JP2002186821A - Organic solvent vapor treatment apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the effective removal of organic solvent vapor even from gas containing moisture in large quantities. SOLUTION: Gas to be treated is passed through a cooling means 9 to be dehumidified by dew formation the gas to be treated passed through the cooling means 9 is lowered in its relative humidity while passed through one passage 13 of a heat exchanger 10 to be passed through the adsorbing zone 3 of a first adsorbing rotor 1 and the gas to be treated passed through the adsorbing zone 3 of the first adsorbing rotor 1 is raised in its relative humidity through the other passage 14 of the heat exchanger 10 to be passed through the adsorbing zone 4 of a second adsorbing rotor 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic solvent vapor processing apparatus for concentrating and removing the vapor of a highly polar organic solvent such as methanol or ethanol.

[0002]

2. Description of the Related Art When an organic solvent vapor is generated from a factory or the like, it is necessary to remove the organic solvent vapor from the air and discharge it to the atmosphere. As a means for removing the organic solvent vapor from the air, there is a decomposition or combustion treatment using a catalyst.

[0003] However, when the concentration of the organic solvent vapor in the air is low, any of the above treatments is difficult, so that the organic solvent vapor is once adsorbed on an adsorbent and concentrated by means for desorbing it. I have. As means for adsorption and desorption to the adsorbent, a two-tower system, a fluidized-bed system or an adsorption rotor system has been developed.

[0004] Among them, an adsorption-rotor type organic solvent vapor treatment apparatus is rapidly spreading because it can treat a large amount of air and is less expensive than other means. Such an organic solvent vapor processing apparatus is also used for removing organic solvent vapor mixed in a gas such as carbon dioxide or nitrogen gas.

[0005]

In such an organic solvent vapor treatment apparatus, when the organic solvent vapor to be treated is a substance having a weak polarity such as toluene or xylene, a hydrophobic material is used as an adsorbent. If used, the adsorbent mainly adsorbs the organic solvent vapor without adsorbing the moisture even when the organic solvent vapor and the moisture are mixed in the gas to be treated.

However, when the organic solvent vapor to be treated is a strongly polar substance such as methanol or ethanol, the adsorption characteristics are similar to that of moisture, and the organic solvent vapor and moisture are mixed in the gas to be treated. In this case, the organic solvent vapor is adsorbed by the adsorbent together with the moisture, and there is a problem that the adsorption efficiency of the organic solvent vapor is reduced.

An object of the present invention is to provide an organic solvent vapor processing apparatus capable of effectively removing a highly polar organic solvent vapor from a gas containing a large amount of moisture.

[0008]

In order to solve the above-mentioned problems, the present invention passes a gas to be treated through a cooling means to dew and dehumidify the gas, and passes the gas to be treated passing through the cooling means to one side of a heat exchanger. The relative humidity is reduced through the passage and passed through the adsorption zone of the first adsorption rotor, and the gas to be processed that has passed through the adsorption zone of the first adsorption rotor is increased in relative humidity through the other passage of the heat exchanger. It was made to pass through the adsorption zone of the second adsorption rotor.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention comprises a heat exchanger having a plurality of independent passages for exchanging heat between the passages, and first and second adsorption rotors. The gas to be treated is dehumidified by condensation through a cooling means, and the gas to be treated having passed through the cooling means is passed through a first passage of a heat exchanger.
The gas to be treated that has passed through the adsorption zone of the adsorption rotor of the first adsorption rotor and passed through the adsorption passage of the second adsorption rotor through the other passage of the heat exchanger, The temperature of the gas whose relative humidity has been increased by dehumidifying by the cooling means is increased by a heat exchanger to lower the relative humidity to increase the adsorption effect, and the gas whose temperature has increased after passing through the adsorption zone of the first adsorption rotor is exchanged with a heat exchanger. Has the effect of lowering the temperature and increasing the adsorption effect of the second adsorption rotor.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 of an organic solvent vapor treatment apparatus according to the present invention will be described below in detail with reference to the drawings. FIG. 1 is a flow chart of an embodiment of the organic solvent vapor processing apparatus of the present invention. Reference numerals 1 and 2 denote first and second adsorption rotors, which are formed, for example, of ceramic paper formed in a honeycomb shape and carrying zeolite thereon, or activated carbon paper formed in a honeycomb shape.

The first adsorption rotor 1 and the second adsorption rotor 2 are divided into adsorption zones 3 and 4, desorption zones 5 and 6, and purge zones 7 and 8, respectively. Each of the first suction rotor 1 and the second suction rotor 2 is driven to rotate in a direction indicated by an arrow by a geared motor (not shown).

