KINETIC MODELING STUDY OF OXY-METHANE COMBUSTION AT ORDINARY PRESSURE

摘要

Oxy-fuel combustion is one promising option among different CO_2 capture technologies. The object of this work is to show the effect of CO_2 dilution on the laminar flame speed, flame structure and reaction pathway for methane oxidation at O_2/CO_2 atmosphere. In this paper, kinetic simulations were made using CHEMKIN with GRI-Mech 3.0 mechanism, which was validated by experimental data of laminar flame speeds. The reaction pathway of CH4/O2/CO_2 mixture was derived from reaction flow analysis. Results showed that CO_2 decreased the flame speeds, lowed concentration of major intermediates and increased flame thickness. The major chemical pathways of CH_4 to CO_2 have not changed at O2/CO_2 atmosphere comparing with O2/N2 atmosphere, but contributions to major intermediates formation from each related elementary reaction have changed a lot. In addition, the secondary chemical pathways of CH_3 oxidation became different at O_2/CO_2 atmosphere.