JP3409028B2 - Method and apparatus for regenerating solvent - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solvent recycling method and a recycling apparatus, and more specifically, to a used stripping solution generated in a stripping step of a substrate resist layer in manufacturing a semiconductor or liquid crystal display module, Alternatively, the present invention relates to a method and apparatus for reusing a solvent containing used thinner and the like, which is used by dissolving a resist resin for other purposes.

[0002]

2. Description of the Related Art Conventionally, a heated stripping solution (solvent) has been used for stripping a substrate resist layer in manufacturing a semiconductor or liquid crystal display module. This stripper is usually composed of a mixture of monoethanolamine (hereinafter abbreviated as MEA) and dimethyl sulfoxide (hereinafter abbreviated as DMSO). This mixture may contain a small amount of water. Further, a mixture of propylene glycol monomethyl ether acetate (hereinafter abbreviated as PGMEA) and propylene glycol monomethyl ether (hereinafter abbreviated as PGMEA) is used as a solvent called thinner, and both are water-soluble and a small amount of water. Is included.

In recent years, the size of substrates has been increasing, and the amount of stripping liquid and thinner used has been increasing. These waste liquids have been collected and disposed of by a waste disposal contractor, but the collection cost is high. Further, since the disposal of the waste liquid has a bad influence on the global environment, it is desired to recycle and use the solvent such as the used stripping solution and thinner without discarding it.

[0004]

Regarding the regeneration of the used solvent, a method using an operation such as distillation separation is being used in recent years. However, it is not possible to regenerate the stripper or thinner into a component equivalent to a new liquid. It is difficult, and it is also difficult to stably operate the regenerator for a long time while maintaining the quality of the reclaimed liquid, and the semiconductor, the method of regenerating the used solvent in the liquid crystal device field, and the dedicated device are not yet established. There has been a desire for a method and an apparatus for recycling used solvents in this field.

Further, regarding the production and installation of the apparatus, if the processing capacity is emphasized, the size tends to increase. However, a small-sized solvent recycling apparatus which has a high recycling capacity, can easily maintain the quality of the recycled liquid, and is desired. Was there.

Therefore, the present invention is to meet the above-mentioned conventional demands, and the first object is to remove a used solvent such as a stripping solution for a resist resin or a thinner used in the manufacture of semiconductors and liquid crystal substrates. It is to provide a method for reusing a solvent that can be reused.

A second object of the present invention is that a stripping solution of a resist resin used in the manufacture of liquid crystal / semiconductor substrates or a used solvent such as thinner can be stably regenerated for a long time, and It is an object of the present invention to provide a solvent recycling device that can be miniaturized.

[0008]

Means for Solving the Problems In order to solve the above-mentioned first problem, the following means are provided as an invention. (1) Impurity with a low boiling point that is lower than that of the resin and solvent components
A method of reproducing a spent solvent containing and objects, resin
The resin component removal process to remove the components and the resin component removal
Process for removing low boiling impurities from the used solvent
And distill the residual liquid obtained in the low-purity point impurity removal step,
Distiller that evaporates the solvent component and recovers it as a condensate
And the inner peripheral surface in the resin component removing step.
And a sealed cylinder body that has
A rotating body that is placed inside the storage cylinder body
A rotating body having a brush in a spray shape, and a resin removing device.
Using the rotation that rotates with the evaporation surface in the cylinder body
Supplying the used solvent between the body or the brush,
Contacting the used solvent with the heated evaporation surface
By evaporating the low boiling point impurities and solvent components,
In order to flow down the resin component in the used solvent,
Law. (2) It has been used before the resin component removing step.
The method according to (1), comprising a step of degassing the solvent. (3) The used solvent is monoethano as a solvent component.
Containing low-temperature boiling point impurities in the low boiling point impurities removal step.
The separation temperature at which the carbon dioxide gas contained in the used solvent is
Described in (1) or (2) above the temperature at which separation is possible
the method of. (4) One or more main components of the used solvent
Any of (1) to (3), which is a stripping solution comprising the components of
The method described in crab. (5) One or more main components of the used solvent
As described in (1) or (2), which is a thinner consisting of
How to list. (6) The resin component removing step, the low boiling point impurity removing step
In the distillation step, the solvent is evaporated from the liquid to be treated.
The separation temperature of the liquid to be separated is below the temperature that can withstand the corrosion of the materials used.
Evaporate under reduced pressure so that (1) to (5)
The method described in some cases. (7) Exhaust gas from an exhaust gas source containing a vaporized solvent component
It is equipped with a step of condensing
Any of (1) to (6) as a part of the used solvent
Some way. (8) A resin component and a low-boiling point impurity having a lower boiling point than the solvent
A device for regenerating used solvent including
A resin component removing device that removes the resin component from the solvent
Low boiling impurities are vaporized from the used solvent from which the fat component has been removed.
First distillation device to generate and remove, and low boiling point impurities are removed
Evaporate and collect solvent components from the used solvent
A second distillation device, and the resin component removing device
Is a sealed cylinder having an inner peripheral surface as a heatable evaporation surface.
A main body and a rotating body arranged in the cylinder main body,
A rotating body having a brush radially on its outer peripheral surface;
Rotate with the evaporation surface in the cylinder body using a fat removing device.
The used solvent between the rotating body or the brush
To supply the used solvent to the heated evaporation surface.
By contacting, low-boiling impurities and solvent components evaporate
And the resin component in the used solvent is allowed to flow down.
A solvent recycling device that is designed to be used . (9) Which of the first distillation apparatus and the second distillation apparatus
Described in (8), one or both of which is a packed distillation column
Equipment . (10) Low boiling point component removed in the first distillation apparatus
The condensing means for condensing the heat is kept warm, and the condensing means is a circulating refrigerant.
The device according to (8) or (9), which maintains a predetermined temperature range of
Place (11) The resin component removing device, the first distillation device
And a storage provided in association with the second distillation device
Equipped with a pumping means for nitrogen gas that carries out the liquid stored in the tank
The device according to any one of (8) to (10) . (12) Treat the residual liquid of the second distillation device as waste liquid
The residual liquid is returned to the resin component removing means to the waste liquid path.
Link the routes to be used and selectively use the return route.
The device according to any one of (8) to (11) . (13) Recirculate or transfer the processing liquid between the above-mentioned devices
Liquid temperature in front of each transfer means used for return
Providing heat exchange means for lowering, (8) to (12)
The device according to any of the above . (14) Recovery solvent component obtained from the second distillation apparatus
Route for taking out a part of the main liquid supply pipe and returning it to the main liquid supply pipe
Provided with a spectroscopic analysis means to continuously monitor the processing liquid components and control the operation.
The device according to any one of (8) to (13) . (15) From an exhaust gas generation source containing a vaporized solvent component
Equipped with means for condensing exhaust gas, this condensate is
Recycled as a part of Mino solvent, (8) to (14)
The device described in any way.

