JPH0312213A - Solvent adsorption body and solvent recovery device - Google Patents

Abstract

PURPOSE:To regenerate adsorption material in a dry state to raise recovery efficiency of alcohol and to improve quality of recovered organic fluorocarbon by providing an adsorption material of monolith molding whose main component is active carbon and heat supply member bonded to said adsorption material. CONSTITUTION:Adsorption materials 2a of monolith molding whose main component is active carbon and heat supply members 2b, e.g. sheet-like heater, bonded to the adsorption materials are provided. Consequently, excellent adsorption capabilities for solvents such as fluorocarbon can be achieved. Since the adsorption materials 2a are made from monolith molding composed of active carbon having good heat transfer property and the materials 2a are heated and/or cooled by means of the heat supply members 2b to accomplish adsorption and desorption (regeneration) of fluorocarbon, wherein steam is not directly applied to the adsorption materials, thereby eliminating various disadvantages caused by the use of steam. That is, waste water treatment can be simplified, generation of oxygen can be prevented, recovery efficiency of alcohol is improved, and quality of recovered organic fluorocarbon can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a solvent adsorbent that adsorbs a solvent and a batch-type solvent recovery device that uses this solvent adsorbent to recover the solvent from a solvent-containing gas. In particular, we propose a solvent recovery technology that does not use water vapor during regeneration.

[Prior Art] Recently, there has been an increased interest in environmental pollution, and regulations have been tightened from the standpoint of environmental conservation, and there is a tendency to prohibit the release of carbon waste into the atmosphere. Among them, air pollution caused by fluorocarbon gases containing fluoride is attracting attention as a serious problem on a global scale, and for this reason, fluorocarbon gas emissions are being regulated.

The use of these fluorocarbon gas emission regulations has been advocated to be discontinued in the future, but until a replacement product is developed, the current state of the art is to prevent the fluorocarbon gas that was previously released into the atmosphere from being emitted outside the system. The next best option is to collect and reuse it. For this reason, various fluorocarbon gas recovery devices are used.

FIG. 6 is a block diagram showing a conventional batch type fluorocarbon gas recovery apparatus.

The fluorocarbon gas recovery equipment can be used for various industrial solvents other than fluorocarbons, just by changing the conditions, but here, the fluorocarbon gas recovery equipment will be described for a typical fluorocarbon gas among various fluorinated hydrocarbon gases. do. That is, this fluorocarbon gas recovery device has two adsorption towers, a first adsorption tower 21 and a second adsorption tower 22, and by alternately repeating a batch-type adsorption process and a desorption process (release of gas from an adsorbent). , both adsorption towers 21 and 22 enable continuous fluorocarbon gas recovery processing. Each of the adsorption towers 21 and 22 is filled with a fluorocarbon adsorbent such as activated carbon.

The fluorocarbon-containing air 23 is passed through the pipe 41 (
41a, 41b) to be branched and supplied to the adsorption tower 21.22. On-off valves 28 and 29 are installed in the pipes 41a and 41b, respectively.
29 controls the supply of fluorocarbon-containing air 23 to each adsorption tower 21 and 22.

The cooling air 24 is passed through the pipes 42 (42a, 42a,
42b) to the adsorption tower 21.22.

And, on-off valves 30 and 31 are provided in the pipes 42a and 42b, respectively.
is installed, and this on-off valve 30.31 is connected to each adsorption tower 2.
1.Control the supply of cooling air to 22.

Further, the steam 25 is branched and supplied to the adsorption towers 21.22 via piping 43 (43a, 43b), and on-off valves 34.35 are interposed in the piping 43a, 43b, respectively. These on-off valves 34 and 35 are connected to adsorption towers 41 and 41, respectively.
The supply of steam for regenerating the adsorbent to 42 is controlled.

On the other hand, pipes 44 are provided at the gas discharge ports of the adsorption towers 21 and 22, respectively.
a, 44b are connected, and these pipes 44a, 44b
are collectively connected to a pipe 44. Each pipe 44a,
On-off valves 32 and 33 are interposed in 44b to control the discharge of purified air 26 from adsorption towers 21 and 22.

Purified air 26 is released from the pipe 44 into the atmosphere.

Further, pipes 45a and 45b are connected to other gas discharge ports of the adsorption towers 41 and 42, respectively.
5b are arranged to gather at the pipe 45. and,
Each pipe 45a, 45b is provided with an on-off valve 38, 37, respectively, to control the discharge of the regenerated gas from each adsorption tower 21, 22. A condenser 38 is connected to the pipe 45, and the gas after regeneration is sent to the condenser 38.
It is cooled by cooling water and liquefied. This liquid is sent to the water separator 39 via piping 46, and the water in the liquid and the fluorocarbon liquid are separated by the water separator 39. This fluorocarbon liquid is sent to the storage tank 40 via piping 47 and stored therein.

