JP2015057967A - Production method of amide compound and production device of amide compound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an efficient production method of an industrially very important amide compound, and a production device of an amide compound suitably used in the method.SOLUTION: A method of producing an amide compound by using a microbial bacterial cell containing nitrile-hydratase and/or a bacterial cell-treated product thereof is characterized by supplying to a reaction tank after mixing a pH modifier with an aqueous medium and/or a mixture of an aqueous medium to be supplied to the reaction tank. A production device of an amide compound is equipped with: a reaction tank for producing an amide compound by using a microbial bacterial cell containing nitrile-hydratase and/or a bacterial cell-treated product thereof; and a supply line for supplying a mixture of a pH modifier with an aqueous medium and/or a mixture containing an aqueous medium.

Description

  The present invention relates to a method for producing an amide compound and an apparatus for producing an amide compound, which use a microbial cell and / or a treated product thereof as a catalyst to obtain an amide compound hydrated with a nitrile compound.

  As one of the main production methods of amide compounds, a hydration method using a nitrile compound as a raw material is used in many cases, and as an industrial production method of amide compounds such as acrylamide, for example, Raney copper or the like A method of hydrating a nitrile compound such as acrylonitrile using a metal copper catalyst as a catalyst, or a microbial cell containing nitrile hydratase and / or a treated product thereof in recent years as a catalyst to hydrate a nitrile compound. How to do is known.

  The method of using microbial cells and / or treated cells thereof as a catalyst has attracted industrial attention because of the high conversion rate and selectivity of nitrile compounds such as acrylonitrile.

  Nitrile compounds such as acrylonitrile cannot be said to have a sufficiently high solubility in water or an aqueous solution of an amide compound at room temperature, and if the nitrile compound is not sufficiently dissolved in water, contact between the nitrile compound and the cell catalyst Inadequate, adverse effects such as a decrease in productivity, catalyst deterioration, and an increase in loss due to evaporation of the nitrile compound into the gas phase occur. The solubility of the nitrile compound in the reaction solution or amide compound aqueous solution can be improved by vigorous stirring of the reaction solution, but such strong stirring may lead to damage of the cell catalyst and resulting decrease in activity. It is not preferable.

For example, Patent Document 1 describes that it is appropriate to cause a reaction by intermittently dropping acrylonitrile while stirring into a mixture of bacterial cells and water. Patent Document 2 also provides good contact and dispersibility between the nitrile compound and the biocatalyst by stirring the required power per unit volume of the reaction fluid within the range of 0.08 to 0.7 kW / m ^3. Thus, a method for producing an amide compound with reduced production cost and environmental burden is disclosed. Patent Document 3 discloses an acrylonitrile supply pipe for supplying acrylonitrile to an aqueous medium in a method of supplying acrylonitrile to an aqueous medium to which a microbial catalyst is added while stirring the aqueous medium to produce acrylamide in the aqueous medium. There has been proposed a method for supplying acrylonitrile by disposing the supply port in an aqueous medium. However, the methods of Patent Documents 1 to 3 are insufficient to efficiently use the bacterial cell catalyst, and there is still room for investigation.

Japanese Patent Publication No. 56-38118 WO09 / 113654 pamphlet WO2011 / 078184

  In the hydration reaction of a nitrile compound using a microbial cell and / or a treated product thereof, there is a suitable pH range in order to keep the activity of the cell catalyst good, and usually the pH of the reaction mixture is A method is used in which the pH regulator is supplied to the reaction vessel so that it is in a range suitable for the reaction. For example, when the pH suitable for the reaction is less than 7, a method of supplying an acid as a pH regulator to the reaction vessel, or when the pH suitable for the reaction is greater than 7, the reaction vessel using a base as the pH regulator. The method of supplying to is used.

  Since the activity of the bacterial cell catalyst decreases when it deviates from a suitable pH range for keeping its activity good, the reaction tank is usually maintained at a suitable pH for carrying out the reaction in order to keep the activity good. In order to maintain the pH of the reaction vessel, a pH adjusting agent is supplied to the reaction vessel, and is usually dispersed by mixing and the pH of the reaction vessel is adjusted.

  However, according to the study by the present inventors, when the pH regulator is supplied to the reaction tank alone, even if the pH regulator is dispersed after being supplied to the reaction tank and the pH is appropriately controlled, the catalyst It has been found that the activity of is reduced. Even if the pH of the reaction vessel is within a suitable range, the vicinity of the pH regulator supply port deviates temporarily from a suitable pH range due to a high concentration of pH regulator, and the cell catalyst is different from a metal catalyst, It is estimated that exposure to reaction mixtures that deviate from the preferred region of pH decreases the activity and does not recover to the original activity.

  An object of the present invention is to provide a method for efficiently producing an amide compound without reducing the activity of the bacterial cell catalyst, and an apparatus for producing an amide compound suitably used in the method.

  The present inventors have conducted intensive research to solve the above problems. As a result, the inventors have found that the above problems can be solved by a method for producing an amide compound having the following steps, and have reached the present invention.

