Title of the invention: Method for producing an amide compound
Technical field
[0001]
　The present disclosure relates to a method for producing an amide compound.
Background technology
[0002]
　As one of the main methods for producing an amide compound, a hydration method using a nitrile compound as a raw material is often used. In particular, acrylamide has long been known to be produced from acrylonitrile as a raw material using a metallic copper catalyst such as Raney copper, or in recent years, a hydration catalyst such as a microbial cell containing nitrile hydratase and a treated product thereof. ing. In particular, the production method using nitrile hydratase has advantages such as mild reaction conditions, high-purity products, and simplification of the production process.
[0003]
　The bacterial cell catalyst has low heat resistance, and if the reaction heat is not removed, the catalytic activity will decrease (deactivate). Therefore, in industrial use, productivity is satisfied while suppressing deactivation. This is very important. Therefore, as a method for efficiently utilizing the bacterial cell catalyst, International Publication No. 2003/000914 discloses a method for continuously producing an amide compound in which the temperature of the reaction vessel on the downstream side is raised. Further, Japanese Patent Application Laid-Open Nos. 2001-3400091 and Japanese Patent Application Laid-Open No. 2013-162746 disclose a method of using a reactor having a plug-flow property region. Examples of the reactor having a plug-flow property include a double-tube type, a shell-and-tube type, and a tube-type reactor such as one provided with a perforated plate or a filler for the purpose of providing plug-flow property. There is.
[0004]
　In a general reaction, a tubular reactor is advantageous because the reaction volume can be reduced as compared with a tank reactor. However, the reaction time required for a normal liquid phase reaction is long, and the tube may become too long when a tubular reactor is applied. In addition, the tank reactor is easier to keep the temperature uniform. Therefore, tank reactors are often used. Therefore, by taking advantage of each of the tank-type reactor and the tube-type reactor, most of the reaction is advanced by the tank-type reactor, and the final stage of the reaction is driven by the tube-type reactor to increase the number of reactors. It can be suppressed and the optimum reaction system can be constructed.
Outline of the invention
Problems to be solved by the invention
[0005]
　However, in the method for producing an amide compound, the method disclosed in JP-A-2001-3400091, which utilizes a combination of a tank reactor and a tubular reactor having a plug-flowable region, improves the reaction conversion rate. In terms of aspects, it is still not enough and there is room for improvement. In addition, there are few findings that can be used as a guideline in the design of tubular reactors in liquid phase reactions.
[0006]
　Therefore, it is an object of the present disclosure to provide a method for producing a nitrile compound having an excellent conversion rate by using a reactor having a plug-flowable basin.
Means to solve problems
[0007]
　The present inventors have conducted diligent research to solve the above problems. As a result, in the method of continuously producing a high-concentration amide compound aqueous solution by hydrating a nitrile compound at a high conversion rate, by paying attention to the Reynolds number in a tubular reactor and conducting a diligent study, a certain range It was found that the reaction conversion rate can be improved in a tubular reactor showing the Reynolds number.
[0008]
　That is, one embodiment of the present invention is as follows.
[0009]
　　<1> In the step of contacting a microbial cell containing nitrile hydratase or a treated product thereof with a nitrile compound in an aqueous medium in a first reactor to obtain a reaction solution containing an amide compound, and in the
　above step. It comprises a step of reacting the obtained reaction solution containing the amide compound in a second reactor having a plug-flow property region, and the
　Reynolds number in the second reactor is 5 or more and 1000 or less. A method for producing an amide compound, which is controlled in such a manner.
　　<2> The method for producing an amide compound according to <1>, wherein the Reynolds number in the second reactor is 10 or more.
　　<3> The method for producing an amide compound according to <1> or <2>, wherein the Reynolds number in the second reactor is 100 or less.
　　<4> Production of the amide compound according to any one of <1> to <3>, wherein the second reactor is a tubular reactor and the tube diameter of the tubular reactor is 10 cm or more. Method.
Effect of the invention
[0010]
　According to one embodiment of the present invention, it is possible to provide a method for producing a nitrile compound having an excellent conversion rate by using a reactor having a plug-flowable watershed.
Mode for carrying out the invention
[0011]
　Hereinafter, an embodiment of the present invention will be described, but the present invention is not limited to this, and may be appropriately modified.
[0012]
　 In the
　present disclosure, a microbial cell containing nitrile hydratase or a treated product thereof is brought into contact with the nitrile compound in an aqueous medium in a first reactor to bring the reaction solution containing the amide compound. The step of reacting the reaction solution containing the amide compound obtained in the step in a second reactor having a plug-flow property region, and the number of Reynolds in the second reactor. This is a method for producing an amide compound, in which (hereinafter, sometimes referred to as “Re number”) is controlled to be 5 or more and 1000 or less.