Next, the operation of the batch type fluorocarbon gas recovery apparatus configured as described above will be explained.

First, the adsorbent stored in the first adsorption tower 21 has been regenerated and is in an active state, and the adsorbent stored in the second adsorption tower 22 has been adsorbed and has sufficiently absorbed CFCs. Suppose that it is in a state of adsorption.

In this case, open the on-off valves 28 and 32, and open the on-off valves 29 and 33.
Close the on-off valves 30 and 31, close the on-off valves 34 and 36,
Open the on-off valves 35 and 37. Then, the fluorocarbon-containing air 23 is sent into the adsorption tower 21 via the pipe 41a by the blower 27a.

This fluorocarbon-containing air 23 passes through an adsorbent in the adsorption tower 21, and after the fluorocarbons are adsorbed and removed, it is discharged from the adsorption tower 21 as purified air 26 via a pipe 44a.

On the other hand, water vapor (hereinafter simply referred to as steam) 25 is supplied to the adsorption tower 22 through a pipe 43b, and this vapor passes through an adsorbent in the adsorption tower 22 and is adsorbed by this adsorption material in the previous adsorption step. The energy of the steam heats and desorbs the fluorocarbons and moisture. This fluorocarbon and moisture are sent to the condenser 38 through the pipe 45 together with the exhaust steam, and are cooled in the condenser 38. As a result, the fluorocarbon gas and water are liquefied and become a mixed liquid of fluorocarbon liquid and water, and this mixed liquid is sent to the water separator 39.
Separated into water and Freon liquid. The fluorocarbon liquid is collected in the storage tank 40.

- Next, after a certain period of time has passed, the on-off valves 28.32 remain open to continue the adsorption process in the first adsorption tower 21, while the on-off valves 35.37 are closed to start the desorption process in the second adsorption tower 22. stop. Then, the on-off valves 31 and 33 are opened to supply the cooling air 24 containing little or no CFCs to the adsorption tower 22, and this cooling air is passed through the adsorbent in the adsorption tower 22, and the cooling air 24 containing little or no CFC is supplied to the adsorption tower 22. The adsorbent such as activated carbon that has absorbed moisture during the desorption process is dried and cooled. The cooled gas discharged from the adsorption tower 22 is discharged to the atmosphere together with purified air via pipes 44b and 44.

Next, after a certain period of time has passed, the on-off valve 29 is opened, and the on-off valve 34 is opened.
．． 38 is opened, on-off valves 28 and 32 are closed, and on-off valve 31 is closed. Note that the on-off valve 33 remains open, and the on-off valve 30.35
．． 37 remains closed.

As a result, the fluorocarbon-containing air 23 passes through the adsorbent of the second adsorption tower 22, and the fluorocarbons are adsorbed.

Further, the steam 25 passes through the adsorbent of the first adsorption tower to desorb fluorocarbons. The gas containing fluorocarbons and water is sent to a condenser 38 and a water separator 39, where a fluorocarbon liquid is recovered.

Then, after a certain period of time has passed, the on-off valves 34 and 36 are closed,
Opening/closing valves 30 and 32 are opened to supply cooling air 24 to the first adsorption tower. Thereby, the first adsorption tower moves from the desorption process to the cooling (drying) process.

In this way, the adsorption process, desorption process and cooling process are carried out in one step.
Each on-off valve switches as a cycle, and the fluorocarbon-containing air 2
Collect the Freon liquid from 3. When the first adsorption tower 21 is in the adsorption process, the second adsorption tower 22 is in the desorption process and the cooling process, and when the second adsorption tower 22 is in the adsorption process, the first adsorption tower is in the adsorption process. 21 is carrying out the desorption process and the cooling process. As a result, fluorocarbon gas can be continuously recovered from the exhaust air. In addition, when the recovery of fluorocarbon gas does not need to be continuous, the adsorption, desorption, and cooling steps may be performed at fixed time intervals using only one adsorption tower. Furthermore, if the time for the adsorption step and the total time for the desorption and cooling steps do not match, three or more adsorption towers may be used.

Incidentally, the above-mentioned batch-type fluorocarbon gas recovery apparatus conventionally uses activated carbon in the form of pellets, particles, or fibers (Japanese Patent Laid-Open No. 174923/1981).

