Partial Oxidation of Methane at Elevated Pressures and Effects of Propene and Ethane as Additive: Experiment and Simulation

Abstract

Partial homogeneous oxidation of methane (CH 4 ) within stationary engines may be one concept for conversion of available energy to alternatively mechanical energy, heat, and additional useful chemicals like syngas (CO/H 2 ), formaldehyde (CH 2 O), methanol (CH 3 OH) or hydrocarbons (e.g. C 2 H 4 ). The present study investigates the formation reactions of chemicals experimentally and theoretically. Methane oxidation is studied under fuel-rich conditions ( = 17.50-22.25) at high pressures (6 bar) and high temperatures ( max = 1030 K) for long residence times in a tubular reactor. The gas composition is determined experimentally by time-of-flight mass spectrometry for different reactor temperatures. Through variation of reactor temperature an overview of the maximum mole fractions of target chemicals, the temperature of observed reaction onset, and the optimal temperature to increase target yields can be determined. The experimental results are compared to kinetic simulations of the methane conversion using literature mechanisms to assess how well the data are reproduced for these uncommon reaction conditions. The potential of activating the conversion reactions with ethane (C 2 H 6 ) and propene (C 3 H 6 ) as additives is investigated. Methanol is chosen as one target compound. Its yield is increased by both additives. In addition, propene as additive reduces the temperature of reaction onset in the experiments and in the simulation. CH 2 O and C 2 H 4 can be identified as other useful chemicals produced in the experiments and the influence of the additives on the yields is discussed.

Ignition Delay Time and Oxidation of a Kerosene Aviation Fuel and a Blended Jet50-Bio50 Fuel

“…In this experiment, it was impossible to make the axial temperature uniform due to heat loss to the surroundings at high temperatures over 968 K. Below the critical temperature, uniform temperatures are attained and temperature profiles are shown at various temperatures in Figure . Axial deviation in temperature is within ±5 K, which is comparable with that reported in previous works. − …”

Speciation data for fuel-rich methane oxy-combustion and reforming under prototypical partial oxidation conditions

“…A summary of the experimental investigations in simple chemical reactors for partial oxidation of methane can be found in [31]. Only a very limited number of studies looked at higher hydrocarbons including propene for partial oxidation conditions [32][33][34][35] and recently for reforming conditions with equivalence ratios up to 22 [36].…”

Experimental Investigation of Ethanol Oxidation and Development of a Reduced Reaction Mechanism for a Wide Temperature Range

“…A plug-flow reactor is used to obtain species data with respect to the oxidation of a CH 4 /C 2 H 5 OH mixture. The experimental setup is described in detail in ref ; therefore, only a short description is given here. The reactor, made of quartz, is housed in a stainless steel tube, encased by a copper shell in order to ensure a homogeneous temperature profile.…”

“…The plug-flow reactor model is implemented in ChemKin-Pro 2020 R1. 61 The geometrical specifications of the experiment 56 were implemented in the model. The measured temperature profiles including the heating and cooling zones served as an input for the simulation.…”