KR20050122668A - Method for lowering voc - Google Patents

Abstract

The present invention relates to a VOC reduction technique for reducing the VOC of the organic solvent containing the paint due to the painting operation of the automobile factory. In particular, in the spray booth equipped with wet coating equipment, VOC reduction method using capsulizer (Bio-1000: viscosity removal effect), coagulase (Bio-2000: flocculation effect), and natural microbial agent (Bio-3000: surfactant activity effect) It is about. The object of the present invention is to inject and multiply the microorganisms during the painting work to reduce the surface tension of water, increase solvent solubility, inhibit solvent evaporation and decompose organic matters such as solvents through carbon metabolites (enzymes) of the microorganisms (carbon gas and water) To reduce VOC emissions and reduce odors. The present invention using the microorganism as described above has the effect of reducing the apparent VOC concentration in the biological treatment method compared to the conventional conventional chemical treatment method.

Description

VOC reduction technique {Method for lowering VOC}

The present invention relates to a VOC reduction technique for reducing the VOC of the organic solvent containing the paint due to the painting operation of the automobile factory.

In general, in the paint shop of an automobile factory, chemicals generated by the organic solvents contained in the paint are discharged to the atmosphere, which affects the environment according to the chemical reactivity of the atmosphere. Volatile Organic Compounds (VOCs) appearing at this time are threatening human environment and health due to the ozone layer destruction and global warming in the stratosphere. As a result, global regulatory management has begun to emerge. Currently, Korea has regulated emission standards for total hydrocarbons (THC), including methane (NH ₄ ), which is less photochemically reactive to reduce VOCs. Will be implemented by the full scale.

According to these environmental policies, technologies to reduce VOCs have been required since the late 1990s, but there was no obvious effect. This technology uses bio-mass to decompose paint introduced into CWS by Bio-mass when paint spraying under CWS (Circulating Water System) of automobile factory, and then reduces VOC by metabolism of microorganisms. Means the treatment method.

So far known as VOC prevention methods, thermal oxidizer (heat incinerator), catalytic oxidizer (catalyst incinerator), flare, compressor, adsorber, absorber, boiler / process heater, biofilters, membrane separator, ultraviolet oxidizer , Corona destruction reactors and plasma technology.

Oxidizers and flares have very high destruction efficiency by burning and reducing VOCs, but many explosive compounds such as Nitroglycerin become very unstable when heated rapidly, which leads to stability problems. The adsorber and the compressor have high collection efficiency, but it is very harmful because of the condensation of explosives during the adsorption, and the absorber and the boiler / process heater are not generally used to prevent VOC. Absorbers usually have high collection efficiencies, but they require the use of absorbents for specific types of compounds and are difficult to handle changes in composition of the emissions. Boiler / process heaters are not used solely for reducing VOCs and can be used to destroy VOCs without compromising the stability and reliability of the primary process. Biofiltration converts VOCs to carbon dioxide, water, and inorganic salts using filters containing microorganisms, which are difficult to process at high flow rates. Membrane separation is semi-permeable polymer (Polymeric) using a film, and to remove the VOC and the discharge gas, an ultraviolet oxidation method is ozone by irradiation, peroxide, OH ^-, O ^- using oxygen present in the radical the VOC into carbon dioxide and water However, these too are difficult to handle large flow rates. Corona destruction and plasma technology have not been commercialized yet.

These conventional techniques are not easy to apply in the current wet coating equipment because each has both advantages and disadvantages.

The present invention has been made in view of the above problems, in the present coating equipment, while the organic solvent is circulated in a mixed state (5% or less Solvent solubility) in the circulating water solvent evaporated and sprayed solvent into the water It is not absorbed and released to the atmosphere at high concentrations. In order to reduce the concentration of air emissions, increasing the solubility of organic solvents and suppressing the regasification of solvents dissolved in water inhibits VOC generation and at the same time, solvents dissolve and accumulate in the circulating water to reach the limit point. (Solution of water-soluble paint) To solve this problem, dissolved solvent must be decomposed and removed, and this role is played by microorganisms (Bacillus species selected from natural microorganisms with high vitality and high digestibility) in hydrocarbon BTX and hydrocarbon chloride solvents. .

In other words, when the microorganism is injected and propagated, the microorganism produces a metabolite (enzyme), and the produced metabolite is a biosurfactant (surfactant), which reduces the surface tension of water, increases solvent solubility, inhibits solvent evaporation, and solvents. By decomposing (carbon gas and water), VOC emissions are reduced and thus odor is reduced.

The above method can be applied immediately in accordance with the current painting equipment situation, there is no need for a special prevention facility, easy maintenance, has the advantage of low cost.

The present invention for achieving the above object,

It is a method to reduce VOC by using natural bacteria belonging to Class I. It consists of three products, Bio-1000, Bio-2000, and Bio-3000.