These have a particle size of 0.5~! The fluorocarbons are desorbed by arranging a large number of particles of about 0.0 mm and passing the fluorocarbon-containing gas between the granules, or by making a felt with thin fibers and passing the fluorocarbon-containing gas through the felt. Such conventional adsorbents are not molded bodies.

[Problems to be Solved by the Invention] However, in the vapor desorption method in which organic solvents such as fluorocarbons adsorbed on adsorbents are desorbed by steam, there is a problem that generation of acids cannot be avoided. be. In other words, fluorocarbons themselves are mainly composed of carbon, chlorine, and fluorine, and are extremely stable substances, but if they remain adsorbed on activated carbon for a long time under conditions exposed to steam, some of the fluorocarbons will decompose. However, hydrochloric acid and hydrofluoric acid are generated. Therefore, if the recovered fluorocarbon is repeatedly collected and reused under such circumstances, the fluorocarbon purity in the recovered fluorocarbon will decrease and the acid concentration will increase, eventually making it unfit for normal use. Furthermore, since the generated acid will also be mixed into the waste water and purified gas, new secondary pollution will occur.

Furthermore, when recovering azeotropic CFCs containing alcohol, the alcohol dissolves in water and most of it is discharged with the wastewater, so BOD and CO in the wastewater are
Measures D will have to be taken.

Furthermore, when steam is used as the regeneration gas, it is necessary to install new steam piping and a steam boiler, resulting in high equipment costs, maintenance costs, and running costs. Furthermore, in the vapor desorption method, since water basically remains on the surface of the adsorbent, it is necessary to provide a drying step to remove the water on the surface of the adsorbent prior to the adsorption step, but in the conventional method, Since the adsorbent cannot be sufficiently dried, it cannot fully demonstrate its inherent adsorption ability, and a large amount of adsorbent is required.

As described above, the conventional techniques that use water vapor due to its recovery principle have various drawbacks due to moisture.

The present invention has been made in view of such problems, and includes:
By regenerating the adsorbent in a dry state without using steam to regenerate the adsorbent, it simplifies wastewater treatment, prevents the generation of acids, improves the recovery efficiency of alcohol content, and improves the quality of recovered organic fluorocarbons. The purpose of the present invention is to provide a heated air regeneration type fluorocarbon recovery device that can improve the Another object of the present invention is to provide a solvent adsorbent comprising a solvent adsorbent having a molded body structure that can be used therefor.

[Means for Solving the Problems] A solvent adsorbent according to the present invention is characterized by having a monolith-shaped adsorbent whose main component is activated carbon, and a heat supply member adhered to this adsorbent.

Further, the solvent recovery device according to the present invention includes an adsorption tower containing the solvent adsorbent configured as described above, and a solvent-containing gas flow means for passing a solvent-containing gas through the adsorption tower to obtain clean gas. , an exhaust means for evacuating the inside of the adsorption tower, a condensing means for cooling the exhaust gas from the adsorption tower and condensing the solvent, and flowing a solvent-containing gas to the adsorption tower and supplying heat to the solvent adsorbent. It is characterized by comprising a selection means for selectively selecting heating or cooling of the adsorbent by the member and exhausting by the exhaust means.

[Function] The solvent adsorbent according to the present invention has an adsorbent composed of a monolith molded body containing activated carbon having excellent solvent adsorption properties and heat conduction properties as a main component and having a large number of communicating pores. The adsorbent is preferably formed into a honeycomb molded body, and a heat supply member for supplying energy for heating the adsorbent is bonded to the adsorbent.

The adsorption of solvent onto activated carbon is due to the fact that the solvent is selectively captured in the micropores of this activated carbon, and the adsorbed solvent not only supplies heat to the adsorbent but also works to lower the vapor partial pressure. The adsorbent is separated from the adsorbent by placing it under a reduced pressure atmosphere.

The solvent adsorbent according to the present invention achieves the solvent removal effect by the adsorbent without using steam or indirect heating with a carrier gas (the adsorbent itself is directly heated with a heat supply member). In this case, since the heat supply member is bonded to the adsorbent, the adsorbent is directly and quickly heated. Also, the heating energy from the heat supply member is quickly and rapidly heated. In order to work effectively, the adsorbent is formed into a monolith molded body.In order to easily and efficiently ventilate the monolith molded body as an adsorbent, the adsorbent is formed into a honeycomb molded body. It is preferable to configure it as follows.

Further, when the heat supply member is configured as a heat exchange member through which a medium flows through at least a portion thereof, the medium supply means causes the heat medium to flow through the heat supply member to raise the temperature of the adsorbent. Can be heated. In this case,
If the medium supply means is configured to selectively supply a refrigerant in addition to the heat medium for raising the temperature of the heat supply member described above, it is possible to not only heat the adsorbent but also cool it.

