KR100591271B1 - A processing method of volatile organic compounds of use electrical change adsorption method and that equipment - Google Patents

Abstract

According to the present invention, when a gas containing a volatile organic compound is introduced through a gas inlet, the inlet valve and the outlet valve are kept open and the vacuum valve is kept closed, so that the inlet gas is pretreated bulk activated carbon fiber. While passing through the adsorption tower filled with gas, the volatile organic compounds are adsorbed and removed by 95% or more, and then discharged through the outlet.

At the entrance and exit of the adsorption tower, a screen is installed to prevent the leakage of activated carbon fibers and to prevent the inflow of dust, and at the same time, the screen is used as an electrode for energization during desorption. And close the outlet valve, open the vacuum valve and supply power to the screen through the power supply installed on both sides of the adsorption tower, and send the volatile organic compounds desorbed by the vacuum pump to the combustor for combustion or to store in a separate container. will be.

Activated carbon fiber, bulk, adsorption tower, electrophoretic adsorption

Description

A processing method of volatile organic compounds of use electrical change adsorption method and that equipment}

1 is a cross-sectional view of the installation state showing a preferred embodiment of the present invention

2 is a performance curve comparing the adsorbent regeneration efficiency by the electrophoretic adsorption method and the conventional pressure swing adsorption method used in the present invention

Figure 3 is a current change curve according to the applied voltage of the present invention

4 is a change curve of temperature and resistance according to the applied voltage of the present invention

5 is a temperature change curve according to the power of the present invention

Figure 6 is a graph comparing the exothermic characteristics of the activated carbon fiber of the present invention according to the pretreatment

[Description of Symbols for Main Parts of Drawing]

10 gas inlet 11 inlet valve

12 outlet valve 13 outlet

20: adsorption device 21: adsorption tower

22, 23: power supply 24: thermocouple

25, 26: screen 30: vacuum valve

31: vacuum pump 32: combustor

 The present invention relates to a method and apparatus for treating volatile organic compounds occurring at small or intermittent levels, and more particularly, to organic materials intermittently discharged from dispersed pollutants such as a laundry, a dye factory, a paint factory, a painting factory, a printing factory, and the like. The solvent is adsorbed and removed with an activated carbon fiber or an activated carbon fiber with finely coated metal components on the activated carbon fiber, and the adsorbent that has completed the adsorption generates electricity by applying electricity to both ends to desorb the adsorbed organic solvent. The present invention relates to a method and apparatus for treating volatile organic compounds using an electrophoretic adsorption method, which is collected in a separate container and recovered, reused or optionally incinerated with a pure solvent.

VOC (Volatile Organic Compound) is a hydrocarbon compound that has a vapor pressure of 0.02 psi or more or a boiling point of less than 100 ℃ among organic compounds. In air quality management, ozone and photochemical oxides are removed by nitrogen compounds and photochemical reactions. It is defined as a precursor to form.

VOC, a volatile organic compound, is a source of harmful air and odors. It has harmful effects on the human body such as respiratory disorders and carcinogenicity. It also causes substances such as smog formation through photochemical reactions, odor generation, and urban ozone concentrations. It is causing environmental pollution.

Therefore, developed countries have already established standard values according to various international agreements such as ISO, mandated the installation of control facilities, or prepared measures to reduce the amount according to long-term plans.

The solvent in the laundry is a volatile organic compound (VOC), which is not only an emission control target, but also a cause of odor and a major cause of making the laundry business one of the 3D industries. Conventional techniques for treating such volatile organic compounds include biofiltering, catalytic oxidation, direct combustion, wet cleaning, and adsorption. These conventional technologies have been applied to an industry in which a large volume of VOCs are constantly discharged due to a large volume, a complicated device, a large initial investment cost, and a high maintenance cost. In addition, since most of the treated volatile organic compounds are consumed, it is difficult to apply them to processes requiring recovery and reuse.

In the case of the adsorption method, activated carbon or zeolite is typically used. The surface area per unit weight is smaller than that of the activated carbon fiber adsorbent used in the present invention, and a large capacity vacuum device or an external heat source is required when regenerating saturated adsorbent. There is this.

Moreover, since high temperature air or steam is used for regeneration of the adsorbent, there is a problem that reuse is very difficult because the purity of the recovered solvent is low.

