JPH0747082B2 - Pressure fractional crystallization method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention pressurizes a mixture of two or more components in a high-pressure container to form a solid-liquid coexisting state, and then solid-liquid separates the mixture. The present invention relates to a pressure fractional crystallization method in which, after obtaining a solid product, the solid product is brought into a fluid state and taken out of the system through a pipe.

(Prior Art) This type of pressure fractional crystallization method uses a pressure fractional crystallizer having a piston and a high-pressure chamber, and a raw material composed of two or more components by a combination of pressure solidification operation and solid-liquid separation operation. A method for separating and refining a target component in a mixture into a solid product, wherein a heating device is arranged in a high-pressure container as a means for taking out the solid product from a high-pressure chamber, and the solid product is melted by the heating device. The means for extracting in liquid form and the structure of the pressure-separation crystallization apparatus are such that a high-pressure container having a high-pressure chamber and a lower lid can be separated, and at least one of them is used as a movable member to mechanically separate and purify solids. It is known to take it out.

However, with the above-mentioned means, it takes a long time to melt due to mechanical restrictions such as the fact that a stirring mechanism cannot be installed in the high-pressure container, so that it cannot be excluded from the range of use as test equipment. On the other hand, the above-mentioned means has a problem in that, due to the structure of the apparatus, incidental equipment such as a solid product automatic take-out apparatus such as a pusher and a shouter is indispensable for enabling automatic continuous operation.

(Problems to be Solved by the Invention) In a method of melting a solid product by disposing a heating device in a high-pressure container, the solid product is a cake-like solid in which solid particles are consolidated, The surface area ratio is very small, so the heat transfer rate is slow, and as a result, the time taken for the solid product to melt during the operating time of the device becomes a determinant factor of the production scale of the device, and the device cost will rise significantly. There's a problem.

There is also a problem that a large temperature distribution is generated in the high pressure container, which adversely affects the device and the product.

On the other hand, in the method of taking out the solid product as it is from the high-pressure container, many pressure-resolving crystallization apparatus main bodies and their peripheral auxiliary devices require many driving mechanisms and driving devices, and the auxiliary devices occupy a large part of the device cost. There is a problem of becoming a thing.

Also, if you take only the pressure-separation crystallizer body,
Since the number of drive parts increases, there is also a problem in device maintenance that the probability of occurrence of trouble in the sliding part of the high-pressure container increases.

In addition, when the product reacts due to the presence of air, light, etc., there arises a problem in product quality, and it is necessary to take measures such as gas sealing and light blocking of the entire pressure fractionation crystallizer.

The present invention is intended to solve these problems.

(Means for Solving Problems) In order to solve the above problems, the present invention has the following configuration. That is, in the pressure-separation crystallization method, a mixture of two or more components is pressurized in a high-pressure container to form a solid-liquid coexisting state, and then the liquid phase component is discharged to the outside of the container. In the pressure fractional crystallization method for producing a solid product, a liquid or gas that dissolves or melts the solid product is supplied into the high-pressure container and is brought into direct contact with the solid product to form a liquid or slurry. It is brought into a state of fluid flow and then taken out of the high-pressure container.

(Embodiment and Action) An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

FIG. 1 shows an embodiment of the present invention, in which (1) is a raw material supply pipe, (2), (4), (9), (10), (11) and (1
2), (13) are valves, (3) are product collection lines, (5)
Is a raw material tank, (6) and (22) are feed pumps, (7) is a high-pressure container, (14) is a piston, (15) is a drainage outflow line, and (1)
6) is a degassing line, (17) is a drainage pressure adjusting mechanism, and (1
8) is a drainage tank, (20) is a melt supply pipeline, (21) is a product tank, and (23) is a heater.

In the pressure fractional crystallization method according to the embodiment of the present invention, the means for extracting the solid in a molten state will be described in detail below.

First, the valve (2) of the raw material supply pipeline (1) and the valve (13) of the degassing pipeline (16) are opened, and the valve (4) of the product recovery pipeline (3) and the drainage outflow pipeline (15). ) Valves (10) and (11) are closed, and the raw material mixture is fed from the raw material tank (5) by the feed pump (6) through the raw material supply pipe (1) to the high pressure vessel (7) of the pressure fractional crystallization device. Supply inside.

Valves (2) and (13) when the feed of the raw material mixture is complete
Close, and pressurize while lowering the piston (14).
When the crystallization of the solid as a specific component proceeds due to pressurization, the valves (10), (1
1) is opened, the drainage pressure adjusting mechanism (17) is adjusted, and the liquid phase other than solid crystals is discharged to the drainage tank (18).

Furthermore, pressing is applied to the solid remaining in the high-pressure container (7),
The pressure of the liquid phase between the solid particles is lowered to partially melt the surface of the solid, and the concentration of the liquid phase is increased to improve the purity of the solid as a whole.

Next, open the valve (4) provided in the product recovery pipeline (3) and the valve (9) provided in the melt supply pipeline (20) (valves (2), (10), (11)). , (12), (13)
The melt of the product having the same composition as the solid is discharged from the product tank (21) to the melt supply pipe (20) with its flow rate adjusted by the feed pump (22). It is further heated by a heater (23) provided in the middle of the passage (20), and this is supplied into the high-pressure container (7) from an existing degassing pipe passage (16) having an opening on the lower surface of the piston (14). To do.

Then, the superheated molten liquid is brought into direct contact with the solid to be melted, and the piston (14) is advanced in accordance with the melting amount of the solid so that the upper surface of the solid in the high pressure container (7) and the lower surface of the piston (14) The piston (14) is lowered while keeping the interval constant. A mixed liquid of the supplied melted liquid and a melted solid melted by the supplied liquid, or a slurry mixture containing a part of the solid remaining in the melted liquid is disposed in the lower part of the high pressure container (7). It is recovered by flowing out to the product tank (21) through the existing product recovery pipeline (3).

