The unsteady investigation of methane-air premixed counterflow flame into newly proposed plus-shaped channel over palladium catalyst

• Published in: Energy (Oxford) Vol. 186; p. 115833
• Main Authors: Edalati-nejad, Ali, Fanaee, Sayyed Aboozar, Khadem, Javad
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.11.2019; Elsevier BV
• Subjects: Air pollution; Algorithms; Carbon dioxide; Catalysts; Counterflow; Counterflow flame; Emissions; Equivalence ratio; Flame structure; Methane; Palladium; Palladium catalyst; Plus-shaped channel; Pollutants; Premixed methane-air mixture; Reaction time; Time dependence; Unsteady solution; Unsteady solution; Palladium catalyst; Plus-shaped channel; Premixed methane-air mixture; Counterflow flame
• ISSN: 0360-5442; 1873-6785
• DOI: 10.1016/j.energy.2019.07.163

In this paper, the time dependent study of methane-air premixed counterflow flame into a newly proposed plus-shaped channel, in order to obtain effects of palladium catalyst surfaces on the flame structure and pollutant emissions, is described. The results are presented at non-catalytic and catalytic conditions with considering effects of reaction time and various equivalence ratios, from lean to rich combustion, on flame characteristics and pollutant emissions. The governing equations are composed of continuity, momentum, energy and mass fraction equations are numerically solved considering a coupled Piso scheme and Simple algorithm. The comparison between the presented model and published data shows an acceptable agreement that confirms the accuracy of this solution. The average values of CH4 mass fraction over the geometry at the presence of palladium catalyst is nearly decreased 25% relative to non-catalytic case. The existence of Palladium catalyst has great impact, mostly 34% decrease, on CO formation but the catalyst leads to increment of CO2 formation 5%. At different values of equivalence ratio, the average temperature of non-catalytic flame is about 16% lower than catalytic one. •Temperature distribution is fully uniformed for the palladium catalytic flame.•The formation of NO2 mass fraction has been affected significantly by catalyst.•At lean flame the increment of equivalence ratio increases CO2 mass fraction.•The existence of Palladium catalyst mostly 34% decreases CO formation.•With changing reaction time from 0.003s to 0.006s, CH4 mass fraction nearly 64% reduces.