Date of Award
Master of Science in Chemical Engineering - (M.S.)
Chemical Engineering, Chemistry and Environmental Science
Joseph W. Bozzelli
Wing T. Wong
This is an experimental study on thermolytic reactions of chloroform with excess water vapor where kinetic parameters are determined and complete product analysis made at atmospheric pressure over a temperature range from 550to 1050°C. In this study, water vapor was introduced as a reactant to convert chlorine in chlorocarbons to stable HCl which is an easily neutralized end-product and thereby completely destroy chloroform. Substantial amounts of thermodynamically stable species: HCl, CO, CO2, C(s) etc. were observed as products.
The reaction was studied in a 46cm tubular flow reactor mounted in a furnace that had three independently temperature-controlled heating zones and was capable of operating temperatures to 1200°C with a constant temperature (+/- 5 °C) profile, over its central (80%) region. Complete end-product analysis was performed by flame ionization/ thermal conductivity gas chromatography (FID/TCD GC) and GC/Mass Spectrometer.
The major products below 700 °C are hydrogen chloride, tetrachloroethylene and carbon tetrachloride, with vinyl chloride, dichloroethylene, trichloroethylene as minor products.Complete destruction of the parant chloroform took place at temperature around 750 °C and residence time of 0.5 sec.. All the chlorocarbon products were destroyed at temperature above 1000 °C. Kinetic parameters are determined as a function of reagent residence time, temperature, concentration and reactor diameter. The results show that the wall reaction contributes to the overall conversion at the higher temperatures (kw/kb = 0.25 ~ 0.5) and the wall reaction has a higher activation energy than the bulk reaction. The vapor phase activation energy of 28.4 kcal/mol is in fair agreement with unimolecular decomposition data in the literature,indicating that the initial step in this study consists primarily of chloroform decomposition via unimolecular reaction.
Hwang, Chii-Guang, "Conversion and kinetics in the reaction of chloroform with water vapor at high temperatures" (1985). Theses. 2067.