent may be distilled off as it is, but usually, the slurry containing fumaric acid crystals is solid-liquid separated into fumaric acid crystals and a mother liquor.
Temperature conditions for solid-liquid separation of the fumaric acid crystal-containing slurry are not particularly limited, but a temperature range of 0 to 80 ° C,
Preferably, it is performed at 10 to 50 ° C. At low temperatures, the viscosity of the slurry becomes high and handling becomes difficult. At high temperatures, the solubility of fumaric acid increases and the recovery rate decreases. The solid-liquid separator may be, but is not limited to, a Nutsche, a centrifuge, or the like. The purity of the fumaric acid crystals obtained by performing this operation is generally 99% or more, depending on the water content of the fumaric acid obtained by the isomerization reaction.

If necessary, the fumaric acid crystals may be rinsed with water. The amount of water used for the rinsing operation is not particularly limited, but is not more than 5 times by weight, preferably 3% by weight based on the wet cake of fumaric acid crystals obtained by solid-liquid separation from the fumaric acid crystal-containing slurry. Perform at least twice. If the amount of water is too small, the rinsing effect is not sufficient, and if it is too large, the recovery of fumaric acid decreases. The temperature of water used for rinsing is not particularly limited. The crystals obtained by performing the rinsing operation can be recovered as fumaric acid having a purity of 99.8% or more.

(Additional step) The mother liquor obtained by solid-liquid separation contains fumaric acid, unreacted maleic acid, an isomerization catalyst and a cocatalyst in an amount corresponding to the solubility. If necessary, water is removed by a concentration step. By adding maleic acid as a raw material to the mother liquor or the concentrated mother liquor, the isomerization reaction can be performed again. In the second and subsequent isomerization reactions, it is preferable to further add an isomerization catalyst, and it is more preferable to further add a cocatalyst in order to improve the maleic acid conversion. The water-soluble bromine donating compound is 80% by weight or less, preferably 70% by weight or less based on the water-soluble bromine donating compound used in the first reaction, and the oxidizing agent is 30 to 30% by weight of the oxidizing agent used in the first reaction. 1000% by weight, preferably 5
The cocatalyst can be carried out by adding an amount corresponding to 80% by weight or less, preferably 70% by weight or less based on the cocatalyst used in the first reaction.

(Discharge of surplus treatment liquid) When the method for producing fumaric acid of the present invention includes a recycling step as an additional step, a mother liquor obtained by solid-liquid separation is required in consideration of accumulation of impurities and reaction by-products. May be discharged. Although the amount of the surplus treatment liquid depends on the raw material used, for example, when purified maleic anhydride is used, it is 0.1 to 40% by weight, preferably 1 to 30% by weight based on the total amount of the mother liquor. In the case of a crudely purified product such as the above-mentioned aqueous solution of maleic acid, the amount is 10 to 90% by weight, preferably 20 to 80% by weight, based on the total amount of the mother liquor. If the emission rate is low, stable continuous operation becomes difficult, and its effect is small and meaningless.
If the discharge rate is high, the load on the wastewater treatment is increased, resulting in poor economy. The method of discharging the surplus processing liquid may be continuous or intermittent as long as the discharge rate is satisfied.

[0022]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the scope of the invention. In addition, maleic acid (hereinafter abbreviated as MA) and fumaric acid (hereinafter abbreviated as FA) were analyzed by high performance chromatography. Maleic anhydride is abbreviated as MAH. Also,
The conversion of MA and the selectivity from MAH to FA are expressed in mol%.

Example 1 1000.0 g of a 40.0% by weight aqueous MA solution prepared by adding MAH to water and 160 mg of ammonium bromide (1.9.times.
10 ^-2 mol%) and 4 mg of copper (II) chloride (MA charged)
(3.5 × 10 ⁻⁴ mol%) was charged into a 2 L glass reactor and heated to 80 ° C. To this aqueous solution, 20 g of a 1% by weight aqueous solution of ammonium persulfate (0.05% by weight based on the charged MA) was added over 1 hour by a metering pump. During this time, the conversion of MA for 20 minutes, 40 minutes and 60 minutes was 40.0%, 70.0% and 74.0%, respectively. Further, the conversion of MA after holding at this temperature for 1 hour was 75.0%.

(Example 2) 4 mg of zinc chloride instead of copper chloride (3.4 × 10 ^-4 mol% based on the charged MA)
The reaction was carried out in the same manner as in Example 1, except that it was used. During this time, the conversions of MA for 20 minutes, 40 minutes and 60 minutes were 30.0%, 55.0% and 63.0%, respectively. After holding at this temperature for one hour, the conversion of MA was 65.0%.