[0013]
　(Nitrile Hydratase) In the
　method for producing an amide compound of the present disclosure, a microbial cell containing nitrile hydratase or a processed product thereof is used. The nitrile hydratase referred to in the present disclosure refers to an enzyme having the ability to hydrate a nitrile compound and produce a corresponding amide compound. Here, as the microorganism containing the nitrile hydrase, the nitrile hydrase having the ability to hydrate the nitrile compound to produce the corresponding amide compound is produced, and the nitrile hydrase is produced in a 30% by mass acrylamide aqueous solution. The microorganism is not particularly limited as long as it retains its activity. Specifically, the genera Nocardia, Corynebacterium, Bacillus, thermophilic Bacillus, Pseudomonas, Micrococcus, rhodochrous. Rhodococcus, Acinetobacter, Xanthobacter, Streptomyces, Rhizobium, Klebsiella, Enterobacter, as represented by , Erwinia, Aeromonas, Citrobacter, Achromobacter, Agrobacterium or thermophila species represented by Pseudonocardia ( A suitable example may be a microorganism belonging to the genus Pseudonocardia).
[0014]
　In addition, a transformant expressing a nitrile hydratase gene cloned from the microorganism in an arbitrary host is also included in the microorganism referred to in the present disclosure. The arbitrary host referred to here is Escherichia coli as a typical example as in the examples described later, but the present invention is not particularly limited to Escherichia coli, and Bacillus subtilis such as Bacillus subtilis is not particularly limited. Other microbial strains such as genus, yeast and Escherichia coli are also included. As an example of such a thing, MT-10822 (this strain is on February 7, 1996, 1-1-3 East, Tsukuba City, Ibaraki Prefecture, Institute of Biotechnology and Industrial Technology, Ministry of International Trade and Industry, Institute of Biotechnology and Industrial Technology (currently Kisarazu, Chiba Prefecture) 2-5-8 Kazusakamatari, Ibaraki Incorporated Administrative Agency, Biotechnology Center, Patent Organism Depositary Center) with accession number FERMBP-5785, based on the Budapest Treaty on International Approval of Deposit of Microorganisms in Patent Procedures It has been deposited.) In addition, acrylamide resistance, acrylonitrile resistance, and temperature resistance are further improved by substituting, deleting, deleting, or inserting one or more of the constituent amino acids of the enzyme with other amino acids using recombinant DNA technology. Transformants expressing the mutant nitrile hydratase are also included in the microorganisms referred to in the present disclosure.
[0015]
　When producing an amide compound using a microorganism as described above, a cell or a processed product of the microorganism is usually used. The cells may be prepared by using general methods known in the fields of molecular biology, biotechnology, and genetic engineering. For example, after inoculating the microorganism in a normal liquid medium such as LB medium or M9 medium, an appropriate culture temperature (generally 20 ° C to 50 ° C, but in the case of thermophiles 50 ° C or higher) A method of growing the microorganism in (good) and then separating and recovering the microorganism from the culture medium by centrifugation can be mentioned.
[0016]
　Further, the microbial cell-treated product in the present disclosure is an extract or pyroclastic material of the above-mentioned microbial cell, a post-isolated product obtained by separating and purifying the nitrile hydratase active fraction of the extract or pyroclastic material, and the microbial cell. It refers to a bacterial cell, an extract of the bacterial cell, a pyroclastic material, a immobilized product obtained by immobilizing a post-separated material using an appropriate carrier, and the like. These correspond to the cell-treated products of the present disclosure as long as they have the activity of nitrile hydratase. These may use a single type, or two or more different forms may be used simultaneously or alternately.
[0017]
　(Nitrile Compound) In the
　present disclosure, a nitrile compound is one that is brought into contact with a microbial cell containing nitrile hydratase or a treated product thereof in an aqueous medium. The nitrile compound is supplied into the aqueous medium of the first reactor, for example, by providing a supply line for the nitrile compound. In the present disclosure, the type of the nitrile compound is not particularly limited, and specifically, it is a nitrile compound having about 2 to 20 carbon atoms, and a wide range of nitriles such as aliphatic nitriles and aromatic nitriles are used. included. The aliphatic nitrile includes saturated or unsaturated nitriles having 2 to 6 carbon atoms, for example, aliphatic saturated mononitriles such as acetonitrile, propionitrile, butyronitrile, isobutyronitrile, valeronitrile, isovaleronitrile, and capronitrile; Alibo-saturated dinitriles such as malononitrile, succinonitrile and adipoinitrile; aliphatic unsaturated nitriles such as acrylonitrile, methacrylonitrile and crotonnitrile can be mentioned. Aromatic nitriles include benzonitrile, o-, m-, and p-chlorobenzonitrile, o-, m-, and p-fluorobenzonitrile, o-, m-, and p-nitrobenzonitrile, o-. , M-, and p-tolunitrile, benzyl cyanide and the like. Among them, acrylonitrile, methacrylonitrile, crotonnitrile and the like are preferable examples.