As mentioned above, the solvent is desorbed by heating the adsorbent, but in the next adsorption step, the lower the temperature of the adsorbent, the higher the adsorption efficiency. This is because the lower the temperature, the lower the level of motion of the solvent molecules to be adsorbed, so the adsorption effect of the solvent by the activated carbon, which is the main component of the adsorbent, improves, and the adsorption capacity improves.

Examples of this heating medium include steam, hot water, heating oil, and heating fluorocarbon liquid. Further, as the refrigerant, there are cooling water, chilled water, cooling oil, and cooling Freon liquid.

On the other hand, in the solvent recovery apparatus according to the present invention, first, the solvent-containing gas is caused to flow through the adsorption tower by the solvent-containing gas flow means. Then, the solvent in the solvent-containing gas is adsorbed by the adsorbent in the adsorption tower to obtain clean gas.

Next, before the adsorption capacity of the adsorbent is saturated, the flow of the solvent-containing gas is stopped by the selection means, and instead the adsorbent is heated by the heat supply member of the adsorbent. That is, when the heat supply member is a sheet-shaped heater, by energizing this heater, or when the heat supply member is a heat exchange member, by passing a heat medium through the heat exchange member, the adsorption is performed. Heat the material. As a result, the temperature of the adsorbent is raised and the inside of the adsorption tower is evacuated by the exhaust means.

Then, the solvent is desorbed (separated) from the adsorbent in the adsorption tower.
The exhaust gas containing a high concentration of solvent is guided to the condensing means and cooled, and the solvent in the exhaust gas is condensed and recovered as a liquid.

[Example] Next, an example of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a perspective view showing an adsorbent used in a solvent recovery device according to a first embodiment of the present invention. The adsorbent 2a of the adsorbent 2 is made of a rectangular parallelepiped monolith molded body, and is formed into a honeycomb shape. A plurality of adsorbents 2a are connected together (only two adsorbents are shown in Figure 1), and between each adsorbent 2a and on the side surfaces of both ends in the arrangement direction, resistive heat is generated when energized. A seat heater 2b is attached to the seat. A lead wire 2C for feeding power to the seat heater 2b is connected to each seat heater 2b.

Note that a thermocouple (not shown) is inserted into the adsorbent 2a, and the thermocouple measures the temperature of the adsorbent 2a, and the sheet heater 2b is adjusted so that the temperature of the adsorbent 2a reaches a predetermined value.
It is designed to control the power applied to the

Note that this seat heater 2b has a thickness of, for example, 1.
(2) There is a thin plate with a width of 130 mm and a length of 400 mm, and a capacity of 430 W at 100 AC. In addition, by using eight sheet heaters 2b and interposing adsorbents 2a of the same size between each sheet heater, an adsorbent 2 with a width of 120111, a length of 240 mm, and a height of 400 V, for example, can be obtained. configured. Note that the width of the seat heater 2b is 130i+n, and the width of the adsorbent 2 is 120s+.
The reason why the length is longer than m is that the end portion of the seat heater needs to protrude beyond the adsorbent because the amount of heat generated at the end portion is small.

In the adsorbent 2 configured in this way, the lead wire 2
When the seat heater 2b is energized through C, the seat heater 2b generates resistance heat and rises in temperature, and this heat is transferred from the seat heater 2b to the adsorbent 2a. As a result, the temperature of the adsorbent 2a rises and the adsorbed fluorocarbons are desorbed.

FIG. 2 is a graph showing the temperature increase characteristics in the adsorbent 2, with time on the horizontal axis and temperature on the vertical axis. This second
As shown in the figure, the temperature of the adsorbent 2a is rapidly increased by energizing the seat heater 2b.

FIG. 3 is a block diagram showing a solvent recovery device according to an embodiment in which the present invention is applied to the recovery of fluorocarbons (fluorocarbons 113).

An adsorbent 2 is housed within the adsorption tower 1 .

A power source 3 is connected to the seat heater 2b of the suction body 2, and a switch 4 is interposed between the suction body 2 and the power source 3. As a result, when the switch 4 is turned on, power is supplied to the adsorber 2 from the power source 3, and the adsorber 2
It is designed to generate heat due to its own resistance.

In addition, air containing fluorocarbons is supplied into the adsorption tower 1 through a pipe 9, and this air containing fluorocarbons is supplied to the adsorbent body in the adsorption tower 1.
The fluorocarbons are adsorbed and removed. The obtained clean gas is discharged from the adsorption tower 1 to the atmosphere through the pipe 11.

