Title:
Characterization of Sunflower Husks Fouling in a Drop Tube Furnace: Comparison of Deposits With H3PO4, CaCO3 AND Al2Si2O5(OH)4 Additives
Author(s):
De Fusco, L., Blondeau, J., Defoort, F., Jeanmart, H., Contino, F.
Document(s):
Paper
Abstract:
Fouling of heat exchangers in biomass combustion plants is an operational problem that can lead to a severe decrease of boilers efficiency and availability. To counteract deposition, additives are used to bind the vaporized alkali in high melting temperature structures, such as solid phosphates or aluminum-silicates. Fouling during the combustion of sunflower husks with a combination of P- and Ca-based additive (H3PO4 and CaCO3) and Al-silicates additives (kaolin or halloysite) was studied in a test campaign in a Drop Tube Furnace. Fouling tests with additives were compared with reference experiments with the raw fuel (two tests). Thermodynamic equilibrium computationswith FactSage 7.0 and state-of-the-art databases were applied to quantifythe ash molten fractionat 900°C, the mass of liquid per kg of biomass, the K-release rate to the gas phase and finally the condensed mass at 200°C.The use of additives decreased Cl and P (apart from the test with P addition) concentrations in the inner deposits and increased the amount of loose deposits on the probe. When computing the enrichment factors of the deposits with respect to the ash injected, K concentration in RAW1 deposits, with respect to RAW1 ash, is enriched of 14% (mol/mol). When using the P+Ca additive, K is depleted in deposits by 46%. With the use of aluminum-silicate additives, K is enriched by 4% for the HAL deposit and depleted of 21% for the KAO case.
Keywords:
fouling, additives, sunflower hulls, drop tube furnace
Topic:
Biomass Conversion Technologies for Heating, Cooling and Electricity
Subtopic:
Biomass combustion in large utilities
Event:
24th European Biomass Conference and Exhibition
Session:
2BV.1.47
Pages:
748 - 755
ISBN:
978-88-89407-165
Paper DOI:
10.5071/24thEUBCE2016-2BV.1.47
Price:
FREE