Reference numeral 9 denotes a cooling means, which is a refrigerator (not shown)
This is a heat exchanger for passing cold water at a temperature of 3 to 10 ° C sent from the heat exchanger. Reference numeral 10 denotes a heat exchanger which has two gas passages, one passage 13 and the other passage 14, which are independent of each other, and performs heat exchange between the two gases. For example, an orthogonal heat exchanger as shown in FIG. It is. Numerals 11 and 12 are heaters for heating the gas sent to the heaters.

The gas to be treated passes through the cooling means 9, passes through one passage 13 of the heat exchanger 10, and enters the adsorption zone 3 of the first adsorption rotor 1. The gas leaving the adsorption zone 3 passes through the other passage 14 of the heat exchanger 10 and enters the adsorption zone 4 of the second adsorption rotor 2. The gas that has left the adsorption zone 4 is sent to a use destination as a product gas.

Outside air is sent to the purge zones 7 and 8 of the first adsorption rotor 1 and the second adsorption rotor 2 respectively.
After passing through the first and second adsorption rotors 1 and 2, they are sent to the desorption zones 5 and 6, respectively. The air that has passed through the desorption zones 5 and 6 is sent to a processing device such as a combustion device or a catalyst.

Embodiment 1 of an organic solvent vapor treatment apparatus of the present invention
Is configured as described above, and its operation will be described below. First, the cooling means 9 is supplied with, for example, a concentration of 500 ppm.
The gas to be treated is fed by mixing methanol vapor of the above in carbon dioxide having a humidity of 50 g / kg in absolute humidity, cooled to 18 ° C. by the cooling means 9, dehumidified to 15 g / kg in absolute humidity, and methanol Some of the steam is also condensed and removed.

The temperature of the gas to be treated that has exited the cooling means 9 rises to 27 ° C. through one passage 13 of the heat exchanger 10. As a result, the condition of the gas to be processed that has exited one of the passages 13 of the heat exchanger 10 is as follows:
m and a relative humidity of 65%.

Then, the adsorption zone 3 of the first adsorption rotor 1
And methanol is adsorbed. That is, when the relative humidity of the gas to be processed is 100%, the adsorption of methanol in the adsorption zone 3 is not effectively performed. However, since the relative humidity of the gas to be processed is reduced to 65%, the methanol vapor concentration of the processing gas becomes lower. Down to 100 ppm. In addition, moisture is partially absorbed, and the relative humidity becomes 35%.

When leaving the adsorption zone 3 of the first adsorption rotor 1, the temperature of the gas to be treated rises due to the heat of adsorption and rises to 35 ° C.
become. The gas to be treated is supplied to the other passage 1 of the heat exchanger 10.
4 and heat exchange with the gas passing through one of the passages 13 to reduce the temperature to 30 ° C. At this time, the relative humidity of the gas to be processed is 50%.

The gas to be treated, whose temperature has been lowered to facilitate adsorption, enters the adsorption zone 4 of the second adsorption rotor 2. Here, methanol in the gas to be treated is adsorbed, and the concentration of methanol in carbon dioxide becomes 10 ppm, which is reused as a carbon dioxide product gas.

Outside air is sent to the purge zones 7 and 8 of the first adsorption rotor 1 and the second adsorption rotor 2 respectively.
Heated to a temperature close to 200 ° C.
It is sent to the desorption zones 5 and 6 of the first adsorption rotor 1 and the second adsorption rotor 2 respectively. The air that has passed through the desorption zones 5 and 6 contains high-concentration methanol and is sent to a processing device such as a combustion device or a catalyst.

Here, the first adsorption rotor 1 is for adsorbing high concentration organic solvent vapor and the second adsorption rotor 2 is for adsorbing organic solvent vapor having reduced concentration to produce a clean gas. It is preferable that the amount of desorbed air of the second adsorption rotor 2 is smaller than the amount of desorbed air of the rotor 1, and the first adsorption rotor 1 has a lower concentration ratio and the second adsorption rotor 2 has a higher concentration ratio. For this reason, the rotation speed of the first suction rotor 1 may be set higher than that of the second suction rotor 2.

Hereinafter, a second embodiment of the organic solvent vapor treatment apparatus of the present invention will be described in detail with reference to FIG. FIG. 3 is a flowchart of an embodiment of the organic solvent vapor processing apparatus of the present invention.
The second embodiment is different from the first embodiment in that the first adsorption rotor 1, the second adsorption rotor 2, the adsorption zones 3, 4, the desorption zones 5, 6, the purge zones 7, 8, the cooling means 9, and the heat exchange. The vessel 10, the heaters 11, 12, the one passage 13, and the other passage 14 are the same constituent elements, and duplicate description will be omitted.

The flow of the first embodiment is different from that of the second embodiment. That is, in the first embodiment, the outside air is passed through the purge zone 7 of the first adsorption rotor 1, whereas in the second embodiment, the first adsorption rotor 1
The gas to be processed that has passed through one of the passages 13 of the heat exchanger 10 passes through the purge zone 7.

