• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.11
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• pp.3246-3252
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• 2009

The interest on the recovery of thermal energy using the waste has been rising to solve the problems of continuous increase of waste generation and the depletion of the fossil fuel recently. The incineration has been used most popularly as a treatment process of the waste for the energy recovery. However, it is expected that incineration and design cost will increase in the treatment of air contaminant emitted from incinerator. This research has simulated the actual incinerator and the flue gas treatment system using the Aspen plus which is the software to simulate the chemical process. The incineration process is composed of the 1st and 2nd combustor to burn the waste, SNCR process to reduce the $NO_x$ using the urea, and the steam generation process to save the energy during incineration. The $Ca(OH)_2$ slurry was used as an acid gas (HCl, $SO_2$) treatment materials and the removal efficiency for the products from the neutralization of acid gas in SDA and combustion ash was simulated at the bag filter. The simulation result has been corresponded with the treatment efficiency of emitted gas from the actual industrial waste incinerator and it is presumed to be used to forecast the efficiencies of flue gas treatment system in the future.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.10
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• pp.901-908
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• 2009

We examine the processing method of the food wastewater to direct spray at living waste incinerator. The demoscale stoker system is used as a incineration facility. The results show that it brings effect on the reduction of nitrogen oxide ($NO_x$) concentration as well as the ammonia ($NH_3$) amount in SNCR (selective non-catalytic reduction) by the incineration of food wastewater which is containing a plentiful ammoniac nitrogen ($NH_3$-N). Furthermore, the stability of incineration facility and the extension of operation period is actualized as a improvement of clogging phenomenon on outer wall of water pipe as the 870~$950^{\circ}C$ maintain of exit temperature in a second combustor by spray of the food wastewater. The 26 items of air pollution matter of nitrogen oxide ($NO_x$), sulfur oxide ($SO_x$) and dioxin etc. are measured. The results show that it is under the value of allowable exhaust standard.

• Journal of ILASS-Korea
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• v.25 no.3
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• pp.132-138
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• 2020

N₂O is hazardous atmosphere pollution matter which can damage the ozone layer and cause green house effect. There are many other nitrogen oxide emission control but N₂O has no its particular method. Preventing further environmental pollution and global warming, it is essential to control N₂O emission from industrial machines. In this study, the thermal decomposition experiment of N₂O gas mixture is conducted by using cylindrical reactor to figure out N₂O reduction and NO formation. And CHEMKIN calculation is conducted to figure out reaction rate and mechanism. Residence time of the N₂O gas in the reactor is set as experimental variable to imitate real SNCR system. As a result, most of the nitrogen components are converted into N2. Reaction rate of the N₂O gas decreases with N₂O emitted concentration. At 800℃ and 900℃, N₂O reduction variance and NO concentration are increased with residence time and temperature. However, at 1000℃, N₂O reduction variance and NO concentration are deceased in 40s due to forward reaction rate diminished and reverse reaction rate appeared.

• Proceedings of the KAIS Fall Conference
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• 2009.12a
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• pp.1046-1049
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• 2009

최근 화석에너지 고갈 문제와 폐기물의 지속적인 발생량 증가로 인해 폐기물을 이용한 열에너지 회수가 이슈화 되고 있다. 폐기물처리를 통한 에너지 회수 공정 가운데 소각이 가장 많이 이용되고 있으나 소각시 발생하는 대기오염 물질을 처리하기 위한 설계 및 설치비용에 많이 소요 된다. 본 연구에서는 화학공정 모사기인 Aspen plus를 이용해 소각공정 및 배가스 처리 공정모사를 실시하였다. 폐기물 소각 공정으로는 1 2차 연소실과 NO2를 환원하는 SNCR공정, 산성가스(HCl, SO2)를 제거하는 SDA공정, 입자상 물질을 처리 하는 bag filter공정을 모사하였다. 공정모사 결과 실제 산업폐기물 소각로의 처리효율과 일치 하였고 이를 바탕으로 동일한 공정 및 조건하에 소각로에 투입되는 폐기물의 조성비를 달리하여 공정 모사한 결과 오염물질의 배출량을 예측할 수 있었다. 이러한 오염물질 발생량 예측은 소각장의 폐기물 투입이 일정하지 않을 경우 조업 조건의 변경에 도움 뿐만아니라 공정개선의 효과적일 것으로 판단된다.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.365-366
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• 2009

