THERMAL-ANALYSIS OF CRUDE-OIL LIGNITE MIXTURES BY DIFFERENTIAL SCANNING CALORIMETRY

Thermal characterization of lignite, crude oils and their 10 and 20% mixtures were investigated by differential scanning calorimetry (d.s.c.). The calorific value of the lignite increased in mixtures depending on the crude oil type. In pyrolysis runs, temperature ranges where distillation and visbreaking occur were identified for the crude oils studied. The effect of heating rate was also studied, and higher reaction temperatures and higher heat flow rates were observed at d.s.c. peak thermograms with increasing heating rate (5, 10, 15, 20 and 25-degrees-C min-1). The specific heat of samples was examined in the temperature range 20-600-degrees-C, and showed an increase with increasing temperature until the decomposition temperature was reached. Kinetic parameters of the samples were investigated and an increase was observed in the activation energy and Arrhenius constant of the mixtures.