The used solvent contains a resist resin and a low boiling point component such as a water component in addition to the solvent component. According to the regenerating method of the present invention, the resist resin component is removed from the used solvent, the low boiling point component such as the water component is removed, and the solvent component is regenerated and recovered. Further, the exhaust system in the step of treating the solvent contains a considerable amount of vaporized solvent components. The vaporized solvent component is recovered as a solvent component without being treated as exhaust gas.

The resin component of the used solvent and low-boiling components such as water can be removed, and then the stripping solution of one component or a plurality of components can be recovered, or the resin component of the used solvent and low-boiling components such as water. It is also possible to remove the components and then recover the thinner of one or more components.

Further, a means for removing the resin component is provided on the inner peripheral surface.
A closed cylindrical main body having a heatable evaporation surface, and
Radiator on the outer peripheral surface of a rotating body placed inside the cylinder body
A rotating body having a brush in a shape of
Using the rotating body that rotates with the evaporation surface in the cylinder body
Or, supply the used solvent between the brush and
Contacting the used solvent with the heated evaporation surface
By evaporating low boiling point impurities and solvent components,
A falling film type that allows the resin component in the used solvent to flow down to
By using the concentration means, the resin component can be used solvent
Removed from. In addition, the subsequent component separation process is easy.
It Solvent components may absorb gas and generate salts.
However, gas components are separated and removed in the low boiling point removal process.
It Unnecessary gas dissolved in the used solvent due to the degassing process
The body is removed. Extra gas dissolved in used solvent
It is possible to improve recovery and regeneration efficiency by removing
Be done.

