Pathways to methylene chloride destruction at low and high concentrations

A two-stage combustor facility is used to investigate mehylene chloride (CH₂Cl₂) incineration and formation of products of incomplete combustion (PIC). For measuring low concentrations of CH ₂Cl₂, on-line microtrap gas chromatography is employed. Destruction efficiency of CH₂Cl₂ over a wide range of feed concentrations was investigated under fuel-lean and fuel-rich ethylene/air combustion conditions. The impact of CH₂Cl₂ on the formation of PICs such as methane, ethylene, ethane, and acetylene is investigated. The combustion process is simulated using an ideal reactor model and a detailed chemical reaction mechanism. Rate-of-production analyses based on modeling results show that there are different pathways for the destruction of CH₂Cl₂ under fuel-lean and fuel-rich conditions. As shown by experimental results, the destruction efficiency is lower at lower inlet concentrations. Simulations of experimental results have shown that the significance of various radicals and destruction channels varies with combustion conditions and concentration of organics, and that atoms and fragments of destroyed molecules play an important role in further destruction of parent species.