Predicting slagging tendencies for biomass pellets fired in residential appliances: a comparison of different prediction methodsShow others and affiliations
2008 (English)In: Energy & Fuels, ISSN 0887-0624, E-ISSN 1520-5029, Vol. 22, no 6, p. 3680-3686Article in journal (Refereed) Published
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Text
Abstract [en]
In this paper, a comparison between four different types (both empirical and theoretical) of techniques to predict the slagging tendencies in residential pellet combustion appliances was performed. The four techniques used were the standard ash fusion test (SS ISO-540) used in the Swedish pellet standard (SS 18 7120), thermal analysis (TGA/DTA), thermochemical model calculations, and a laboratory-scale sintering test. The tests were performed with 12 pelletized biomass raw materials, and the results were compared with measured slagging tendencies in controlled combustion experiments in a commercial under-fed pellet burner (20 kW) installed in a reference boiler. The results showed significant differences in the prediction of slagging tendencies between different predicting techniques and fuels. The method based on thermal analysis (TGA/DTA) of produced slags must be further developed before useful information could be provided of the slagging behavior of different fuels. The used sintering method must also be further improved before the slagging tendency of fuels forming slags extremely rich in silicon (e.g., some grasses) can be predicted. Relatively good agreement was obtained between results from chemical equilibrium calculations and the actual slagging tendencies from the combustion tests. However, the model calculations must be further improved before quantitative results can be used. The results from the standard ash fusion test (SS ISO 540) showed, in general, relatively high deformation temperatures, therefore predicting a less problematic behavior of the fuels in comparison to the actual slagging tendencies obtained from controlled combustion experiments in commercial pellet burner equipment. Nevertheless, the method predicted, in most cases, the same fuel-specific slagging (qualitatively) trends as the corresponding combustion behavior.
Place, publisher, year, edition, pages
Washington: American Chemical Society (ACS), 2008. Vol. 22, no 6, p. 3680-3686
Keywords [en]
bed agglomeration tendencies, ash, combustion, fuels
National Category
Chemical Engineering Bioenergy
Identifiers
URN: urn:nbn:se:umu:diva-117474DOI: 10.1021/ef800321hISI: 000261057100018Scopus ID: 2-s2.0-57849121741OAI: oai:DiVA.org:umu-117474DiVA, id: diva2:911629
2016-03-142016-03-012023-03-23Bibliographically approved