JPS5876101A - Apparatus for purifying organic solvent - Google Patents

Abstract

PURPOSE:To separate an org. solvent and water simply in high preciseness, by a method wherein the org. solvent containing water after precooling is further cooled by brine to remove water as an ice crystal and the separated org. solvent is recovered through a precooling apparatus. CONSTITUTION:A water containing org. solvent (e.g.; a mixture consisting of 85vol% THF and 15vol% water) is supplied to a precooling apparatus 4 to be cooled by the cold org. solvent at about -10 deg.C recovered from a succeeding apparatus for separating an ice crystal from the org. solvent. This precooled water containing org. solvent is sent to a crystallizing apparatus 5 and cooled by brine or a cooling medium cooled to -10--40 deg.C sent from a freezing apparatus 6 to obtain the two-phase (sherbet like) org. solvent having water as an ice crystal contained therein. In the next step, this org. solvent is sent to the separation apparatus 7 such as a vibration screen to discharge the ice crystal precipitated therein to the outside. On the other hand, the recovered org. solvent with a low temp. of about -10 deg.C is sent into the apparatus 4 to carry out heat exchange with the water containing solvent in the apparatus 4 to precool the same and recovered as the purified org. solvent.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for producing dead gold water in an organic solvent (
For example, tetrahydrofuran asv4 and water 15 V
The present invention relates to an organic solvent purification apparatus that cools a mixed liquid (oL%) to around -10° C. to precipitate only water as ice crystals and separate water from an organic solvent.

Figure 1 is a block diagram showing a conventional organic solvent purification apparatus of this type, in which (1) shows a heating device (3) for heating the supplied water-containing organic solvent.
), and the organic solvent gas that evaporates before the heating temperature reaches 100°C is sent to the cooling device (2), and the water separated from the organic solvent as a gas is discharged outside as a drain. The above cooling device (2
) is condensed and liquefied, and is recovered outside as an organic solvent.

Since the conventional organic solvent purification apparatus is configured as described above, it not only requires a cumbersome heating device to heat the distillation apparatus (1), but also has problems with the purity of the purified and recovered organic solvent. For example, an organic medium such as tetrahydro-7rane and water mixed or dissolved therein have a water content of 4.
Since both azeotropically occur at around 5%, there is a limit to the degree of purification of the organic solvent using only the heat distillation method using the conventional distillation apparatus (1) described above. After one stage of purification, e.g. adsorption,
This method has the drawback of requiring complicated procedures such as extraction and repeated various operations for water separation.

This invention was made with attention to this point, and unlike the conventional methods described above, the water-containing organic solvent is not heated and evaporated, but is cooled, and only the water in the organic solvent is precipitated as ice crystals. It is an object of the present invention to provide an organic solvent purification device that can easily and highly accurately separate an organic solvent and water.

That is, Fig. 2 is a block showing an example of 4M, in which a water-containing organic solvent (for example, 85 VoLfb of tetrahydrofuran and 15 oz of water) is supplied, and the ice crystal and solvent separation device described later is used. -1 recovered from (7)
A pre-cooling device consisting of a shell tube heat exchanger that pre-cools the water-containing organic solvent supplied by exchanging heat with the recovered organic solvent at a low temperature of around 0°C, (5) refers to the water-containing solvent pre-cooled by this pre-cooling device (4). The organic solvent is pumped in from the freezing device (6) through a cooling line at a temperature of 10 to 40 degrees Celsius, and is also cooled by a line refrigerant in a crystallizer comprising a shell tube heat exchanger. The water is turned into ice crystals by step 5), and the two-phase (sherbet-like) organic solvent is sent to the next stage separator (7), such as a "vibration sieve", and the separator (7) The ice crystals deposited in the precooler (4) are discharged to the outside, and the recovered organic solvent at a low temperature (around -10°C) is sent to the precooler (4) as described above. After pre-cooling this by heat exchange with an organic solvent, it is recovered as a purified organic solvent.

As described above, the organic solvent purification apparatus of the invention cools the water-containing organic solvent without heating it to evaporate it, as in the conventional method, and precipitates only the water in the organic solvent as ice crystals, thereby separating the organic solvent from the organic solvent. Since water is separated, the structure is simpler than conventional distillation methods, and organic solvents can be purified with significantly less energy. Since there is no azeotrope between the two, it is possible to purify high-precision organic solvents inexpensively and quickly without the need for complicated means of repeating various operations for water separation such as adsorption, extraction, etc. It also has the effect of being able to.

In addition, in one embodiment mentioned above, the precooling device (4),
Although the case where a shell tube type heat exchanger is used as the heat exchanger of the crystallizer (5) has been described, it is not necessarily limited to this, and the same effect can be obtained by using a flat plate type or a coiled tube type. Needless to say, it can be done. Furthermore, the separation device (7) that separates the organic solvent and ice crystals is not limited to the "vibrating sieve"; a centrifugal separator, centrifugal V overload, belt filter, etc. can also achieve the same effect. be. Furthermore, in the above-mentioned embodiment,
Although we have described the case where a mixture of tetrahydrofuran and water is used as the organic solvent, any other solvent such as ethyl alcohol may be used as long as the water in the solvent crystallizes within the cooling temperature of the refrigeration equipment. .

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a conventional organic solvent purification apparatus, and FIG. 2 is a block diagram showing an embodiment of the present invention. In the drawing, (4) is a pre-cooling device, (5) is a crystallizer, (6)
is a freezing device, and (7) is a separation device. Agent Shin Kuzuno −

Claims (1)

[Claims] (1) A pre-cooling device for pre-cooling a water-containing organic solvent to be purified;
A crystallizer in which the dead water organic solvent pre-cooled by the pre-cooling device is pumped in from the freezing device and cooled by the nine-cooled brine to freeze water, and the ice crystals and organic solvent generated by this crystallizer. (2) A shell-tube heat exchanger is used as a pre-cooling device and a crystallization device. organic solvent purification equipment. (3) Water-containing organic solvent is tetrahydrofuran 85 Vot
4 and water 15Vo4 (08). (4) The recovered organic solvent at a low temperature of about -10°C separated by the crystallizer. 2. The organic solvent purification device according to claim 1, wherein the water-containing organic solvent is pre-cooled by exchanging heat between the water-containing organic solvent and the water-containing organic solvent in a pre-cooling device.