A blower 5 is interposed in the piping 9 to feed air containing fluorocarbons to the adsorption tower 1, and the piping 8.
11 is provided with on-off valves 10 and 12, respectively, to control the supply and discharge of gas to and from the adsorption tower 1, respectively.

Further, a pipe 13 is also connected to the gas outlet of the adsorption tower 1 , and the exhaust gas from the adsorption tower 1 is supplied to the condenser 7 via the vacuum pump 6 through the pipe 13 . That is, the vacuum pump 6 vacuums the inside of the adsorption tower 1 and sends the exhaust gas from the adsorption tower 1 to the condenser 7. Note that the piping 13 is provided with an on-off valve 14 that controls suction within the adsorption tower 1 .

Cooling water is allowed to flow through the condenser 7, and the gas fed into the condenser 7 is cooled in the condenser 7, and the fluorocarbons and moisture in the gas are condensed and become liquid. . This liquid is sent to the separator 8 via piping 16 and separated into water and fluorocarbon liquid by specific gravity, and the fluorocarbon liquid is stored in a storage tank 8.
It is collected in a.

In the fluorocarbon recovery apparatus configured as described above, first, the on-off valves 10 and 12 are opened, the on-off valve 14 is closed, and air containing fluorocarbons is supplied to the adsorption tower 1 by the blower 5. Also,
Switch 4 is turned off.

Then, the adsorbent 2a at room temperature adsorbs fluorocarbons in the fluorocarbon-containing air, and the clean gas from which fluorocarbons have been removed is sent to the adsorption tower 1.
is discharged from. This clean gas is diffused into the atmosphere via piping 11.

After a predetermined period of time has passed and the adsorption capacity of the adsorbent 2a made of a honeycomb molded body is saturated, or just before saturation, the on-off valve 10 is closed to stop the supply of fluorocarbon-containing air, and the on-off valve 12 is closed, opened and closed. Open valve 14.

Then, switch 4 is turned on. Then, the seat heater 2b of the adsorbent 2 is supplied with power from the power source 3, generates resistance heat, and is heated to a predetermined temperature. As a result, the heat of the seat heater 2b is transferred to the adsorbent 2a, and the temperature of the adsorbent 2a increases 1, and the fluorocarbons adsorbed to the adsorbent 2a in the above-mentioned adsorption process are desorbed. The released air in the adsorption tower 1 containing a high concentration of fluorocarbons is sucked by the pump 6 and supplied to the condenser 7. The exhaust gas from the adsorption tower 1 is cooled in the condenser 7, and the fluorocarbons and water are condensed to form a liquid. This liquid is sent to the separator 8 and separated into water and fluorocarbon liquid, and the fluorocarbon liquid is collected in the tank 8a.

Next, after a predetermined period of time has elapsed and the desorption process by the adsorbent 2 is completed, the on-off valves 10.12 are opened, the on-off valve 14 is closed, and the adsorption process is started again. In this way, by alternately performing the adsorption step and the desorption step, fluorocarbons are recovered from the fluorocarbon-containing air.

In this embodiment, since steam is not used in the regeneration process for desorbing fluorocarbons from the adsorbent, various drawbacks of conventional fluorocarbon recovery devices associated with the use of steam can be overcome.

Moreover, by using the fluorocarbon adsorbent 2 according to the present invention, the adsorbent 2 can be heated by applying electricity to the seat heater 2b.
Since the temperature of a can be raised rapidly, the processing efficiency does not decrease. In addition, when regenerating the adsorbent using steam, the adsorbent is heated to about 100°C, but in this embodiment, the vacuum pump 6 (exhaust means)
Since the inside of adsorption tower 1 is evacuated by
Even temperatures as low as 0°C are sufficient. Therefore, the required heating energy for the adsorbent is low.

FIG. 4 is a block diagram showing a batch type fluorocarbon gas recovery apparatus according to another embodiment of the present invention. This fluorocarbon gas recovery equipment has two adsorption towers, a first adsorption tower 21 and a second adsorption tower 22, and by alternately repeating a batch adsorption process and a desorption process, both adsorption towers 21 and 22 are continuously operated. This makes it possible to perform a fluorocarbon gas recovery process. Each adsorption tower 21, 22 houses an adsorbent (not shown) similar to that in the first embodiment, and the temperature of each adsorbent is controlled by heating the sheet heater with electricity.