[0018]
　(Aqueous medium) In the
　present disclosure, a reaction for obtaining an amide compound is carried out in an aqueous medium containing a nitrile compound. Further, the aqueous medium in the present disclosure is prepared by dissolving, for example, water, a buffer such as a phosphate, an inorganic salt such as a sulfate or a carbonate, an alkali metal hydroxide, an amide compound, or the like at an appropriate concentration. Examples include aqueous solutions. The water is not particularly limited, and purified water such as distilled water and ion-exchanged water can be used. Water is supplied to the first reactor from the raw water supply pipe. Further, when a component other than water is added, a separate supply line may be provided.
[0019]
　(Step in the First Reactor) The
　present disclosure is a step of contacting a microbial cell containing nitrile hydratase or a processed product thereof with a nitrile compound in an aqueous medium in the first reactor (hereinafter, "step" It may be referred to as a "first reaction step"). In the first reaction step, a reaction solution containing an amide compound is obtained. In the present disclosure, two or more reactors are used as the reaction form when an amide compound is obtained from a nitrile compound by using a microbial cell containing nitrile hydratase or a processed product of the microbial cell. In the first reaction step, the first reactor is supplied with microbial cells or treated cells, a nitrile compound and an aqueous medium. The reaction form at this time is not particularly limited, and may be, for example, a suspension bed or a fixed bed, but usually, a stirrer is used because of the ease of removing the heat of reaction. A suspension bed in a tank reactor equipped with is more preferably used. In this case, the microbial cells containing nitrile hydratase or the processed product thereof may be supplied from the cell catalyst tank.
[0020]
　In the present disclosure, the concentration of the nitrile compound supplied to the first reactor is preferably a concentration equal to or higher than the saturation concentration of the nitrile compound at the start of the reaction. The upper limit of its concentration is not particularly limited, but the supply of too large an excess of nitrile compound is excessive for a reactor having a large amount of catalyst and an excessive volume to complete the reaction, and for heat removal. A heat exchanger, etc. is required, which increases the financial burden on the equipment. Therefore, the supply concentration of the nitrile compound is more specific so that the theoretical product concentration of the nitrile compound when it is converted into the corresponding amide compound is in the range of 40 to 80% by mass in the case of acrylamide. It is preferable to supply 0.4 to 1.5 parts by weight of acrylonitrile with respect to 1 part by weight of water.
[0021]
　(Step in the Second Reactor) The
　present disclosure is a step of reacting a reaction solution containing an amide compound obtained in the first reaction step in a second reactor having a plug-flowable region (hereinafter, "step". It may be referred to as a "second reaction step"). The second reactor in the present disclosure is a reactor having a plug-flowable region, and is a reactor generally also referred to as a tubular reactor or a tubular reactor. The second reactor is a double-tube type reactor in which the reaction liquid is moved by the piston flow in a pipe-shaped pipe to allow the reaction to proceed, and in order to remove the heat of reaction. A shell & tube type or the like can be used. The liquid feed method to the second reactor, such as upflow or downflow, does not matter.
　Further, in order to make the flow state of the reaction solution in the reactor uniform, even if the reactor is provided with a perforated plate or a filler, the plug flow property of the reaction solution depends on the conditions such as the flow velocity. Once formed, it can be used as a reactor with a plug-flowable basin.
[0022]
　In the method for producing an amide compound of the present disclosure, the Re number in the second reactor is controlled to be 5 or more and 1000 or less. Here, the Re number is the Reynolds number of the reaction fluid, means the ratio of the inertial force and the viscous force, and is a dimensionless number that is an index of fluidity, and is expressed by the following formula.
　In the Re = ρud / μ
　formula, ρ represents the fluid density [kg / m 3 ], u represents the average flow velocity in the pipe [m / s], d represents the pipe diameter [m], and μ represents the fluid viscosity [Pa · s]. ..
　Although the density and viscosity of the fluid are affected by the temperature, they are values ​​peculiar to the fluid. Therefore, the Re number is adjusted by the average flow velocity u and the pipe diameter d, that is, the flow rate and the reactor size.
　The density can be measured by a floating method, a pycnometer method, a vibration hydrometer method, or the like. For the viscosity measurement, a method such as a thin tube viscometer method, a falling ball viscometer method, or a rotary viscometer method can be used.
　In the present disclosure, the Re number is calculated from the average flow velocity in the tube, the tube diameter, and the density and viscosity of the reaction solution containing the amide compound before being charged into the second reactor. The density and viscosity of the reaction solution containing the amide compound refer to the values ​​obtained at the temperature inside the second reactor.