Example 3 The same operation as in Example 1 was carried out except that 5 mg of iron (II) chloride (3.6 × 10 ⁻⁴ mol% based on the amount of the charged MA) was used instead of copper chloride. The reaction was performed. During this time, the conversion of MA for 20 minutes, 40 minutes, and 60 minutes was 35.0%, 55.0%, and 63.0%, respectively. After holding at this temperature for one hour, the conversion of MA was 65.0%.

Example 4 The same operation as in Example 1 was carried out except that 5 mg of copper (II) sulfate (3.6 × 10 ^-4 mol% based on the amount of MA charged) was used instead of copper chloride. The reaction was performed. During this time, the conversions of MA for 20 minutes, 40 minutes, and 60 minutes were 45.0%, 75.0%, and 78.0%, respectively. After holding at this temperature for one hour, the conversion of MA was 80.0%. Table 1 shows the results.

Comparative Example 1 A reaction was carried out in the same manner as in Example 1 except that no copper chloride was used. Analysis of the MA concentration for 20 minutes, 40 minutes, and 60 minutes during this period revealed that the conversion was 20.0%, 50.0%, and 58.
It was 0%. After further stirring at this temperature for 1 hour, the MA concentration was analyzed, and the conversion was 60.0%.

(Example-5) (Preparation of mother liquor) The amount of copper (II) chloride added was 12 mg (1 × 10 ^-3 mol% based on the amount of MA charged), the concentration of the ammonium persulfate aqueous solution was 5% by weight, Example 1 except that the addition amount was 16 g (0.2% by weight based on the amount of the charged MA).
Reaction was carried out in the same manner as described above. The conversion of MA is 99.0.
%Met. FA obtained by the reaction was collected using a centrifuge. The recovered amount of FA was 425.7 g (recovery rate of 97.8%), the water content of the obtained FA was 8% by weight, and the amount of mother liquor was 590.5 g. (Recycle) MAH 334.7g to the collected mother liquor,
75.4 g of pure water (1000.0% as a 40% MA aqueous solution)
g), 60 mg of ammonium bromide and 1 m of copper (II) chloride
g was charged into a 2 L stainless steel reactor and heated to 75 ° C. A 5% by weight aqueous solution of ammonium persulfate 1
6 g (0.2% by weight based on the charged MA) were added over 2 hours. After stirring at this temperature for 1 hour, the mixture was cooled to 30 ° C. The selectivity from the additionally added MAH to FA at this time was 97.3%. This recycling operation was repeated three times in total. The results are shown in Table 2.

(Comparative Example 2) (Preparation of mother liquor) Example 1 except that copper chloride was not used.
Reaction was carried out in the same manner as in Example 5. At this time, the conversion of MA was 99.0%. FA obtained by the reaction was collected using a centrifuge. 425.7 g of FA was collected.
(The recovery rate was 97.8%), the water content of the obtained FA was 8% by weight, and the mother liquor amount was 590.5 g. (Recycle) Example-Except that copper chloride was not used
The reaction was carried out using the mother liquor recovered in the same manner as in Example 5. At this time, the selectivity from additionally added MAH to FA was 95.8.
%Met. This recycling operation was repeated three times in total. The results are shown in Table 2.

[0030]

Table 1 Cocatalyst Reaction time (min) After holding for 1 hour 20 40 60 Example-1 Copper chloride 40.0 70.0 74.0 75.0 Example-2 Zinc chloride 30.0 55. 0 63.0 65.0 Example-3 Iron chloride 35.0 55.0 63.0 65.0 Example-4 Copper sulfate 45.0 75.0 78.0 80.0 Comparative example-1 None 20. 0 50.0 58.0 60.0 The numerical values indicate the conversion of MA.

[0031]

Table 2 Number of recycling times Example-5 Comparative example-2 (times) (%) (%) 197.3 95.8 2 97.4 93.8 3 97.3 91.8 The selectivity from additionally added MAH to FA is shown.

[0032]

According to the method of the present invention, in the production of fumaric acid by isomerization of maleic acid, the conversion and reaction rate of maleic acid are improved, and the conversion does not decrease even if the mother liquor is reused. Therefore, it is industrially advantageous.

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Claims (3)

[Claims] 1. A metal salt containing a heavy metal belonging as a promoter when isomerizing maleic acid to produce fumaric acid in the presence of a compound having a standard electrode potential of 1 V or more and a water-soluble bromine donor compound. A method for producing fumaric acid. 2. The method for producing fumaric acid according to claim 1, wherein the metal salt is a metal salt containing iron, copper, or zinc. 3. The method according to claim 1, wherein the metal salt is a metal salt containing copper.