Thermodynamic Analysis and Ash Behavior of Biomass Cofiring with Kaolin Additives in Coal-Fired Power Plant
Keywords:
Biomass Cofiring, slagging, kaolinite, thermodynamic modeling, FactSage, PLTU Suralaya, ash behaviorAbstract
The implementation of biomass cofiring in coal-fired power plants (CFPPs) has become a key strategy in Indonesia's energy transition, aimed at reducing carbon emissions while maintaining energy security. However, the introduction of biomass—particularly those with high alkali and chlorine content—poses significant operational challenges, including increased slagging potential. Slagging can deteriorate boiler performance, reduce heat transfer efficiency, and increase maintenance costs. This study investigates the thermodynamic effects of kaolinite (Al₂Si₂O₅(OH)₄) as an additive for mitigating slagging in the cofiring process at PLTU Suralaya.
Using FactSage 7.2, a thermochemical equilibrium modeling software, this research simulate ash behavior and slag formation under various blending ratios of coal, biomass, and kaolinite. The model evaluates the formation of liquid phases and predicts the interactions between potassium-rich biomass ash and kaolinite. Results show that kaolinite effectively captures alkali elements, promoting the formation of high-melting-point aluminosilicates such as leucite and kalsilite, thereby reducing the amount of low-temperature eutectic compounds responsible for slag formation.
This research provides a predictive approach to slagging control through additive selection and supports the optimization of biomass cofiring strategies in CFPPs. The findings are expected to contribute to more stable and efficient operation of power plants integrating renewable biomass fuels.
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