Reflux or transfer of the treatment liquid of each step
The liquid temperature of the transfer means for returning the liquid is lowered by the heat exchange means.
By doing so, the treatment liquid whose temperature has been lowered is introduced into the transfer means.
Can be passed. According to this, depending on the temperature
The life of the affected pump can be extended.
If a spectroscopic analysis means is provided, for example, from 900 nm to 2
Infrared light with a wavelength of 100 nm causes the molecular solids in the treatment liquid component to
Continuously monitors the components of the processing liquid by utilizing the existing infrared light absorption effect
The quality of the regenerated solvent is constantly checked by controlling the operation.
it can. Therefore, not only the main component ratio of the solvent,
Impurity components (water content, resist content, etc.) can also be measured.
Therefore, it is possible to continuously analyze the components of the regenerated solvent during operation of the equipment.
Can respond to abnormalities immediately, and always has stable liquid quality
Can be supplied to the chemical solution supply tank. Materials used for handling liquids
The amount of liquid separated from the mixed liquid in consideration of the thermal corrosion resistance of the quality.
Reduce the separation temperature to below the temperature that can withstand the corrosion of the materials used.
By applying pressure, the corrosion resistance can be improved. By this
Parts can be replaced in a short period of time without using a special material.
It is possible to operate the device stably for a long time without
It becomes Noh. Low boiling point is adjusted by adjusting the solvent concentration in the removed material.
The outlet temperature of the substance removal process is higher than the refrigerant temperature of the condensation process.
By setting the temperature to a moderate temperature, low boiling point components become liquid.
Be recovered. This allows the condenser temperature to be taken into consideration in consideration of the refrigerant temperature.
The low boiling point component can be liquefied under optimum conditions in the stage.
It Supply of liquid from storage tank and / or processing liquid tank to the next process
The solvent after purification is carried out by pumping nitrogen gas.
Clean solvent is supplied without touching unnecessary gas.
Be done. Therefore, without mixing impurities in the liquid quality,
Stable liquid transfer is possible. Waste liquid remaining in the purification process
The residual liquid component is removed from the resin component in the disposal route to be treated as
There is a return path to return to, and the return path can be used selectively
As a result, the solvent components contained in the residual liquid side are re-refined.
Manufacturing and extraction can be achieved. As a result, high boiling point components in the purification process
Can be separated and extracted again, and the regeneration efficiency can be improved.
Used including the resin component used to dissolve the resist resin component
Removal process of solvent or resist resin overlaid on the substrate
Spent solvent containing a resin component resulting in the final to fine
After evaporating the solvent, it is recovered as a condensate.
The resist resin component is removed and the low boiling point components such as water components are removed.
The component is removed, and the solvent component is regenerated and recovered. Falling film
Type concentrator removes resin components from used solvent
To be done. The packed distillation column, even if small, is equivalent to the tray type.
Distillation performance is obtained. This makes the distillation column smaller.
Therefore, it is possible to reduce the size of the entire device.
Cost and workability can be improved. Also, condensing means
Installed by maintaining the specified temperature range of the circulating refrigerant
A certain condensation performance can be obtained regardless of the ambient temperature. This
Even if the ambient temperature changes depending on the season,
In addition, it prevents the generation of precipitates due to overcooling due to the decrease in outside temperature during the winter.
The quality and operation of the equipment can be stabilized. further,
The entire device is divided between at least two devices
By constructing from a unit, workability can be improved.
It Also, the entire device is functionally divided into multiple units.
It is possible to improve transportability and workability.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The used solvent used in the present invention is dissolution of resist resin in the production of semiconductors and liquid crystal substrates,
It is a used waste liquid used for peeling, and mainly contains a resist resin as a resin component and a small amount of water in addition to a main solvent component.

In the method of the present invention, as shown in FIG. 1, a used solvent is first removed in a resin component removing step to remove a resin component (resist resin), and then a low boiling point removing step is performed to remove low boiling point substances such as water. Finally, it comprises a purification step in which the regenerated solvent component is obtained as a condensate after evaporation. By this step, the non-volatile resin component can be removed first, so that there is no need to consider the influence of the floating resin component in the subsequent operation, and there is an advantage that a stable operation can be performed. After removing the resin component, the low boiling point component is removed, and finally the solvent is evaporated and separated for purification and condensation to obtain a regenerated solvent. This method can simplify the flow.

As shown in FIG. 2, the exhaust gas of the exhaust system in the atmosphere containing the solvent vaporized in the solvent handling step is used as a condensate in the exhaust gas condensing step before reaching the exhaust gas treatment step, and the condensate is used. It can be used solvent. This used solvent can be regenerated into a regenerated solvent.

In the method of the present invention, a used solvent such as a stripping solution waste solution (for example, containing MEA and DMSO as a main component) or the like used in the step of stripping the resist resin is used as shown in FIG. As shown, the stripping solution can be regenerated by removing the resist resin, water and the like.

The method of the present invention, as shown in FIG.
It is also applied to the case where the used solvent is a thinner waste liquid (for example, PGMEA and PGME as main components) composed of one or more components used in the stripping step and other steps. That is, the thinner can be regenerated by removing the resist resin, water and the like from the thinner waste liquid.

By using the falling film type concentration means in the resin component removing step, it is possible to separate the resin component at a high concentration.

Among the solvent components, MEA or the like easily absorbs gas (CO2) in the atmosphere and easily produces salts (carbonates). Gas is separated from the salts in the low boiling point substance removing step.

When the component liquid separated in each step is fed to the next or previous step or tank, a heat exchange means is provided in front of or in the middle of the liquid feeding means (such as a pump) to control the temperature of the treatment liquid. As a result, the life of the liquid feeding means can be extended.

As described above, the solvent component may absorb gas to form a salt, or the gas may be dissolved. By adding a treatment in the degassing step (separation of dissolved gas by ultrasonic wave application method, etc.), the used solvent and solvent that have absorbed such gas can reduce various adverse effects in the latter stage and improve the purity of the regenerated solvent. This can be improved (see FIG. 5).

As shown in FIG. 6, by continuously monitoring the quality of the regenerated solvent after the refining step and controlling it for optimization, the solvent quality can be kept stable.

By increasing the degree of reduced pressure, the separation temperature of the solvent components from the used solvent can be lowered, and a special metal (such as Hastelloy) is used as the material having temperature corrosion resistance against the solvent having corrosiveness. Corrosion resistance is obtained even if it is not used.