[0023]
　Further, in a reactor having a plug-flow property basin, there is a Peclet number (Pe number) which is a dimensionless number which is an index of extrusion flow property. The Pe number means the ratio of the convection speed and the diffusion speed, and is a dimensionless number that is an index of the extrusion flowability. In the case of an empty pipe, it is expressed by the following formula.
　D in the Pe = ud / D
　equation is the diffusion coefficient [m 2 / s], which is obtained by dividing the thermal conductivity λ [W / m / K] by the specific heat Cp [J / kg / K] and the density ρ. Be done. Further, u represents the average flow velocity [m / s] in the pipe, and d represents the pipe diameter [m].
　Although D is a value peculiar to the fluid, its measurement is not easy compared to the density and viscosity of the fluid used for calculating the Re number. The larger the value of Pe, the better the extrusion flowability. However, like the Re number, the Pe number is adjusted by the average flow velocity u and the pipe diameter d, and the increase / decrease of the value shows the same tendency as the Re number. That is, when the average flow velocity u and the pipe diameter d of the fluid are adjusted so that the Re number becomes a larger value, the Pe number tends to show a larger value. Further, when the average flow velocity u and the pipe diameter d of the fluid are adjusted so that the Re number becomes a smaller value, the Pe number tends to show a smaller value. Therefore, in the method for producing an amide compound of the present disclosure, an appropriate range is defined by a Re number that is more easily measurable and practical than the Pe number.
[0024]
　The more the fluid flow deviates from the plug-flow region, the lower the reaction rate per unit volume. In order to ensure the plug flow property, it is required to be a laminar flow and to have a range in which the influence of mixed diffusion in the axial direction, that is, the flow direction can be ignored. For this purpose, the Re number needs to be 5 or more, preferably 10 or more, and more preferably 11 or more from the viewpoint of achieving a higher conversion rate.
　The Re number should be 1000 or less in order to prevent the fluid flow from approaching turbulence and to prevent the burden on the equipment from becoming excessive due to the length of the tubular reactor becoming too long. Is necessary, it is preferably 500 or less, more preferably 300 or less, and further preferably 100 or less from the viewpoint of achieving a higher conversion rate.
[0025]
　The control of the Re number is achieved by adjusting the reaction tube diameter and the tube length if the flow rate (supply amount) of the reaction solution, that is, the production amount of the amide compound is fixed. As the flow rate increases, the reaction volume required to complete the reaction increases, but by increasing the number of reaction tubes as a shell and tube type, the length of the reaction tubes can be adjusted so as not to become excessive. The smaller the diameter (inner diameter) of the reaction tube, the better the temperature controllability, but the number of reaction tubes required may increase and the reactor may become large. In addition, it may clog in a highly viscous fluid. Therefore, the diameter of the reaction tube is preferably 5 cm or more from the viewpoint of operational stability and maintainability, more preferably 10 cm or more, and further preferably 12 cm or more from the viewpoint of making the reactor smaller. .. Further, the upper limit of the tube diameter of the reaction tube is not particularly limited as long as the Re number is set to be 5 or more and 1000 or less in relation to the fluid density ρ and the average flow velocity u in the tube. Further, in the case of a reactor provided with a perforated plate or a filler to have plug flow property, the diameter of the reaction tube tends to be larger than that of a reactor not provided with these members. The diameter of the reaction tube may be, for example, 300 cm or less in the case of a reactor including a perforated plate or a filler. On the other hand, the diameter of the reaction tube may be, for example, 30 cm or less in the case of a reactor not provided with these members.
[0026]
　In the present disclosure, the first reactor and a reactor other than the second reactor may be connected. For example, a reactor having the same configuration as the first reactor may be connected to the first reactor, or a reactor having the same configuration as the second reactor may be connected to the second reactor. Good. Further, the first reactor and the second reactor are connected via a connecting tube, but in this case, there is another reactor between the first reactor and the second reactor. May be good.
[0027]
　The amount of the catalyst used in the first reactor and the second reactor may be changed depending on the reaction conditions, the type of catalyst, and the form thereof. For example, in terms of the weight of the dried microorganism cells, the reaction solution may be used. On the other hand, it may be 10 to 50,000 mass ppm, preferably 50,000 to 30,000 mass ppm.
[0028]
　The amidation reaction is usually carried out at normal pressure or near normal pressure, but it can also be carried out under pressure in order to increase the solubility of the nitrile compound in the aqueous medium. The reaction temperature is not particularly limited as long as it is above the freezing point of the aqueous medium, but it is usually preferably carried out in the range of 0 to 50 ° C, more preferably in the range of 10 to 40 ° C. The reaction can also be carried out in a slurry state in which the product is crystallized in the reaction solution. The pH of the reaction solution during the amidation reaction is not particularly limited as long as the nitrile hydratase activity is maintained, but is preferably in the range of pH 6 to 10, and more preferably pH 7 to 9. Is the range of.
