JP2766793B2 - Treatment and recovery of gaseous hydrocarbons contained in waste gas - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for treating and recovering gaseous hydrocarbons contained in waste gas, and more particularly, to reducing the concentration of gaseous hydrocarbons, one of the causative substances of photochemical smog, to 1 VOL% or less. The present invention relates to the above-mentioned method for exhausting to the atmosphere and the above-mentioned method for suppressing abnormal temperature rise in the adsorbent layer and making the temperature in the adsorption device uniform.

[0002]

2. Description of the Related Art Conventionally, activated carbon which is inexpensive and easily available has been heavily used for removing and recovering gaseous hydrocarbons contained in waste gas. (Note that activated carbon is about 3,00 g / g.
It has a specific surface area of 0 m ² and its adsorption performance is unparalleled. )

[0003] However, activated carbon is a flammable material that has low thermal conductivity and is easily combustible, as is clear from the example used as a heat insulating material, while the heat of adsorption of gaseous hydrocarbons is about 20 KCAL / MOL. From where they often ignite,
Cause an explosion. For example, "Research on Disasters" Volume 23 (1992)
As described in detail in “Activated Carbon Accident Cases and Ignition Risk Assessment”, most of the ignition accidents are caused by heat storage and ignition due to local heating in the adsorbent layer. Since it is not possible to identify the part where the temperature starts to rise, it is extremely difficult to detect the initial ignition.

For this reason, according to the “Guidelines for Installation of Hydrocarbon Emission Prevention Equipment” of the related government agencies, (1) the flammable vapor at the inlet of the adsorber has a safety hazard such as a concentration below the lower explosion limit. No concentration (or measures)
(2) It is stipulated that the processing device for desorbing and recovering combustible hydrocarbons recovers using steam or nonflammable gas.

[0005] The most effective means as a measure against the above-mentioned fire accident is to make the concentration of gaseous hydrocarbons in the waste gas treated in the adsorption tower a dilute state of about 1 VOL% or less. (Thus, if the concentration of gaseous hydrocarbons in the waste gas is high, it will be diluted with air.) Thus, the concentration of the gaseous hydrocarbons in the waste gas is reduced to about 1 VOL.
%, The amount of gaseous hydrocarbons adsorbed in the activated carbon layer is reduced, and the generation of heat of adsorption is suppressed, thereby preventing a fire accident.

Also, exhaust gas containing high boiling (heavy) hydrocarbon vapor such as paint mist as well as low boiling (light) hydrocarbon vapor, such as exhaust gas from a coating bus. In the case of treating benzene, as described in JP-B-54-4707, a high-boiling hydrocarbon base which may hinder the adsorption ability is used.
There is known a method of adsorbing and removing a parr in advance on activated carbon having a large pore diameter, filling the activated carbon with activated carbon having a small pore diameter, and adsorbing light hydrocarbon paper.

When the above-described high-boiling-point hydrocarbon vapor remains on the activated carbon after desorption, it is frequently heated and cooled.
In addition, due to reactions such as oxidation and polymerization due to oxygen contained in the waste gas to be treated, it may cause explosion or ignition in combination with the catalytic function of the activated carbon surface. For this reason, according to the method described in the above-mentioned publication, when desorbing a high-boiling hydrocarbon vapor adsorbed on activated carbon having a large pore size, a sufficient amount of non-combustible steam is used for a long time. Purge over time,
Residues must be reduced as much as possible. Fortunately, activated carbon with a larger pore size is more effective because it is easier to adsorb and desorb.

On the other hand, “Chemical Engineering Handbook (Revised 4th Edition)” (Showa 5
According to the standard operating condition of the adsorption tower, the cycle of adsorption and desorption (switching) in the case of recovery of hydrocarbon solvent using activated carbon is 0.5 to 2 in the horizontal adsorption tower.
The time is described as 2 to 6 hours for a vertical adsorption tower, and 4 to 20 hours for silica gel.
In the case of an industrial device, the operation is generally performed within this range.