미분탄 순산소 연소는 기존의 연소 방법과는 달리 산화제로 O2/CO2를 사용함으로써 NOx의 발생을 감소시킬 수 있으며, 고농도의 CO2를 쉽게 회수 할 수 있어 큰 주목을 받고 있다. NOx의 배출저감을 위한 기술로는 로 내에서의 재연소(reburning), 단계(staging) 연소등이 있으며, 후처리 NOx 저감기술로는 SCR, SNCR등이 있다. 그러나 이러한 기술들은 비용이 비싸다는 단점이 있으며, 미분탄 순산소 연소조건에서는 화염 안정성이 감소하는 문제점이 있다. 따라서 본 연구에서는 화염의 안정성과 밀접한 관련을 가지는 화염전파속도에 대해 미분탄 순산소 연소에서 석탄 입자의 물성치와 주위 기체의 특성이 화염전파속도에 미치는 영향을 수치적 방법을 통하여 해석하였으며, NO 저감의 한 방법인 연소가스 재순환(Flue Gas Recirculation)에 따른 연소특성 및 NO 생성 메커니즘의 영향과 석탄을 가스화 시키는 방법에 따른 연료의 연소특성에 대해 해석하였다.

• Proceedings of the KAIS Fall Conference
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• 2009.05a
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• pp.848-850
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• 2009

화석에너지 고갈로 인한 유가 상승으로 폐기물 에너지화가 이슈화 되고 있다. 폐기물 고형 연료 RDF는 에너지 문제를 해결하기위한 대안 중 하나로 수송성, 저장성, 연소안정성이 우수하나 환경오염 물질의 발생이 문제가 된다. 이러한 오염물질을 처리하기 위한 배가스 오염 물질처리를 위한 plant 설비 비용과 시간이 많이 투자된다. Aspen plus는 mass energy balance와 화학적평형, 열역학을 이용하여 공정 모사를 할 수 있는 프로그램으로 검증되었다. RDF의 삼성분, 원소분석, 발열량을 입력을 통해 HCl, SOx, NOx, CO의 배출량을 예측하고 이에 맞는 SNCR, SDA 등과 같은 반응기를 적용 하므로써 다양한 배가스 처리를 모사 할 수 있다. NOx를 제어하기위에 urea주입과 SOx와 HCl을 제거하기 위한 CaO를 주입을 모사 하므로써 실제 운영 적용 전 단계에 역할로 유용한 도구로 판단된다.

• Journal of Korea Society of Waste Management
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• v.35 no.7
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• pp.647-652
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• 2018

The emission of nitrogen oxides has a great environmental impact. It leads to Los Angeles type smog, and it recently has attracted attention as a source of ultrafine dust. The main sources of nitrogen oxides are internal combustion engines and industrial boilers. These emission sources are processes that are essential for human industrial activities, so the regulation of original use is impossible. Therefore, special control methods should be applied to reduce NOx emissions into the atmosphere. In this study, we investigated how the supply of ER and urea influences the removal of nitrogen oxides from SRF combustion boilers. Experimental results show that the removal efficiency of nitrogen oxides can be up to 80% under the conditions of ER 2.0 and a urea feed of 0.5 LPM.