[0029]
　In the present disclosure, a step other than the steps described above may or may not be included. Examples of steps other than the steps described above include a step of purifying an amide compound produced by using a cell catalyst containing nitrile hydratase by contacting it with activated carbon.
[0030]
　Generally, activated carbon uses coal, wood, coconut shells, etc. as raw materials, but there is no particular limitation as long as it has adsorptive ability, and any of them should be used. Is possible. However, when the amide compound to be treated has a particularly unsaturated bond, the activated carbon having a low metal content is selected in consideration of the storage stability and the ease of polymerization of the amide compound. It is preferable to use it, and it is more preferable to use a wood-based material or a coconut shell.
[0031]
　If the amount of activated carbon used in the purification treatment of the amide compound is too small, it is difficult to obtain a sufficient purification effect, and if it is used too much, it is uneconomical. Therefore, the amount of amide used is amide. It is usually in the range of 0.01 to 20% by mass, more preferably in the range of 0.05 to 10% by mass, based on the compound-containing liquid. When a powdered activated carbon is used as the activated carbon, the activated carbon may be added directly to the amide compound-containing liquid as it is, or the activated carbon is once dispersed in a medium such as water to form a slurry. It may be added or supplied to the amide compound-containing liquid.
[0032]
　Next, in the present disclosure, the activated carbon may be separated from the contact-treated amide compound-containing liquid to obtain a purified liquid of the amide compound-containing liquid. The method for separating the activated carbon is not particularly limited as long as it uses a commonly used solid-liquid separator, and examples thereof include a pressure filter, a vacuum filter, and a centrifuge, and further, batch type and continuous. It can be any of the expressions. Further, in the present disclosure, a further purified amide compound can be obtained by adopting a method of cooling the amide compound-containing liquid after separating the activated carbon and crystallizing the target amide compound from the liquid. Is also possible.
[0033]
　In the present disclosure, a pH adjuster may be used to adjust the pH of the amide compound-containing solution to a suitable range for maintaining good purification efficiency in the purification process.
[0034]
　When the pH suitable for the purification treatment is less than 7, an acid can be used as the pH adjuster.
[0035]
　As the acid used as the pH adjuster, either an inorganic acid or an organic acid can be used. Examples of the inorganic acid include hydrohalogenic acids such as hydrogen chloride, hydrogen bromide and hydrogen iodide, hypochlorous acid, chloronic acid, chloric acid, perchloric acid, hypobromic acid, bromine acid and bromine. Examples thereof include oxo acids halides such as acids, perbromic acids, hypochlorous acids, iodic acids, iodic acids and perioic acids, sulfuric acid, nitric acid, phosphoric acid and boric acid. Examples of organic acids include carboxylic acids such as formic acid, acetic acid, propionic acid, acrylic acid, methacrylic acid, crotonic acid, oxalic acid, malonic acid, fumaric acid, maleic acid, citric acid, lactic acid, and benzoic acid, and methanesulfonic acid. Examples thereof include sulfonic acids such as ethanesulfonic acid, benzenesulfonic acid and p-toluenesulfonic acid. The acid used as the pH adjuster can be used in any of gas, solid and liquid states, but considering the ease of supply to the purification treatment tank, it is preferable to use an acid in a liquid state, and it is preferable to use a gas or solid state. It is more preferable to use the acid in the above state as an aqueous solution. Considering the controllability of pH adjustment in the purification treatment tank, it is more preferable to use the acid in a liquid state as an aqueous solution. The concentration of the acid when used as an aqueous solution is not particularly limited, but since it becomes difficult to adjust the pH when a high-concentration aqueous solution is used, it is preferably 0.1% by mass or more and 99% by mass or less, more preferably 1% by mass. It is 90% by mass or less, more preferably 1% by mass or more and 50% by mass or less.
[0036]
　When the pH suitable for the purification treatment is greater than 7, a base can be used as the pH adjuster.