The fluorocarbon-containing air 23 is passed through the pipe 41 (
41a, 41b) to be branched and supplied to the adsorption towers 21, 22. On-off valves 28 and 29 are installed in the pipes 41a and 41b, respectively.
29 controls the supply of fluorocarbon-containing air 23 to each adsorption tower 21 and 22.

Cooling air is supplied to piping 42 (42a, 42 by blower 27b).
b) is drawn off from the adsorption tower 21.22. And, on-off valves 30.31 are interposed in each of the pipes 42a and 42b, and these on-off valves 30.31 are connected to each adsorption tower 21.
．． Controls the suction of cooling air to 22.

Further, the carrier gas for regeneration is supplied through the pipe 43 (43a).

43b) to the adsorption towers 21 and 22, and the pipes 43a and 43b are each equipped with an on-off valve 3.
4.35 is interposed. The on-off valves 34 and 35 control the supply of carrier gas for regeneration to the adsorption towers 41 and 42, respectively. Further, the piping 43 is provided with a constant pressure valve 50, and carrier gas for regeneration can be supplied from outside the adsorption tower via the constant pressure valve 50 only when the adsorption tower 21 or 22 is sucked to a predetermined pressure or less. It looks like this.

On the other hand, pipes 44 are provided at the gas discharge ports of the adsorption towers 21 and 22, respectively.
a, 44b are connected, and these pipes 44a, 44b
are collectively connected to an exhaust air tank 44. Opening/closing valves 32 and 33 are installed in each of the pipes 44a and 44b to control the discharge of purified air 26 from the adsorption towers 21 and 22. Purified air 26 is released from the exhaust air tank 44 into the atmosphere.

Further, pipes 45a and 45b are connected to other gas discharge ports of the adsorption towers 41 and 42, respectively.
5b are arranged to gather at the pipe 45. and,
Each pipe 45a, 45b is provided with an on-off valve 38, 37, respectively, to control the discharge of the regenerated gas from each adsorption tower 21, 22. A vacuum pump 51 is provided in the pipe 45, and the vacuum pump 51 sucks the gas after regeneration. Further, a pipe 52 is provided on the outlet side of the vacuum pump 51 and connected to a condenser 38, and the regenerated gas is cooled by cooling water in the condenser 38 and liquefied. This liquid is sent to the water separator 39 via piping 46, and the water in the liquid and the fluorocarbon liquid are separated by the water separator 39. This fluorocarbon liquid is delivered to the storage tank 40 via piping 47 and stored therein. In addition, non-condensable gas in the condenser 38 is collected in a recycle air tank 53 via a water separator 39, and is sent to a blower 27a via a pipe 54 in order to perform an adsorption action again.
A part of the gas is returned to the inlet of the gas tank, and a portion thereof is used as a carrier gas for regeneration via piping 43. Note that a flow ff1g regulating valve 55 is provided in the pipe 54 in order to prevent the supply of recycled air more than necessary.

Next, the operation of the batch type fluorocarbon gas recovery apparatus according to the present embodiment configured as described above will be explained.

First, the adsorbent stored in the first adsorption tower 21 has been regenerated and is in an active state, and the adsorbent stored in the second adsorption tower 22 has been adsorbed and has sufficiently absorbed CFCs. Suppose that it is in a state of adsorption.

In this case, on-off valves 28 and 32 are opened, on-off valves 29 and 33 are closed, on and off valves 30 and 31 are closed, on and off valves 34 and 36 are closed, and on and off valves 35 and 37 are opened. Then, the fluorocarbon-containing air 23 is sent into the adsorption tower 21 via the pipe 41a by the blower 27a.

This fluorocarbon-containing air 23 passes through an adsorbent in the adsorption tower 21 to adsorb and remove the fluorocarbons, and then is discharged from the adsorption tower 21 as purified air 26 via the exhaust air tank 44 via a pipe 44a.

On the other hand, inside the adsorption tower 22, a pipe 45 is operated by a vacuum pump 51.
b, 45, and the adsorbent in the adsorption tower 22 is further supplied with electricity from a separately provided power source, its sheet heater generates resistance heat, and the adsorbent is heated to a predetermined temperature. and,
The temperature of the adsorbent in this adsorption tower 22 is controlled by measuring the temperature with a thermocouple provided in the adsorbent. As a result, the temperature of the adsorption tower 22 is rapidly raised under reduced pressure to desorb fluorocarbons, and the exhaust gas containing a high concentration of fluorocarbons is transferred to the condenser 3.
8. Furthermore, when the inside of the adsorption tower 22 reaches a predetermined pressure or lower due to the suction action of the vacuum pump 51, the gas in the recycle air tank 53 is adsorbed from the pipes 43, 43b as a carrier gas for regeneration via the constant pressure valve 50 provided in the pipe 43. It is supplied to the column 22 to promote regeneration of the adsorbent within the adsorption column 22.