[0009]

As described above, the conventional method for treating and recovering gaseous hydrocarbon-containing waste gas using activated carbon involves fire and explosion accidents, which is dangerous.

As a countermeasure against this fire and explosion accident, it is effective to mix air with the waste gas to make the concentration of gaseous hydrocarbons in the waste gas lean as about 1 VOL% or less, as described above. However, it is uneconomical to dilute the waste gas with air, and the adsorber and its associated equipment must be enlarged in proportion to the increase in the gas to be treated due to the mixing of air. have.

The method described in the above-mentioned publication also uses activated carbon which is liable to cause a fire or explosion accident, and is also accompanied by danger.

In order to solve the above-mentioned problems and disadvantages, the present inventors prior to the filing of the present application filed a method which does not use activated carbon as a means for treating and recovering gaseous hydrocarbons in waste gas, A method has been proposed in which a synthetic zeolite and / or hydrophobic silica gel having a pore size corresponding to the size of each single molecule constituting a multi-component hydrocarbon is used in combination or in a multi-layered combination (hereinafter referred to as “the prior art”). Requested invention "
That. (See Japanese Patent Application No. 7-152706).

[0013] The method according to the invention of the prior application includes: [0014] a gaseous hydrocarbon concentration in the waste gas can be discharged into the atmosphere as a "clean gas" of 1 VOL% or less; It is a technical object of the present invention to control the amount of adsorption of hydrocarbons, and thus the heat of adsorption, to make the heat distribution of the entire adsorbent layer uniform and prevent rapid local heating due to the heat of adsorption. ).

[0014] The inventors of the present invention have stated that
(Synthetic zeolite and / or hydrophobic silica gel) Adsorbed pore size was adjusted to the molecule to be adsorbed. When high concentration gas was treated, it was proved that the above object could be achieved.

That is, when the above-mentioned high-concentration gas is treated in the commercial-scale plant according to the invention of the prior application, the concentration of hydrocarbons in the gas discharged from the plant to the atmosphere is reduced to 1 VOL% or less to 250 PPM, and the cleansing is performed. Could be released into the atmosphere as a safe gas. During this operation, a slight rise in temperature was observed, but no rapid local heating was observed, and gaseous hydrocarbons in the purge exhaust gas were washed with liquid hydrocarbons of the same quality. By that, 99%
We succeeded in obtaining the above high recovery efficiency.

The present inventors have examined in detail the reason why the method according to the invention of the prior application achieved more success than expected,
In addition, as a result of further intensive studies based on the operational experience of the prior invention with the actual machine, the present invention has been completed, which ensures the safety of the adsorption device even more than the prior invention.

That is, the present invention is an invention obtained by further improving the invention of the prior application, and its technical problems (objects) are as follows:-The concentration of gaseous hydrocarbons, one of the causative substances of photochemical smog, is reduced to 1 VOL%. The following is a “method of treating and recovering gaseous hydrocarbons contained in waste gas” for discharging into the atmosphere, comprising:-suppressing abnormal temperature rise in the adsorbent layer and reducing the temperature in the adsorber. It is an object of the present invention to provide a "method for treating and recovering gaseous hydrocarbons contained in waste gas", which is made uniform and further enhances safety as compared with the prior invention.

[0018]

SUMMARY OF THE INVENTION The method according to the present invention is particularly characterized in that: a double-cylinder type adsorber comprising an inner cylinder for cooling water circulation and an outer cylinder for adsorbent filling is used as the adsorber; The use of synthetic zeolite and / or hydrophobic silica gel having a pore size of 4 to 100 Å as the agent; the use of the above adsorbent pre-coated with gaseous hydrocarbons; 15 minutes or less;-At the time of desorption, purging and simultaneous use of vacuum are characterized by the above-mentioned features, whereby the above-mentioned "method of treating and recovering gaseous hydrocarbons contained in waste gas" is achieved. Is provided.

