• Clean Technology
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• v.16 no.1
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• pp.59-63
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• 2010

The concentration process of 2-ethyl hexanol used for the intermediate material in the production of plasticizer is examined for the energy conservation of energy-efficient distillation system instead of the conventional two column system through numerical simulation. Some 41 % of energy conservation is expected from the proposed system, and its conservation principle is explained with column profiles. In addition, not only the operating cost but also investment cost can be reduced for the additional benefit of the column application when the thermally coupled distillation is implemented.

• Clean Technology
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• v.4 no.1
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• pp.24-34
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• 1998

Eco-labelling programs contributed to the promotion of international trade of environmentally friendly products. However, it has potential trade implications. From the WTO's point of view, environmental measures relevant to eco-labelling should not discriminate between home produced goods and imported goods. Transparency should be guaranteed in preparation, adoption and application of eco-labelling. Developed countries address that eco-labelling of non-product PPM criteria is included in the provisions of TBT of WTO. However, there are more general afraids that non-product PPM-based eco-labelling can be unfairly discriminately trade measures without transparency Thus, transparency of procedures of eco-labelling, harmonization and mutual recognition of eco-labelling criteria, and technical assistance should be recommended in order to reduce trade-discriminating effects of eco-labelling.

• Clean Technology
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• v.11 no.4
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• pp.181-188
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• 2005

Developed is the new gas-solid flow ball valve where air injection purging concept is applied for the control and the reduction of particle fouling. CFD analyses are conducted for investigating the interaction between gas-sold and air injection streams and the fouling phenomena in valve, and the analysis results are reflected in the design of valve geometry and air injection condition. Through the actual tests on designed ball valve, the present valve is shown to be superior in fouling reduction.

• Clean Technology
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• v.18 no.4
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• pp.341-346
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• 2012

Many researchers have studied that many processes to effectively remove heavy metals in water/wastewater. Especially, among many processes, physical and chemical processes are relatively simple and obtain high treatment efficiency for removal heavy metals compared with biological treatment. Recently, interests in physical and chemical methods are sharply increasing again because of dangerousness for radioactive element. In this study, various physical and chemical processes such as chemical precipitation, ion-exchange, electrodialysis, and membrane separation are introduced.

• Clean Technology
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• v.23 no.1
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• pp.34-41
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• 2017

The scrubber wastewater should be replaced frequently to maintain efficiency. Most chemical companies consign scrubber wastewater, because there are no wastewater treatment facilities. So scrubber wastewater is not frequently replaced because of high treatment cost. For this reason, the most scrubber exhaust gas exceeds the odor emission limit or has a phenomenon that the odor intensity of exhaust gas becomes higher. Therefore we have developed a scrubber wastewater cleaning system consisting of filtration and adsorption processes. The scrubber wastewater cleaning system was applied two chemical companies. We evaluated the water quality and odor reduction effect before and after system application. As a result, scrubber wastewater quality improved by 50% or more, odor reduction efficiency of scrubber exhaust gas improved by 20% or more. And the total operating costs of the scrubber could be reduced by 40% or more.

• Clean Technology
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• v.13 no.2
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• pp.127-133
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• 2007

Celite with enormous pore space inside can hold small molecules and can be well blended with polyethylene (PE) to make a Celite-PE film. Two types of Celite-PE film were prepared, one with Celite surface-treated with surfactant to reduce the hydrophilicity and another with plain Celite. The anti-rust chemical such as dicyclohexylamine, dicyclohexylamine nitrite, or diisopropylamine was allowed to permeate into celite pore in the film, and slowly evaporated to protect the packaged steel material from the rust for a long period of time. The chemical concentration in the different packaging film bags was analyzed by a gas chromatography for a month, and the anti-rust effect on iron labware was compared for a six month period. The Celite film was superior to PE film in anti-rust effect and the long-term anti-rust chemical evaporation.