[0037]
　As the base used as the pH adjuster, either an inorganic base or an organic base can be used. Examples of the inorganic base include alkali metal hydroxides such as lithium hydroxide, sodium hydroxide and potassium hydroxide, alkaline earth metal hydroxides such as magnesium hydroxide and calcium hydroxide, lithium carbonate and sodium carbonate. , Alkali metal carbonates such as potassium carbonate, lithium hydrogen carbonate, sodium hydrogen carbonate, alkali metal hydrogen carbonates such as potassium hydrogen carbonate, and ammonia. Examples of the organic base include trimethylamine, triethylamine, aniline and pyridine. The base used as the pH adjuster can be used in any of gas, solid, and liquid states, but considering the ease of supply to the purification treatment tank, it is preferable to use a base in a liquid state, and it is preferable to use a gas or solid. It is more preferable to use the base in the above state as an aqueous solution. Considering the controllability of pH adjustment in the purification treatment tank, it is more preferable to use the base in a liquid state as an aqueous solution. The concentration of the base when used as an aqueous solution is not particularly limited, but since it becomes difficult to adjust the pH when a high-concentration aqueous solution is used, it is preferably 0.1% by mass or more and 99% by mass or less, more preferably 1% by mass. 90% by mass or less, more preferably 1% by mass or more and 50% by mass or less.
Example
[0038]
　Hereinafter, the present disclosure will be described in more detail with reference to examples, but the present disclosure is not limited to the following examples. In the following examples,% indicates mass% unless otherwise specified.
[0039]
[Example 1]
　[Preparation of bacterial cells containing nitrile hydratase]
　No. 1 according to the method described in Example 1 of JP-A-2001-3400091. Three clone cells were obtained and cultured in the same manner as in Example 1 to obtain wet cells containing nitrile hydratase.
[0040]
　[Production of acrylamide] As
　the first reactor, a tank reactor (volume: 1 m 3 ) with a SUS jacket-type heat exchanger equipped with a stirrer and having a tank inner diameter of 1 m and a straight body length of 1.5 m . As the second reactor, a SUS multi-tube cylindrical reactor having a volume of 0.4 m 3 was prepared. As the configuration of the second reactor, one having 15 tubes having an outer diameter of 89.1 mm, an inner diameter of 80.7 mm and a tube length of 5 m was used. The second reactor was installed vertically, and the reaction solution was circulated from the lower part of the pipe part, and the cooling water was circulated to the body part.
　The raw water supply pipe, the pH adjuster supply pipe, the acrylonitrile supply pipe, and the bacterial cell catalyst supply pipe are each directly connected to the first reactor. A reaction solution supply line equipped with a reaction solution supply pump is installed in the first reactor, and the reaction solution supply line is connected to the second reactor.
　The first reactor was charged with 400 kg of water in advance. The wet cells obtained by the above culture method were suspended in pure water. The suspension was continuously fed at a rate of 11 kg / h with stirring in the first reactor. Further, acrylonitrile having a purity of 99.8% was continuously supplied to the first reactor through the acrylonitrile supply tube at a rate of 32 kg / h. Pure water was continuously supplied to the first reactor through the pure water supply pipe at a rate of 37 kg / h. The temperature of the reaction solution during the reaction was controlled by flowing cooling water at 5 ° C. through the jacket-type heat exchanger of the first reactor and the body of the second reactor so that the temperature of the reaction solution was 20 ° C. .. Using a 0.1 M-NaOH aqueous solution as a pH adjuster, adjust the supply amount so that the pH of the reaction solution is 7.5 to 8.5, and then to the first reactor via the supply pipe of the pH adjuster. Supplied continuously. The pH of the reaction solution was measured at the outlet of the first reactor using the glass electrode method.
　The reaction solution was continuously withdrawn from the first reactor at a rate of 80 kg / h so that the liquid level of the reaction solution during the reaction was 1 m above the bottom surface of the tank, and the extracted reaction solution was taken out from the second reactor. Was continuously fed to the reactor to allow further reaction in the second reactor. The residence time in the first reactor was 10 hours, and the residence time in the second reactor was 5 hours.
　When the analysis was performed under the following HPLC conditions 200 hours after the start of the reaction, the conversion rate to acrylamide at the first reactor outlet was 90%, and the acrylonitrile concentration at the second reactor outlet was 40 mass ppm. Met. The acrylamide concentration at the outlet of the second reactor was 53% by mass.
[0041]
Here, the analysis conditions were as follows.
-Acrylamide analysis conditions:
　　High performance liquid chromatograph device: LC-10A system (manufactured by Shimadzu Corporation) (UV detector wavelength 250 nm, column temperature 40 ° C.)
　　Separation column: SCR-101H (manufactured by Shimadzu Corporation)
　　Eluent: 0.05% (volume basis) -Aqueous phosphate solution
/ acrylonitrile Analytical conditions:
　　High performance liquid chromatograph device: LC-10A system (manufactured by Shimadzu Corporation) (UV detector wavelength 200 nm, column temperature 40 ° C)
　　Separation column: Wakosil -II 5C18HG (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.)