That is, the present invention relates to a method for treating and recovering gaseous hydrocarbons contained in waste gas using a single-tower or multi-tower type adsorption apparatus. Consisting of an inner cylinder for adsorbent and an outer cylinder for adsorbent filling
(2) gaseous carbonization in which the outer cylinder for charging the adsorbent is filled with a synthetic zeolite having a pore size of 4 to 100 angstrom and / or a hydrophobic silica gel alone or in a mixture. An adsorbent layer formed by pre-coating with hydrogen is formed, (3) the time for switching between adsorption and desorption to the adsorbent layer is 1 to 15 minutes, and (4) the adsorbent layer is discharged from the adsorbent layer during desorption. And (5) recovering gaseous hydrocarbons from the purge exhaust gas while purging with a portion of the clean gas and / or air and simultaneously using vacuum. For the treatment and recovery of gaseous hydrocarbons contained in coal. ”.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below in detail. In the present invention, the reason for using a "double cylinder type adsorption device comprising an inner cylinder for cooling water circulation and an outer cylinder for adsorbent filling" is as follows. The adsorbent used in the present invention (synthetic zeolite and / or hydrophobic silica gel), in addition to having a structure capable of maximizing the cooling area for removing heat generation in the adsorbent layer
This is because the thermal conductivity of the adsorbent layer is extremely low, so that it is necessary to limit the thickness of the adsorbing layer in order to transfer heat rapidly.

The adsorbent used in the present invention has a pore size of
It is a synthetic zeolite and / or hydrophobic silica gel of 4 to 100 angstroms, as long as the pore size and its distribution are similar to those of activated carbon, and each of them can be used in any of single-layer, multi-layer and mixed-layer filling methods .

The reason why the synthetic zeolite and / or hydrophobic silica gel used in the present invention is "pre-coated with gaseous hydrocarbons" is that the present invention also uses an adsorbent having relatively large adsorption pores. , Regardless of the size of each molecule constituting the gaseous hydrocarbons in the waste gas, all of the multicomponent gaseous hydrocarbons are adsorbed. This is to limit the amount of adsorption in order to avoid this.

In the present invention, as a precoating means, a gas mainly composed of gaseous hydrocarbon is charged by a method such as spraying before or after filling the adsorbent into the adsorption tower. do it.

Further, the present invention is characterized in that the switching time (Swing Time) between adsorption and desorption is set to 1 to 15 minutes. Particularly, 3 to 10 minutes are preferable, and about 5 minutes is optimal.
Swin as a standard operating condition in industrial equipment
As described above, g Time is operated in the range of 4 to 20 hours in the case of using silica gel.
It is characterized by switching in as short as 15 minutes.

In the present invention, the Swing Time is
The reason for 1 to 15 minutes is to limit the amount of adsorption of gaseous hydrocarbons, suppress abnormal temperature rise due to this heat of adsorption, and only use industrial water for cooling, which is generally used widely, This is because heat generated in the adsorbent layer is promptly removed, and the temperature of the adsorbent layer is controlled to be slightly higher than the atmospheric temperature.

In the present invention, the switching is performed in a short time as described above. However, when the adsorption process is completed and the desorption process is switched under these operating conditions, that is, at the time of desorption, "the vacuum is simultaneously used while purging." This is a feature of combining the means of In order to complete the desorption step within a short period of time in accordance with the short adsorption time, (a) increase the temperature of the desorption tower and use vacuum together, or (b) increase the amount of purge gas and use vacuum together Or (c) a combination of both.

However, when the means for raising the temperature of the desorption tower is adopted, the adsorption tower must be cooled when switching to the adsorption step, and any place where steam can be easily obtained may be used. It is not economical to use and heat the desorption tower. In addition, although it is of course not impossible to perform cooling and heating in a cycle within a range of 1 to 15 minutes, this does not smoothly transfer heat, and it is questionable whether a desired effect can be obtained. Remains. This problem does not occur when the switching time is longer than the conventional operating condition of 30 minutes or several hours.

