The Interaction of Fuel-Bound Nitrogen and Fuel-Bound Chlorine During Air-Staged Incineration

Abstract

The simultaneous air-staged combustion of methyl amine (CH₃NH₂ and methyl chloride (CH₃Cl) was studied in a two zone turbulent flow reactor at atmospheric pressure. The temperature in the first stage was held constant at 1750 K. The feed consisted of ethylene (C₂H₄), CH₃NH₂, CH₃CI, air, and N₂ (for first stage temperature control). Fuel-lean and fuel-rich mixtures were fed into the first stage. During the fuel-rich reed runs, secondary air was injected into the second stage to make the overall system fuel-lean. Measurements of species including NO, CO, CO₂ and O₂ were made in both stages. Three major observations were made: 1) The additon or CH₃Cl during air staged combustion of CH₃NH₂ does not alter the attainment of an NO minimum emission from the second stage; 2) The optimal first stage equivalence ratio corresponding to the minimum NO in the second stage outlet is approximately 1.3 in both cases; and 3) The minimum NO emission level from air staged combustion significantly decreases when CH₃Cl is added to the reed at constant equivalence ratio. A perfectly stirred – plug flow sequential reactor simulation is used with a detailed chemical reaction mechanism to model the observed species concentrations. The experimental data are well predicted, especially the staged combustion NO minimums. Model-based rate of production calculations suggests that the loss or OH radicals via OH + HCl = H₂O + Cl and the consumption of N radicals via N + Cl + M = NCl + M slow the reaction N + OH = NO + H, leading to the reduced NO minimum emission during the simultaneous air-staged combustion or the fuel-bound chlorine and nitrogen species.

Keywords:

• Incineration
• chlorine
• nitrogen
• stages