The Informative Value of Ash Fusibility Tests

article in a collection out of WoS and Scopus

en

Slagging and fouling are some of the more prominent problems associated with firing solid fuels. The vast experience with firing coal led to the creation of fouling and slagging indicators based purely on the chemical composition of ash. These indicators are usually based on the results of ash fusibility tests. Other than actual long-term fuel firing, ash fusibility tests are the only empirical indicator of slagging and fouling propensity. Both the predictive indices and ash fusibility tests have been shown to be inaccurate when directly used with biofuels and alternative fuels. Several changes have been made to the tests to better suit the different nature of biomass ash composition and behavior. However, certain standardized procedures in the ash sample preparation as well as in the actual ash fusion temperatures evaluation are still somewhat questionable. To that end, the results of an extensive study of ash fusion temperatures and ash composition have been evaluated and the discussion and conclusions are presented in this article. Severe problems in the standardized procedures are listed in the discussion part of the article and are further elaborated upon. Several new methods have already been proposed within the scientific community, however, the ash fusibility tests remain the technical standard, despite their somewhat flawed nature.

Slagging and fouling are some of the more prominent problems associated with firing solid fuels. The vast experience with firing coal led to the creation of fouling and slagging indicators based purely on the chemical composition of ash. These indicators are usually based on the results of ash fusibility tests. Other than actual long-term fuel firing, ash fusibility tests are the only empirical indicator of slagging and fouling propensity. Both the predictive indices and ash fusibility tests have been shown to be inaccurate when directly used with biofuels and alternative fuels. Several changes have been made to the tests to better suit the different nature of biomass ash composition and behavior. However, certain standardized procedures in the ash sample preparation as well as in the actual ash fusion temperatures evaluation are still somewhat questionable. To that end, the results of an extensive study of ash fusion temperatures and ash composition have been evaluated and the discussion and conclusions are presented in this article. Severe problems in the standardized procedures are listed in the discussion part of the article and are further elaborated upon. Several new methods have already been proposed within the scientific community, however, the ash fusibility tests remain the technical standard, despite their somewhat flawed nature.

Ash Fusion Temperatures, Ash Fusibility Tests, Slagging and Fouling

28.06.2021

Low carbon technologies conference proceedings

68–76

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