By the way, in places where steam is not easily available, such as "gasoline oil depots and gas stations" which are particularly targeted in the present invention, when gaseous hydrocarbons are treated and recovered from waste gas. In addition to the short switching time of 1 to 15 minutes, the present inventors have found that "combined use of purge gas and vacuum" is desirable as a desorption means, and have completed the present invention. That is, in order to quickly perform desorption without heating the desorption tower at the time of desorption, it was found that it is effective to increase the amount of purge more than necessary and to operate at high vacuum. The invention has been completed.

In the present invention, as the amount of the purge increases, the concentration of gaseous hydrocarbons in the purge exhaust gas decreases. 50
The absorption of gaseous hydrocarbons by absorption into liquid hydrocarbons of low temperature of the same temperature (absorption method) or liquefaction by deep cooling (deep cooling method) does not cause any trouble.

In the first place, if the amount of adsorption is constant, the adsorbing capacity of the adsorbent increases as the swing time increases. That is, Sw
Although it is proportional to the ing time, it is desirable to avoid the problem by appropriately selecting the operating conditions in consideration of the troublesomeness of controlling the calorific value in the adsorbent layer and the danger of local heating.

The present invention has been made by paying attention to the above points. Specifically, the non-liquefied or uncondensed gaseous hydrocarbons from the gaseous hydrocarbon recovery unit are returned to the adsorption tower again. Means are employed, whereby gaseous hydrocarbons will gradually accumulate in the adsorption tower without this gas being released to the atmosphere. As a result, the concentration in the adsorbent layer increases, reaching a concentration level convenient for desorption. Therefore, the present invention is to appropriately set the swing time of adsorption / desorption in accordance with this concentration level while taking care not to cause local heating during operation.

However, the concentration in the purge exhaust gas is about
If it is less than 50%, there is a problem that it is not absorbed or liquefied by the recovery device. In order to solve this problem, in the present invention, it is extremely effective to add a concentration adsorption tower (adapter) using a cascade method.
This joint reduces the concentration of gaseous hydrocarbons in the purge exhaust gas.
This is a preferred embodiment of the present invention when it is 50% or less.

That is, in the above-described preferred embodiment of the present invention, prior to the recovery of gaseous hydrocarbons, an adapter is used to concentrate lean gaseous hydrocarbons in the purge exhaust gas sucked by a vacuum pump. Is to adopt means for doing so. The amount of purge exhaust gas processed by the adapter is much smaller than the amount of waste gas processed by the adsorption tower. For example, even if two small towers are used alternately, there is almost no economic disadvantage.

As means for avoiding a rapid rise in temperature due to the heat of adsorption of the adapter, particularly local heating, a method described in Japanese Patent Application No. 7-23377, filed by the present inventors, has been proposed. Alternatively, the method of mixing or adsorbing the adsorbents with the changed adsorption holes according to the prior invention is effective, but the enrichment adsorption tower smaller than the main adsorption tower is used, and the present invention is practiced. In this case, using a heat storage agent is one method, and is a preferable method.

This is a method of dispersing heat by uniformly dispersing and mixing metal fine particles such as iron, copper, and aluminum in an adsorbent and storing heat of adsorption therein. In place of the above metal fine particles, fine particles such as ceramics, slag, or bricks can also be used, but compared to metal fine particles in which the balance between heat absorption and heat radiation can be repeated in a short time. The effect is slightly inferior, which is not preferable.

