Reactivity assessment of coals via a weighted mean activation energy

A method has been developed for describing the reactivity or combustibility of solid fuels, such as lignite, bituminous coals and petroleum coke, in terms of a weighted mean apparent activation energy, derived from simultaneous $\text{TG}\text{DTG}$ readings on a 20 mg sample heated at a constant rate in a flowing air atmosphere. It is proposed that this quantity, labelled E_m′, could supplant the established method which involves recording several temperatures on the DTG (burning profile) curve.