That is, the present invention is as follows.
[1] In a method for producing an amide compound using a microbial cell containing nitrile hydratase and / or a processed product thereof, pH is added to the aqueous medium and / or the mixture containing the aqueous medium supplied to the reaction vessel. A method for producing an amide compound, wherein the regulator is mixed and then supplied to the reaction vessel [2] The method for producing an amide compound according to [1], wherein the pH regulator is a base [3] ] The production method according to [1] or [2] above, wherein the nitrile compound is acrylonitrile or methacrylonitrile, and the amide compound is acrylamide or methacrylamide [4] A microbial cell containing nitrile hydratase and / or its microbial cell A reaction vessel for producing an amide compound using a treated bacterial cell, and an aqueous medium and / or a mixture containing an aqueous medium Apparatus for producing an amide compound comprising a supply line for supplying a mixture of a pH adjusting agent

  In the present invention, the pH regulator is mixed with the aqueous medium and / or the mixture containing the aqueous medium before being supplied to the reaction tank, thereby reducing local fluctuations of pH in the reaction tank, An amide compound can be produced efficiently without reducing the activity of the bacterial cell catalyst.

FIG. 1 is a schematic view showing an embodiment of the production apparatus of the present invention. FIG. 2 is a schematic view showing an embodiment of the production apparatus of the present invention. FIG. 3 is a schematic view showing an embodiment of the production apparatus of the present invention.

  Hereinafter, the manufacturing method and manufacturing apparatus of the amide compound of this invention are demonstrated.

[Method for producing amide compound]
The method for producing an amide compound according to the present invention is a method for producing an amide compound using a microbial cell containing nitrile hydratase and / or a treated product thereof, wherein an aqueous medium and / or an aqueous system supplied to a reaction vessel are used. It has the process of supplying a reaction tank, after mixing pH regulator with the mixture containing a medium.

<Microbial cells containing nitrile hydratase and / or treated cells thereof>
In the present invention, a microbial cell containing nitrile hydratase and / or a treated product thereof (hereinafter, also simply referred to as “bacterial catalyst”) is used as a catalyst for amidation of a nitrile group of a nitrile compound.
Nitrile hydratase refers to an enzyme (protein) having the ability to hydrolyze a nitrile compound to produce a corresponding amide compound (hereinafter also referred to as “nitrile hydratase activity”).

  The microorganism containing nitrile hydratase is not particularly limited as long as it is a microorganism that produces nitrile hydratase and retains nitrile hydratase activity in an aqueous solution of a nitrile compound and an amide compound. Microorganisms producing nitrile hydratase include Nocardia, Corynebacterium, Bacillus, thermophilic Bacillus, Pseudomonas, Micrococcus, Rhodococcus genus represented by Rhodochrous species, Acinetobacter genus, Xanthobacter genus, Streptomyces genus, Rhizobium genus, Klebsiella genus, Klebsiella genus Typically represented by the genus Enterobacter, Erwinia, Aeromonas, Citrobacter, Achromobacter, Agrobacterium or thermophila Pseudonocardia, Bacteridium, Breviva Such as a microorganism belonging to the Agrobacterium (Brevibacterium) genus, and the like. These may be used alone or in combination of two or more.

  In addition, a transformant in which the nitrile hydratase gene cloned from these microorganisms is highly expressed in any host, and one or more of the constituent amino acids of the nitrile hydratase using other amino acids using recombinant DNA technology. Examples include a transformant expressing a mutant nitrile hydratase with further improved amide compound resistance, nitrile compound resistance, and temperature resistance by substitution, deletion, deletion or insertion. As an arbitrary host mentioned here, Escherichia coli can be mentioned as a representative example as in Examples described later, but is not particularly limited to Escherichia coli, and Bacillus subtilis and other Bacillus subtilis. Other microbial strains such as genera, yeasts and actinomycetes are also included. As an example of such, MT-10822 (this strain was founded on February 7, 1996, 1-3-1 Higashi 1-chome, Tsukuba, Ibaraki Prefecture, Institute of Biotechnology, Institute of Industrial Technology, Ministry of International Trade and Industry (currently Tsukuba, Ibaraki Prefecture). 1-1-1, City East Tsukuba Center Central 6th Japan Incorporated Administrative Agency (National Institute of Technology and Evaluation, Patent Biological Deposit Center) under the deposit number FERMBP-5785, deposited based on the Budapest Treaty concerning the international approval of the deposit of microorganisms under patent procedures ).

  Among these microorganisms, in terms of having a highly active and highly stable nitrile hydratase, a microorganism belonging to the genus Pseudonocardia and a nitrile hydratase gene cloned from the microorganism can be highly expressed in any host. The transformant and the transformant expressing the mutant nitrile hydratase are preferable. In addition, the said transformant is preferable at the point which raises the stability of nitrile hydratase more and the activity per microbial cell is higher.

  Also preferred are Rhodococcus rhodochrous J-1, which can highly express nitrile hydratase in microorganisms, and transformants in which the nitrile hydratase gene cloned from the microorganism is highly expressed in any host. The microbial cell producing the nitrile hydratase can be prepared by a general method known in the fields of molecular biology, biotechnology, and genetic engineering.

  The recombinant vector according to the present invention contains a gene encoding nitrile hydratase, and can be obtained by linking a gene encoding nitrile hydratase to the vector. The vector is not particularly limited. For example, a gene encoding nitrile hydratase in a commercially available expression plasmid represented by pET-21a (+), pKK223-3, pUC19, pBluescriptKS (+), pBR322, etc. Thus, the expression plasmid of nitrile hydratase can be constructed. The host organism used for transformation may be any organism as long as the recombinant vector is stable and capable of self-propagation and can express foreign DNA traits. For example, E. coli is a good example. The transformant having the ability to produce nitrile hydratase can be obtained by introducing it into Bacillus subtilis, yeast or the like.

