The Autoignition Chemistry of n-Butane: An Experimental Study

n-Butane autoignition chemistry was examined in a single-cylinder engine by measuring intermediate species, performing heat release analyses, and measuring visible emissions. The motored engine technique was employed at engine speeds of 600 and 1600 r/min, and compression ratio was varied to affect different levels of chemical activity.

At 1600 r/min, species measurements, heat release and visible emissions all exhibited a wide “negative-temperature” coefficient region; thus, “intermediate-temperature” chemistry controls autoignition at 1600 r/min. By implication, classic “low-temperature” chemistry controls at 600 r/min. Experimental measurements are compared with literature values, and specific n-butane autoignition chemistry is discussed in light of the measurements.