Combustion and Diffusion Flames at High Pressures to 2000 bar

Abstract

Abstract The combustion of methane with oxygen in supercritical homogeneous aqueous fluids has been investigated and stationary diffusion flames generated to pressures of 2000 bar. A reaction autoclave with sapphire windows contains high pressure homogeneous mixtures of water and methane to 500°C. A typical mixture composition is 70 to 30 mole percent of H 2 O and CH 4 . A quasi‐circular fluid flow permits the steady injection of oxygen through a 0.5 mm nozzle at rates of 1 — 10 mm 3 s −1 at constant pressures. — Above 400°C spontaneous ignition of flames occurred. The flames were observed and recorded with microscope and video camera. Emission spectra in the UV‐region were obtained and samples could be taken for analysis. Below about 400°C flame‐less oxidation is detected. The stationary diffusion flames are cone‐shaped and typically about 3 mm high. Flame examples for pressures between 300 and 2000 bar are shown. Preliminary temperatures derived from OH‐spectra are close to 3200 K. — Water can be replaced by argon.