A novel laser-heating technique, referred to as the laser-driven thermal reactor (LDTR), was used to determine sample thermal behavior, specific heat release rate, and total specific heat release of three volatile single-component liquid hydrocarbons, i.e., n-decane, n- butylcyclohexane and n-butylbenzene. The objective was to demonstrate measurement repeatability and expand the theoretical analysis of the LDTR. The experimental apparatus consists of a copper sphere-shaped reactor mounted within a vacuum chamber, with sample and substrate supported on a thermocouple near the center of the reactor. The reactor is heated from opposing sides by a near-infrared laser to achieve nearly uniform sample temperature. The change in temperature with time (i.e., thermogram) is compared to a previously recorded baseline (no sample) thermogram. A theoretical model based on thermal energy conservation is used to evaluate the thermograms for the thermochemical characteristics of interest. This study represents a step towards applying this technique to more complex volatile multi-component fuels of unspecified composition. Results for the LDTR were compared with a DSC/TGA. The analysis was extended to include an estimation of the hydrocarbon mass change with increasing temperature, based on the temporal change in the specific heat release rate. An estimate of the total specific heat release was obtained for these three liquid hydrocarbons and found to be consistent with the literature values when the measurements were carried out under suitable operating conditions.
Energy and Fuels
calorimetry, heating value, laser-driven thermal reactor, n-butylbenzene, n-butylcyclohexane, n-decane, single-component liquid hydrocarbons, total specific heat release