　　Eluent: 7% (volume basis) -Acetonitrile, 0.1 mM-acetic acid, 0.2 mM-sodium acetate in each concentration
[0042]
　[Example 2] In
　the production of acrylamide of Example 1, instead of having the configuration of the second reactor having 15 tubes having an outer diameter of 89.1 mm, an inner diameter of 80.7 mm and a tube length of 5 m, an outer diameter of 114 Acrylamide was produced in the same manner as in Example 1 except that nine tubes having a diameter of 0.3 mm and an inner diameter of 105.3 mm and a tube length of 5 m were provided. The residence time in the first reactor was 10 hours, and the residence time in the second reactor was 5 hours.
　When the analysis was performed under the above HPLC conditions 200 hours after the start of the reaction, the conversion rate to acrylamide at the first reactor outlet was 90%, and the acrylonitrile concentration at the second reactor outlet was 15 mass ppm. there were.
[0043]
　[Example 3] In
　the production of acrylamide of Example 1, instead of having the configuration of the second reactor having 15 tubes having an outer diameter of 89.1 mm, an inner diameter of 80.7 mm and a tube length of 5 m, the outer diameter is 139. Acrylamide was produced in the same manner as in Example 1 except that six tubes having a diameter of 0.8 mm and an inner diameter of 130.8 mm and a tube length of 5 m were provided. The residence time in the first reactor was 10 hours, and the residence time in the second reactor was 5 hours.
　When the analysis was performed under the above HPLC conditions 200 hours after the start of the reaction, the conversion rate to acrylamide at the first reactor outlet was 90%, and the acrylonitrile concentration at the second reactor outlet was below the detection limit ( It was 10 mass ppm or less).
[0044]
　[Example 4] In
　the production of acrylamide of Example 1, instead of having the configuration of the second reactor having 15 tubes having an outer diameter of 89.1 mm, an inner diameter of 80.7 mm and a tube length of 5 m, the outer diameter is 165. Acrylamide was produced in the same manner as in Example 1 except that four tubes having a diameter of .2 mm and an inner diameter of 155.2 mm and a tube length of 5 m were provided. The residence time in the first reactor was 10 hours, and the residence time in the second reactor was 5 hours.
　When the analysis was performed under the above HPLC conditions 200 hours after the start of the reaction, the conversion rate to acrylamide at the first reactor outlet was 90%, and the acrylonitrile concentration at the second reactor outlet was below the detection limit ( It was 10 mass ppm or less).
[0045]
　[Example 5]
　[Preparation of bacterial cells containing nitrile hydratase]
　No. 1 according to the method described in Example 1 of JP-A-2001-3400091. Three clone cells were obtained and cultured in the same manner as in Example 1 to obtain wet cells containing nitrile hydratase.
[0046]
　[Manufacture of acrylamide] As
　the first reactor, a tank reactor (volume: 1 m 3 ) with a SUS jacket-type heat exchanger equipped with a stirrer and having a tank inner diameter of 1 m and a straight body length of 1.5 m . As the second reactor, a SUS double-tube reactor having a volume of 0.4 m 3 was prepared. The configuration of the second reactor has an outer diameter of 165.2 mm, an inner diameter of 155.2 mm, a pipe length of 20 m as an inner pipe, and an outer pipe having an inner diameter of 267.4 mm as a jacket. The second reactor was installed vertically, and the reaction solution was circulated from the lower part of the inner pipe, and the cooling water was circulated to the outer pipe.
　The raw water supply pipe, the pH adjuster supply pipe, the acrylonitrile supply pipe, and the bacterial cell catalyst supply pipe are each directly connected to the first reactor. A reaction solution supply line equipped with a reaction solution supply pump is installed in the first reactor, and the reaction solution supply line is connected to the second reactor.
　The first reactor was charged with 400 kg of water in advance. The wet cells obtained by the above culture method were suspended in pure water. The suspension was continuously fed at a rate of 11 kg / h with stirring in the first reactor. Further, acrylonitrile having a purity of 99.8% was continuously supplied to the first reactor through the acrylonitrile supply tube at a rate of 32 kg / h. Pure water was continuously supplied to the first reactor through the pure water supply pipe at a rate of 37 kg / h. The temperature of the reaction solution during the reaction is controlled by flowing cooling water at 5 ° C through the jacket-type heat exchanger of the first reactor and the outer tube of the second reactor so that the temperature of the reaction solution becomes 20 ° C. It was. Using a 0.1 M-NaOH aqueous solution as a pH adjuster, adjust the supply amount so that the pH of the reaction solution is 7.5 to 8.5, and then to the first reactor via the supply pipe of the pH adjuster. Supplied continuously. The pH of the reaction solution was measured at the outlet of the first reactor using the glass electrode method.
