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The oxidation of 1-butene and n-butane in air at elevated pressure was investigated in a high pressure chemical flow reactor. Results are presented for pressures of 3, 6, and 10 atm, temperatures near 900K, and lean equivalence ratio. Gas samples were analyzed using gas chromatography with aldehydes sampled using a dinitrophenylhydrazine/acetonitrile procedure employing gas chromatography/mass spectrometry analysis. Major common products observed include CO, CH2O, C2H4, C3H6, and CO2. Additional major products included 1,3-C4H6 for 1-butene and 1-C4H8 for n-butane. Fuel conversion was increased with increased pressure, temperature, and equivalence ratio with 1-butene more reactive than n-butane. Large levels of lower molecular weight carbonyls resulted from 1-butene whereas significant amounts of conjugate and lower molecular weight alkenes resulted from n-butane. Trends in product distributions with increasing pressure were successfully accounted for by current autoignition theories.

Investigations have concluded that methane does not appear to be photochemically reactive in the atmospheric system and does not participate in smog formation. Since methane is “nonreactive,” and may in the future be excluded from the total unburned hydrocarbon emissions, an instrument was designed and developed (termed the “methane analytical system”) enabling methane emissions to be quantified separately from total unburned hydrocarbon emissions. The instrument employed gas chromatographic principles whereby a molecular sieve column operating isothermally separated methane from the nonmethane hydrocarbons. Direct on-line sampling occurred via constant volume sample loops. The effluent was monitored with a flame ionization detector. The instrument was fully calibrated (i.e., extremely linear response over a large concentration range) for use with Diesel engines as part of an ongoing alternative fuels research program.