FIG. 2 is a flow chart showing an embodiment in which a drainage outflow conduit is used when supplying a superheated melt, and the reference numerals shown in the flow chart are the same as those shown in FIG. is there.

That is, when the overheated melt is supplied to the solid in the high pressure container (7), the overheated melt is passed from the melt supply pipe (20) through the drainage outflow pipe (15) to the high pressure container (7). ) Is supplied to the inside of the high pressure vessel (7) from below to melt the solid.
After that, the solid that is melted into a liquid or slurry state can be recovered by flowing down the product recovery conduit (3) through the gas vent conduit (16) provided in the piston (14). it can.

Next, a comparative example of the time required for melting all the solids obtained in the high-pressure container is shown below.

The above example is an experiment for demonstrating the usefulness of the present invention, which is the prior art, and the experimental example of the present invention is shown by the prior art. In melting a solid of p-cresol having a height of 80 mm separated and purified with a pressure crystallization pilot test apparatus having a high-pressure container having an inner diameter of 80 mm provided with a jacket having a function for temperature adjustment,
It took about 80 minutes to maintain the temperature of the high pressure vessel at 50 ° C. and melt all the solids.

Using a pressure crystallization pilot tester equipped with a high-pressure container with an inner diameter of 80 mm, when melting the separated and purified solid of p-cresol with a height of 80 mm, p-cresol solution heated to 50 ° C. was pressurized at a rate of 6 l / min. The time required to supply all of the solid in the container and melt the whole solid was about 11 minutes.

Under the conditions of the above signs, when the piston was further advanced at a rate of 15 mm / min, the time required to melt the entire solid amount was about 4 minutes.

Since the already melted liquid is heated using a heat exchanger, it is easy to control the temperature of the liquid to be supplied, and it is possible to control the temperature of the device and the product below the limit temperature. In this case, since the solid product is brought into direct contact with the solid product, the heat transfer rate is significantly increased.

Further, in the state where the solid particles are dispersed, it will flow out as a slurry liquid, and it is not always necessary to melt the entire amount of the solid, so the required melting time in the high-pressure container can be further shortened.

Further, in the method of using a liquid that is separable from the solid product components as a substitute for the overheated molten liquid, the temperature of the supply liquid does not necessarily need to be set higher than the melting point of the solid product, The purpose is achieved by keeping the melting point or higher. Therefore, it is possible to significantly reduce the thermal energy required for melting or melting, and in some extreme cases it may not be necessary. Furthermore, when the solid product is a substance that undergoes sublimation or a chemical change in the vicinity of the melting point, it becomes difficult or impossible to take out the solid product by heating and melting, but by adopting the present method, This solid product can be extracted in a liquid or slurry state. In addition, when this method is adopted, it is necessary to re-separate, and the most suitable heating medium or solvent is selected for each substance that is a solid product.

It is also possible to bring the solid product obtained in the high-pressure container into direct contact with a gas that is an ingredient inert to the solid product to form a liquid or slurry and take it out of the high-pressure container. Is.

Further, when the liquid or gas supplied into the high pressure container is a substance that is a component to be mixed or reacted with the product produced by the pressure fractional crystallization method in the next step, re-separation is unnecessary, and It can be carried out as easily as or more than the method using a superheated melt.

(Effects of the Invention) The present invention significantly shortens the time required to dissolve or melt a solid product obtained in a high-pressure vessel and take it out from the high-pressure vessel in the pressure crystallization method.

Further, the accessory device, the drive mechanism and the drive device of the main body of the pressure fractional crystallizer are not required, and the pressure fractional crystallizer itself is simplified and the cost of the apparatus is reduced.

In addition, it does not require a mechanism to open and close the high-pressure container, eliminates the effects of air and light (ultraviolet rays), and can prevent problems such as product quality deterioration and purity deterioration. It also produces an effect that cannot be achieved.

[Brief description of drawings]

FIG. 1 is a flow chart showing an embodiment in which a gas venting pipe is used when supplying the melt of the present invention, and FIG. 2 is a drainage pipe when supplying the melt of the present invention. It is a flow figure showing an example when a road is used. (3) …… Product recovery line, (7) …… High-pressure container, (14)
...... Piston, (15) …… Drainage outflow line, (16) …… Gas release line, (20) …… Melting liquid supply line, (23) …… Heating device.

Claims (5)

[Claims] 1. A solid product in a container by pressurizing a mixture of two or more components in a high-pressure container to bring it into a solid-liquid coexisting state, and then discharging the liquid phase component outside the container. In the pressure-separation crystallization method for producing, a liquid or gas that dissolves or melts the solid product is supplied into the high-pressure container and brought into direct contact with the solid product so that it is in a liquid or slurry fluid state. None, after which, the pressure fractional crystallization method is characterized in that it is taken out of the high-pressure vessel. 2. The pressure fractional crystallization method according to claim 1, wherein the liquid supplied into the high-pressure container is a molten liquid taken out of the high-pressure container and heated in a fluidized state. 3. The liquid according to claim 1, wherein the liquid supplied into the high-pressure container is a substance that is a component that is separable from the solid product component after being taken out of the high-pressure container. Pressure fractional crystallization method. 4. The pressure fractional crystallization method according to claim 1, wherein the gas supplied into the high-pressure container is a gas which is an inert gas component with respect to the solid product components. 5. The liquid or gas supplied into the high-pressure container is a substance as a component to be mixed or reacted with the product produced by the pressure fractional crystallization method in the next step.
The pressure fractional crystallization method as described in the above item.