An Experimental Investigation on the Incineration of Waste Containing Volatile Organic Chlorinated Compounds --The Case of 1,1,1-Trichloroethane and Carbon Tetrachloride--

Shin-ichi Sakai*, Haruki Shimazu* and Hiroshi Takatsuki*

+ Correspondence should be addressed to Shinichi Sakai:
*Environmental Preservation Center, Kyoto University
(Hon-machi, Yoshida, Sakyo-ku, Kyoto, 606-01 Japan)

Abstract

Volatile organic chlorinated compounds have been used in large quantities because they have various useful properties industrially. Some of them, however, have been proved to be carcinogenic or ozone depleting substances. Optimal incineration conditions have been investigated for liquid waste containing 1,1,1-trichloroethane (C2H3Cl3), carbon tetrachloride (CCl4) . Incineration tests with varying mean residence time, in which the temperature of incinerator was about 950*C[Celsius degeree], were carried out in a commercial field plant. In spite of long and short mean residence times (9.1sec vs. 1.8sec), there was little difference in DREs (destruction and removal efficiencies) of C2H3Cl3 and emissions of PICs (products of incomplete combustion) . Additionally, incineration tests with varying temperature of incinerator were carried out in a laboratory-scale incineration plant. In higher temperature conditions, above 800*C[Celsius degeree], DREs of C2H3Cl3 and CCl4 exceeded 99.999%. But in the lowest temperature condition, about 700*C[Celsius degeree], DREs decreased and some PICs increased greatly. When experimental DREs were compared with theoretical DREs, which were calculated with gas phase reaction rate as rate-determining step, experimental DREs of C2H3Cl3 were much lower than theoretical DREs. It was thought that these results were due to not considering the evaporation rate of drops formed when liquid waste was fed to the incinerator. Therefore, atomizing conditions were considered to be one of the important factors of C2H3Cl3 thermal destruction. However, DREs of CCl4 were higher than theoretical DREs. Waste was fed with liquefied petroleum gas to the incinerator, so the atmosphere in the incinerator was hydrogen-rich. Hence, H/Cl the ratio of waste was considered to be one important factor in CCl4 thermal destruction.

Key words: 1,1,1-trichloroethane, carbon tetrachloride, incineration, destruction and removal efficiency, products of incomplete combustion.