Plug-Flow Reactor Study of the Partial Oxidation of Methane and Natural Gas at Ultra-Rich Conditions

ABSTRACT

The homogeneous partial oxidation of fuel-rich CH₄/O₂, CH₄/C₂H₆/C₃H₈/O₂ as well as CH₄/C₂H₆/C₃H₈/H₂/O₂ mixtures is investigated in a plug-flow reactor at intermediate temperatures (473 ≤ T ≤ 973 K) and a pressure of 6 bar. Experiments are carried out at equivalence ratios (Φ) of 2, 10, and 20. Product species are analyzed using time-of-flight molecular-beam mass spectrometry. The experimental results are further compared with kinetic simulations. It was found that under the investigated conditions, the onset temperature for CH₄ oxidation is above 773 K. The highest methane conversion at equivalence ratios of 10 and 20 was between 0–3% for neat methane as fuel and 10–13% for natural gas as fuel. The conversions yield useful chemicals like synthesis gas (H₂/CO), C₂H₄, C₂H₆, or C₃H₆. Higher CH₄ conversion in the natural gas mixtures results in much higher yields of all products. The natural gas components ethane and propane do not influence the reaction onset temperature.

KEYWORDS:

• Partial oxidation
• methane
• natural gas
• plug-flow reactor
• polygeneration

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

Financial support by the Deutsche Forschungsgemeinschaft within the framework of the DFG research unit FOR 1993 (GV1) “Multifunctional conversion of chemical species and energy” under grant number KA3789/1-2 is gratefully acknowledged.