Korean Chemical Engineering Research

The Korean Institute of Chemical Engineers (한국화학공학회)
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Optimal Condition for Decomposition of Ethylenediaminetetraacetic Acid (EDTA) in Supercritical Water Oxidation

초임계수 산화공정에서 Ethylenediaminetetraacetic Acid (EDTA) 분해 최적화 연구

  • Lee, Hyeon-Cheol (Department of Chemical Engineering, Yonsei University) ;
  • In, Jung-Hyun (Department of Chemical Engineering, Yonsei University) ;
  • Kim, Jong-Hwa (Department of Chemical Engineering, Yonsei University) ;
  • Lee, Chang-Ha (Department of Chemical Engineering, Yonsei University)
  • Received : 2004.11.02
  • Accepted : 2005.03.10
  • Published : 2005.04.30
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Abstract

Supercritical water oxidation (SCWO, P>221 bar, T>$374^{\circ}C$) is a promising method for the decomposition of refractory organic compounds. In this study, the SCWO of Ethylenediaminetetraacetic acid (EDTA) was carried out in a tubular-type continusous reactor system with an $H_2O_2$ oxidant at $387-500^{\circ}C$, 250 bar and residence time (RT) of 15.9-88.9 s. The decomposition efficiencies increased with increasing temperature and oxidant amount, while it was inversely proportional to feed flow rate. The decomposition efficiency of 99.6% was obtained at $500^{\circ}C$, 250 bar, oxidant amount of 400% and residence time of 40.1 s. The effect of temperature on the decomposition efficiency was more significant than that of oxidant amount. In the case of the decomposition efficiency of 5,000 mg/L of EDTA (3,063 mg/L as $COD_{Cr}$), the decompostion of 99% or higher was obtained at the condition of over 40.1 s (RT) and 200 stoichiometric % of $H_2O_2$ in the supercritical water of $500^{\circ}C$ and 250 bar.

초임계수 산화는 난분해성 유기화합물의 분해를 위한 공정으로 각광받고 있다. 본 연구에서는 연속반응기에서 온도 $387-500^{\circ}C$, 압력 250 bar의 초임계수 조건하에서(EDTA 분해효율) 체류시간 15.9-88.9초의 범위의 EDTA 분해효율을 측정하였다. 이때 산화제로는 과산화수소($H_2O_2$)를 사용하였다. EDTA의 분해효율은 온도 및 산화제투입량의 증가에 따라 상승하였으며, 반응물 도입유속의 감소 즉, 체류시간의 증가에 따라서 상승하였다. 본 연구결과 온도 $500^{\circ}C$, 압력 250 bar, 산화제 투입량 400%의 조건에서 최대 99.6%의 분해효율을 나타내었다. 분해효율에 미치는 온도의 영향이 산화제 투입량 증가의 영향보다 컸으며, 5,000 mg/L의 EDTA($COD_{Cr}$로서 3,063 mg/L)의 99% 이상 분해효율은 온도 $500^{\circ}C$와 압력 250 bar의 초임계수 산화조건에서 산화제투입량 200% 이상 및 체류시간 40.1초 이상에서 얻을 수 있었다.

Keywords

Acknowledgement

Grant : The Eco-technopia 21 Project

Supported by : 환경부

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