Methane and methanol diffusion flames in supercritical water

Technical Report · Mon Jun 01 04:00:00 EDT 1992

OSTI ID:10115121

Steeper, R R; Rice, S F; Brown, M S; Johnston, S C

Our interest in understanding supercritical water oxidation as a process for the destruction of hazardous wastes has led us to examine hydrothermal diffusion flames that can ignite in supercritical water-fuel-oxygen mixtures. We injected pure oxygen into water-methane and water-methanol mixtures at 275 bar, varying fuel concentrations from 1 to 50 mole% and temperatures from 380 to 510{degrees}C. The first measurements of minimum fuel concentrations required for the spontaneous ignition of diffusion flames in supercritical water are reported. The flames ignite at methane or methanol concentrations as low as 6 mole% at temperatures near 500{degrees}C. The ignition-threshold concentrations rise as temperature is decreased to 400{degrees}C. Visual and shadowgraph video records reveal an insensitivity of flame height to diminishing fuel concentration. In contrast, both luminosity and flame temperature vary strongly with fuel concentration. Flame structures are detectable long after flame luminosity is no longer visible with measured temperatures just a few hundred degrees above background temperature.

• Research Organization: Sandia National Labs., Livermore, CA (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: AC04-76DR00789
• OSTI ID: 10115121
• Report Number(s): SAND--92-8474; ON: DE93006455
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
320305
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400800
CHEMICAL REACTORS
CHEMICAL WASTES
COMBUSTION, PYROLYSIS, AND HIGH-TEMPERATURE CHEMISTRY
DECOMPOSITION
DIFFUSION
FLAMES
HAZARDOUS MATERIALS
IGNITION
INDUSTRIAL WASTE MANAGEMENT
METHANE
METHANOL
OXIDATION
OXYGEN
SUPERCRITICAL STATE
TEMPERATURE RANGE 0400-1000 K
WATER