Ignition Delay Time Measurements on CH₄/CH₃Cl/O₂/Ar Mixtures for Kinetic Analysis

Abstract

Ignition delay times of CH4/CH3Cl/O2/Ar mixtures are measured using a shock tube at 1350–1950 K and 4–18 atm. Equivalence ratios of 0.5 and 1 and CH3Cl blending ratios ranging from 0 to 1 are explored. Correlations for the measured delay times are obtained through multiple linear regression. Increasing the blending ratio facilitates ignition, but this effect becomes saturated at a blending ratio of ∼0.2. Two existing chemical kinetic models for CH4/CH3Cl mixtures are examined against the measurements, and a modified chloromethane–Polimi–kin model incorporating the Aramco 2.0 model is proposed and validated through comparison with these new data. Based on the proposed model, sensitivity analysis, peak concentration analysis, and reaction pathway analysis are carried out to provide further insight into the ignition process of CH4/CH3Cl/O2/Ar mixtures.

Shock‐Tube Experiments and Kinetic Modeling of CH3NHCH3 Ignition at Elevated Pressures

“…The overall uncertainty in ignition delay times is ∼20%. The details of uncertainty analysis were presented elsewhere . To demonstrate the reliability of our shock tube measurements, we perform ignition delay time measurements on 1.067%CH 3 NHCH 3 /4%O 2 /94.933%Ar, which are in excellent agreement with previous measurements at the same experimental conditions (Fig.…”

“…Ignition delay time measurements are performed on a stainless‐steel shock tube with an inner diameter of 50 mm. Details of the present shock tube platform are described previously , and we briefly introduce it here. The shock tube is separated into two sections by a single diaphragm: the driver section (3.26 m in length) and the driven section (4.52 mm).…”

“…Given the modified model, sensitivity and reaction pathway analyses are carried out to gain insight into ignition of CH 3 NHCH 3 /O 2 /Ar mixtures. The sensitivity coefficient is defined as …”

Theoretical and kinetic modeling study of chloromethane (CH3Cl) pyrolysis and oxidation

“…Available experimental targets to validate the kinetic model cover a wide range of operating conditions ( T = 1000–2500 K, p = 0.5–18 atm, φ = 0.5–∞) for both pure CH 3 Cl and its mixtures with H 2 , CO, and CH 4 . Specifically, we have considered speciation measurements in plug flow reactors, 5,6,65,92–95 laminar flame speciation, 73 laminar flame speed measurements, 96–98 and ignition delay time data from shock tube experiments 99–101 . For sake of brevity, only a representative subset of these targets will be shown and discussed in the paper: additional comparisons are reported and briefly discussed in the Supporting Information (Figures S3–S11).…”

“…Shi et al 101 . recently measured ignition delay times for a number of CH 4 /CH 3 Cl/O 2 /Ar mixtures using a shock tube.…”