Kinetic properties of gas-phase combustion of gel fuels based on oil-filled cryogels

Abstract

The combustion mechanisms and characteristics of gel fuels and of combustible liquids in a normal state are different. Therefore, in this paper, the kinetic properties of gas-phase combustion of gel fuel evaporation products have been determined using the data of thermogravimetric analysis (TG) and differential thermal analysis (DTA) at the experimental sample heating rates of 5, 15 and 30 °C per minute. It was prepared a group of oil-filled cryogels (with 40, 50, and 60 vol% of oil) based on the aqueous solution of polyvinyl alcohol (10 wt%). The value of activation energy 13.8 kJ mol–1 has been established for the combustion of oil-filled cryogels using the Friedman method. The thermal effects of these processes, measured using a calorimeter, are 41.78–43.34 MJ kg–1, which is 5–8% lower than the thermal effect of the combustion of oil in a normal state. It has been shown that the kinetic properties of the gas-phase combustion of gel fuels based on oil-filled cryogels are significantly different from the identical characteristics of the combustion of oils in a normal state. At the gas-phase combustion stage, the TG curves for the oil-filled cryogel and for oil in a normal state look similar, but the rate of mass change of the latter is much higher as a result of burnout.