Chemical Effects of CO2 Concentration on Soot Formation in Jet-stirred/Plug-flow Reactor

doi:10.1016/S1004-9541(13)60624-2

Chinese Journal of Chemical Engineering

Volume 21, Issue 11, November 2013, Pages 1269-1283

https://doi.org/10.1016/S1004-9541(13)60624-2 Get rights and content

Abstract

Soot formation was investigated numerically with CO₂ addition in a jet-stirred/plug-flow reactor (JSR/PFR) C₂H₄/O₂/N₂ reactor (C/O ratio of 2.2) at atmospheric pressure. An updated Kazakov mechanism emphasizes the effect of the O₂/CO₂ atmosphere instead of an O₂/N₂ one in the premixed flame. The soot formation was taken into account in the JSR/PFR for C₂H₄/O₂/N₂. The effects of CO₂ addition on soot formation in different C₂H₄/O₂/CO₂/N₂ atmospheres were studied, with special emphasis on the chemical effect. The simulation shows that the endothermic reaction CO₂ + HCO + OH is responsible of the reduction of hydrocarbon intermediates in the CO₂ added combustion through the supplementary formation of hydroxyl radicals. The competition of CO₂ for H radical through the above forward reaction with the single most important chain branching reaction H + O₂O + OH reduces significantly the fuel burning rate. The chemical effects of CO₂ cause a significant increase in residence time and mole fractions of CO and OH, significant decreases in some intermediates (H, C₂H₂), polycyclic aromatic hydrocarbons (PAHs, C₆H₆ and C₁₆H₁₀, etc.) and soot volume fraction. The CO₂ addition will leads to a decrease by only about 5% to 20% of the maximum mole fractions of some C₃ to C₁₀ hydrocarbon intermediates. The sensitivity analysis and reaction-path analysis results show that C₂H₄ reaction path and products are altered due to the CO₂ addition.

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: Supported by the Foundation of State Key Laboratory of Coal Combustion, the National Natural Science Foundation of China (51306022, 51176059) and the Natural Science Foundation of Hubei Province (2013CFB398).

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Chemical Effects of CO2 Concentration on Soot Formation in Jet-stirred/Plug-flow Reactor

Abstract

Chin. J. Chem. Eng.

Combust. Flame

Combust. Flame

Chin. J. Chem. Eng.

Chin. J. Chem. Eng.

Combust. Flame

Chem. Eng. Sci.

Combust. Flame

Proc. Combust. Inst.

Proc. Combust. Inst.

Combust. Flame

Combust. Flame

J. Colloid Interface Sci.

Combust. Flame

Combust. Flame

“CO2 addition and pressure effects on laminar and turbulent lean premixed CH4 air flames”

Proc. Combust. Inst.

“The effect of oxygen and carbon dioxide concentration on soot formation in non-premixed flames”

Fuel

“PAH chemistry in a jet stirred/plug flow reactor system”

“Computation and measurement for distributions of temperature and soot volume fraction in diffusion flames”

Journal of Central South University of Technology

Chemical Effects of CO₂ Concentration on Soot Formation in Jet-stirred/Plug-flow Reactor

“CO₂ addition and pressure effects on laminar and turbulent lean premixed CH₄ air flames”