KINETICS OF LIQUID-HYDROCARBON COMBUSTION USING THE DSC TECHNIQUE

TGA/DSC techniques were applied to the combustion of crude oil in the presence of solid particles of various specific surface areas. The major physical and chemical transitions observed were classified into three groups, namely distillation, liquid hydrocarbon combustion and coke combustion. This paper deals with the peak associated with the liquid hydrocarbon combustion. Kinetic study revealed that the liquid hydrocarbon combustion peak consisted of two types of combustion reactions which could not be modelled with a single power-law-type kinetic model. Oxygen concentration of the purging gas was varied and its effect on the DSC curve was monitored. It was noticed that at low oxygen concentration, i.e. in the range of 5 to 10%, two distinct peaks emerged. Kinetic analysis of each peak produced a power-law kinetic model for each reaction. The kinetic model was first-order with respect to oxygen partial pressure for both peaks. The order of reaction with respect to the hydrocarbon content was unity for the first peak and 1.5 for the second peak. Optimization of all the data produced a reaction order with respect to the surface area of -0.57 for the first peak and -0.2 for the second peak. © 1990.