Japanese Patent Laid-Open Publication No. 2004-148211 (published on May 27, 2004), which is a technique of adsorbing volatile organic compounds using activated carbon fibers and desorbing them by energization, is used to clean gas containing contaminants. At least one unit by using the adsorption apparatus which combined the at least two of the unit adsorption apparatus which has two electrodes and becomes an airtight container which arrange | positioned inside the activated carbon fiber sheet which generate | occur | produces heat generation by electricity supply. An adsorption step of adsorbing the activated carbon fiber sheet by adsorbing the activated carbon fiber sheet in at least one unit adsorbing device by adsorbing the adsorbent to the activated carbon fiber sheet; The adsorption step is to supply the contaminant-containing gas to the unit adsorption device, and the desorption step is performed in the unit adsorption device. It is made by energizing between the electrodes while exhausting and generating the activated carbon fiber sheet.

However, when the bulk fiber is used, the exothermic density is low, and there is a risk of explosion due to the spark between the fiber and the fiber, so the fabric is woven in the form of felt.

By using the felt form, it is not easy to use the reactor in the form of a packed bed, and there is also a disadvantage in controlling the size and shape. In addition, the fabric woven in the felt form is expensive compared to the bulk activated carbon fibers, so there are many disadvantages in terms of securing economic feasibility.

The present invention has been invented to solve the above-mentioned drawbacks, and adsorption and removal of gases in places where volatile organic compounds are generated at small and intermittent intervals, such as laundry, paint shop, printing industry, etc. with an adsorbent based on activated carbon fibers. The purpose of the present invention is to provide a device for suppressing the discharge of pollutants and supplying power for regeneration of saturated adsorbents to induce desorption through self-heating and then collecting or incineration them into separate containers.

In this case, the activated carbon fiber used as the adsorbent is not woven into the felt form, but uses the inexpensive bulk form and heat-treated to improve the heat generation characteristics by electricity or the metal component is finely applied to the surface of the activated carbon fiber to solve the problem. It is characterized by being applied and used.

The present invention is composed of a technique using an activated carbon fiber heat-treated or finely coated a metal component on the surface in order to improve the exothermic properties of the adsorbent and a device for adsorbing and desorbing volatile organic compounds using such an adsorbent.

Figure 1 shows a preferred embodiment of the present invention, Figure 2 is a performance curve comparing the adsorbent regeneration efficiency by the electrosorption adsorption method of the desorption method used in the present invention and the pressure swing adsorption method of the prior art, Figures 3 to 5 shows the relationship between voltage, current, resistance, and temperature when the adsorbent is electrically charged, and shows NTCR (Negative Temperature Coefficient Resistivity) characteristics, where the resistance decreases as the temperature of the adsorbent increases.

The material having the NTCR characteristic has a disadvantage in that the resistance value decreases as the temperature is increased when applied as a heater, and thus the increase in the current value increases the heat generation, thereby making it difficult to control the heat.

Therefore, in order to control the heating element, control through the current control circuit will enable more stable control than control through the voltage control circuit.

In FIG. 1, a gas inlet 10 through which a gas containing a volatile organic compound is introduced is installed, and an inlet valve 11 for determining the opening and closing of the gas inlet 10 is installed therein.

An adsorption device 20 is installed inside the inlet valve 11, and the adsorption device 20 is pretreated to increase the content of carbon island through heat treatment under vacuum in order to improve heat generation characteristics therein. Sealing rings (27, 27 ') at both sides to prevent leakage of activated carbon fibers and to prevent dust from entering the adsorption tower (21) and the gas inlet (10) and outlet (13) side filled with fibers in bulk form. And stainless steel screens 25 and 26 were installed to fix them with fixing plates 28 and 28 'and at the same time utilize them as electrodes for inducing heat generation when energizing.

A portion (center) of the adsorption tower 21 is provided with a thermocouple 24 for controlling the temperature when the internal temperature rises by energization during desorption, and the fixing plates 28, 28 'are mounted on the screens 25, 26. The power supplies 22, 23 are connected.

In the adsorption tower 21, an outlet valve 3 is installed in the direction of the outlet 13 to control the opening and closing of the outlet 13.

Between the inlet valve 11 and the screen 15 is connected a vacuum pump 31 for sucking the volatile organic compounds desorbed and the vacuum side valve 30, the volatile desorbed on one portion of the vacuum pump 31 The combustor 32 which burns or sends an organic compound to the outside and collects and stores in a separate container is installed.

Specific examples of increasing the content of the carbon component through heat treatment in a vacuum to improve the exothermic characteristics of the adsorption column 21, after filling the activated carbon fibers in a quartz reactor having a radius of 3cm, length 20cm to block both ends of the reactor and vacuum pump Removing the air in the reactor (<700 torr) and raising the temperature at a rate of 8-15 ° C./min and maintaining it at 450-550 ° C. for 40 minutes to 1 hour 20 minutes increased the carbon content by 2.8%. It can be confirmed from Table 1 below that the reduction of impurities.