The fluorocarbon gas desorbed in this way is transferred to the condenser 38.
The water and fluorocarbon are condensed and liquefied, and the fluorocarbon liquid is separated from the water in the separator 8 and then collected in the storage sink 40. On the other hand, the gas component that has not been condensed in the condenser 38 is led from the separator 8 to the recycle air tank 53 via the pipe 56 and is used as the carrier gas for regeneration mentioned above. The air is then returned to the inlet of the blower 27a for air containing fluorocarbon gas to be recovered again, thereby minimizing external discharge.

Next, after a certain period of time has elapsed, the on-off valves 28 and 32 remain open and the adsorption process in the first adsorption tower 21 is continued, while the on-off valves 3 and 32 remain open.
5.37 is closed to stop the desorption process of the second adsorption tower 22. Then, the on-off valves 31 and 33 are opened to supply cooling air with little or no fluorocarbon to the exhaust air tank 4.
4 to the adsorption tower 22, and this cooling air is supplied to the adsorption tower 22 from
The activated carbon or other adsorbent heated in the previous desorption step is cooled. The cooled gas discharged from the adsorption tower 22 is sucked by the cooling blower 27b via the pipes 42b and 42, and then returned to the exhaust air tank 44 again. In addition, in the case of a large-capacity machine, it is better to draw the air directly into the adsorption tower 22 from the outside and discharge it to the outside through the blower 27b. Further, during this cooling process, the electricity supply to the adsorbent in the adsorption tower 22 is stopped, and the adsorbent is cooled to a temperature range in which it can perform its adsorption action.

Next, after a certain period of time has passed, the on-off valve 29 is opened, and the on-off valve 34 is opened.
．． 38 is opened, on-off valves 28 and 32 are closed, and on-off valve 31 is closed. Note that the on-off valve 33 remains open, and the on-off valve 30.35
．． 37 remains closed.

As a result, the air 23 containing fluorocarbons passes through the adsorbent of the second adsorption tower 22, and the fluorocarbons are adsorbed.

On the other hand, the fluorocarbons adsorbed by the first adsorbent are desorbed by heating the first adsorption tower with electricity under reduced pressure.

The gas containing fluorocarbons and water is sent to a condenser 38 and a water separator 38, where a fluorocarbon liquid is recovered.

Then, after a certain period of time has passed, the on-off valve 3413θ is closed,
The on-off valves 30 and 32 are opened to supply cooling air to the first adsorption tower. Thereby, the first adsorption tower moves from the desorption process to the cooling process.

In this way, the adsorption process, desorption process and cooling process are carried out in one step.
Each on-off valve switches as a cycle, and the fluorocarbon-containing air 2
Collect the Freon liquid from 3. When the first adsorption tower 21 is in the adsorption process, the second adsorption tower 22 is in the desorption process and the cooling process, and when the second adsorption tower 22 is in the adsorption process, the first adsorption tower is in the adsorption process. 21 is carrying out the desorption process and the cooling process. As a result, fluorocarbon gas can be continuously recovered from the exhaust air. In addition, when the recovery of fluorocarbon gas does not need to be continuous, the adsorption, desorption, and cooling steps may be performed at fixed time intervals using only one adsorption tower. Furthermore, if the time for the adsorption step and the total time for the desorption and cooling steps do not match, three or more adsorption towers may be used. The number of towers is not limited to two, and a large number of three or more towers may be provided.

FIG. 5 is a schematic cross-sectional view showing a solvent adsorbent 5 according to another embodiment of the present invention. In this embodiment, the solvent adsorbent is constructed in the form of a heat exchanger. That is, thin plate-shaped fins 7 are fitted into a plurality of vibros through which heat medium and coolant flow. The fins 7 are arranged in parallel with an appropriate distance between them, and are adhesively fixed to the vibro. An adsorbent 8 made of a honeycomb molded body similar to the adsorbent 2a shown in FIG. 1 is fitted between the fins 7.
It is fixed with adhesive.

In the solvent adsorbent 5 configured in this manner, by passing a heat medium through the vibro, the fins 7 are heated and the temperature thereof increases, and the temperature of the adsorbent 8 adhesively fixed to the fins 7 is increased. As a result, the adsorbent 8 desorbs the fluorocarbon. On the other hand, by causing the refrigerant to flow through the vibro, the fins 7 are cooled and the temperature is lowered, and the adsorbent 8 in contact with the fins 7 is cooled down to a temperature range where the adsorption effect is excellent.

