JP2003104959A - Method for producing methionine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing methionine involving using a highly corrosion-resistant material for the production equipment. SOLUTION: This method for producing methionine or a salt thereof comprises the steps of producing 5-(2-methylmercaptoethyl)hydantoin by reaction between 3-methylmercaptopropionaldehyde, an aqueous solution containing hydrogen cyanide or a salt thereof, ammonia (or aldehydecyanhydrin) and carbon dioxide (or ammonium bicarbonate) optionally in the presence of water and then hydrolyzing the thus produced 5-(2-methylmercaptoethyl)hydantoin; wherein as the material of the equipment for producing the 5-(2-methylmercaptoethyl) hydantoin, a Ni-based alloy including 18-25 wt.% Cr and 11-24 wt.% Mo is used.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an aqueous solution containing 3-methylmercaptopropionaldehyde, hydrogen cyanide or a salt thereof, ammonia, and carbon dioxide, or
An aqueous solution containing 3-methylmercaptopropionaldehyde, hydrogen cyanide or a salt thereof, and ammonium hydrogen carbonate, or a component capable of producing the above-mentioned components is added to 5- (2-methylmercaptoethyl)-, optionally in the presence of water.
The present invention relates to a device material used in the process of producing hydantoin.

[0002]

2. Description of the Related Art 5- (2-Methylmercaptoethyl) -hydantoin (hereinafter sometimes abbreviated as MHD), which is a raw material of methionine, is usually an aqueous solution containing 3-methylmercaptopropionaldehyde, hydrogen cyanide or a salt thereof, ammonia. , And carbon dioxide, or an aqueous solution containing 3-methylmercaptopropionaldehyde, hydrogen cyanide or a salt thereof, and ammonium hydrogen carbonate, or a component capable of producing the above-mentioned components can be mixed and heated.

As the reaction conditions in this manufacturing process, a pressure of about 0 to 0.3 MPa and a temperature of about 70 to 110 ° C. are generally used. Further, from the viewpoint of resource reuse, the ammonia and carbon dioxide to be used, or ammonium hydrogen carbonate is recovered from ammonia and carbon dioxide generated in the next step of hydrolyzing MHD to obtain methionine or a methionine metal salt, It may be used and used.

[0004]

Under the above-mentioned reaction conditions, the corrosiveness of the metal material in the reaction tank, especially in the vapor phase part is high, and SUS is used.
Even if a 316L stainless steel reaction vessel is used,
There was a problem of severe corrosion. Further, the titanium material has a drawback that it exhibits a certain degree of corrosion resistance in the application of the use, but it is not perfect, is expensive, and is difficult to be used as an industrial device material. An object of the present invention is to find a device material having excellent corrosion resistance in the process of producing MHD which is a raw material of methionine.

The inventors of the present invention have conducted extensive studies to solve the above problems, and as a result, as a Ni-based alloy, when a predetermined amount of Cr element or Mo element was contained as an alloy element, excellent corrosion resistance was obtained. The inventors have found that the material can be the device shown, and have completed the present invention.

[Means for Solving the Problems]

That is, the present invention provides (1) an aqueous solution containing 3-methylmercaptopropionaldehyde, hydrogen cyanide or a salt thereof, ammonia, and carbon dioxide;
Aqueous solution containing methylmercaptopropionaldehyde, hydrogen cyanide or a salt thereof, and ammonium hydrogen carbonate; 3-methylmercaptopropionaldehyde cyanohydrin, ammonium hydrogencarbonate; 3-Methylmercaptopropionaldehyde cyanohydrin, ammonia, carbon dioxide; Alternatively, a step of producing 5- (2-methylmercaptoethyl) -hydantoin, optionally in the presence of water, from the ingredients capable of producing the above-mentioned ingredients, 5- (2-
Methyl (mercaptoethyl) -hydantoin, wherein the method for producing methionine or a salt of methionine comprises the step of hydrolyzing 5- (2-methylmercaptoethyl)-
% As a material for the equipment used to manufacture hydantoin
The present invention provides a method for producing methionine, characterized by using a Ni-based alloy containing Cr: 18 to 25% and Mo: 11 to 24%.