By adjusting the ratio of the solvent component mixed in the low boiling point component (moisture etc.) evaporated and separated in the low boiling point substance removing step,
By vaporizing at a temperature higher than the refrigerant temperature in the subsequent condensation process, the vapor is introduced into the condensation process and becomes a condensed liquid.

By mainly feeding the liquid of the regenerated solvent after purification to the storage tank of the purified solvent by pressure feeding of nitrogen gas,
The quality of the regenerated solvent can be maintained.

The high boiling point component separated in the refining step can be selected from both the waste liquid treatment and the resin component removal step by the return pump, and usually, the high boiling point component is returned and treated again from the beginning to improve the separation efficiency. Can be increased.

In order to process each step shown in FIG. 7, in the former stage of the resin component removing device, next in the low boiling point substance removing device, and finally in the spent solvent regenerating device which is the main constituent of the purifying device, the resin component removing device is used. By removing in advance, it is possible to prevent the adverse effect of the resin component in the subsequent apparatus. Further, by finally evaporating and condensing the regenerated solvent, a regenerated solvent having high purity can be obtained.

When the resin component removing device is a falling film evaporator as shown in FIG. 8, the resin component can be easily separated.

Further, by removing the resin component (non-volatile component) in advance, the harmful factors in the operation of the apparatus and the liquid quality are
After removal, the distillation column after the low boiling point removal step in the latter stage has no possibility of deposits and the like, and thus the packed distillation column can be used.

By maintaining the temperature of the condensing means for liquefying the low boiling point component removed by vaporizing from the low boiling point substance removing device, a predetermined temperature range of the refrigerant can be maintained and stable operation can be performed.

Further, by adopting the packed distillation column, the regenerator can be easily miniaturized, so that it is possible to construct the whole apparatus into a plurality of unit structures in consideration of workability and transportability.

[0032]

Embodiments of the present invention will now be described with reference to the drawings. First, a solvent regenerator (hereinafter abbreviated as a regenerator) used for carrying out the solvent regenerating method will be described.

The structure of the reproducing apparatus 1 is shown in FIGS. The used solvent L is a liquid obtained by collecting waste liquid from the semiconductor or liquid crystal manufacturing process or condensate of the exhaust system. In FIG. 7, the solvent recovery tank 2 for storing the used solvent L is a pump 3
It is connected to the upper part of the resin component removing machine 5 (corresponding to the resin component removing device of the present invention and the falling film type concentrating means) via the first conduit 4. The resin component removing machine 5 has a heating vapor inlet 6a, an outlet 6b on the lower side surface, and a resin outlet 6c on the bottom, and the resin outlet 6c.
Is connected to the resin component storage tank 7 so that the resin component can be discharged.

The vapor discharge port 8 is provided at the upper portion of the resin removing machine 5.
It has a return liquid receiving port 8b. The vapor discharge port 8a is connected to almost the middle stage of the distillation column 9 (corresponding to the low boiling point substance removing device of the present invention) via the second conduit 8. The main distillation column 9 is a packed distillation column, in which a packing 10a is built in the upper side, a reflux port 11 is formed in the upper part, and a vapor discharge port 12 is formed in the vicinity of the uppermost part.

The vapor discharge port 12 reaches a reflux tank 16 via a third conduit 13 and a first condenser 14 and a first vent condenser 15 each having a cooling water reciprocating path. The reflux tank 16 takes out the liquid from the lower part of the tank, and returns to the reflux tank 16 via a reflux pump 17, a reflux path 18 leading to the reflux port 11, and a three-way valve 19 from the reflux path 18, and a return pipe 20 returning to the reflux tank 16, and a tank. It has a low boiling point component discharge passage 21 taken out from the upper side of.

The low boiling point component discharge passage 21 reaches the low boiling point component storage tank 22 and can be discharged. On the other hand, the packing 10b is built in the lower side of the distillation column 9 and the in-column storage tank 23 is formed at the lowermost part. A circulation pipe 25 from the heating reboiler 24 is connected to the in-tower storage tank 23, and a fourth conduit 28 is connected to the rectification tower 27 via a transfer pump 26 on the other hand.

The rectification column 27 is a vertical multi-stage distillation column in which a plurality of trays 29 are built in on the upper side, a reflux port 30 is arranged at the upper part, and a vapor discharge port 31 is formed near the uppermost part. There is. The vapor discharge port 31 is connected through a fifth conduit 32,
A second condenser 33 each having a cooling water return path,
It reaches the reflux tank 35 via the second vent condenser 34.

The reflux tank 35 has a reflux passage 37 for taking out the liquid from the lower portion of the tank and reaching the reflux port 30 via a reflux pump 36, and a regeneration component discharge passage 38 for taking out the liquid from the upper portion of the tank.

On the other hand, on the lower side of the rectification column 27, an in-column storage tank 39 is formed at the lowermost portion, the internal storage tank 39 is connected to a circulation pipe line 41 from a heating reboiler 40, and the other side is heated. A return passage 44 is connected to the return liquid receiving port 8b of the resin content remover 5 via an exchanger (heat exchange means) 42 and a return pump 43.

