Thermal decomposition of trichloroethylene under a reducing atmosphere of hydrogen

Abstract

The thermal reaction of trichloroethylene (TCE: C 2 HCl 3 ) has been conducted in an isothermal tubular flow reactor at 1 atm total pressure in order to investigate characteristics of chlorinated hydrocarbons decomposition and pyrolytic reaction pathways for formation of product under excess hydrogen reaction environment. The reactions were studied over the temperature range 650 to 900 o C with reaction times of 0.3-2.0 s. A constant feed molar ratio C 2 HCl 3 : H 2 of 4 : 96 was maintained through the whole experiments. Complete decay (99%) of the parent reagent, C 2 HCl 3 was observed at temperature near 800 o C with 1 s reaction time. The maximum concentration (28%) of C 2 H 2 Cl 2 as the primary intermediate product was found at temperature 700 o C where up to 68% decay of C 2 HCl 3 occurred. The C 2 H 3 Cl as highest concentration (19%) of secondary products was detected at 750 o C. The one less chlorinated methane than parent increased with temperature rise subsequently. The number of qualitative and qualitative chlorinated products decreased with increasing temperature. HCl and dechlorinated hydrocarbons such as C 2 H 4 , C 2 H 6 , CH 4 and C 2 H 2 were the final products at above 800 o C. The almost 95% carbon material balance was given over a wide range of temperatures, and trace amounts of C 6 H 6 , C 4 H 6 and C 2 HCl were observed above 800 o C. The decay of reactant, C 2 HCl 3 and the hydrodechlorination of intermediate products, resulted from H atom cyclic chain reaction via abstraction and addition replacement reactions. The important pyrolytic reaction pathways to describe the important features of reagent decay, intermediate product distributions and carbon mass balances, based upon thermochemical and kinetic principles, were suggested. The main reaction pathways for formation of major products along with preliminary activation energies and rate constants were given.

Flash point of binary mixtures of chlorinated hydrocarbons with toluene and their predictability with existing mixing rule

“…Nevertheless, it doesn't prevent against possible flammability issues in industrial conditions. Subjacent phenomenon can be attributed to the flame-retardant behavior of halogenated decomposition products of trichloroethylene [38]. The retarding effect of halogenated compounds is well known and has been notably demonstrated by Tewarson et al by studying Halion 1301 (CBrF3) as flame extinction solution [39].…”

Experimental Evaluation Method of Mass Transfer Coefficient on Biotrickling Filtration for Air Pollution Control

“…/hr 정도의 많은 유량을 처리할 수 있는 효 과적인 방법이다 [5][6][7][8]. 현재 산업체에서 배출되고 있는 VOC 배출 농도와 유량을 감안한다면 생물학적 처리방법은 기존에 이용되어 왔던 대기오염 제어방법을 대체할 수 있는 경제성 높은 기술이다 [2,7,8].…”

“…현재 산업체에서 배출되고 있는 VOC 배출 농도와 유량을 감안한다면 생물학적 처리방법은 기존에 이용되어 왔던 대기오염 제어방법을 대체할 수 있는 경제성 높은 기술이다 [2,7,8]. † To whom correspondence should be addressed.…”

Pyrolytic Reaction Pathway of Chloroethylene in Hydrogen Reaction Atmosphere

“…C 2 H 6 에서 C-C 결합에너지: 90.5 kcal/mol, C-H 결합에너지: 100.7 kcal/mol [13])가 가장 작은 C-C(탄소결합) 단분자분해반응 (1) [13,20]. 참고문헌…”

“…Complete decay(99%) of the parent reagent, CH [5]. 그러나 염화유기화합물은 화학적 구조와 염화정도(degree of chlorination), 반응조건 및 운반가스 종류와 조성 등에 따라 열적 안정성, 생성물 종류와 량이 크게 달라진다 [6][7][8]. elimination)의 복합 단분자 분해(complex unimolecular decomposition) 로 구분된다 [13].…”