　The reaction solution was continuously withdrawn from the first reactor at a rate of 80 kg / h so that the liquid level of the reaction solution during the reaction was 1 m above the bottom surface of the tank, and the extracted reaction solution was taken out from the second reactor. Was continuously fed to the reactor to allow further reaction in the second reactor. The residence time in the first reactor was 10 hours, and the residence time in the second reactor was 5 hours.
　When the analysis was performed under the above HPLC conditions 200 hours after the start of the reaction, the conversion rate to acrylamide at the first reactor outlet was 90%, and the acrylonitrile concentration at the second reactor outlet was below the detection limit ( It was 10 mass ppm or less). The acrylamide concentration at the outlet of the second reactor was 53% by mass.
[0047]
　[Example 6] In
　the production of acrylamide of Example 5, the second reactor is composed of an outer diameter of 165.2 mm, an inner diameter of 155.2 mm, a pipe length of 20 m as an inner pipe, and a jacket having an inner diameter of 267.4 mm. Acrylamide is the same as in Example 5 except that instead of having a tube, a tube having an outer diameter of 139.8 mm and an inner diameter of 130.8 mm and a tube length of 28 m is used as an inner tube, and an outer tube having an inner diameter of 267.4 mm is used as a jacket. Was manufactured. The residence time in the first reactor was 10 hours, and the residence time in the second reactor was 5 hours.
　When the analysis was performed under the above HPLC conditions 200 hours after the start of the reaction, the conversion rate to acrylamide at the first reactor outlet was 90%, and the acrylonitrile concentration at the second reactor outlet was below the detection limit ( It was 10 mass ppm or less).
[0048]
　[Example 7] In
　the production of acrylamide of Example 5, the configuration of the second reactor is a tube having an outer diameter of 165.2 mm, an inner diameter of 155.2 mm and a tube length of 20 m as an inner tube, and an outer diameter of 267.4 mm as a jacket. Instead of having a tube, a tube having an outer diameter of 89.1 mm, an inner diameter of 80.7 mm and a tube length of 25 m was used as an inner tube, and three double-tube reactors having an outer tube having an inner diameter of 155.2 mm were connected in series as a jacket. Except for this, acrylamide was produced in the same manner as in Example 5. The residence time in the first reactor was 10 hours, and the residence time in the second reactor was 5 hours.
　When the analysis was performed under the above HPLC conditions 200 hours after the start of the reaction, the conversion rate to acrylamide at the first reactor outlet was 90%, and the acrylonitrile concentration at the second reactor outlet was 30 mass ppm. there were.
[0049]
　[Comparative Example 1] In
　the production of acrylamide of Example 1, instead of having 15 tubes having an outer diameter of 89.1 mm, an inner diameter of 80.7 mm and a tube length of 5 m, the second reactor has an outer diameter of 27. Acrylamide was produced in the same manner as in Example 1 except that 209 tubes having a diameter of 2 mm and an inner diameter of 21.6 mm and a tube length of 5 m were provided. The residence time in the first reactor was 10 hours, and the residence time in the second reactor was 5 hours.
　When the analysis was performed under the above HPLC conditions 200 hours after the start of the reaction, the conversion rate to acrylamide at the first reactor outlet was 90%, and the acrylonitrile concentration at the second reactor outlet was 120 mass ppm. there were.
[0050]
　The results of Examples 1 to 7 and Comparative Example 1 are shown in Table 1.
[0051]
[table 1]

[0052]
　From the results described above, it was found that the amount of acrylonitrile remaining in the reaction solution can be reduced by controlling the Re number within a predetermined range in the second reactor having a plug-flow property region.
[0053]
　The disclosure of Japanese Patent Application No. 2018-62126, filed March 28, 2018, is incorporated herein by reference in its entirety.
　All documents, patent applications, and technical standards described herein are to the same extent as if the individual documents, patent applications, and technical standards were specifically and individually stated to be incorporated by reference. Incorporated herein by reference.
The scope of the claims
[Claim 1]
　A step of contacting a microbial cell containing nitrile hydratase or a treated product thereof with a nitrile compound in an aqueous medium in a first reactor to obtain a reaction solution containing an amide compound, and a
　step obtained in the above steps. It has a step of reacting a reaction solution containing the amide compound in a second reactor having a plug-flow property region,
　and is controlled so that the Reynolds number in the second reactor is 5 or more and 1000 or less. A method for producing an amide compound.
[Claim 2]
　The method for producing an amide compound according to claim 1, wherein the Reynolds number in the second reactor is 10 or more.
[Claim 3]
　The method for producing an amide compound according to claim 1 or 2, wherein the Reynolds number in the second reactor is 100 or less.
[Claim 4]
　The method for producing an amide compound according to any one of claims 1 to 3, wherein the second reactor is a tubular reactor and the tube diameter of the tubular reactor is 10 cm or more.