The regeneration component discharge passage 38 is provided in the first processing liquid tank 4
5 and the second processing liquid tank 46. The first processing liquid tank 45 and the second processing liquid tank 46 are connected to the concentration adjusting tank 48 from the lower portions through sixth conduits 47a and 47b, respectively. Further, the concentration adjusting tank 48 is connected to the chemical solution supplying tank 51 via a seventh conduit 50 passing through a filter 49 having a Teflon filter medium inside, and can be supplied to the semiconductor and liquid crystal manufacturing process.

The seventh conduit 50 is branched between the filter 49 and the chemical solution supply tank 51, and the branch pipe 50a is provided with the spectroscopic analysis means 5
It is returned to the seventh conduit 50 via 2.

Further, the pressure reducing device 53 (for example, a vacuum pump or the like) is connected to the first vent condenser 15, the second vent condenser 34, the low boiling point component storage tank 22, and the processing liquid tanks 45 and 46 through the pressure reducing conduits 54a and 54b. Therefore, the distillation column 9, the rectification column 27, and the resin component removing machine 5 are also configured to be capable of reducing the pressure.

As shown in FIG. 8, the resin component removing machine 5 is
The closed cylinder-shaped cylinder body 55 is heated by the heating means 56 that introduces steam or the like on the outer peripheral surface, and the cylinder body 55 serves as an evaporation surface 57. A cylindrical rotating body 58 is provided inside the cylinder body 55.
Is coaxially rotatable with the cylinder body 55.
The peripheral surface of the rotating body 58 has brushes 59 radially, and the surface of the brush 59 and the inner surface of the cylinder body 55 are arranged so as to be rotatable in contact with each other.

Further, both the distillation column 9 and the rectification column 27 are provided with a thermometer and a pressure gauge at the upper, middle and lower stages so that the internal temperature and pressure inside the column can be measured. In this embodiment, both the distillation column 9 and the rectification column 27 have external reboilers 24 and 40.
Provided as an integral type in 9 (for example, calandria type)
Also in this case, the heating effect is the same, and a more space-saving effect can be obtained.

As shown in FIGS. 7 and 9, the low boiling point storage tank 2
2 is a nitrogen conduit 60 for introducing nitrogen gas and an opening / closing valve 61.
a, and switching valves 61b, 6 for switching each situation
1c, 61d, 61e are provided. Reference numeral 61b is an atmosphere opening system, 61c is a liquid sending system from the previous stage (low boiling point component discharge passage 21), 61d is a decompression system, and 61e is a discharge system from the tank.

Similarly, as shown in FIG. 10, the first treatment liquid tank 45 and the second treatment liquid tank 46 also have nitrogen conduits 62, 63 and opening / closing valves 64a, 65a for introducing nitrogen gas, respectively, and are provided for each situation. Switching valves 64b, 64c, 64
d, 64e and 65b, 65c, 65d, 65e are provided. 64b and 65b are open to the atmosphere, 64c and 6
5c is a liquid delivery system from the previous stage (regenerated component discharge paths 38a, 38
b), 64d and 65d are provided in the pressure reducing system, and 64e and 65e are provided in the discharge system from the tank.

Further, as shown in FIG. 11, the first condenser 14, the first vent condenser 15, and the refrigerant pipe (cooling water) connected from the upper part of the distillation column 9 are provided with a heat insulating material 67 and a pressure reducing pipe on the outer peripheral surface thereof. A heat insulating material 67 enclosing the heating means 66 is covered. Steam as the heating means 66,
A heater is effective.

Next, the operation of the regenerating apparatus 1 will be described along with the apparatus operating procedure and the flow of the used solvent. In FIG.
The decompression device 53 (vacuum pump) is operated, and the decompression pipe 54
The resin content remover 5, the distillation column 9, and the rectification column 27 are maintained under a reduced pressure close to a vacuum via a and 54b. Also,
The resin content remover 5, the distillation column 9, and the rectification column 27 are heated to a predetermined temperature by heating means.

After that, the used solvent L in the solvent recovery tank 2
Is sent to the resin content remover 5 by the pump 3. The used solvent L introduced into the resin content removing machine 5 is blown off by the rotating body 58 and the brush 59 in the machine shown in FIG. 8 to come into contact with the evaporation surface 57, disperse in a film form, and vaporize the volatile component L1. It is evaporated and separated into a liquid non-volatile component (resin component) L2, and the volatile component L1 is introduced into the distillation column 9 through the vapor discharge port 8a. As the resin component removing machine 5, the "thin film evaporator" manufactured and sold by Japan Vehicle Manufacturing Co., Ltd. having the same structure as the resin component removing machine 5 can be used.

