In the quest for sustainable energy solutions, researchers are turning to biomass co-firing in circulating fluidized bed (CFB) boilers as a promising avenue. However, the use of biomass fuels rich in alkali metals, particularly potassium, presents significant operational challenges, including bed agglomeration and superheater fouling. A recent study published in the journal “Achievements in Engineering” sheds light on these issues, offering valuable insights for the energy sector.
Led by S. Sungworagarn from the Department of Mechanical Engineering at Mahanakorn University of Technology in Bangkok, the research focuses on two under-researched tropical biomass fuels: oil palm empty fruit bunch (EFB) and palm kernel shell (PKS). These fuels are abundantly available in tropical Asian countries but remain underexplored in CFB applications.
The study, conducted in a 100 kWth CFB reactor, aims to examine fired-side problems such as bed agglomeration and fouling, determine the critical potassium accumulation level leading to defluidization, and quantify the evolution of fouling thermal resistance. The findings reveal that EFB and PKS co-firing significantly increases the risk of agglomerate formation through both reactive (coating-induced) and non-reactive (melt-induced) mechanisms.
“Our results indicate that the formation of low-melting potassium silicates is responsible for agglomeration,” explains Sungworagarn. “This understanding is crucial for developing effective strategies to mitigate these issues and improve the reliability and efficiency of biomass CFB systems.”
The research also highlights the need for adaptive cleaning schedules to maintain heat transfer efficiency. By quantifying the evolution of fouling thermal resistance, the study provides a foundation for optimized soot-blowing strategies.
The implications of this research are significant for the energy sector, particularly in regions where tropical biomass fuels are abundant. “These findings are particularly valuable for tropical Asian countries where these fuels are abundantly available but remain underexplored in CFB applications,” notes Sungworagarn.
As the world continues to seek sustainable energy solutions, this study offers a crucial step forward in understanding and mitigating the challenges associated with biomass co-firing in CFB boilers. By improving fuel management and fouling mitigation strategies, the energy sector can move closer to achieving reliable and efficient sustainable power generation.
The research not only addresses immediate operational challenges but also paves the way for future developments in the field. As Sungworagarn concludes, “This work provides foundational insights for improving the reliability and efficiency of biomass CFB systems through better fuel management and fouling mitigation strategies.”