Oxidation of Pentane in Mixtures with Air and the Negative Temperature Coefficient of Reaction

Abstract

n-PENTANE in a chemically correct mixture with air was oxidized in a reactor formed by the annulus between concentric tubes of ‘Vycor’ (96 per cent silica). The inside diameter of the outer tube was 19 mm. and the outside diameter of the inner was 17 mm. Thus the annulus was 1.0 mm. wide. The reactor was supported concentrically in a vertical tubular electrical furnace 2 in. in diameter. The heated length of the furnace was 6½ in. Temperature as measured on the exterior surface of the reactor attained a maximum value at approximately the mid-section of that length and was taken as related to rate of reaction and to the occurrence of ignition. Air plus the required concentration of pentane was supplied to the reactor at rates ranging from 50 c.c. to 400 c.c./min. Rates of reaction as based on oxygen consumption were determined by Orsat analysis of samples from the reactor effluent. Experimental results for rates of air supply decreasing by steps from 400 c.c. to 100 c.c./min. are given by the graphs of Fig. 1.