Gasification of palm empty fruit bunch in a bubbling fluidized bed: a performance and agglomeration study

Area of Science:

• Chemical Engineering
• Biomass Energy Conversion
• Thermodynamics

Background:

• Palm empty fruit bunch (EFB) is an abundant lignocellulosic biomass resource.
• Efficient conversion of EFB into syngas is crucial for sustainable energy production.
• Fluidized bed gasification offers a promising pathway for biomass valorization.

Purpose of the Study:

• To investigate the gasification performance of palm empty fruit bunch (EFB) in a pilot-scale air-blown fluidized bed.
• To evaluate the effect of bed temperature and equivalence ratio (ER) on gasification efficiency.
• To compare EFB gasification with sawdust and address operational challenges like agglomeration.

Main Methods:

• Gasification of EFB and sawdust in a pilot-scale air-blown fluidized bed reactor.
• Systematic variation of bed temperature (650-1050 °C) and equivalence ratio (ER: 0.17-0.32).
• Analysis of syngas composition, higher heating value (HHV), dry gas yield, carbon conversion, and cold gas efficiency.

Main Results:

• Optimal gasification of EFB and sawdust at 1050 °C and ER 0.25 yielded comparable results: HHV (5.37 MJ/Nm3 vs 5.88 MJ/Nm3), dry gas yield (2.04 Nm3/kg vs 2.0 Nm3/kg), carbon conversion (93% vs 85%), and cold gas efficiency (72% vs 71%).
• Bed agglomeration was identified as a significant issue for EFB gasification at high temperatures.
• Operating at 770±20 °C with varying ER, a maximum HHV of 4.53 MJ/Nm3 was achieved at ER 0.21 without agglomeration.

Conclusions:

• EFB is a viable feedstock for fluidized bed gasification, yielding high-quality syngas.
• Controlling bed temperature and equivalence ratio is critical to mitigate agglomeration and optimize energy output.
• Further research into agglomeration mitigation strategies can enhance EFB's industrial gasification potential.