Rich methane laminar flames doped with light unsaturated hydrocarbons. Part III : cyclopentene

TL;DR

This study investigates the structure and chemical pathways of a rich methane flame doped with cyclopentene, identifying key species and proposing a new oxidation mechanism for cyclopentene.

Contribution

It introduces a new oxidation mechanism for cyclopentene and details the reaction pathways leading to benzene and toluene formation in methane flames.

Findings

Identified key combustion products including benzene and toluene.

Proposed a novel mechanism for cyclopentene oxidation.

Mapped main reaction pathways for pollutant formation.

Abstract

In line with the studies presented in the parts I and II of this paper, the structure of a laminar rich premixed methane flame doped with cyclopentene has been investigated. The gases of this flame contains 15.3% (molar) of methane, 26.7% of oxygen and 2.4% cyclopentene corresponding to an equivalence ratio of 1.79 and a ratio C5H8 / CH4 of 16 %. The flame has been stabilized on a burner at a pressure of 6.7 kPa using argon as dilutant, with a gas velocity at the burner of 36 cm/s at 333 K. The temperature ranged from 627 K close to the burner up to 2027 K. Quantified species included usual methane C0-C2 combustion products, but also propyne, allene, propene, propane, 1-butene, 1,3-butadiene, 1,2-butadiene, vinylacetylene, diacetylene, cyclopentadiene, 1,3-pentadiene, benzene and toluene. A new mechanism for the oxidation of cyclopentene has been proposed. The main reaction pathways of consumption of cyclopentene and of formation of benzene and toluene have been derived from flow rate analyses.