Thermal behavior of co-combustion of oil shale semi-coke with torrefied cornstalk

- The co-combustion of oil shale semi-coke with torrefied cornstalks shows additive behavior.
- The effects of oil shale semi-coke with torrefied cornstalks are studied by TG-DTG-DSC curves and mathematical formulas.
- Vyazovkin method is successfully used to evaluate the kinetic parameters.

Oil shale semi-coke is a hazardous byproduct from the thermal processing of oil shale, with potential dangerous environmental impacts. Previous studies have found that adding various biomass matters to the retorting waste allows for easier combustion of the retorting waste, making for safer disposal of materials. Here, oil shale semi-coke from Huadian retorts were mixed with torrefied cornstalks of various degrees (250, 275, 300 °C) in order to assess the combustion behavior and effect of the mixture. Kinetic parameters of combustion were then calculated by using the Vyazovkin method. Based on TG-DTG-DSC curves, co-combustion of oil shale semi-coke and cornstalk increased with the greater degree of heat-treated cornstalk. From activation energy distribution curve, the interaction of torrefied cornstalk in the combustion process mainly occurred in the co-firing transition phase, and the activation energy of the 275 °C cornstalk was the least of the three samples and had the most obvious influence on the process.