Experimental and modeling of autoignition of gaseous hydrocarbon fuels in the presence of H2 and C2H4. (15th July 2021)

• Record Type: Journal Article
• Authors: Gokulakrishnan, Ponnuthurai; Fuller, Casey; Klassen, Michael; Davidson, David; Hanson, Ronald
• Is Part Of: Fuel. Volume 296(2021)
• Publication Date: 2021-07-15
• Subjects: Autoignition -- Low-temperature chemistry -- Uncertainty quantification -- Ethylene -- Propylene -- Hydrogen; Fuel -- Periodicals; Coal -- Periodicals; Coal; Fuel; Periodicals; 662.6
• DOI: 10.1016/j.fuel.2021.120713
• Languages: English
• ISSNs: 0016-2361

Abstract

Highlights: The focus of the investigation is to understand the kinetic interactions of H2 and C2 H4 with other gaseous fuel components that are formed in combustion systems due to the pyrolysis of long-chained hydrocarbon fuels. Ignition delay time measurements obtained in the current work will add value to the literature database for future model validation efforts, especially for binary mixtures which lack data in the literature. Model improvements are made for low-temperature kinetics of C3 H6 ignition based on the experimental measurements. The model was validated for high- and low-temperature conditions. Uncertainty analysis is used to quantify model uncertainty in predicting ignition delay times, and to identify reactions that need further study to reduce the overall model uncertainty. Abstract: The focus of the present work is to understand the effect of H2 and C2 H4 on the ignition characteristics of other gaseous fuels, namely, CH4, C2 H6 and C3 H6 . Atmospheric-pressure flow reactor experiments were performed to measure the ignition delay times of CH4, C2 H6 and C3 H6 binary mixtures with H2 or C2 H4 between 800 and 950 K. Most of the experiments were conducted at stochiometric conditions with 21% O2 . Select tests were performed to examine the effects of equivalence ratios and oxygen concentrations. Ignition delay time were also measured for ternary mixtures of C3 H6 -C2 H4 -H2 at select conditions. Based on the experimental data, the overall effectiveness of H2 or C2 H4 in reducing the ignition delay time of the binary mixtures can be listed in the following order: CH4 > C3 H6 > C2 H6 . The experimental data were used to refine and validate the chemical kinetic mechanism for allyl-HO2 system relevant to low-temperature ignition chemistry of C3 H6 . A detailed sensitivity analysis is presented to identify the important reaction pathways, and their implications for the experimental observations are discussed. Monte Carlo simulations were used to quantify the model uncertainty for ignition delay time predictions, and to identify reactions that have significant contribution to the model uncertainty. Among the binary mixtures studied, CH4 -H2 mixture produced the largest model uncertainty, primarily due to the sensitive reactions involving HO2 radical.