(2) The Ni-based alloy, in wt%,
Fe: 0.01 to 6% is contained in the Ni-based alloy, the production method according to (1), (3) the Ni-based alloy is wt%, Ta: 1.1 ~. The manufacturing method according to (1) or (2), which is a Ni-based alloy containing 3.4%, and (4) the Ni-based alloy is wt%.
And further W: 0.1-4.0%, Nb: 0.1-1
%, Cu: a Ni-based alloy containing at least one of 0.1 to 4%, (5) the production method according to (2), wherein the Ni-based alloy has a weight. %
In addition, Ti: 0.05 to 0.8%, Al: 0.0
1 to 0.8%, Co: 0.1 to 5%, V: 0.1 to 0.
The manufacturing method according to any one of (1) to (3), which is a Ni-based alloy containing at least one of 5%.

Further, in the step of hydrolyzing (6) 5- (2-methylmercaptoethyl) -hydantoin (MHD), carbon dioxide and ammonia produced are recovered and reused in the step of producing MHD. The production method according to any one of (1) to (5), wherein (7) the methionine salt is a potassium salt or a sodium salt of methionine.
The manufacturing method according to any one of (6).

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION In the method for producing methionine of the present invention, the step of producing MHD is performed by an aqueous solution containing 3-methylmercaptopropionaldehyde, hydrogen cyanide or a salt thereof, ammonia and carbon dioxide, or 3-
Methyl mercaptopropionaldehyde, an aqueous solution containing hydrogen cyanide or a salt thereof, and ammonium hydrogen carbonate, or 3-methylmercaptopropionaldehyde cyanohydrin, ammonium hydrogencarbonate, or 3-methylmercaptopropionaldehyde cyanohydrin,
A step of mixing and heating ammonia, carbon dioxide, or a component capable of producing the above components, optionally in the presence of water. The method of mixing each component is not particularly limited, but for example, a method of mixing and heating 3-methylmercaptopropionaldehyde with an aqueous solution of hydrogen cyanide or ammonium hydrogen carbonate, a solution of 3-methylmercaptopropionaldehyde and hydrogen cyanide, and ammonia and dioxide. A method of preparing an aqueous solution with carbon and mixing and heating these solutions can be exemplified.

Ammonia and carbon dioxide are preferably recovered and reused from the hydrolysis process of MHD. The ratio of each component used is such that hydrogen cyanide is 1.00 to 1 mol of 3-methylmercaptopropionaldehyde.
1.10 moles, ammonia and carbon dioxide are 1.5-
It is preferable to use 2.5 mol.

When an aqueous solution of ammonia and carbon dioxide is used, the aqueous solution may be a saturated or dilute solution, and the content of ammonia is preferably about 5% by weight or more.

The reaction is preferably carried out in the range of 60 to 140 ° C, more preferably 70 to 110 ° C. The conversion can be carried out at any pressure, but it is preferably carried out under pressure, for example in the range of 0.1 to 0.5 MPa.

The reaction can be carried out in a continuous system or a semi-batch or batch system. When the reaction is carried out continuously, a plurality of reaction tanks are provided depending on the residence time of the reaction.
A method of charging the initial raw material in the tank and moving it between the reaction tanks to complete the reaction can be exemplified.

The MHD thus obtained is in the presence of alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, alkali metal carbonates such as sodium carbonate and potassium carbonate, sodium hydrogen carbonate and potassium hydrogen carbonate. It can be hydrolyzed below to the alkali metal salt of methionine. Hydrolysis is usually 0.3-1.0MP
a, the temperature is about 130 to 200 ° C. Ammonia and carbon dioxide gas generated during hydrolysis are recovered, and M
Recovered in HD manufacturing process.

Then, a mineral acid such as sulfuric acid, hydrochloric acid or carbon dioxide is introduced into the hydrolyzed solution for neutralization to crystallize methionine. The precipitated methionine is filtered, separated, washed with water if necessary, and dried to obtain the product methionine.

The present invention relates to an aqueous solution containing 3-methylmercaptopropionaldehyde, hydrogen cyanide or a salt thereof, ammonia, and carbon dioxide, or an aqueous solution containing 3-methylmercaptopropionaldehyde, hydrogen cyanide or a salt thereof, and ammonium hydrogen carbonate. Alternatively, a component capable of producing the above-mentioned components is used as a device material used in the step of producing MHD, optionally in the presence of water, in weight% Cr: 18 to 25%, Mo: 11 to 11.
A Ni-based alloy containing 24% is used, wherein the Ni alloy constitutes all or part of a reactor in the MHD manufacturing process, or all or part of the reactor is lined. -Including lining such as clad coating, and further including the construction of pumps, valves, piping, etc. attached to it.