  The microorganism producing nitrile hydratase as described above may be appropriately cultured and grown by a known method to produce nitrile hydratase. As a medium used in this case, either a synthetic medium or a natural medium can be used as long as it contains a suitable amount of carbon source, nitrogen source, inorganic salts and other nutrients. For example, after inoculating microorganisms in a normal liquid medium such as LB medium, M9 medium, etc., an appropriate culture temperature (generally 20 ° C. to 50 ° C., but in the case of thermophilic bacteria, 50 ° C. or more It can be prepared by culturing in the above. Culturing can be performed using a conventional culture method such as shaking culture, aeration and agitation culture, continuous culture, or fed-batch culture in a liquid medium containing the culture components. The culture temperature of the transformant is preferably 15 to 37 ° C. The culture conditions are not particularly limited, and may be appropriately selected depending on the type of culture and the culture method, as long as the strain can grow and produce nitrile hydratase.

  In the present invention, in order to react the microbial body producing the above-mentioned nitrile hydratase with a nitrile compound, various treatments such as collection by centrifugation or crushing to produce a crushed microbial cell body may be performed. Well, microbial cells that have been subjected to some kind of treatment are collectively referred to as processed microbial cells.

  The form of the microbial cell to be crushed is not particularly limited as long as it includes the microbial cell producing nitrile hydratase. For example, the culture itself containing the microbial cell itself, Examples of the collected and collected bacterial bodies, and those obtained by washing the collected bacterial bodies with physiological saline and the like.

  The device for disrupting the cells is not particularly limited as long as the cells can be disrupted, and examples include grinding devices such as an ultrasonic crusher, a French press, a bead shocker, a homogenizer, a dyno mill, and a cool mill. It is done. Among these, a homogenizer is preferable because it can be scaled up at low cost.

  The temperature at which the cells are crushed is not particularly limited, and is preferably 0 ° C. or higher and 50 ° C. or lower, more preferably 0 ° C. or higher and 25 ° C. or lower.

  Moreover, pH when crushing a microbial cell is not specifically limited, Preferably it is pH 4-10, More preferably, it is pH6-8.

  The pressure in the case of crushing the microbial cells using a homogenizer is not particularly limited as long as the microbial cells are crushed, and is preferably 10 MPa or more and 300 MPa or less, more preferably 30 MPa or more and 100 MPa or less.

<Nitrile compound>
Examples of the nitrile compound include an aliphatic nitrile compound having 2 to 20 carbon atoms and an aromatic nitrile compound having 6 to 20 carbon atoms, which may be used alone or in combination of two or more.

  Examples of the aliphatic nitrile compound include saturated or unsaturated nitriles having 2 to 6 carbon atoms; specifically, acetonitrile, propionitrile, butyronitrile, isobutyronitrile, valeronitrile, isovaleronitrile, capronitrile Aliphatic saturated mononitriles such as malononitrile, succinonitrile, adiponitrile, and the like; and aliphatic unsaturated nitriles such as acrylonitrile, methacrylonitrile, and crotonnitrile.

  Examples of the aromatic nitrile compound include benzonitrile, o-, m- or p-chlorobenzonitrile, o-, m- or p-fluorobenzonitrile, o-, m- or p-nitrobenzonitrile, o- , M- or p-tolunitrile, benzyl cyanide. Among the nitrile compounds, acrylonitrile and methacrylonitrile are preferable.

<Water (raw water)>
The raw water is not particularly limited, and purified water such as distilled water or ion exchange water can be used.

<PH regulator>
The pH adjusting agent is used to adjust the pH of the reaction mixture to a suitable range for keeping the activity of the cell catalyst good.

When the pH suitable for the reaction is less than 7, an acid can be used as a pH regulator.
As the acid used as the pH regulator, either an inorganic acid or an organic acid can be used. Examples of the inorganic acid include hydrohalic acid such as hydrogen chloride, hydrogen bromide, hydrogen iodide, hypochlorous acid, chlorous acid, chloric acid, perchloric acid, hypobromite, bromite, bromine Examples thereof include halogenated oxo acids such as acid, perbromic acid, hypoiodic acid, iodic acid, iodic acid, and periodic acid, sulfuric acid, nitric acid, phosphoric acid, boric acid, and the like. Examples of the organic acid include carboxylic acid such as formic acid, acetic acid, propionic acid, acrylic acid, methacrylic acid, crotonic acid, succinic acid, malonic acid, fumaric acid, maleic acid, citric acid, lactic acid, benzoic acid, methanesulfonic acid, Examples include sulfonic acids such as ethanesulfonic acid, benzenesulfonic acid, and p-toluenesulfonic acid. The acid used as the pH adjusting agent can be used in any state of gas, solid, and liquid, but considering the ease of supply to the reaction vessel, it is preferable to use the acid in the liquid state. The acid in the state is more preferably used as an aqueous solution. In consideration of controllability of pH adjustment of the reaction tank, it is more preferable to use a liquid acid as an aqueous solution. The concentration of the acid when used as an aqueous solution is not particularly limited, but pH adjustment becomes difficult when an aqueous solution with a high concentration is used. Therefore, it is preferably 0.1 wt% or more and 99 wt% or less, more preferably 1 wt% or more and 90 wt% or less. More preferably, it is 1 wt% or more and 50 wt% or less.