In the present invention, the exhaust gas from the enrichment adsorption tower (adapter) is returned to the inlet of the adsorption tower, which is the main body, so that even if this adapter breaks through, it is not scattered to the atmosphere. Absent. On the other hand, in order to desorb the concentrated gaseous hydrocarbon from the adapter, the time until breakthrough is relatively long, and it is not necessary to desorb in a short time. If a high vacuum is applied at the time of the desorption, the desorption can be performed simply by suction without using a purge gas, which is a preferred embodiment of the present invention. Since the purge gas thus desorbed has a high concentration, it is efficiently treated and treated by the aforementioned absorption method or cryogenic method.
Can be recovered.

As described in detail above, the method according to the present invention uses (A) a double-cylindrical adsorption device composed of an inner cylinder and an outer cylinder as the adsorption device, and (B) a cooling device for cooling the inner cylinder. Fill the outer cylinder with an adsorbent to form an adsorbent layer, and (C) using a synthetic zeolite and / or hydrophobic silica gel having a pore size of 4 to 100 Å as the adsorbent, After pre-coating with gaseous hydrocarbons, adsorption and desorption operations are performed, and adsorption and desorption are one of the important operating factors.
Swing time for desorption is reduced to 1 to 15 minutes,
(D) At the time of desorption, a vacuum is simultaneously used while purging.

Then, the method according to the present invention comprises the above (A) to
By combining (D), in particular, the amount of gaseous hydrocarbons adsorbed on the adsorbent is controlled to a low level, the abnormal temperature rise in the adsorbent layer is suppressed, and the temperature in the adsorber is made uniform. Is a successful one. In other words, the temperature in the adsorbent layer at this time is only slightly higher than the outside air temperature, and it has been confirmed that the safety of the adsorber can be further secured as compared with the invention of the prior application.

In the method according to the present invention, a known PSA method or PTSA method can be applied.
The SA method, the VTSA method, and the like can also be applied, and these applications are also included in the present invention. The present invention is suitable for treating and collecting gasoline vapor-containing waste gas, but can also be applied to waste gas containing low-boiling gaseous hydrocarbons such as benzene, acetone, and methanol. Application to the present invention is also included in the present invention.

[0040]

Next, an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a flow chart illustrating a method for treating and recovering gaseous hydrocarbons according to one embodiment of the present invention.

(Embodiment 1) In this embodiment 1, as shown in FIG. 1, a double-cylindrical adsorption tower comprising cooling water circulation inner cylinders 2a, 3a and adsorbent-filling outer cylinders 2b, 3b. This is an example relating to a method for treating and recovering gaseous hydrocarbons contained in waste gas using the adsorption tower 2 and the adsorption tower 3. Then, the first embodiment
As a sorbent, "CARIACT-" manufactured by Fuji Silysia Chemical Ltd. is a hydrophobic silica gel with a pore size of about 30 angstroms.
Q3 "(trade name)" is filled in the outer cylinders 2b and 3b of the adsorption towers 2 and 3, and n-pentane is blown in advance to prepare the pre-coat.
And put into practice.

Hereinafter, the first embodiment will be described in detail with reference to FIG.
(Waste gas containing about 40 VOL% of gasoline vapor) is blown by a blower (not shown) or by its own pressure.
The gas is further sent to the adsorption towers 2 and 3. The treated waste gas that has completed the adsorption step is discharged from the top of the adsorption tower 2 (or the adsorption tower 3 after switching to the desorption step) through a discharge pipe 12 (or discharge pipe 12 ') to a gasoline base of 1 VOL% or less. It is released into the atmosphere as air containing particles (clean gas).

The adsorption towers 2 and 3 are operated while alternately switching the adsorption step and the desorption step described later.
The switching time (Swing Time) was set to about 5 minutes.

On the other hand, the purge tower 2 (or the adsorption tower 3 after switching to the desorption step) after the completion of the adsorption step is purged through the purge gas air pipe 13 '(or 13). The working gas is supplied and desorbed by suctioning with the vacuum pump 4. In the first embodiment, a part of the clean gas discharged from the top during the adsorption operation was used as the purge gas, and the vacuum pump 4 was operated at about 25 Torr.