• Transactions of Materials Processing
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• v.32 no.3
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• pp.107-113
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• 2023

The importance of dual-fuel engines has increased for reducing CO₂ emissions. However, the low operating temperature of this engine may induce low-temperature corrosion at combustion parts, which reduces the engine service life. To overcome this problem, NiCr38Al4 alloy was developed for valve spindle, but the cost of this alloy is expensive due to its high Cr content. For reducing the manufacturing cost of valve spindle, in the present work, NiCr38Al4 alloy was welded with Nimonic80A alloy by conducting friction welding. The tensile test results show that the strength of friction-welded specimens follows the properties of the lower-strength parent materials, without severe cracks at the interface. The large shear strain and frictional heat from friction welding not only reduce grain size but also induce solute element diffusion at the interfacial region. Because of the low Cr diffusivity compared with Ti, Cr carbides were not observed in the Nimonic80A matrix, while Ti carbides were distributed in both the Nimonic80A and SNCrW matrices.

• Journal of Korean Society for Atmospheric Environment
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• v.20 no.2
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• pp.205-213
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• 2004

The emission characteristics of mercury in waste incinerators were investigated to get basic data for the policy development on the emission reduction of mercury (Hg). For the study several important factors were analysed from 4 incinerators such as mercury concentration, emission factors and removal rate for control devices. The results are listed below. Mercury concentrations in the flue gas were 0.39～5.96 $\mu\textrm{g}$/S㎥ in MWI and 2.5～8.8 $\mu\textrm{g}$/S㎥ in IWI. The distributions of gaseous and particulate mercury in flue gas were above 99% and below 1 %, respectively. Therefore, in order to remove mercury effectively, it is important to control the gaseous mercury. Mercury concentrations in fly ash collected from control device were found as 16.2～35.6 mg/kg- ash in FF of MWI. Also mercury concentrations at the front and back point of control device of MWI were 33.45～62.65 $\mu\textrm{g}$/S㎥ and 0.88～3.49 $\mu\textrm{g}$/S㎥, respectively. Emission factors were estimated as 3.67～11.67 mg/ton in FF, 2.6～24.5 mg/ton in MWI with SNCR, SDR and FF, 54.9～192.7 mg/ton in IWI with Cyclone and FF. Emissions from Municipal Waste Incinerator were found both in minimum and maximum ranges. Annual mercury emissions emitted from MWI was estimated as 20.0 kg (6.0～33.9 kg).

• Clean Technology
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• v.27 no.4
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• pp.341-349
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• 2021

In combustion facilities, the nitrogen and sulfur in fossil fuels react with oxygen to generate air pollutants such as nitrogen oxides (NO_X) and sulfur oxides (SO_X), which are harmful to the human body and cause environmental pollution. There are regulations worldwide to reduce NO_X and SO_X, and various technologies are being applied to meet these regulations. There are commercialized methods to reduce NO_X and SO_X emissions such as selective catalytic reduction (SCR), selective non-catalytic reduction (SNCR) and wet flue gas desulfurization (WFGD), but due to the disadvantages of these methods, many studies have been conducted to simultaneously remove NO_X and SO_X. However, even in the NO_X and SO_X simultaneous removal methods, there are problems with wastewater generation due to oxidants and absorbents, costs incurred due to the use of catalysts and electrolysis to activate specific oxidants, and the harmfulness of gas oxidants themselves. Therefore, in this research, microbubbles generated in a high-pressure disperser and reducing agents were used to reduce costs and facilitate wastewater treatment in order to compensate for the shortcomings of the NO_X, SO_X simultaneous treatment method. It was confirmed through image processing and ESR (electron spin resonance) analysis that the disperser generates real microbubbles. NO_X and SO_X removal tests according to temperature were also conducted using only microbubbles. In addition, the removal efficiencies of NO_X and SO_X are about 75% and 99% using a reducing agent and microbubbles to reduce wastewater. When a small amount of oxidizing agent was added to this microbubble system, both NO_X and SO_X removal rates achieved 99% or more. Based on these findings, it is expected that this suggested method will contribute to solving the cost and environmental problems associated with the wet oxidation removal method.