Pyrolytic Reaction Pathway of Dichloromethane in Excess Hydrogen

과잉수소 반응분위기에서 Dichloromethane 열분해 반응경로에 관한 연구

  • Won, Yang-Soo (Department of Environmental Engineering, Yeungnam University)
  • Received : 2006.08.29
  • Accepted : 2006.10.18
  • Published : 2006.12.10

Abstract

Pyrolytic reaction study of dichloromethane ($CH_{2}Cl_{2}$) in excess hydrogen was performed to investigate pyrolytic reaction pathways at a pressure of 1 atm with residence times of 0.3~2.0 sec in the temperature range of $525{\sim}900^{\circ}C$. A constant feed molar ratio $CH_{2}Cl_{2}$:$H_{2}$ of 4:96 was maintained through the experiment. Reagent loss and product formation were monitored by using an on-line gas chromatograph, where batch samples were analyzed by GC/MS. Complete destruction(99%) of the parent reagent was observed at temperature near $780^{\circ}C$ with residence time over 1 sec. Major products observed were $CH_{3}Cl$, $CH_{4}$, $C_{2}H_{4}$, $C_{2}H_{6}$, and HCl. Minor products included $CHClCCl_{2}$, CHClCHCl, $CH_{2}CHCl$, and $C_{2}H_{2}$. The pyrolytic reaction pathways to describe the important features of intermediate product distributions and reagent loss, based upon thermodynamic and kinetic principles, were suggested. The results of this work provided a better understanding of pyrolytic decomposition processes which occur during the pyrolysis of $CH_{2}Cl_{2}$ and similar chlorinated methanes.

과잉수소 반응조건하에서 dichloromethane ($CH_{2}Cl_{2}$)의 열분해 생성물질의 반응경로를 규명하기 위해서 등온 관형반응기를 이용하여 무산소, 1 atm, 반응온도 $525{\sim}900^{\circ}C$, 반응시간 0.3~2.0 sec에서 반응을 수행하였다. $CH_{2}Cl_{2}$ : $H_{2}$ mole 비는 전 실험에서 4 : 96으로 유지하였으며 반응물 $CH_{2}Cl_{2}$ 분해 및 생성물의 농도는 on-line GC를 이용하여 정량 분석하였으며, 미량의 미지 화합물은 batch 시료로써 GC/MS로 정성 분석하였다. 반응시간 1 sec를 기준으로 반응물 $CH_{2}Cl_{2}$$600^{\circ}C$ 부근에서 분해가 시작되어 $780^{\circ}C$에서 99% 이상 분해되었다. 반응 주요생성물은 $CH_{3}Cl$, $CH_{4}$, $C_{2}H_{4}$, $C_{2}H_{6}$, HCl이 생성되었으며, 미량 생성물로는 $CHClCCl_{2}$, CHClCHCl, $CH_{2}CHCl$, $C_{2}H_{2}$가 생성되었다. 본 연구에서는 반응물질 분해 및 중간생성물 분포 특성과 열역학 및 반응속도 원리를 근거로 주요 생성물질 반응경로를 제시하였으며, 그 결과는 $CH_{2}Cl_{2}$ 및 유사한 염화탄화수소 화합물 열분해시 일어날 수 있는 열분해공정 이해를 위한 자료로 이용된다.

Keywords

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