On the Occurrence of Transient Puffs in a Rotary Kiln Incinerator Simulator II. Contained Liquid Wastes on Sorbent

The generation of transient puffs resulting from the batch introduction of liquid waste into a 73 kW (250,000 Btu/h) rotary kiln incinerator simulator was investigated. The liquid was added onto a sorbent, enclosed in cylindrical cardboard containers that were introduced into the combustion chamber one at a time. A statistically designed parametric investigation determined the effects of liquid mass, liquid composition, kiln temperature, and kiln rotation speed on the total magnitude and instantaneous intensity of the pollutant puff leaving the kiln. Liquid "wastes" investigated included toluene, methylene chloride, carbon tetrachloride, and No. 5 fuel oil. Transient puffs from these wastes were monitored using on-line measurements for FID-measurable hydrocarbons, CO, and integrated particulate filter loadings, although the suitability of any one of these indicators depended on the chemical nature of the waste involved.

Results demonstrate that puffs formed during transient conditions are generated easily, even with small quantities of wastes and with the kiln operating at 100 percent excess air. High kiln temperatures and increased kiln rotation speeds exacerbated the generation of puffs, due to increased liquid evaporation rates. Transient puffs may contain hazardous products of incomplete combustion (PICs) even though adequate destruction and removal efficiencies are achieved. Mixtures of chlorinated and nonchlorinated principal organic hazardous constituents (POHCs) in the waste can lead to the formation of more diverse chlorinated compounds than are formed from a single chlorinated POHC such as carbon tetrachloride alone.

This paper is the second of a series. Its companion paper, Part I, which has been published previously,¹ is concerned with solid plastic wastes.