Bio-1000 is a bio-capsulizer that emulsifies and decomposes VOCs during water (lower area) with over sprayed paint in the paint booth and forced spraying, and retains them in water. To prevent release to the atmosphere.

Bio-2000 is a coagulant that aggregates over sprayed paint to separate from paint wastewater and creates environment to maintain microbial density.

Bio-3000 is a microbial agent with high concentration of highly active bacteria. It removes viscous paints and completely removes odors and converts VOCs, odors and sludges during metabolism to carbon dioxide and water.

Hereinafter, application examples are described in order to describe the present invention in more detail, and the following application examples are only described to facilitate the implementation of the invention, and are not described to limit the invention.

<Application example>

Hereinafter, the application example of the present invention is to present the results of the test operation of 2003. 11. 20 ~ 2004. 01. 14 (55 days) in Hyundai I Asan factory Top Base I.

○ Emission VOC Measurement Table

1.Measured value of measurement agency commissioned by Hyundai Motor Asan factory (acquisition method)

Date Blower capacity (㎥ / min) Measurement result Remarks # 15 # 16 # 19 # 20 # 15 # 16 # 19 # 20 03.11.24 3,328 3,328 3,328 3,328 108 105 - - 12.15 3,328 3,328 3,328 3,328 45 34 - - 12.29 3,328 3,328 3,328 3,328 39 43 109 94 04.01.12 3,328 3,328 3,328 3,328 48 39 96 85 01.13 3,328 3,328 3,328 3,328 41 45 86 78

( # 15, # 16: apply microorganism # 19, # 20: apply chemical)

Environmental Conservation Act (Atmosphere): Grounds for the Regulation of Total Hydrocarbons (THC)

                 2005. 01. 01 to be implemented

(VOC less than 50ppm / more than 10,000㎥ per hour discharged)

Date # 15 # 16 medium Remarks Total AVG Count Total AVG Count # 15 # 16 03.12.04 1724.30 19 2921.50 28 90.75 104.34 12.09 1259.20 25 1355.20 35 50.37 38.72 12.23 1167.20 25 1252.80 24 46.69 52.20 12.29 1118.37 33 1018.44 27 33.89 37.72 04.01.06 1247.30 29 1282.90 27 43.01 47.51 01.12 1131.20 28 1048.50 25 40.40 41.94 01.13 776.20 26 1132.70 27 29.85 41.95

2. Self-measured value of environmental safety team of Hyundai Asan factory (Micro FID direct measurement method)

-Microbial Density Measurement of Microbiology Laboratory, Korea Maritime Research Institute (Final Result, 2004. 01. 17)

1. Purpose of Experiment

The purpose of this study is to investigate the change of total bacterial counts over time after adding microbial agent in VOC dust collection treatment water at Hyundai Motor Asan Plant.

2. Materials and Methods

1 ml of the sample was taken from the prepared dilution water, followed by dilution up to 10 ^-7 , and all dilution waters were sterilized distilled water. 100 μl of the LB agar plate (Bacto-peptone 10g, Yeast extract 5g, Bacto-agar 15g, 1 liter of distilled water, pH 7.0, 15 minutes sterilization at 121 ° C) was inoculated at 100 μl and plated with glass road. Dilution orders were used in the range of 10 ⁻³ to 10 ⁻⁷ . The culture temperature was 25 ℃ and the incubation period was counted after 3-4 days. Samples were provided by BJC.

Bio-1000 Series Inputs (Optimum Condition Range)

division Basic input amount (ppm) Remarks Normal daily dose (%) Remarks Bio-1000 2,500 ~ 3,500 Based on total quantity 9-12 Over-spray amount standard Bio-2000 2,700-3,700 Based on total quantity 10-13 Over-spray amount standard Bio-3000 20,000-25,000 Based on total quantity 3.3 ~ 3.5 Organic solvent standard

It can be seen that when the population of microorganisms is maintained at 10 ⁷ , the VOC concentration also drops proportionally.

As such, it can be seen that the chemicals are significantly reduced and the concentration reduction stability is maintained continuously.

The present invention using the microorganism as described above has brought a clear reduction in the concentration of VOC as a biological treatment method compared to the conventional conventional chemical treatment method.

Claims (3)

VOC reduction method using capsulizer (Bio-1000: viscosity removal effect), coagulant (Bio-2000: flocculation effect), natural microbial agent (Bio-3000: surfactant effect) in spray booth equipped with wet coating equipment. According to claim 1, Melamine resin, Cationic, Anionic, Nonionic Polymer, VOC reduction method characterized in that it comprises a breathable microbial agent. The circulating water quality of the wet coating booth according to claim 1, wherein the circulating water quality of the wet coating booth includes 600 to 900 ppm CO2, turbidity 900 to 1500 NTU, suspended solids (SS) 100 to 300 ppm, and microbial population 3.2 × 10 ° ± 4.2 × 10 ¹ CFU / m1. VOC reduction method characterized in that.