The desorbed gas exhaust gas containing gasoline vapor is sent to the gasoline recovery unit 5 through the air supply pipe 14 '(or 14), and is brought into contact with liquid gasoline through the distribution pipe 6, and the liquid ( The gasoline vapor in the purge exhaust gas is recovered as a gasoline absorbent. This gasoline collector 5 has
A liquid level gauge 7 for detecting the liquid level of the liquid gasoline is attached. The effect of the recovery device 5 is the same whether it is a countercurrent contact type packed tower or a column tower.
The same applies to the use of a cryogenic liquefier using a refrigerant, and any of them can be used.

The exhaust gas from the gasoline recovery unit 5 contains
Since a small amount of gasoline vapor remains, the gas is returned to the waste gas pipe 11 again via the return pipe 15, and the adsorption treatment is performed together with the waste gas from the waste gas generation source 1. Although not shown, the adsorbent layers in the adsorption towers 2 and 3 are cooled.
Cooling water is circulated through the inner cylinders 2a and 3a, and an adjusting tank (not shown) is provided to supply the cooling water and keep the pressure constant.

In the first embodiment, as described above,
Since the switching time of the desorption is as short as about 5 minutes, the adsorption amount of the gaseous hydrocarbons is only 2%. As a result, local heating is avoided, and during the operation period, the adsorption tower 2 (3) The temperature was kept almost uniform from the top to the bottom (about 40 ° C). According to the first embodiment, the gasoline vapor concentration in the exhaust gas discharged from the discharge pipe 12 (12 ') into the atmosphere was substantially 0%.

(Embodiment 2) In this embodiment 2, the gasoline vapor in the purge exhaust gas taken out at the time of desorption from the adsorption tower 2 (3) after the adsorption step in the above-described embodiment 1 is completed. This is an example in which the concentration adsorption tower (adapter) 8 is operated only when the concentration is low. The enrichment adsorption tower (adapter) 8 performs the same operation as the adsorption tower 2 (3), except that aluminum granules (not shown) of about 50% of the adsorbent are uniformly dispersed in the enrichment adsorption tower 8. Is used. The exhaust gas from the concentration adsorption tower (adapter) 8 is returned to the return pipe 15 via the return pipe 16.

In the second embodiment, the gasoline vapor in the purge gas is concentrated by the concentration adsorption tower (adapter) 8 before the gasoline is recovered by the gasoline recovery device 5. It has the advantage that gasoline can be recovered efficiently even if the gasoline vapor concentration in the gasoline vapor is low.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments.
Various changes and modifications are possible within the scope of the present invention.

[0051]

As described in detail above, the present invention uses (A) a double-cylindrical adsorption device consisting of an inner cylinder and an outer cylinder as the adsorption device, and (B) water for cooling in the inner cylinder. The outer cylinder is filled with an adsorbent to form an adsorbent layer. (C) As the adsorbent, a synthetic zeolite having a pore size of 4 to 100 angstroms and / or hydrophobic silica gel is used. After pre-coating with hydrocarbons, the adsorption / desorption operation is performed, and the adsorption / desorption Sw
ing Time (switching time) is reduced to 1 to 15 minutes, and
(D) At the time of desorption, simultaneously use vacuum while purging,
According to the combination of (A) to (D), regardless of the concentration of gaseous hydrocarbons, a waste gas containing gaseous hydrocarbons is treated and discharged to the atmosphere.
The amount of gaseous hydrocarbons adsorbed on the adsorbent can be controlled to a low level, and the abnormal hydrocarbons in the adsorbent layer can be easily controlled. The remarkable effect that the temperature in the adsorption device can be made uniform by suppressing the temperature rise and the safety of the adsorption device can be ensured can be obtained.

