Mineral phase transformation of wood and cereal pellets – electrical test and factsagetm calculations

• Autorzy: Gonzalez Valdes L. , Nowak-Woźny D.
• Języki publikacji: EN

Abstrakty

EN

The fusion behaviour of biomass ash-forming materials is an important factor in assessing the propensity to form undesirable slag and fouling deposits in the boiler. The characteristics of the fuel used affect the extent and severity of the problem, thus growing efforts are put on finding reliable methods for its characterization. Combustion and co-combustion of biomass have gained popularity in combating climate change and reducing carbon dioxide emissions into the atmosphere. Nevertheless, biomass encompasses a wide range of different types and its use increases operational risks due to the diversity of the chemical composition. This study is based on characterising the mineral phase transformations of two kinds of biomass (wood pellets and cereal pellets) using various laboratory-based methods on fuel ashes. Measurements of changes in the electrical properties of the ash during the sintering process (dielectric loss factor) were performed using a QuadTech Plus 7600 bridge in the frequency range 500Hz - 1MHz. Thermodynamic analyses were performed by means of FactSage™ modelling. The results were compared with those of standard tests, AFT and oxide index calculations, which were employed to predict slagging and fouling propensities. The observed changes in dielectric loss depend on the frequency and temperature of sintering. FactSageTM thermodynamic equilibrium calculations proved very useful in predicting the ash melting behaviour and the chemical changes occurring in the ash. The existence of a melt phase, occurring at even lower temperatures of those given by the AFT, is in accordance with the high slagging and fouling hazards predicted by empirical indices.

Słowa kluczowe

EN

biomass; ash; slagging; fouling

• Wydawca: ADVSEO sp. z o. o.
• Czasopismo: Technical Issues
• Rocznik: 2016
• Tom: nr 3
• Strony: 126--134
• Opis fizyczny: Bibliogr. 12 poz., rys., tab.

Twórcy

autor

Gonzalez Valdes L.

• Politechnika Wrocławska Wydział Mechaniczno-Energetyczny Katedra Technologii Energetycznych, Turbin i Modelowania Procesów Cieplno-Przepływowych Wybrzeże Wyspiańskiego 27 50-370 Wrocław

autor

Nowak-Woźny D.

• Politechnika Wrocławska Wydział Mechaniczno-Energetyczny Katedra Technologii Energetycznych, Turbin i Modelowania Procesów Cieplno-Przepływowych Wybrzeże Wyspiańskiego 27 50-370 Wrocław

Bibliografia

• 1. Du, D., Yang, H., Qian, K., et al., Fusion and transformation properties of the inorganic components in biomass ash, 2014, Fuel, 117, pp. 1281–1287.
• 2. Vassilev, S.V., Baxter, D., Vassileva, C.G., An overview of the behaviour of biomass during combustion: Part I, Phase-mineral transformations of organic and inorganic matter, Fuel, 2013, 112, pp. 391–449.
• 3. Rizvi, T., Xing. P., Pourkashanian, M., et al., Prediction of biomass ash fusion behaviour by the use of detailed characterisation methods coupled with thermodynamic analysis, Fuel, 2015, 141, pp. 275–284.
• 4. Vassilev, S.V., Baxter, D., Vassileva, C.G., An overview of the behaviour of biomass during combustion: Part II, Ash fusion and ash formation mechanisms of biomass types, Fuel, 2014, 117, pp. 152–183.
• 5. Evgueni, J., Prediction of coal ash fusion temperatures with the FACT thermodynamic computer package, Fuel, 2002, 81, pp. 1655-1668.
• 6. van Dyk, J.C., Keyser, M.J., Influence of discard mineral matter on slag–liquid formation and ash melting properties of coal – A FACTSAGETM simulation study, Fuel, 2014, 116, pp. 834–840.
• 7. Zhang, G., Chou, K., Correlation Between Viscosity and Electrical Conductivity of Aluminosilicate Melts, Metallurgical and materials transactions B, 2012, Vol, 43, Issue 4, pp. 849-855.
• 8. Adnan, S.B.R.S., Mohamed, N.S., Conductivity and Dielectric Studies of Li2ZnSiO4 Ceramic Electrolyte Synthesized via Citrate Sol Gel Method, Int. J. Electrochem. Sci., 2012, 7, pp. 9844-9858.
• 9. González Valdés, L., The analysis of the ash from coal. Zagadnienia aktualnie poruszane przez młodych naukowców, 2015, 2. T. 1, s. 287-291.
• 10. Pronobis, M., Evaluation of the influence of biomass co-combustion on boiler furnace slagging by means of fusibility correlations, Biomass and Bioenergy, 2005, Vol. 28, Issue 4, pp. 375–383.
• 11. van Loo, S., Koppejan, J., Handbook of biomass combustion and Co-firing, Routledge, 2002.
• 12. Bateni, N.H., Hamidon, M.N., et al., Electrical evaluation of ceramic obtained from white rice husk ashand soda lime silica glass for electronic applications, J. MaterSci: MaterElectron, 2014, 25, pp. 5491–5495.

Uwagi

PL

Opracowanie ze środków MNiSW w ramach umowy 812/P-DUN/2016 na działalność upowszechniającą naukę (zadania 2017).