       Comparison of Properties of Activated Carbon Fiber Before and After Vacuum Heat Treatment Elemental analysis * wt%) Surface area (㎡ / g) Total pore volume (mg / g) Pore size r (Å) C H N O (diff :) Ash Raw carbon fiber 95.5 0.9 0.3 2.8 0.5 1,894 0.81 5.3 Vacuum Heat Treatment Activated Carbon Fiber 98.3 0.22 0.11 0.88 0.49 1,568 0.748 6.2

When the gas containing the volatile organic compound is introduced through the gas inlet 10, the inlet valve 11 and the outlet valve 12 are kept open and the vacuum valve 30 is kept closed. The inlet gas passes through the screen 25 and passes through an adsorption device 20 equipped with an adsorption tower 21 filled with pre-treated activated carbon fibers, and at least 95% of volatile organic compounds are adsorbed and removed. Only clean gas is discharged through (12) and outlet (13).

At the inlet and outlet sides of the adsorption tower 21, stainless steel screens 25 and 26 are installed to prevent leakage of activated carbon fibers and to prevent dust from entering, and at the same time, to utilize electrodes for energization during desorption. When the adsorption capacity of the adsorbent reaches a saturation state after operating for a while, the vacuum pump 31 is operated while supplying current from the outside to the power supply devices 22 and 23 installed on both sides of the adsorption tower 21 for regeneration. .

When the vacuum valve 31 is opened and the vacuum valve 30 is opened, the volatiles adsorbed on the activated carbon carbon fibers installed inside the adsorption tower 21 by the screens 25 and 26 generated by the power supply devices 22 and 23. After the organic compound is desorbed by heat, it is sent to the combustor 32 to be burned or collected and stored in a separate container.

At this time, the inlet valve 11 and the outlet valve 12 are kept closed and the vacuum valve 30 is kept open to easily supply the volatile organic compounds desorbed to the adsorption tower 21 to the combustor 32. do.

When the temperature of the adsorption tower 21 is increased by energization of the power supply devices 22 and 23 when the volatile organic compounds are desorbed, the thermocouple 24 installed at the center of the adsorption tower 21 controls the temperature to overheat a certain temperature or more. Keep it stable so as not to.

The present invention increases the content of the carbon component through heat treatment in a vacuum to improve the exothermic characteristics, and provides a desorption efficiency of at least 17% higher than conventional vacuum desorption by applying a metal (copper) component on the surface of the activated carbon fiber .

A specific embodiment of increasing the carbon content by applying a copper component or heat treatment to the surface of the activated carbon fiber will be described.

Example 1

1. Washing process

Epic 30 g / l was deposited at a temperature of 40 ° C.

2. Washing and drying process

Pure water washing process is repeated three times and dried using a centrifuge.

3. Accelerator Course

Liquid composition: PdCl ₂ 2H ₂ O b: 0.1 to 1 g / l, Conc (dark)-HCl: 0.1 to 1 g / l, PH: 3 to 4, perform the process for 2 to 5 minutes at a temperature of 50 ℃ .

4. Washing and drying process

Pure water washing process is repeated three times and dried using a centrifuge.

5. Accelerator Course

Liquid composition: NaH ₂ PO ₄ .H ₂ O: 75g / L, PH: 6-7, the accelerator process is performed for 3 to 5 minutes at a temperature of 40 to 60 ℃.

6. Washing and drying process

Pure water washing process is repeated three times and dried using a centrifuge.

7. Copper Plating Process

Composition: ① Copper sulfate: 10 g / ℓ, ② Rotsel salt: 40 g / ℓ, ③ Adjusted with sodium hydroxide, PH: 12.5, ④ Paraformaldehyde: 13 g / ℓ, ⑤ Thiourea (chlorinating agent): 0.1 ～ 2mg / l, ⑥ air agitation (bubble generated air mixture)-5 minutes at a speed of 1 ~ 2㎛ 1 hour, ⑦Temperature: room temperature (25 ℃).

4. Washing and drying process

Pure water washing process is repeated three times and dried using a centrifuge.

Example 2

Fill the inside of the adsorption column with bulk activated carbon fibers, block both ends of the adsorption tower, and remove the air inside the adsorption tower with vacuum pump (<700 torr) to raise the temperature at the rate of 8-15 ℃ / min and 40 at 450 ~ 550 ℃. The content of the carbon component is increased in the process of heat treatment by maintaining for 1 to 20 minutes.

When comparing the energy required to pretreat the activated carbon fiber and raise the temperature to 100 ℃ as described above, the energy saving effect of the heat treatment and the copper support reached 13% and 33%, respectively.

