Corrosion of High Alumina Castables by Liquid Ashes during the Gasification of Sewage Sludge

C. Bourgel, J. Poirier, R. Boigelot

CNRS, CEMHTI UPR3079, Univ. Orléans 45071 Orléans/France

Revision 31.05.2014, 23.09.2014

Volume 7, Issue 1, Pages 69 - 72

Abstract

The overall objective of this work is to understand the thermo chemical interactions between different high alumina refractory materials and slag during the gasification of biomass (sewage sludge). The slag behaviour and the corrosion between different high alumina-based castables and the liquid ashes are studied. Corrosion tests were carried out using static and dynamic tests. The loss of thickness of the initial interface was used to evaluate the amount of corrosion and impregnation, whereas the dynamic test was performed out in order to quantify the erosion phenomenon. Quantitative and qualitative analysis were carried out using SEM and DRX. These techniques were also used to determine the liquidus temperature of sewage sludge ashes after quench at high temperature. Results shows the presence iron oxide, lime, and iron/lime phosphate crystals (Ca9Fe(PO4)7). The liquidus temperature of slag is located between 1250 °C and 1300 °C. Trials of corrosion indicate a higher impregnation and corrosion for rich alumina castables (tabular/alumina and alumina/spinel). Chrome alumina refractory presents a very limited corrosion and andalusite-based refractory exhibits limited penetration.

Keywords

gasification, sewage sludge, inorganics, refractories

References

[1] Dupont, C.; et. al.: Biomass pyrolysis experiments in an analytical entrained flow reactor between 1073 K and 1273 K. Fuel 87 (2008) [7] 1155–1164 [2] Watson, E.B.: Two-liquid partition coefficients: experimental data and geochemical implications. Contributions to Mineralogy and Petrology 56 (1976) [1] 119–134 [3] Dickey jr., J.S.; et al.: Geochemistry and petrology of dredged basalts from the Bouvet triple junction, South Atlantic. Geochimica et Cosmochimica Acta 41 (1977) [8] 1105–1118 [4] Hart, S.R.; Davis, K.E.: Nickel partitioning between olivine and silicate melt. Earth and Planetary Sci. Letters 40 (1978) [2] 203–219 [5] Irving, A.J.: A review of experimental studies of crystal/liquid trace element partitioning. Geocastables chimica et Cosmochimica Acta 42 (1978) [6] 743–770 [6] Berjonneau, J.; et al.: Determination of the liquidus temperatures of ashes from the biomass gasification for fuel production by thermodynamical and experimental approaches. Energy and Fuels 23 (2009) [12] 6231– 6241 [7] Weidong, L.; et al.: Study on the ash fusion temperatures of coal and sewage sludge mixtures. Fuel 89 (2010) [7] 1566–1572 [8] Poirier, J.; et al.: An overview of refractory corrosion: observation, mechanisms and thermodynamic modelling. Refractories Applications Transactions 3 (2007) [2] 2–12 [9] Poirier, J.: Recent tendencies in refractories in relation with services conditions in the steel industry. Proc. of the 39th Int. Colloquium on Refractories, Aachen (1996) 6–16 [10] Meyer-Rau, S.; Telle, R.J.: Testing strategies for corrosive interactions of ceramics with semisolid and molten metal alloys. J. of Europ. Ceram. Soc. 25 (2005) [7] 1049–1054 [11] Peregrina, C.; Large, M.: Caractérisation de la partie minérale des boues de STEP, Suez environnement (2009) [12] Bourgel, C.; et al.: Behaviour of phosphorous and other inorganics during the gasification of sewage sludge. Energy and Fuels 25 (2011) [12] 5707–5717

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