CO and NOx emissions in porous inert media (PIM) burner system operated under elevated pressure and inlet temperature using a new flame stabilization technique

The rapid advances in technology necessitate abundant use of fossil fuels which poses two major challenges to any nation. One is fast depletion of fossil fuel resources; the other is environmental pollution. The porous medium combustion has proved to be one of the technically feasible options to tackle the environmental pollution problem to a remarkable extent. This work presents an experimental investigation to study combustion emissions using a premixed methane–air mixture within a non-homogeneous porous inert medium (PIM) under high pressure ratio (1–9), temperature (20–400 °C) and thermal output power (5–40 kW). A new flame stabilization technique in porous inert media (PIM) combustion under high pressure and temperature has been developed and evaluated. The proposed technique avoids the draw backs of the hitherto developed techniques by properly matching the flow and flame speeds and, consequently, ensuring a stable combustion, for a wide range of operating pressure and temperature. The validity of this new technique has been assessed experimentally in details by analyzing combustion inside a prototype burner. The superiority of the new concept was confirmed by low CO and NOx emissions, where a zero value was recorded for CO emissions throughout the whole investigation. The NOx emissions revealed remarkable performance as compared with conventional PIM techniques. Values less than 10 ppm were obtained at relative air ratios larger than 1.65 and 1.85 with temperatures of 200 and 400 °C, respectively. This indicates the high combustion efficiency and emissions performance of the proposed technique. Observed results proved remarkable emission performance with respect to environmental pollution legislation.