The present invention provides a method of selectively adsorbing and removing volatile organic compounds from a gas containing volatile organic compounds generated at small or intermittently, and energizing both sides of the adsorbent when the adsorption is completed. It can reduce the price by 1/2 or more.

The present invention is used by finely applying a metal component on the surface of the activated carbon fiber or by increasing the carbon content through heat treatment, using an electrophoretic method provides a higher desorption efficiency than conventional vacuum desorption.

The present invention has been described through a specific example of using a method of increasing the carbon content by applying a metal component or heat treatment to the surface of the activated carbon fiber, but the scope of the present invention is not limited to that described herein, Changes to the extent that those skilled in the art can easily be carried out in the art, but will not depart from the scope of the invention.

Claims (7)

In the small or intermittent volatile organic compound treatment method, When gas containing volatile organic compounds is introduced through the gas inlet, the inlet and outlet valves remain open and the vacuum valve remains closed, so that the inlet gas is filled with pre-treated bulk activated carbon fiber. While passing through the adsorption tower, more than 95% of volatile organic compounds are adsorbed and removed, and then discharged through the outlet. At the entrance and exit of the adsorption tower, a screen is installed to prevent the leakage of activated carbon fibers and to prevent the inflow of dust, and at the same time, the screen is used as an electrode for energization during desorption. Close the outlet valve and open the vacuum valve, supply power to the screen through the power supply devices installed on both sides of the adsorption tower, generate heat, and send the volatile organic compounds desorbed by the vacuum pump to the combustor for combustion or to store in a separate container. A method of treating volatile organic compounds using electrophoretic adsorption. In the small or intermittent volatile organic compound treatment method, After filling the activated carbon fiber with adsorption tower, block both ends of the adsorption tower to remove the air inside the adsorption tower with vacuum pump (<700 torr) and raise the temperature at a rate of 8-15 ℃ / min, and 40 ~ 1 hour 20 minutes at 450 ~ 550 ℃. A method of treating volatile organic compounds using an electrophoretic adsorption method characterized in that the volatile organic compounds are treated by increasing the content of carbon in the adsorption tower by maintaining them for a while. In the small or intermittent volatile organic compound treatment method, Washing process of depositing 30 g / l of Eskise at a temperature of 40 ° C .; After repeated washing with pure water three times and dried using a centrifuge, PdCl ₂ 2H ₂ O b: 0.1 to 1 g / L, concentrated HCl: 0.1 to 1 g / L, PH: 3 to 4, the process performed for 2 to 5 minutes at a temperature of 50 ℃; After repeated washing with pure water three times and dried using a centrifuge, NaH ₂ PO ₄ .H ₂ O: 75 g / L, PH: 6 to 7 minutes at an temperature of 40 to 60 ° C. for an accelerator process; And After repeated washing with pure water three times and dried using a centrifuge, ① Copper sulfate: 10 g / ℓ, ② Rotsel salt: 40 g / ℓ, ③ Controlled with sodium hydroxide, PH: 12.5, ④ Paraformaldehyde: 13 g / ℓ, ⑤ Thiourea (chlorine remover): 0.1 ~ 2mg / ℓ And treating the volatile organic compound using an electrophoretic adsorption method using an adsorption tower for copper plating at 25 ° C. for 5 minutes while stirring the air at a rate of 1 to 2 μm per hour. In treating small or intermittent volatile organic compounds, An inlet valve that opens when a gas containing a volatile organic compound is introduced and is installed in a gas inlet direction; An outlet valve installed in an outlet direction after the gas introduced through the inlet valve passes through the adsorption tower and is adsorbed and removed; An adsorption tower installed between the inlet valve and the outlet valve and filled with pretreated activated carbon fibers to adsorb and remove organic compounds; A screen installed in an inlet valve and an outlet valve of the adsorption tower and connected to a power supply device for energizing when detached; When the vacuum side valve installed between the inlet valve and the screen is opened, the volatile organic compound using the electrophoretic adsorption method comprises a vacuum pump for sending the desorbed volatile organic compound to the combustor and collecting or storing it in a separate container. Apparatus for treating compounds. 5. The apparatus of claim 4, wherein the adsorption column uses bulk activated carbon fibers. The apparatus for treating volatile organic compounds using the electrophoretic adsorption method according to claim 4, wherein the metal component is finely coated on the surface of the activated carbon fiber of the adsorption column. The apparatus for treating volatile organic compounds using the electrophoretic adsorption method according to claim 4, wherein the carbon content of the activated carbon fiber of the adsorption column is increased by heat treatment in vacuo.

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