Experimental and numerical analysis of oxy-fuel combustion in a porous plate reactor

The present work focuses on studying experimentally and numerically the oxy-fuel combustion characteristics inside a porous plate reactor towards the application of oxy-combustion carbon capture technology. Initially, non-reactive flow experiments are performed to analyze the permeation rate of oxygen in order to obtain the desired stoichiometric ratios. A numerical model is developed for non-reactive and reactive flow cases. The model is validated against the presently recorded experimental data for the non-reacting flow cases, and it is validated against the available literature data for oxy-fuel combustion for the reacting flow cases. A modified two-step oxy-combustion reaction kinetics model for methane is implemented in the present model. Simulations are performed over wide range of operating oxidizer ratios (O₂/CO₂ ratio), from OR=0.2 to OR=0.4, and over wide range of equivalence ratios, from ϕ=0.7 to ϕ=1.0. The flame length was decreased as a result of the increase of the oxidizer ratio. Effects of CO₂ recirculation amount on the oxy-combustion flame stability are examined. A reduction in combustion temperature and increase in flame fluctuations are encountered while increasing CO₂ concentration inside the reactor. At high equivalence ratio, the combustion temperature and flame stability are improved. At low equivalence ratio, the flame length is increased, and the flame was moved towards the reactor center line.