When the pH suitable for the reaction is larger than 7, a base can be used as a pH regulator.
As the base used as the pH regulator, 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, ammonia and the like. Examples of the organic base include trimethylamine, triethylamine, aniline, pyridine and the like. The base used as the pH regulator can be used in any state of gas, solid, and liquid, but considering the ease of supply to the reaction vessel, it is preferable to use a base in the liquid state. The acid in the state is more preferably used as an aqueous solution. In consideration of controllability of pH adjustment of the reaction tank, it is more preferable to use a liquid base as an aqueous solution. The concentration of the base when used as an aqueous solution is not particularly limited, but pH adjustment becomes difficult when a high concentration aqueous solution is used, and therefore, preferably 0.1 wt% or more and 99 wt% or less, more preferably 1 wt% or more and 90 wt% or less. More preferably, it is 1 wt% or more and 50 wt% or less.

  When the pH regulator is used as an acid or base aqueous solution, the acid or base aqueous solution contains an aqueous medium. The acid or base aqueous solution containing the aqueous medium is used as the pH regulator, and an aqueous medium and After mixing with a mixture containing an aqueous medium, the mixture is supplied to the reaction vessel.

<Reaction tank>
As the reaction tank, a single-stage reaction tank composed of one reactor may be used, or a multi-stage reaction tank composed of a plurality of reactors may be used. As the reactor, a tank reactor or a tube reactor may be used. As the tank reactor, a reactor equipped with a stirrer is preferable.

  The reaction tank is provided with a supply line for supplying an aqueous medium and / or a mixture containing the aqueous medium and a pH regulator. One supply line or a plurality of supply lines may be installed in one reactor.

  As the supply line of the aqueous medium and / or the mixture containing the aqueous medium and the pH adjuster provided in the reaction tank, for example, raw water is used as the aqueous medium, and the mixture of the raw water and the pH adjuster is supplied. Examples thereof include a line and a supply line of a mixture of raw water and a nitrile compound as a mixture containing an aqueous medium and a mixture of raw water and a nitrile compound and a pH regulator. Alternatively, an external circulation line equipped with a pump for returning a part of the reaction mixture to the reaction tank is installed in the reaction tank, and a part of the reaction mixture taken out from the reaction tank as a mixture containing an aqueous medium is used. A supply line for a part of the reaction mixture and a mixture of the pH adjusting agent may be mentioned.

  When an external circulation line having a pump is installed in the reaction tank, the pump provided in the external circulation line is not particularly limited. For example, a turbo pump such as a centrifugal pump, a tilt pump, or an axial flow pump And positive displacement pumps such as reciprocating pumps and rotary pumps.

  When installing an external circulation line equipped with a pump in the reaction tank, a part of the reaction mixture is taken out from the reaction tank using the pump provided in the external circulation line and reacted via the external circulation line. Returned to the tank. It is preferable that a temperature control device is installed in the external circulation line installed in the reaction tank. As the temperature control device, a heat exchanger is preferably used. Examples of the heat exchanger include multi-tubular cylindrical, spiral tube, spiral plate, plate, and double tube types.

  When installing an external circulation line equipped with a pump in a multistage reaction tank composed of a plurality of reactors, all of the external circulation lines equipped with a pump may be installed in each reactor. It may be installed in only one reactor. In the case of multiple reactors, if the external circulation line equipped with a pump is installed in only one of the reactors, it is installed in the first-stage reactor (the most upstream reactor) It is preferred that

  Using a reaction tank composed of a first-stage tank reactor and a second-stage tube reactor, the reaction liquid taken out from the tank reactor is further reacted in the tube reactor, and the tank reaction A reaction tank in which an external circulation line equipped with a pump is installed in the vessel is more preferable because the conversion rate can be improved.

  The tank reactor and the tube reactor may or may not be equipped with a heat exchanger as long as the nitrile hydratase activity of the bacterial cell catalyst is maintained. In order to control, the reactor preferably comprises a heat exchanger. As the heat exchanger, for example, a multi-tubular cylindrical type, a spiral tube type, a spiral plate type, a plate type, a double pipe type or the like is preferably installed on the external circulation line. The thing of the form directly installed in a reactor, such as a formula and a coil type, is mentioned. When the reactor is a tubular reactor, the reactor itself can be composed of a multi-tubular cylindrical or double-tube heat exchanger.

  Examples of the reaction method include (1) a method in which a reaction is carried out after all of the cell catalyst, reaction raw material (nitrile compound and raw water) and pH regulator are charged in a reaction tank at once (batch reaction), (2) fungus After a part of the body catalyst, reaction raw material (nitrile compound and raw water) and pH regulator are charged into the reaction tank, the remaining cell catalyst, reaction raw material (nitrile compound and raw water) and pH are continuously or intermittently added. A method of performing a reaction by supplying a regulator (semi-batch reaction), (3) a continuous or intermittent supply of a cell catalyst, a reaction raw material (nitrile compound and raw water) and a pH regulator, and a reaction solution (bacteria) Including continuous catalyst, unreacted raw material, pH adjuster and generated amide compound, etc.), while continuously taking out the reaction solution in the reaction tank without taking out the whole reaction solution. (Continuous reaction) and the like. Among these, a continuous reaction is preferable because it is easy to industrially produce an amide compound in large quantities and efficiently.

  The reaction is performed in the presence of a cell catalyst. An appropriate form such as a suspension bed or a fixed bed can be selected as the form of use of the cell catalyst. For example, in the case of continuous reaction, a suspension of bacterial cell catalyst may be prepared and the suspension may be supplied to the reaction vessel.