In the first embodiment, the first adsorption rotor 1 is used.
The gas to be treated that has passed through the desorption zone 5 of the first adsorption rotor 1 is sent to a treatment device such as a combustion device. Back to the entrance.

As described above, in the case of the second embodiment, the gas to be treated, which has passed through the desorption zone 5 of the first adsorption rotor 1 and the concentration of the methanol vapor has increased and the humidity has increased, returns to the inlet of the cooling means 9. The concentration of methanol vapor at the inlet of 9 increases and the humidity also increases, and the effect of condensing and removing methanol vapor and moisture in the cooling means 9 increases.

In the second embodiment, since the gas to be treated which has passed through the desorption zone 5 of the first adsorption rotor 1 is returned to the inlet of the cooling means 9, the gas to be treated is externally passed through the first adsorption rotor 1. When a gas in which organic solvent vapor is mixed with carbon dioxide as a gas to be treated is treated, carbon dioxide does not go out through the first adsorption rotor 1.

In the first and second embodiments described above, the case where a gas in which an organic solvent vapor is mixed in carbon dioxide as a gas to be treated is treated. However, a gas in which an organic solvent vapor is mixed in air as a gas to be treated. Even if there is, it can be processed similarly. In this case, atmospheric release is possible after the organic solvent vapor has been removed from the air.

[0028]

Since the organic solvent vapor treatment apparatus of the present invention is constructed as described above, the gas to be treated is in a condition where organic solvent vapor is easily adsorbed before entering the two adsorption zones. It is also possible to effectively remove steam from a gas containing a large amount of moisture. Moreover, since the conditions can be created by the heat exchanger, no special energy is required.

Further, the organic solvent vapor treatment apparatus of the present invention
The organic solvent vapor can be efficiently concentrated by making the amount of desorbed air of the second adsorption rotor smaller than the amount of desorbed air of the first adsorption rotor and making the concentration ratio of each adsorption rotor different. Moreover, the desorption energy of the second adsorption rotor can be reduced.

Since the rotation speed of the first adsorption rotor is higher than the rotation speed of the second adsorption rotor, the concentration ratios of the respective adsorption rotors can be more effectively varied.

In the second embodiment, since the gas to be treated which has passed through the desorption zone 5 of the first adsorption rotor 1 is returned to the inlet of the cooling means 9, the gas to be treated is discharged through the first adsorption rotor 1 to the outside. When processing a gas in which an organic solvent vapor is mixed in an inert gas such as carbon dioxide as a gas to be processed, the inert gas does not leak to the outside through the first adsorption rotor 1 and the amount of the product gas is secured. be able to.

[Brief description of the drawings]

FIG. 1 is a flowchart showing Example 1 of an organic solvent vapor treatment device of the present invention.

FIG. 2 is a perspective view showing an example of a heat exchanger used in the present invention.

FIG. 3 is a flowchart showing a second embodiment of the organic solvent vapor treatment device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st adsorption rotor 2 2nd adsorption rotor 3, 4 Adsorption zone 5, 6 Desorption zone 7, 8 Purge zone 9 Cooling means 10 Heat exchanger 11, 12 Heater 13 One passage 14 The other passage

Claims (4)

[Claims] A heat exchanger having a plurality of independent passages for exchanging heat between the passages and first and second adsorption rotors, wherein a gas to be treated containing an organic solvent vapor is used as cooling means. The gas to be treated, which has passed through the cooling means, is passed through the adsorption zone of the first adsorption rotor through one of the passages of the heat exchanger, and passed through the adsorption zone of the first adsorption rotor. An organic solvent vapor treatment device, wherein the treatment gas is passed through the adsorption zone of the second adsorption rotor via the other passage of the heat exchanger. 2. The organic solvent vapor treatment apparatus according to claim 1, wherein the amount of desorbed air of the second adsorption rotor is smaller than the amount of desorbed air of the first adsorption rotor. 3. The organic solvent vapor treatment apparatus according to claim 1, wherein the rotation speed of the first adsorption rotor is higher than the rotation speed of the second adsorption rotor. 4. A heat exchanger having a plurality of independent passages for exchanging heat between the passages and first and second adsorption rotors, wherein a gas to be treated containing an organic solvent vapor is used as cooling means. The gas to be treated, which has passed through the cooling means, is passed through the adsorption zone of the first adsorption rotor through one of the passages of the heat exchanger, and passed through the adsorption zone of the first adsorption rotor. The processing gas is caused to pass through the adsorption zone of the second adsorption rotor through the other passage of the heat exchanger, and the gas that has passed through the desorption zone of the first adsorption rotor is supplied to the inlet of the cooling means. Organic solvent vapor processing unit that is returned.