Abstract

Objective: The reactivity and combustion performance of mixtures of lignite with peach kernel and cardoon were investigated, through thermal analysis experiments, for assessing the potential impacts of these wastes as co-firing fuels.

Methods: Additionally, a control method was applied to reduce problematic elements from biomass ashes in order to mitigate deposition phenomena in co-firing units. The results showed that combustion performance of raw fuels followed the order cardoon>peach kernel>lignite, however in case of blends, this order was reversed lignite/peach kernel> lignite/cardoon, revealing synergistic effects between component fuels.

Results: The combustion performance of lignite was improved by blending it with biomass fuels. Deposition problems should be expected in boilers firing peach kernel and cardoon fuels above 900°C.

Conclusion: After alkalis leaching, the reactivity and efficiency of woody materials and mixtures with lignite were enhanced, while the slagging/fouling propensity was reduced.

Keywords: Combustion, lignite, biomass, blends, slagging/fouling, co-firing fuels.