  In addition, when using the multistage reaction tank comprised from several reactors as a reaction tank, as the structure, (a) Cell body catalyst, reaction raw material (nitrile compound and raw material water), and pH regulator are the upper reaction. A serial mode in which a reaction liquid (including a bacterial cell catalyst, an unreacted raw material, a pH adjuster, and a generated amide compound) is supplied to the lower reactor and supplied to the lower reactor, (B) A parallel mode in which a cell catalyst, a reaction raw material (nitrile compound and raw water) and a pH adjuster are directly supplied to two or more reactors (without going through other reactors) can be mentioned.

  For example, in the case of performing a continuous reaction using a multistage reaction tank, the supply destination of the cell catalyst, the reaction raw material (nitrile compound and raw water), and the pH regulator is the first-stage reactor (most upstream) It is not limited only to (reactor), The reactor after the 2nd stage (reactor located downstream) may be sufficient.

  Although the reaction tank temperature which is the liquid temperature in a reaction tank is based also on the heat resistance of a microbial cell catalyst, it is normally set to 0-50 degreeC, Preferably it is set to 10-40 degreeC. When the reaction vessel temperature is in the above range, it is preferable in that the nitrile hydratase activity of the bacterial cell catalyst can be maintained well.

  When the reaction tank is composed of only one reactor, the reaction tank temperature refers to the liquid temperature in the reactor; when the reaction tank is composed of a plurality of reactors, Refers to the liquid temperature. The reaction vessel temperature can be measured, for example, by a thermocouple method (eg, K type). The reaction vessel temperature can be measured at an arbitrary location in the reaction vessel, and specifically can be measured at the reaction vessel outlet (reaction liquid outlet).

Volume of the reaction vessel is not particularly limited, considering the industrial production, usually 0.1 m ³ or more, preferably from 1 to 100 m ^3, more preferably 5 to 50 m ^3. When the reaction vessel is composed of a plurality of reactors, the volume refers to the volume of each reactor.

  The reaction is generally carried out under normal pressure, but can also be carried out under pressure in order to increase the solubility of the nitrile compound.

  The pH in the reaction vessel is not particularly limited as long as it is a suitable range for maintaining the activity of the bacterial cell catalyst, but is preferably in the range of pH 5 to pH 10. When the pH is within the above range, it is preferable in that the nitrile hydratase activity can be favorably maintained.

  When the reaction tank is composed of only one reactor, the pH of the reaction tank refers to the pH within the reactor; when the reaction tank is composed of a plurality of reactors, The pH of the The pH of the reaction vessel can be measured by, for example, an indicator method, a hydrogen electrode method, a quinhydrone electrode method, an antimony electrode method, or a glass electrode method. The pH of the reaction vessel can be measured at any place in the reaction vessel, and specifically, can be measured at the reaction vessel outlet (reaction liquid outlet).

<Supply of reaction raw materials>
The raw water supplied to the reaction vessel may be supplied alone to the reaction vessel, or may be supplied to the reaction vessel after mixing with the nitrile compound. When supplying raw material water to the reaction tank alone, there is no particular restriction on the position of the supply port to the reaction liquid in the reaction tank of the raw water supply pipe, and even if it is installed above the reaction liquid, May be installed.

  The method for supplying raw water when supplying raw water alone to the reaction vessel is not particularly limited, and a known method can be used. As a method for supplying raw material water to the reaction tank, a device having a liquid transport function can be used. For example, a centrifugal pump, a tilting pump or an axial flow pump, a reciprocating pump, a rotary pump, etc. Pumps such as positive displacement pumps and conveyors such as screw conveyors can be used. As a method for supplying the raw water to the reaction tank, the raw water can be supplied without using the equipment having the liquid transport function. When equipment with a liquid transport function is not used, for example, a raw water storage tank for storing raw water is installed at the top of the reaction tank, the raw water storage tank and the reaction tank are connected by a raw water supply pipe, and gravity is used. There is a method of supplying by dropping. Or the method of supplying using the pressure difference of the raw material water storage tank and reaction tank which arise by pressurizing a raw material water storage tank is mentioned.

  There may be one raw water supply pipe for supplying raw water to the reaction tank, or a plurality of raw water supply pipes may be provided for one reaction tank. There is no restriction | limiting in particular in the shape of the supply port of a raw material water supply pipe, Any can be used suitably if it is a shape normally used.

  As a method of mixing raw water and nitrile compound in the case of supplying raw water and nitrile compound to the reaction tank, a known method can be used, for example, a method of stirring and mixing using a stirring tank, The method of mixing raw material water and a nitrile compound in piping is mentioned. In the case of using a stirring and mixing tank, the shape of the mixing tank is not particularly limited, but generally a cylindrical mixing tank is used, and in any case, a vertical cylindrical shape or a horizontal cylindrical shape is used. Can do. The mixing tank may be provided with a baffle plate or may not be provided with a baffle plate.

  In the case of using a stirring and mixing tank, a stirring blade having an arbitrary shape can be selected. For example, a propeller blade, a flat paddle blade, a pitched paddle blade, a flat turbine blade, a pitched turbine blade, a ribbon blade, an anchor blade, a full zone blade, etc. Is mentioned. One stirring blade may be provided, or a plurality of stirring blades may be provided.

  In order to mix the raw material water and the nitrile compound in the pipe, the raw water and the nitrile compound can be directly mixed by combining the raw water supply pipe and the nitrile compound supply pipe. The method of mixing positively by installing a line mixer is mentioned.

  When the raw water and nitrile compound are mixed and then supplied to the reaction vessel, the nitrile compound may be completely dissolved in water after mixing with water, but it is not necessarily required to be completely dissolved in water. What is necessary is just to mix by arbitrary ratios. Preferably, the ratio of water: nitrile compound is 100: 1 to 1: 100, more preferably 50: 1 to 1:50, and even more preferably 10: 1 to 1:10 by volume.

