De Fusco, Lucio
[UCL]
Defoort, Françoise
Blondeau, Julien
[Laborelec]
Jeanmart, Hervé
[UCL]
Contino, Francesco
[VUB]
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 (H 3 PO 4 and CaCO 3) 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 computations with FactSage 7.0 and state-of-the-art databases were applied to quantify the ash molten fraction at 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.
Bibliographic reference |
De Fusco, Lucio ; Defoort, Françoise ; Blondeau, Julien ; Jeanmart, Hervé ; Contino, Francesco. Characterization of sunflower husks fouling in a Drop Tube Furnace: comparison of deposits with H3PO4, CaCO3 and Al2Si2O5(OH)4 additives.the 24th European Biomass Conference and Exhibition (EUBCE 2016) (Amsterdam, du 06/06/2016 au 09/06/2016). In: Proceeding of the 24th European Biomass Conference and Exhibition, , p. 748-755 (2016) |
Permanent URL |
http://hdl.handle.net/2078.1/183132 |