• Clean Technology
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• v.4 no.2
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• pp.41-53
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• 1998

Most of flame furnace with uncontrolled atmosphere forms oxidation scales in the surface during heat treatment. In this case, shot blasting and pickling are commonly used for reduction of oxidation scales. These processes have many disadvantages, such as long process time, high operating cost and environmental problems due to polishing dust, etc. Hence, this study aimed to develop the advanced heat treating equipment which could make a controlled atmosphere using a heatresisting structure into the flame furnace. The analysis result with SEM, EPMA, and EDX revealed that the amount of scales formed is much less than that with the conventional flame furnace. A brightness of the sample treated with the advanced process is similar compared to the treatment with vacuum furnace. In the present work, it was recommended that the inside structure of the furnace and gas line system could made up of SBB410 and STS310, respectively. The operating cost with the advanced heat treatment system could be reduced annually by forty million won. As a result of this study, it may be possible to reduce the oxidation scales. The fundamental information obtained in this study will be useful not only for improving the heat treatment process(reduction of shot blast and cleaning process), but for promoting the manufacture of bright products.

• 발명특허
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• v.26 no.10 s.306
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• pp.76-83
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• 2001

본 발명은 승화성 고체 미립자 제트를 이용한 분사로 표면의 오염물을 제거하는 공정이다. 이는 극저온에서 고화된 입자가 표면에 고속 충돌 후 오염물을 제거하고 자신은 승화되어 잔사를 남기지 않는 청정 세척 공정을 말하는데 반도체 장비, 정밀 제품, 인쇄회로 기판 등의 다양한 표면의 각종 오염막 제거에 널리 사용될 수 있다. 본 장치의 특징은 세정 매체인 $CO_2$와 Carrier gas인 $N_2$를 사용하였고 현재 특허에 출원되어 있는 단순한 액체$CO_2$를 이용한 세정범위를 넘어 다양한 세정매체 즉, 복합인자($CO_2$ + ice, Ar + ice)를 이용하여 세정효율의 다변화를 이루었고 자체 개발한 냉동기를 이용하여 고화율이 액체 $CO_2$보다 상대적으로 낮은 기체 $CO_2$의 고화율을 증대 시킴으로써, 세정매체의 소모시간이 현격히 감소되어 원가절감 효과를 증대 시켰다. 세정대상물을 효과적으로 제거하기 위해 주 세정 매체인 $CO_2$의 수농도를 조절할 수 있는 Multi-Nozzle의 개발과 이로 인하여 세정력의 강도를 조절하도록 하였다. 세정 후 발생되는 오염입자를 효과적으로 제거하도록 국부 Exhaust를 Nozzle전단에 달아 재 오염의 방지효과를 극대화 시켰다.

• Applied Biological Chemistry
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• v.14 no.1
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• pp.1-7
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• 1971

In order to develop an enzyme preparation for clarification of fruit juices, a microbial strain having a strong pectolytic activity was selected and a crude enzyme preparation from this strain was examined for the effects in the preparation of grape juice and wine. The results are summarized as follows: 1) A strain of Aspergillus niger was selected as having the highest productivity of pectolytic enzymes among many species of Aspergillus and Rhizopus. 2) A pectolytic enzyme preparation was purified from this selected strain and the effects of pH and temperature on its enzyme activity and stability were investigated. 3) The use of the enzyme preparation brought about the increase in the free run yield and clarity of grape juice. 4) Whereas the use of the enzyme preparation did not exhibit any effect in the brewing of red wine, its use showed a good effect on the rates of filtration and clarity in the case of white wine.

• Clean Technology
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• v.15 no.2
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• pp.116-121
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• 2009

In this paper, we investigated the effect of an indirect oxidation zone in an electrolysis reactor that used Ti/$IrO_2$ as the anode and SUS 316L as the cathode. Based on our preliminary results, the electrolysis reactor was operated with pole plate interval of 6 mm, current density 1.0 $A/dm^2L$ and electrolyte concentration 15%. The removal efficiency, COD (chemical oxygen demand), was additionally increased by 55% and 12.5${\sim}$15.0% in the direct and indirect oxidation zones, respectively. The removal efficiencies of T-N (total nitrogen) and T-P (total phosphorus) were found to be 88% and 75%, respectively. It was shown that the additional effect of the indirect oxidation zone on the removal was nearly negligible. Also, as the removal of COD,T-N and T-P took place during the initial2${\sim}$5 days of reaction, it was concluded that there was no need to extend the retention time of the electrolysis reactor.