  When the raw water and the nitrile compound are mixed and then supplied to the reaction vessel, a known method can be used for supplying the raw water and the nitrile compound mixture. Specifically, the above raw water is used alone. The method illustrated by the supply method of raw material water in the case of supplying to a reaction tank can be used.

  When the raw water and the nitrile compound are mixed and then supplied to the reaction tank, the supply pipe for supplying the raw water and the mixture of the nitrile compound to the reaction tank may be one for each reaction tank. Also good. There is no restriction | limiting in particular in the shape of the supply port of a supply pipe | tube, Any can be used suitably if it is a shape normally used.

  The nitrile compound supplied to the reaction vessel may be supplied to the reaction vessel after being mixed with the raw water, or may be supplied alone to the reaction vessel. When supplying the nitrile compound alone to the reaction vessel, there is no particular restriction on the position of the supply port to the reaction solution in the reaction vessel of the nitrile compound supply pipe, and even if it is installed above the reaction solution, May be installed.

  The supply method of the nitrile compound when supplying the nitrile compound alone to the reaction vessel is not particularly limited, and a known method can be used. Specifically, the raw material water is supplied to the reaction vessel. The method exemplified in the method can be used.

  There may be one nitrile compound supply pipe for supplying the nitrile compound to the reaction tank, or a plurality of nitrile compound supply pipes per reaction tank. The supply port of the nitrile compound supply pipe may be one for each supply pipe, or a plurality of supply ports may be provided.

  The shape of the supply port of the nitrile compound supply pipe is not particularly limited, and any shape that is usually used can be suitably used.

<Supply of pH regulator>
The pH regulator is mixed with the aqueous medium and / or the mixture containing the aqueous medium supplied to the reaction tank, and then supplied to the reaction tank. The aqueous medium mixed with the pH adjuster is preferably raw water. Examples of the mixture containing an aqueous medium in which the pH adjuster is mixed include a reaction liquid containing a mixture of raw water and a nitrile compound, a bacterial cell catalyst, an unreacted raw material, a pH adjuster, and a generated amide compound. .

  A known method can be used as a method of mixing the pH adjuster and the raw water when the pH adjuster is supplied to the reaction tank after being mixed with the raw water. The method illustrated by the method of mixing water and a nitrile compound can be used.

  The pH regulator and the aqueous medium and / or the mixture containing the aqueous medium supplied to the reaction tank may be mixed at an arbitrary ratio, and preferably, the pH regulator: the aqueous medium and / or the mixture containing the aqueous medium. The ratio by volume is 1: 1 to 1: 100,000,000, more preferably 1:10 to 1: 10,000,000. A known method can be used as the method of supplying the mixture of the pH adjuster and the raw water when the pH adjuster is mixed with the raw water and then supplied to the reaction vessel. The method illustrated by the supply method of raw material water in the case of supplying water independently to a reaction tank can be used.

  A known method can be used as a method of mixing the mixture of the pH regulator, the raw water, and the nitrile compound when the pH regulator is supplied to the reaction vessel after being mixed with the raw water and the nitrile compound. Specifically, the method exemplified in the method of mixing the raw material water and the nitrile compound can be used.

  For example, the following method can be used as a method of mixing with a reaction solution containing a pH regulator and a bacterial cell catalyst, an unreacted raw material, a pH regulator, and a generated amide compound. An external circulation line equipped with a pump for returning a part of the reaction mixture to the reaction tank is installed in the reaction tank, and the reaction is performed as a mixture containing an aqueous medium by coupling the external circulation line and the pH regulator supply pipe. Examples include a method in which a part of the reaction mixture taken out from the tank is used and a part of the reaction mixture and the pH adjuster are directly mixed in an external circulation line. A part of the reaction mixture and the pH adjuster directly mixed in the external circulation line are supplied to the reaction tank as they are using the external circulation line.

<Supply of bacterial cell catalyst>
The supply of the bacterial cell catalyst is not particularly limited, and a known method can be used. As a method for supplying the bacterial cell catalyst to the reaction tank, a device having a liquid transport function can be used. For example, a turbo pump such as a centrifugal pump, a diagonal flow pump or an axial flow pump, a reciprocating pump or a rotary pump Pumps such as positive displacement pumps and conveyors such as screw conveyors can be used. As a method of supplying the bacterial cell catalyst, it can be supplied without using the device having the liquid transport function. When a device having a liquid transport function is not used, for example, a cell storage tank for storing cell catalysts is installed at the top of the reaction tank, the cell storage tank and the reaction tank are connected by a cell catalyst supply pipe, There is a method of supplying by dropping using. Or the method of supplying using the pressure difference of the microbial cell storage tank and reaction tank which arises by pressurizing a microbial cell storage tank or depressurizing a reaction tank is mentioned.

  The amount of the bacterial cell catalyst used varies depending on the reaction conditions, the type of catalyst and its form, but is usually 10 to 50,000 ppm by weight, preferably 50 ppm, based on the dry cell weight of the microorganism, relative to the reaction solution. ~ 30,000 ppm by weight.

  The reaction time (retention time of the reaction solution) is usually 0.5 to 50 hours, preferably 2 to 25 hours. When a multistage reaction vessel is used, the reaction time refers to the total reaction time (retention time of the reaction liquid) in all reactors.

