• Proceedings of the KSME Conference
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• 2001.06d
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• pp.115-120
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• 2001

The present study examined the possibility of $NO_{x}$ reduction in the high temperature industrial furnaces. duct burner of gas turbine cogeneration and two-stage gas turbine combustor. The experimental study was carried out for the diffusion flame of second stage combustor with the variations of oxygen concentration and supplying rate of hot exhaust gas from first stage combustor. It also examined the flammability range and $NO_{x}$ formation of the second stage combustor in which the fuel is supplying into the mixture of oxygen hot exhaust gas from first stage combustor. The results show that the enrichment of oxygen and increase of exhaust gas lead to increase the $NO_{x}$ up to 50 ppm with 23% $O_{2}$ condition.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.25 no.6
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• pp.252-256
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• 2015

Nitrogen oxides ($NO_X$) was emitted from flue gas of stationary sources and exhaust gas of mobile sources, can leads to various environments problems. Selective Catalysts Reduction (SCR) is the most effective $NO_X$ removal system. Commercial $V_2O_5-WO_3/TiO_2$ catalysts, usually containing $V_2O_5$ 0.5~3 wt%, $WO_3$ 5~10 wt%, and $V_2O_5$ is active in the reduction of $NO_X$ but also in the desired oxidation of $SO_2$ to $SO_3$. To reduce the amount of vanadium, using graphene matrix supported vanadium to synthesize nanocomposite. Then, we fabricated to 1 inch honeycomb type of SCR catalysts adding graphene-vanadium nanocomposite. The chemical-physical characteristics and the catalytic activity were performed by XRD, XRF, BET and Micro-Reactor (MR). As a result, the De-NOX performance was showed, similar to the commercial catalyst activity as 77.8 % and using nanocomposite catalyst as 77.1 % at $350^{\circ}C$.

• 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.

• Korean Chemical Engineering Research
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• v.47 no.5
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• pp.630-638
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• 2009

A computational fluid dynamics(CFD) model is developed and validated with on-site experiments for a urea-based SNCR(selective non-catalytic reduction) process to reduce the nitrogen oxides($NO_x$) in a municipal incinerator. The three-dimensional turbulent reacting flow CFD model having a seven global reaction mechanism under the condition of low CO concentration and 12% excess air and droplet evaporation is used for fluid dynamics simulation of the SNCR process installed in the incinerator. In this SNCR process, urea solution and atomizing air were injected into the secondary combustor, using one front nozzle and two side nozzles. The exit temperature($980^{\circ}C$) of simulation has the same value as in situ experiment one. The $NO_x$ reduction efficiencies of 57% and 59% are obtained from the experiment and CFD simulation, respectively at NSR=1.8(normalized stoichiometric ratio) for the equal flow rate ratio from the three nozzles. It is observed in the CFD simulations with varying the flowrate ratio of the three nozzles that the injection of a two times larger front nozzle flowrate than the side nozzle flowrate produces 8% higher $NO_x$ reduction efficiency than the injection of the equal ratio flowrate in each nozzle.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.8
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• pp.2015-2020
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• 2009

$NO_x$ reduction of stationary exhaust was performed at atmospheric condition and the temperature ranging from $200^{\circ}C$ to $500^{\circ}C$ over ZSM-5 supported metal catalyst. The characteristics of the prepared catalysts were investigated using the analytical techniques such as SEM, XRD, EDX, ICP and ITR. The results of EDX and ICP analysis demonstrated that the most part of transition metal existed on the exterior surface of support. Maximum de-$NO_x$ yield over Fe/ZSM-5 shown between $380^{\circ}C$ and $400^{\circ}C$ was presumed to be due to the maximum H2 reduction rate at $400^{\circ}C$ of ITR.

• 한국생물공학회:학술대회논문집
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• 2002.04a
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• pp.399-402
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• 2002

Industrial wastewater with high ammonium concentration was treated in batch biological systems which was a modified Ludzack- Ettinger process. Up to 78% conversion of $NH_4\;^+-N$ to $NO_x\;^--N$ was achieved in batch culture condition. Under anoxic condition with methanol as the carbon source, the denitrifiers decreased $NO_x\;^--N$ concentration from 608 mg/L to 5.6 mg/L in 22 d. As well as anoxic denitrification of $NO_x\;^-$ to $N_2$, dissimilatory nitrate reduction to ammonium also occurred under the condition as respiratory denitrification.

• Journal of the Korean Society of Combustion
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• v.19 no.3
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• pp.26-33
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• 2014

We examined the characteristics of $NO_x$ emission for CH4/air non-premixed flames using the exhaust gas recirculation(EGR) methods, which are the air-induced EGR(AI-EGR) and fuel-induced EGR(FI-EGR) methods. Our experimental results show that the $NO_x$ emission index($EI_{NOx}$) decreased with increasing EGR ratio. In the range needed to form a stable flame, the reduction rate of $EI_{NOx}$ for the FI-EGR method was approximately 29% when the EGR ratio was 20%, and the reduction rate for the AI-EGR method was approximately 28% with 25% of the EGR ratio. According to the flame structure based on numerical results, high temperature regions for the FI-EGR method were narrower and lower than those for the AI-EGR method at the same EGR ratio. Furthermore, based on the experimental results for swirl flames, the reduction rate of $EI_{NOx}$ for the FI-EGR method was approximately 49% with 15% of the EGR ratio, while the maximum reduction rate for AI-EGR method was approximately 45% with 25% of the EGR ratio. Consequently, we verified that the FI-EGR method was more effective than the AI-EGR method in reducing $NO_x$ emission for non-premixed flames with EGR. We expect that the results of this study will provide fundamental information relating to hybrid combustion systems, which can be used in the design of combustion systems in the future.

• Journal of the korean Society of Automotive Engineers
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• v.11 no.2
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• pp.8-12
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• 1989

본 강좌에서는 연소과정중에서의 NOx 생성기구 및 기존의 NOx 저감방법과 최근에 발표된 바 있는 연소방법의 변화에 의한 NOx의 생성억제 가능성에 대한 결과를 소개한다.

• Proceedings of the Korean Ceranic Society Conference
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• 2003.10a
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• pp.44.1-44
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• 2003

• Korean Chemical Engineering Research
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• v.52 no.4
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• pp.443-450
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• 2014

Selective catalytic reduction of nitrogen monoxide by hydrogen ($H_2$-SCR of NO) over platinum catalysts impregnated on zirconia-incorporated silica ($ZrO_2-SiO_2$) and manganese oxide ($MnO_x$) was investigated. $Pt-MnO_x$ catalyst showed low conversions and low yields of $N_2O$ and $NO_2$ at $100{\sim}350^{\circ}C$. On the other hand, NO conversions over $Pt/ZrO_2-SiO_2$ were very high, but $N_2O$ was predominantly produced at $100-150^{\circ}C$ and the yield of $NO_2$ increased with temperature at $200-300^{\circ}C$, resulting in poor $N_2$ yields. $Pt-MnO_x/ZrO_2-SiO_2$ exhibited a small enhancement in $N_2$ yield at $100-150^{\circ}C$ due to the synergy of $MnO_x$ and $ZrO_2-SiO_2$. The surface composition and oxidation state of the catalyst components and the acidity of the catalysts were examined. IR spectra of the adsorption of NO and their subsequent reactions with hydrogen on these catalysts were also recorded. The variations of conversion and product yield according to the catalyst components in the $H_2$-SCR of NO were discussed in relation to their catalytic roles.