The non-volatile component L2 travels down the inner wall to the lower side of the resin content remover 5, is stored at the bottom, and is stored in the resin content storage tank 7 (see FIGS. 7 and 8). On the other hand, as shown in FIG. 7, the volatile component L1 introduced into the distillation column 9 is the filler 10
Distillation is carried out by vapor-liquid contact between the reflux liquid Lr1 descending in a and 10b and the vapor rising by heating, and the low boiling point component L3 is vaporized and rises to vapor discharge port 12
Condenser 1 which is discharged from the tank and circulates cooling water
4, condensed in the second vent condenser 15, and returned to the reflux tank 16
Is temporarily stored in the recirculation tank 16 and is fed from the lower portion to the recirculation port 11 of the distillation column 9 as the recirculation liquid Lr1 while maintaining the balance of distillation, and the surplus liquid Le is returned to the recirculation tank 16. The high-level overflow of the reflux tank 16 is stored in the low-boiling-point component storage tank 22 via the low-boiling-point component discharge passage 21 and prepared for discharge.

Low boiling point component L in low boiling point component storage tank 22
3 is discharged by opening / closing valves (switching valves) 61c, 6
1d is closed, the open / close valve (switching valve) 61b is opened to return to atmospheric pressure, then the valve 61b is closed, and then the open / close valves 61a and 61e are opened to open / close the open / close valve 6
It can be performed by sending nitrogen gas from 1a. At the end of discharging, the on-off valves 61a and 61e are closed,
Open 61b and return to atmospheric pressure. Next, the open / close valve 61
Open c and 61d and prepare for the storage tank.

On the other hand, in FIG. 7, the high boiling point component L4 is stored as a liquid in the in-column storage tank 23, and is supplied by the transfer pump 26 to the lower layer portion of the rectification column 27 via the fourth conduit 28. The high boiling point component L4 introduced into the rectification column 27 is stored in the column internal storage tank 39 in the column, and part of it vaporizes and rises by heating. Distillation by gas-liquid contact between the reflux liquid Lr2 that descends in the tray 29 and the vapor that rises is performed, and the rectification component L5 (final regenerated component) rises and vapor discharge port 31
Second condenser 3 that is circulated by the cooling water discharged from the
3, the second vent condenser 34 is condensed, the reflux tank 3
It is temporarily stored in 5. The low boiling point component L5 stored in the reflux tank 35 is fed from the lower portion of the reflux tank 35 by the reflux pump 36 as the reflux liquid Lr2 to the reflux port 30 of the rectification column 27 while maintaining the balance of distillation. As shown in FIG.
The overflow of the set liquid level of the reflux tank 35 is stored as a regenerated liquid component (rectification component) L5 in one of the treated liquid tanks 45 and 46 via the regenerated component discharge passage 38, and the stored regenerated liquid tank becomes full. In that case, alternate storage is performed in which the other processing liquid tank is used.

As shown in FIG. 10, when the first processing liquid tank 45 is full, the open / close valves 64c and 64d are closed,
The opening / closing valves 65c and 65d on the second processing liquid tank 46 side are opened to start storage on the second processing liquid tank 46 side. The regenerant liquid component L5 stored in the first treatment liquid tank 45 or the second treatment liquid tank 46 is pressure-fed with nitrogen gas from the filled tank to pass through the sixth conduits 47a and 47b, and the concentration adjusting tank 48 is supplied. The liquids are alternately delivered to.

As shown in FIG. 10, the discharge from the first processing liquid tank 45 is performed by opening the open / close valve 64b and returning to the atmospheric pressure.
After that, 64b is closed, and then the open / close valves 64a, 6
4e is opened, and nitrogen gas is sent from the opening / closing valve 64a. At the end of discharging, the open / close valves 64a and 64e are closed and 64b is opened to return to atmospheric pressure. Next, the opening / closing valves 64c and 64d are opened to prepare for the storage tank. The discharge from the second processing liquid tank 46 is also performed by the same opening / closing valve operation.

In the concentration adjusting tank 48, the spectroscopic analysis means 5 in the subsequent stage is used.
According to the immediate analysis result of No. 2, if necessary, so that a predetermined component concentration is obtained, for example, when the regenerating solvent is a stripping solution composed of MEA and DMSO, a necessary amount of a component that does not reach the predetermined concentration is supplied. When the concentration is within the predetermined component concentration, it is not necessary to adjust the concentration in the concentration adjusting tank 48 (see FIGS. 6 and 7).

The spectroscopic analysis means measures the component concentration of the regenerating solvent L6 flowing through the branch pipe 50a by utilizing the inherent absorption function of infrared light. When the regenerating solvent L6 is out of the predetermined concentration, The quality of the regenerated solvent L6 is known by stopping the operation or adjusting the concentration. Various spectroscopes can be used as the spectroscopic analysis means. The concentration-adjusted treatment liquid L6 is stored in the chemical liquid supply tank 51 after the coarse particles contained in the liquid are removed in the filter 49, and is prepared for supply to the manufacturing process.

According to this embodiment, the efficiency of reusing the waste liquid of the solvent can be improved, the quality of the regenerated solvent can be stabilized, the life of the apparatus can be extended, and the waste liquid amount and the waste liquid treatment cost can be reduced. In addition, it is possible to reduce adverse effects on the global environment.