  In the method for producing an amide compound of the present invention, the obtained amide compound can be recovered and purified by, for example, a concentration operation (eg, evaporation and concentration), activated carbon treatment, ion exchange treatment, filtration treatment, and crystallization operation. .

  As described above, an amide compound corresponding to the nitrile compound as a reaction raw material, for example, (meth) acrylonitrile, (meth) acrylamide can be obtained.

[Amide compound production equipment]
An apparatus for producing an amide compound of the present invention comprises a reaction vessel for producing an amide compound by a hydration reaction of a nitrile compound using a microbial cell containing nitrile hydratase and / or a treated product thereof, an aqueous medium, A supply line for supplying a mixture of a mixture containing an aqueous medium and a pH adjusting agent is provided.

The configuration of the reaction tank is as described above.
Hereinafter, specific examples of the amide compound production apparatus of the present invention will be described with reference to the drawings.

  1 includes a reaction tank 1 equipped with a stirrer 7, a raw water supply pipe 2 and a pH regulator supply pipe 3 connected to the reaction tank 1 through a feed pipe 6 of a mixture of raw water and a pH regulator, A nitrile compound supply pipe 4 and a cell catalyst supply pipe 5 are provided.

  The production apparatus of FIG. 2 includes a reaction tank 1 provided with a stirrer 7, a raw water supply pipe 2 and a pH regulator supply pipe connected to the reaction tank 1 through a feed pipe 6 of a mixture of raw water, a nitrile compound and a pH regulator. A 3 nitrile compound supply pipe and a fungus body catalyst supply pipe 5 are provided.

  The production apparatus of FIG. 3 includes a reaction tank 1 provided with a stirrer 7, an external circulation line 8 installed in the reaction tank connected to the reaction tank 1 through a supply pipe 6 of a mixture of the reaction mixture and the pH regulator, and a pH regulator. A supply pipe 3, a raw water supply pipe 2, a nitrile compound supply pipe 4, and a cell catalyst supply pipe 5 are provided. A circulation pump 9 and a heat exchanger 10 are provided on the external circulation line.

Next, examples of the present invention will be specifically described, but the present invention is not limited to these examples.

[Example 1]
[Preparation of microbial cells containing nitrile hydratase]
In accordance with the method described in Example 1 of JP-A-2001-340091, no. Three clonal cells were obtained and cultured in the same manner as in Example 1 to obtain wet cells containing nitrolyl hydratase.

[Production of acrylamide]
As a final product, in order to obtain a product having an acrylamide concentration in an aqueous solution of 50% by weight, the production apparatus shown in FIG. 1 (however, only the first reactor is shown as a reaction apparatus) is used as follows. The reaction was conducted under conditions.

A tank reactor with a SUS jacket heat exchanger (volume: 1 m ³ ) having a tank inner diameter of 1 m and a straight body length of 1.36 m, equipped with a stirrer as the first reactor, and a volume of 0.5 m as the second reactor. ³ SUS double tube reactors were prepared. The raw water supply pipe and the pH regulator supply pipe are joined pipes connected in the middle, and the raw water and the pH regulator are mixed in the merge pipe and supplied to the first reactor as a mixture. Each of the acrylonitrile supply pipe and the cell catalyst supply pipe is directly connected to the first 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. This suspension was continuously fed at a rate of 11 kg / h while stirring in the first reactor. Further, acrylonitrile having a purity of 99.8% was continuously supplied to the first reactor independently through an acrylonitrile supply pipe at a rate of 32 kg / h. Pure water is continuously supplied through a pure water supply pipe at a rate of 37 kg / h, and the pure water supply pipe and the pH regulator supply pipe are connected to each other before being connected to the first reactor, and then the first reaction. Connected to the vessel. The temperature of the reaction solution during the reaction is 20 ° C., and 5 ° C. cooling water is circulated through the double tube of the heat exchanger and the second reactor installed on the external circulation line of the first reactor. Control was performed. A 0.1 M NaOH aqueous solution was used as a pH adjuster, and the supply amount was adjusted so that the reaction pH was 7.5 to 8.5. The reaction pH was measured using the glass electrode method at the outlet of the first reactor.

  The reaction solution is 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 is 1 m from the bottom of the tank, and continuously supplied to the second reactor. The reaction was allowed to proceed further in the second reactor.

  Analysis was conducted 200 hours after the start of the reaction under the following HPLC conditions. The conversion to acrylamide at the first reactor outlet was 95%, and the acrylonitrile concentration at the second reactor outlet was below the detection limit (10 Weight ppm or less). The acrylamide concentration at the outlet of the second reactor was 53.1% by weight.

Here, the analysis conditions were as follows.
・ Acrylamide analysis conditions:
High-performance liquid chromatograph: LC-10A system (manufactured by Shimadzu Corporation)
(UV detector wavelength 250nm, column temperature 40 ℃)
Separation column: SCR-101H (manufactured by Shimadzu Corporation)
Eluent: 0.05% (volume basis)-phosphoric acid aqueous solution / acrylonitrile Analysis conditions:
High-performance liquid chromatograph: LC-10A system (manufactured by Shimadzu Corporation)
(UV detector wavelength 200nm, column temperature 40 ℃)
Separation column: Wakosil-II 5C18HG (Wako Pure Chemical Industries)
Eluent: 7% (volume basis) -acetonitrile, 0.1 mM-acetic acid,
Aqueous solution containing 0.2 mM sodium acetate at various concentrations

[Example 2]
In the production of acrylamide of Example 1, instead of connecting the acrylonitrile supply pipe directly to the first reactor, the acrylonitrile supply pipe and the pure water supply pipe are connected, and further before being connected to the first reactor in the downstream portion thereof. The reaction was carried out in the same manner as in Example 1 except that a pH adjusting agent supply pipe was connected to the first reactor and supplied to the first reactor as a pH adjusting agent mixture in addition to the mixture of acrylonitrile and pure water. When the above HPLC analysis was performed 200 hours after the start of the reaction, the conversion to acrylamide at the outlet of the first reactor was 95%, and the acrylonitrile concentration at the outlet of the second reactor was below the detection limit (less than 10 ppm by weight) It became. The acrylamide concentration at the outlet of the second reactor was 53.2% by weight.

