Application of Computational Fluid Mechanics to Modeling the Incineration of Chlorinated Hydrocarbon Wastes in Thermal Oxidizers

ABSTRACT

Manufacture of chlorinated hydrocarbon (RCI) based products includes treating the associated waste streams. On the basis of “Best-Available-Technology, ”waste disposal is generally accomplished using vent incinerators (thermal oxidizers). Vent incineration may lead to the formation of undesirable Products of Incomplete Combustion (PIC's). The recent Boiler & Industrial Furnace (BIF) regulations have required that companies certify the ability of their Thermal Oxidizers (TOXs) to meet these new emissions∗ regulations.

Earlier work has focused on identifying and investigating the chemical processes leading to PIC formation. Past work has shown that PIC formation depends greatly on local process conditions. Thus, developing and implementing a methodology to predict local conditions inside a TOX may significantly enhance the ability to predict PIC formation during incineration.

The present work includes developing and applying a Computational Fluid Dynamics (CFD) based incineration model to simulate the turbulent combustion processes occurring inside a TOX. Two examples demonstrate the application of the incineration model to thermal oxidation. Results illustrate the ability of the model to estimate HCl/Cl₂ production from a TOX and to evaluate the impact that various process variables have on TOX operation. This work elucidates the importance of local process conditions on HCl/Cl₂ formation and demonstrates the potential impact of using such an incineration model to help reduce emissions from thermal oxidizers.

Key Words:

• Thermal oxidation
• vent incineration
• computational fluid dynamics