The Flynn–Wall– Ozawa method was used for evaluating the
kinetic parameters of biomass and coal blends during combustion,
leading to successful results. Biomass in the blends
led to segregation: devolatilisation was independent of combustion.
Adding low proportions of biomass to coal did not reveal interactions
modifying coal combustion behaviour. However,
combustion and devolatilisation were independent processes
for blends having more than 30% biomass. The latter could
cause a drop in industrial burners’ energy efficiency if it were
not possible to use additional combustion air to burn-off the
volatile material.
Coal-solid waste burner design should consider devolatilisation
and combustion separately. A designer must consider a
short time-scale for completing the overall process, one timescale
for completing the combustion of all volatile material
released first and another time-scale for pyrolysed material.
This means that larger combustion chambers must be built
for solid waste or that mixed with coal for others which only
use coal.