Ni-based alloys are known to have excellent corrosion resistance, but an alloy composition in which Cr and Mo in the above range are mixed exhibits particularly high corrosion resistance in the MHD manufacturing process, and has strength and cost. Has also obtained satisfactory results.

The Cr element in the Ni-based alloy has a function of forming a solid solution in the base material to improve the corrosion resistance, but if the content is less than 18% by weight, the desired effect cannot be obtained, while 25% by weight is not obtained. If the content exceeds the above range, the corrosion resistance decreases, so the range of the content is preferably 18 to 25% by weight.

Mo element has an effect of improving corrosion resistance and strength at the same time, but if its content is less than 11% by weight, the desired effect cannot be obtained, while if it exceeds 24% by weight, TCP phase (σ phase, P phase, Lavas
Phase, μ phase and other harmful intermetallic compounds), which is not preferable because the corrosion resistance is significantly reduced. Therefore, the content of Mo is set in the range of 11 to 24% by weight.

The element Fe has the effect of forming a solid solution in the matrix to improve the hot workability, but if the content of Fe is less than 0.01% by weight, the desired effect cannot be obtained, while 6% by weight is obtained. If it is contained in excess of%, the corrosion resistance is lowered, so the content was set to 0.01 to 6%.

The Ta element has the effect of forming a solid solution in the matrix to stabilize the passivation film and, at the same time, to promote the passivation. In other words, passive film of Ni-Cr-Mo-based alloy is formed consists NiO ₂ -Cr ₂ O _3, it is known the contribution of dense Cr ₂ O ₃ is larger as a protective coating,
When Ta is added, it has a function of forming Ta ₂ O ₅ which is stronger than Cr ₂ O ₃ in the passivation film to further stabilize the passivation film and further improve the corrosion resistance. However, if its content is less than 1.1% by weight, the desired effect cannot be obtained, while if it exceeds 3.4% by weight, the TCP phase precipitates beyond the allowable range of the amount of precipitation and corrosion resistance. Therefore, the content is preferably in the range of 1.1 to 3.4% by weight, and more preferably in the range of 1.2 to 3.3% by weight.

The element W is a very effective component element that has the effects of solid solution strengthening and improving the strength, and suppressing the embrittlement due to the precipitation of the sigma phase while improving the corrosion resistance.
W element is about 4.0% by weight or less, usually about 0.10 to
Used in the range of 3.50% by weight.

Further, the stainless steel applied in the present invention contains Nb element and / or Cu element in addition to Cr, Ni and Mo in the above range and Ta element and W element which are added as required. May be. In this case, the Nb element content is about 2.0% by weight or less, usually about 0.10 to 1.0.
%, Cu element is used in an amount of about 5.0% by weight or less, usually about 0.1 to 4.0% by weight. The Nb element improves grain boundary corrosion resistance by fixing C and also improves high temperature strength. C is an element that reduces corrosion resistance,
Nb has the effect of forming a carbide and preventing the Cr-deficient layer due to sensitization. On the other hand, Cu element is an effective component element that improves general corrosion resistance.

Ti, Al, Co, V These components have the effect of improving the strength, so they are added when further strength is required, but their content is Ti: less than 0.05% by weight, Al: If the amount is less than 0.01% by weight, Co: less than 0.1% by weight, and V: less than 0.1% by weight, the desired effect cannot be obtained.
On the other hand, Ti: more than 0.8% by weight, Al: 0.8% by weight
%, Co: more than 5% by weight, and V: more than 0.5% by weight, the ductility decreases, which is not preferable. Therefore, Ti: 0.05 to 0.8% by weight, Al: 0.01 to
0.8% by weight, Co: 0.1 to 5% by weight, V: 0.1
It was set to 0.5% by weight.

The presence of other elements not specified in the present invention is not limited as long as it does not significantly impair the corrosion resistance of the device material used in the MHD manufacturing process. For example, as other components, in% by weight, Mn:
0.0001-3%, Si: 0.0001-0.3%,
C: 0.001-0.1%, P: 0.001-0.3%
The Ni-based alloy containing can be illustrated.

The Ni-base alloy applicable in the present invention is not particularly limited as long as it has the above-mentioned chemical components, but as a commercially available nickel-base alloy, HC22
(Registered trademark), MAT21 (registered trademark) and the like are compatible with the above components, and their use is economical.

Hereinafter, the method of the present invention will be described in more detail with reference to examples, but the examples are merely one aspect, and the method of the present invention is not limited thereto. The chemical composition of stainless steel in the examples is a value measured by a fluorescent X-ray analyzer.

