Journal of the Korean Applied Science and Technology (한국응용과학기술학회지)

The Korean Society of Applied Science and Technology (한국응용과학기술학회)
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Evaluation of nitrogen oxide removal characteristics using TiO2

TiO2를 이용한 질소산화물 제거 특성 평가

  • Park, Jun-Gu (Dept. of Earth and Environmental Engineering, College of Engineering, Kangwon National University) ;
  • Lim, Hee-Ah (Dept. of Earth and Environmental Engineering, College of Engineering, Kangwon National University) ;
  • Park, Young-Koo (Dept. of Earth and Environmental Engineering, College of Engineering, Kangwon National University)
  • 박준규 (강원대학교 공학대학 지구환경시스템공학과) ;
  • 임희아 (강원대학교 공학대학 지구환경시스템공학과) ;
  • 박영구 (강원대학교 공학대학 지구환경시스템공학과)
  • Received : 2019.06.04
  • Accepted : 2019.06.28
  • Published : 2019.06.30
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Abstract

Fine dust in air pollutants is recognized as one of the most serious social environmental problems. Most of the NOx is generated in a combustion process such as that of a coal-fired power plant, and therefore efficient elimination of the NOx from the coal-fired power plants is needed. This study investigates the removal efficiency of using $TiO_2$, a photocatalyst, to remove NOx by Selective Catalytic Reduction (SCR). To evaluate the NOx removal efficiency, $TiO_2$ catalyst and phosphate binder were mixed on the surface of the $Al_2O_3$ substrate with the exothermic agent, and the substrate was heat-treated. The NOx removal efficiency of the catalysts was evaluated according to the temperature, and XRD, SEM, TG-DTA and BET analyzes were performed to investigate the physicochemical properties of the catalysts. NOx removal efficiency was 58.7%~65.9% at 20min, 63.7~66.0% at 30min with temperature change according to time($250^{\circ}C{\sim}500^{\circ}C$). The $TiO_2$ used in the SCR for NOx removal is judged to have the most efficient removal efficiency at $300^{\circ}C$.

대기오염물질 중 미세먼지는 심각한 사회적 환경문제로 인식되고 있다. 미세먼지의 원인 물질 중 하나인 질소산화물(NOx)은 석탄화력발전소의 연소공정에서 주로 발생하므로 효율적인 NOx 제거가 필요한 실정이다. 본 연구에서는 선택적 촉매 환원법(Selective Catalytic Reduction, SCR)을 이용한 NOx 제거에서 $TiO_2$ 광촉매의 NO 제거효율을 연구하였다. NO 제거효율을 평가하기 위해 발열제가 내장된 $Al_2O_3$ 기판 표면에 $TiO_2$ 촉매와 인산염의 접착 바인더를 혼합하여 도포한 후 제조된 기판을 열처리하면서 실험을 수행하였다. 온도에 따른 촉매의 NO 제거효율을 평가하였고, 촉매의 물리화학적 특성을 위하여 XRD, SEM, TG-DTA, BET 분석을 수행하였다. NOx 제거 효율은 시간에 따른 온도변화($250^{\circ}C{\sim}500^{\circ}C$)로 20분에서 제거효율은 58.7%~65.9%이며, 30분에서 63.7%~66.0%로 나타났다. 질소산화물 제거용 SCR로 사용되는 $TiO_2$는 $300^{\circ}C$가 제거효율이 가장 효율적인 것으로 판단된다.

Keywords

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Fig. 1. Flow chart of experimental procedure by process.

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Fig. 2. Schematic diagram of De-NO reactor.

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Fig. 4. Scanning electron microphotograph (× 30,000) of catalyst. (a) TiO2 Powder, (b) 400℃ TiO2 Powder

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Fig. 5. X-ray diffraction patterns of standard catalyst.

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Fig. 5. Thermogravimetric-differential thermal analysis of standard catalyst.

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Fig. 6. NO removal efficiency by reaction time by temperature.

Table 1. Temperature by voltage

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Table 2. Experimental conditions in the reactor

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Table 3. Specific surface area by temperature

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Table 4. NO removal efficiency results

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