If the solvent adsorbent 5 shown in FIG. 5 is used in the solvent recovery device shown in FIG. 4, since the solvent adsorbent 5 itself has a cooling function, the cooling process of the solvent recovery device shown in FIG. The fins 27b and valves 30, 31 used in can be omitted.

[Effects of the Invention] According to the present invention, a monolith molded body made of activated carbon, which has excellent adsorption ability for solvents such as fluorocarbons and excellent heat transfer performance, is used as an adsorbent, and a Because fluorocarbons are adsorbed and desorbed (regenerated) by heating and/or cooling the adsorbent with a heat supply member, steam is not applied directly to the adsorbent during the fluorocarbon desorption (regeneration of the adsorbent) process. Various drawbacks associated with the use of steam can be overcome. Further, in the present invention, since the inside of the adsorption tower is evacuated during desorption (regeneration), the required heating temperature of the adsorbent is low, so that the energy required for regeneration can be reduced.

Furthermore, by using a solvent adsorbent with heating and cooling functions, it is possible to select the optimum temperature swing and pressure swing for adsorption and desorption of the solvent, thereby making it possible to construct an extremely highly efficient solvent recovery device.

[Brief explanation of drawings]

FIG. 1 is a schematic perspective view showing an adsorbent used in a solvent recovery device according to an embodiment of the present invention, FIG. 2 is a graph diagram showing its temperature increase characteristics, and FIG. 3 is a diagram showing an adsorbent according to an embodiment of the present invention. FIG. 4 is a block diagram showing a solvent recovery device according to another embodiment of the present invention, and FIG. 5 is a block diagram showing a solvent recovery device according to another embodiment of the present invention. FIG. 6 is a block diagram showing a conventional solvent recovery device. 1; Adsorption tower, 2, 5; Adsorbent % 2 al 8 ; Adsorbent, 2b; Sheet heater, 3: Power supply, 4; Switch, 5
; Blower, 6; Vacuum pump, 7; Condenser, 8; Separator Figure 1 Figure 2 Figure Figure Figure Figure

Claims (7)

[Claims] (1) A solvent adsorbent comprising a monolithic adsorbent whose main component is activated carbon and a heat supply member bonded to the adsorbent. (2) The solvent adsorbent according to claim 1, wherein the heat supply member is a sheet-shaped heater that generates heat when energized. (3) The heat supply member is a heat exchange member through which a medium flows through at least a portion thereof, and the temperature of the heat supply member is raised by causing a heat medium to flow through the heat exchange member. Item 1. Solvent adsorbent according to item 1. (4) The solvent adsorbent according to claim 1, wherein the heat supply member is selectively heated or cooled by selectively flowing a heat medium and a refrigerant through the heat supply member. (5) An adsorption tower containing the solvent adsorbent according to claim 1, a solvent-containing gas flow means for passing a solvent-containing gas through the adsorption tower to obtain clean gas, and evacuating the inside of the adsorption tower. an exhaust means, a condensing means for cooling the exhaust gas from the adsorption tower and condensing the solvent, passing the solvent-containing gas to the adsorption tower, and heating and exhausting the adsorbent by a heat supply member of the solvent adsorbent. 1. A solvent recovery device comprising: a selection means for selectively selecting between evacuation by means of evacuation and evacuation by evacuation means. (6) An adsorption tower containing the solvent adsorbent according to claim 4, a solvent-containing gas flow means for passing a solvent-containing gas through the adsorption tower to obtain clean gas, and evacuating the interior of the adsorption tower. an exhaust means, a condensing means for cooling the exhaust gas from the adsorption tower and condensing the solvent, a flow of the solvent-containing gas to the adsorption tower, cooling of the adsorbent by the heat supply member, and a condensation means for cooling the exhaust gas from the adsorption tower to condense the solvent; A solvent recovery device comprising a selection means for selectively selecting heating of the adsorbent by the heat supply member and exhaust by the exhaust means. (7) An adsorption tower containing the solvent adsorbent according to claim 2, a solvent-containing gas flow means for passing a solvent-containing gas through the adsorption tower to obtain clean gas, and the heater of the solvent adsorbent. an energizing heating means for applying electricity to heat the adsorbent, an exhaust means for exhausting the inside of the adsorption tower, a condensing means for cooling the exhaust gas from the adsorption tower to condense the solvent, and a solvent for the adsorption tower. 1. A solvent recovery device comprising a selection means for selectively selecting flow of a contained gas, electrical heating, and exhaust.