Example 1 3-Methylmercaptopropionaldehyde, hydrogen cyanide, carbon dioxide gas recovered from the MHD hydrolysis step, and a 16 wt% ammonium bicarbonate aqueous solution adjusted from ammonia in a molar ratio of 1: 1.05: Charged at a ratio of 2.0, temperature range of 80 to 105 ° C, 0.1 to 0.3MP
Under the pressure of a, the residence time in the reaction tank was set to 2 hours to carry out a continuous reaction. The metal test pieces shown in Table 1 were set in the solution part and the gas phase part of the reaction tank, and after 40 days, the test pieces were taken out, washed with water, and further washed with alkali,
Rust and other deposits are brushed off and weighed.
The erosion degree was calculated by the following formula.

Degree of erosion (mm / year) = {(W1-W2) /
(D × S)} / number of test days × 365 W1: weight before test (g) W2: weight after test (g) S: surface area before test (mm ² ) d: density before test (g / mm ³ )

The test results are summarized in Table 1, and the material component ratios (% by weight) of the test pieces used are summarized in Table 2.

[0031]

[Table 1]

[0032]

[Table 2]

[0033]

As described above, as described above, an aqueous solution containing 3-methylmercaptopropionaldehyde, hydrogen cyanide or a salt thereof, ammonia, and carbon dioxide, or an aqueous solution containing 3-methylmercaptopropionaldehyde, hydrogen cyanide or a salt thereof, Ni-based alloy is used as a device material which can be used for a reaction device having particularly corrosive properties in the step of producing MHD, optionally in the presence of water, with ammonium hydrogen carbonate or a component capable of producing the above components. It has been found that it has excellent corrosion resistance in both the liquid phase and the gas phase of the reaction, and by using it as a device material, the methionine production process can be stably operated for a long period of time. Therefore, it can be said that its industrial utility value is great.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Takeomi Koga             950 Fujisawa, Nakago Village, Nakakubiki District, Niigata Prefecture             Tatsu Co., Ltd. Nihongi Factory Production Technology Laboratory F-term (reference) 4H006 AA02 AC46 AC52 BB31 BD60                       BE06 BE14 BE41 TA04 TB52

Claims (7)

[Claims] 1. An aqueous solution containing 3-methylmercaptopropionaldehyde, hydrogen cyanide or a salt thereof, ammonia, and carbon dioxide; an aqueous solution containing 3-methylmercaptopropionaldehyde, hydrogen cyanide or a salt thereof, and ammonium hydrogen carbonate; Methyl mercaptopropionaldehyde cyanohydrin, ammonium hydrogen carbonate; 3-methylmercaptopropionaldehyde cyanohydrin, ammonia, carbon dioxide; or a component capable of producing the above-mentioned components, optionally in the presence of water, to 5- (2 -Methylmercaptoethyl) -hydantoin, a method for producing methionine or a salt of methionine, which comprises the step of hydrolyzing 5- (2-methylmercaptoethyl) -hydantoin.
As a device material for the step of producing (2-methylmercaptoethyl) -hydantoin, Cr: 18 to 2 by weight%
A method for producing methionine, which comprises using a Ni-based alloy containing 5% and Mo: 11 to 24%. 2. A Ni-based alloy, in% by weight, further comprising Fe:
The manufacturing method according to claim 1, wherein the Ni-based alloy contains 0.01 to 6%. 3. A Ni-based alloy, in% by weight, further comprising Ta:
The manufacturing method according to claim 1 or 2, wherein the Ni-based alloy contains 1.1 to 3.4%. 4. A Ni-based alloy, in% by weight, further containing W: 0.
1-4.0%, Nb: 0.1-1%, Cu: 0.1-4
%, Which is a Ni-based alloy containing at least one of the alloys, and the manufacturing method according to claim 1 or 2. 5. A Ni-based alloy, in% by weight, further comprising Ti:
0.05-0.8%, Al: 0.01-0.8%, C
The manufacturing method according to claim 1, wherein the Ni-based alloy contains at least one of o: 0.1 to 5% and V: 0.1 to 0.5%. 6. Carbon dioxide and ammonia produced in the step of hydrolyzing 5- (2-methylmercaptoethyl) -hydantoin are recovered and regenerated in the step of producing 5- (2-methylmercaptoethyl) -hydantoin. It utilizes, The manufacturing method in any one of Claims 1-5 characterized by the above-mentioned. 7. The methionine salt is a potassium salt or sodium salt of methionine.
7. The manufacturing method according to any one of to 6.