Further, according to the present invention, in the treatment of gaseous hydrocarbons, which are air pollutants, the absorption method and membrane method conventionally used in Japan could not achieve at all. Not only is it possible to completely clear the EPA's regulated value of 1 VOL% or less, but it is also capable of responding satisfactorily to the measures of the EPA, which announced that this value should be reduced to less than half. It is a thing.

[Brief description of the drawings]

FIG. 1 is a view showing a flow sheet of a gaseous hydrocarbon treatment / recovery apparatus according to an embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 Waste gas generation source 2, 3 Adsorption tower 2a, 3a Cooling water circulation inner cylinder 2b, 3b Adsorbent filling outer cylinder 4 Vacuum pump 5 Gasoline collector 6-minute pipe 7 Liquid level gauge 8 Compression adsorption tower (adapter) 11 , 11 'Waste gas supply pipe 12, 12' Discharge pipe 13, 13 'Purge gas supply pipe 14, 14' Purge gas supply pipe after desorption 15 Return pipe 16 Return pipe

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Toshinaga Kawai 7-43-12 Konandai, Konan-ku, Yokohama, Kanagawa Prefecture (72) Inventor Kenichiro Suzuki 205-12 Minamiiriso, Sayama-shi, Saitama (56) References JP JP-A-5-237333 (JP, A) JP-A-5-337323 (JP, A) JP-A-3-135410 (JP, A) JP-A-50-117680 (JP, A) A) JP-A-5-23586 (JP, A) JP-B-54-4707 (JP, B2) (58) Fields investigated (Int. Cl. ⁶ , DB name) B01D 53/72 B01D 53/04 B01D 53 / 34 ZAB B01J 20/10 B01J 20/18

Claims (6)

(57) [Claims] 1. A method for treating and recovering gaseous hydrocarbons contained in waste gas by using a single-tower or multi-tower type adsorption device, comprising: (1) an inner cylinder for cooling water circulation and an adsorption device as the adsorption device; (2) A hole diameter of 4 to 100 was used in the adsorbent-filling outer cylinder using
Forming an adsorbent layer filled with a gaseous hydrocarbon, which is filled with angstrom synthetic zeolite and / or hydrophobic silica gel alone or as a mixture, and (3) adsorbing / desorbing the adsorbent layer. The switching time is 1 to 15 minutes,
And (4) a cleaner discharged from the adsorbent layer at the time of desorption.
(5) recovering gaseous hydrocarbons from the purged exhaust gas while purging with a part of a clean gas and / or air and simultaneously using a vacuum. Treatment and recovery method for hydrocarbons. 2. The pre-coated adsorbent layer of (2) is formed by pre-coating with a gaseous hydrocarbon before or after filling the outer cylinder. Item 1. Treatment of gaseous hydrocarbons contained in waste gas according to item 1.
Collection method. 3. A cascade enrichment adsorption column prior to recovering gaseous hydrocarbons from said purge exhaust gas.
The method for treating and recovering gaseous hydrocarbons contained in waste gas according to claim 1, wherein the concentration of gaseous hydrocarbons in the purge gas is concentrated via an (adapter). 4. As means for recovering gaseous hydrocarbons from said purge gas, cleaning is performed by using liquid hydrocarbons of the same quality as gaseous hydrocarbons contained in waste gas, and the liquid hydrocarbons are subjected to gaseous hydrocarbons. The method for treating and recovering gaseous hydrocarbons contained in waste gas according to claim 1 or 3, wherein hydrogen is absorbed. 5. The gas exhaust system according to claim 1, wherein said gaseous hydrocarbon is liquefied by deep cooling said gaseous exhaust gas as means for recovering gaseous hydrocarbons from said purge gas.
3. A method for treating and recovering gaseous hydrocarbons contained in waste gas according to item 1. 6. A cleaner radiated from the adsorption layer to the atmosphere.
The method for treating and recovering gaseous hydrocarbons contained in waste gas according to claim 1, wherein the concentration of hydrocarbons in the waste gas is 1 VOL% or less.