The separation temperature of the liquid, such as the distillation column 9 and the rectification column 27, which evaporates and separates the solvent from the solvent containing the mixed components can be lowered by evaporating the liquid at a reduced pressure. If the separation is performed, it becomes possible to stably operate the apparatus for a long time without replacing parts in a short time without using a special material. For example, as shown in Table 1, a mixed liquid of MEA and DMSO has a conventional state (pressure, temperature: P0,
By reducing the pressure by 12.7 kpa from T0), the temperature can be reduced by about 40 ° C, the corrosion rate can be significantly improved, the life can be extended without using special materials, and the cost and delivery time can be reduced. it can.

[0059]

[Table 1]

Further, in the present embodiment, the used solvent L can be regenerated and reused, and as shown in Table 2, the regeneration can be performed with a high efficiency of about 90%, which was conventionally purchased. The amount of new solvent can be greatly reduced to 10% or less, and the cost can be reduced accordingly. The amount of waste liquid and the cost of waste liquid treatment can be greatly reduced. Further, by performing exhaust gas condensation, the amount of recovered waste liquid can be further increased, the absolute amount of regenerated liquid can be increased, the environmental load in the exhaust gas treatment process can be reduced, and the purchase amount of new liquid can be reduced. Further, in terms of quality, stable quality of the regenerated solvent can be maintained, and the life of the device can be extended.

[0061]

[Table 2]

The above-mentioned regenerator 1 is formed by sequentially assembling the resin content remover 5, the distillation column 9, the rectification column 27, etc., but the regenerator 1 is divided into parts for each device in advance. It is possible to configure a plurality of units assembled as described above, and connect the units at the installation site to form a predetermined reproducing apparatus 1.
For example, the units 68 and 69 shown in FIG. 12 are preliminarily assembled and configured, and the units 68 and 69 are set at the setting site.
Are connected by bolts, and connecting pipes between the mutual units 68 and 69 can be easily installed if the flange structure can be connected.

[0063]

According to the present invention, a usable solvent can be obtained by recovering and regenerating a solvent component from a used solvent.

[Brief description of drawings]

FIG. 1 is a diagram showing each processing step of an example of the present invention.

FIG. 2 is a diagram showing a first-stage processing step of the example.

FIG. 3 is a diagram showing processing steps of the embodiment.

FIG. 4 is a diagram showing a processing step of the embodiment.

FIG. 5 is a diagram showing each processing step of a modified example of the method of the present invention.

FIG. 6 is a diagram showing processing steps of a further modified example of the method of the present invention.

FIG. 7 is a schematic view of a solvent recycling apparatus according to an embodiment of the present invention.

FIG. 8 is a structural diagram of a resin component removing machine in which the same portion is broken.

FIG. 9 is a schematic diagram around the low boiling point component storage tank.

FIG. 10 is a schematic diagram around the both treatment liquid tanks.

FIG. 11 is a schematic view around the condensing means.

FIG. 12 is a device configuration diagram of another embodiment of the present invention.

[Explanation of symbols]

1 ... Playback device 2 ... Solvent recovery tank 5 …… Resin removal machine 7 ... Resin storage tank 9 ... Distillation tower 10 ... Filling material 14 ... 1st condenser 15 …… First vent condenser 16 ... Reflux tank 22 ... Low boiling point component storage tank 23 ... In-tower storage tank 27 ... rectification tower 33 …… Second condenser 34 …… Second vent condenser 35 ... Reflux tank 42 ... Heat exchange means 43 ... Return pump 44 ... Return route 48 ... Concentration adjustment tank 49 ... Filter 51 ... Chemical supply tank 52 ... Spectroscopic analysis means 53 ... Pressure reducing device 66 ... Heating means 67 ... Heat insulation material 68 …… First unit 69 …… Second unit

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor, Kyo Inoue, Yamada, Kawakita-machi, Nomi-gun, Ishikawa 25, Matsushita Tamaki Sakai Air-Conditioning Engineering Co., Ltd. Ishikawa branch office (72) Inventor, Norio Yamaguchi, Kawakita-machi, Nomi-gun, Ishikawa, 25, Matsuda Environmental Air-Conditioning Engineering Co., Ltd. Ishikawa Branch Office (72) Inventor Yoshito Masuda Yamada, Kawakita-cho, Nomi-gun, Ishikawa No. 25 Matsushita Environment Air-Conditioning Engineering Co., Ltd. Ishikawa Branch Office (72) Yasushi Kawase 2 Marunouchi, Chiyoda-ku, Tokyo 2-1 Kishimoto Building 11F Japan Refine Co., Ltd. Tokyo office (72) Inventor Yoshishiba Aoshima 74-18 Hachiman Kaigan Dori, Ichihara City, Chiba Prefecture Japan Refine Co., Ltd. Chiba Factory (72) Inventor Akimasa Oda Chiba Prefecture 74-18 Hachiman Kaigan-dori, Ichihara City Japan Refine Co., Ltd. Chiba Field (56) Reference JP-A-9-49093 (JP, A) JP-A-8-318263 (JP, A) JP-A-9-205056 (JP, A) JP-A-7-171552 (JP, A) JP 5-142781 (JP, A) JP 6-262003 (JP, A) JP 9-34121 (JP, A) JP 2000-305285 (JP, A) JP 2001-145802 (JP , A) JP 2001-194807 (JP, A) JP 2000-508572 (JP, A) International Publication 97/025127 (WO, A1) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01L 21/027 G03F 7/42

