Korean Chemical Engineering Research, Vol.49, No.5, 510-515, October, 2011
수소 반응분위기에서 Chloroethylene 열분해 반응경로 특성
Pyrolytic Reaction Pathway of Chloroethylene in Hydrogen Reaction Atmosphere
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초록
염화탄화수소의 고온열분해 반응에서 생성물 반응경로 특성을 파악하기 위해 H2 반응분위기에서 1,1-
dichloroethylene(CH2CCl2) 열분해반응 실험을 수행하였다. 열분해반응 실험은 등온관형반응기를 이용하여 반응온도 650~900 ℃, 반응시간 0.3~2.0초에서 진행하였으며, 반응물 mole 분율은 전체 실험에서 CH2CCl2:H2 = 4:96 일정하게 유지하였다. 반응물 CH2CCl2가 완전분해온도는(분해율 99% 이상) 825 oC(반응시간 1초 기준)였으며, H2 반응분위기에서 CH2CCl2 주요 분해반응경로는 H원자 추출 및 첨가교체치환 연쇄반응으로 파악되었다. CH2CCl2가 46% 분해되는 700 ℃에서 1차 생성물로 CH2CHCl가 28%로 가장 높은 농도로 검출되었다. 775 oC 이상에서는 탈염소화된 C2H4가 2차 생성물로 가장 많이 생성되었으며, 반응온도가 증가할수록 염소 원자수가 작은 화합물이 생성되었으며 이들 화합물은 열화학적으로 안정된 물질이다. 825 ℃ 이상의 고온반응영역에서 탈염소반응의 부산물인 HCl과 C2H4, C2H6, CH4 C2H2 등과 같은 열화학적으로 안정된 탄화수소가 주요생성물로 검출되었다. 본 연구에서 고찰된 반응계에서 분해와 생성물분포 특성을 고려하고 열화학이론 및 반응속도론을 기초로 주요 반응경로를 제시하였다.
The pyrolytic reaction of 1,1-dichloroethylene(CH2CCl2) has been conducted to investigate thermal decomposition of chlorocarbon and product formation pathways under hydrogen reaction environment. The reactions were studied in a isothermal tubular flow reactor at 1 atm total pressure in the temperature range 650~900 ℃ with reaction times of 0.3~2.0 sec. A constant feed molar ratio CH2CCl2:H2 of 4:96 was maintained through the whole experiments. Complete decay(99%) of the parent reagent, CH2CCl2 was observed at temperature near 825 ℃ with 1 sec. reaction time. The important decay of CH2CCl2 under hydrogen reaction environment resulted from H atom cyclic chain reaction by abstraction and addition displacement. The highest concentration (28%) of CH2HCl as the primary product was observed at temperature 700 ℃, where up to 46% decay of CH2CCl2 was occurred. The secondary product, C2H4 as main product was detected at temperature above 775 ℃. The one less chlorinated ethylene than parent increase with temperature rise subsequently. The HCl and dechlorinated hydrocarbons such as C2H4, C2H6, CH4 and C2H2 were the main products observed at above 825 ℃. The important decay of CH2CCl2 resulted from H atom cyclic chain reaction by abstraction and addition displacement. The important pyrolytic reaction pathways to describe the features of reagent
decay and intermediate product distributions, based upon thermochemical and kinetic principles, were suggested.
Keywords:Chloroethylene;Pyrolytic Reaction;Thermal Decomposition;Reaction Pathway;Hydrogen Reaction Atmosphere
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