[Example 3]
As a final product, in order to obtain a product having an acrylamide concentration in an aqueous solution of 50% by weight, the production apparatus shown in FIG. 3 (however, only the first reactor is shown as the reaction apparatus) is used as follows. The reaction was conducted under conditions.

A SUS tank reactor (volume: 1 m ³ ) having a tank inner diameter of 1 m and a straight body length of 1.36 m equipped with a stirrer as the first reactor, and a SUS double tank having a volume of 0.5 m ³ as the second reactor. A tube reactor was prepared. An external circulation line equipped with a pump was installed in the first reactor, and a spiral plate heat exchanger was installed on the external circulation line. A part of the reaction mixture in the reactor is extracted by a pump provided in an external circulation line, and returned to the first reactor via the circulation line. The external circulation line is branched downstream of a pump installed on the line, the branched line is connected to the second reactor, and a part of the circulation flow is supplied to the second reactor.

  The supply pipe for the pH regulator is connected to the external circulation line downstream of the branch line to the second reactor of the external circulation line. The pure water supply pipe, the acrylonitrile supply pipe, and the bacterial cell supply pipe are each directly connected to the first 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. This suspension was continuously fed at a rate of 11 kg / h while stirring in the first reactor. Further, acrylonitrile having a purity of 99.8% was continuously supplied via an acrylonitrile supply pipe at a rate of 32 kg / h, and pure water was continuously supplied via a pure water supply pipe at a rate of 37 kg / h. The temperature of the reaction solution during the reaction is 20 ° C., and 5 ° C. cooling water is circulated through the double tube of the heat exchanger and the second reactor installed on the external circulation line of the first reactor. Control was performed. A 0.1 M NaOH aqueous solution was used as a pH adjuster, and the supply amount was adjusted so that the reaction pH was 7.5 to 8.5. The reaction solution was extracted from the first reactor at a speed of 5 m 3 / h using a pump installed on the external circulation line, and returned to the first reactor via the external circulation line. Using a line connected to the second reactor branched from the external circulation line, the reaction liquid is fed from the first reactor at a speed of 80 kg / h so that the liquid level of the reaction liquid is 1 m from the bottom of the tank. And continuously supplied to the second reactor, and the reaction was further advanced in the second reactor.

  Analysis was conducted 200 hours after the start of the reaction under the following HPLC conditions. The conversion to acrylamide at the first reactor outlet was 95%, and the acrylonitrile concentration at the second reactor outlet was below the detection limit (10 Weight ppm or less). The acrylamide concentration at the outlet of the second reactor was 53.3% by weight.

[Comparative Example 1]
In the production of acrylonitrile of Example 1, the same procedure as in Example 1 was conducted except that the pH regulator supply pipe was directly connected to the first reactor, and the pH regulator was directly fed to the first reactor. Manufactured. When the above HPLC analysis was performed 200 hours after the start of the reaction, the conversion to acrylamide at the outlet of the first reactor was 92%, and the acrylonitrile concentration at the outlet of the second reactor was 80 ppm by weight. The acrylamide concentration at the outlet of the second reactor was 53.0% by weight.

[Comparative Example 2]
In the production of acrylonitrile in Example 3, the same procedure as in Example 3 was repeated except that the pH regulator supply pipe was directly connected to the first reactor and the pH regulator was directly fed to the first reactor. Manufactured. When the above HPLC analysis was conducted 200 hours after the start of the reaction, the conversion to acrylamide at the outlet of the first reactor was 93%, and the acrylonitrile concentration at the outlet of the second reactor was 50 ppm by weight. The acrylamide concentration at the outlet of the second reactor was 53.1% by weight.

1: Reaction tank 2: Raw material water supply pipe 3: pH adjuster supply pipe 4: Nitrile compound supply pipe 5: Cell catalyst supply pipe 6: A mixture of an aqueous medium and / or a mixture containing an aqueous medium and a pH adjuster Supply pipe 7: Stirrer 8: External circulation line 9: Circulation pump 10: Heat exchanger 11: Cooling water inlet 12: Cooling water outlet

Claims (4)

In a method for producing an amide compound using a microbial cell containing nitrile hydratase and / or a treated product thereof, a pH regulator is added to the aqueous medium and / or the mixture containing the aqueous medium supplied to the reaction vessel. A method for producing an amide compound, characterized by being fed to a reaction vessel after mixing The method for producing an amide compound according to the above [1], wherein the pH regulator is a base. The method according to claim 1 or 2, wherein the nitrile compound is acrylonitrile or methacrylonitrile, and the amide compound is acrylamide or methacrylamide. A reaction vessel for producing an amide compound using a microbial cell containing nitrile hydratase and / or a treated product thereof, an aqueous medium and / or a mixture containing an aqueous medium and a pH regulator are supplied. Amide compound production equipment with supply line