Claims (15)

(57) [Claims] 1. A low boiling point having a boiling point lower than that of a resin component and a solvent component.
It is a method to recycle used solvent containing point impurities.
The resin component removal step of removing the resin component and the low boiling point impurities from the used solvent from which the resin component has been removed.
The step of removing by evaporation and the residual liquid obtained in the step of removing low-boiling-point impurities are distilled,
A distillation step of evaporating the solvent component and collecting it as a condensate;
In the resin component removing step, the inner peripheral surface can be heated.
The sealed cylindrical body that has the emitting surface and the
It is a rotating body placed, and brushes are radially arranged on its outer peripheral surface.
A rotating body having a resin removing device including
The rotating body or the bra rotating with the evaporation surface in the main body
Supply the used solvent between the
By bringing the used solvent into contact with the evaporation surface,
Boiled impurities and solvent components are evaporated and used as above
A method of flowing down the resin component in the solvent. 2. The use of the resin prior to the resin component removing step.
The method according to claim 1, comprising a step of degassing the spent solvent.
Method. 3. The used solvent is a mono solvent as a solvent component.
The step of removing low-boiling point impurities containing ethanolamine
The separation temperature of the carbon dioxide contained in the used solvent is
The temperature is equal to or higher than the temperature at which the gas can be separated, according to claim 1 or 2.
The method described. 4. The main component of the used solvent is one component or
Is a stripping solution composed of a plurality of components.
The method described in some cases. 5. The main component of the used solvent is one component or
Is a thinner composed of a plurality of components.
The method described in. 6. The resin component removing step, the low boiling point impurities
In the removal step and the distillation step, the solvent is removed from the liquid to be treated.
The separation temperature of the liquid to be vaporized and separated is the temperature that can withstand the corrosion of the materials used.
6. Evaporating under reduced pressure so as to be less than 100 degrees Celsius.
The method described in any one of . 7. From an exhaust gas source containing a vaporized solvent component
Of the exhaust gas of the above step.
Condensed liquid is used as a part of said used solvent, and
Either way. 8. A low boiling point impurity having a boiling point lower than that of the resin component and the solvent.
A device for regenerating a used solvent containing a substance, which removes a resin component from the used solvent.
Low boiling impurities from the equipment and used solvent from which resin components have been removed
The first distillation device that evaporates and removes it, and the solvent composition consisting of the used solvent from which low-boiling point impurities have been removed.
A second distillation device for evaporating and recovering the component,
The resin component removal device uses the inner surface as a heatable evaporation surface.
A closed cylindrical body having a ring and a rotation arranged in the cylindrical body.
A rotating body that has radial brushes on its outer surface
Using a resin removing device including a body and
Between the evaporation surface and the rotating body or brush that rotates
The used solvent is supplied to the heated evaporation surface.
By contact with used solvent, low boiling point impurities
And the solvent components are evaporated and
Solvent recycling equipment designed to allow resin components to flow down
Place 9. The first distillation apparatus and the second distillation apparatus
Either one or both of them as a packed distillation column,
8. The device according to item 8 . 10. The low removed in the first distillation apparatus.
The condensing means for condensing the boiling point components is kept warm and the condensing means circulates.
The ring refrigerant according to claim 8 or 9, which maintains a predetermined temperature range.
Equipment . 11. The resin component removing device, the first steam
A distillation device and an auxiliary device for the second distillation device
Nitrogen gas pressure feed means for carrying out the liquid stored in the storage tank
An apparatus according to any of claims 8 to 10, comprising: 12. The residual liquid of the second distillation apparatus is used as waste liquid.
In the waste liquid path to be processed, the residual liquid component is used as a resin component removing means.
You can use the return route selectively by connecting the return route
The device according to any one of claims 8 to 11, which is capable . 13. The processing liquid between the respective devices is refluxed or transferred.
In front of each transfer means used for sending or returning
A heat exchange means for lowering the liquid temperature is provided, and the heat exchange means is provided.
2. The device according to any one of 2 . 14. A recovered solvent obtained from the second distillation apparatus.
Take a part of the component from the main liquid feed pipe and return it to the main liquid feed pipe.
A spectroscopic analysis means is installed in the path to continuously monitor the processing liquid components.
The device according to claim 8, which controls operation.
Place 15. An exhaust gas generation source containing a vaporized solvent component.
Means for condensing the exhaust gas from the
15. Recycle as part of the used solvent.
The device according to any one of 1.