THERMODYNAMIC AND KINETIC STUDY ON EMISSION CONTROL IN GLASS MELTING

Swantje  Thielea; Amelie  Neumannb; Reinhard  Conradt

Authors

Swantje Thielea Aachen University, Institute of Mineral Engineering, Mauerstr. 5, Aachen, D-52064, Germany.
Amelie Neumannb SAINT-GOBAIN Sekurit Deutschland GmbH, Glasstr. 1, Herzogenrath, D-52134, Germany.
Reinhard Conradt Aachen University, Institute of Mineral Engineering, Mauerstr. 5, Aachen, D-52064, Germany.

Keywords:

Emission control, flue gas, condensate formation, boron emission

Abstract

Aggressive fluxes or gaseous species, that slip through flue gas filters, complicate the process control and maintenance of the complex filters behind industrial glass melting tanks. Partly due to a lack of accurate thermodynamic data and kinetic analyses of condensation phenomena, the process control is often based on experience. The two projects presented in this paper focus on condensation phenomena in Na-O-H-S and Na-O-H-B containing flue gases. It can be shown that the important phases in sulfur containing flue gas are Na2SO4, NA2S2O7 and NaHSO4. Aggressive fluxes format low water partial pressures between 400°C and 250°C. In boron containing flue gas, the most important species are NaBO2, condensing between 320°C and 160°C, and H3BO3, condensing at temperatures lower than 90°C. The kinetic experiments can be supported by thermodynamic calculations made with the help of Factsage®.

References

Beerkens, R.G.C. (2001). Modeling the kinetics of volatilization from glass melts. J. Am. Cer. Soc., 84(9):1952–1960.

Conradt, R. and Scholze, H. (1986). Zur nerdampfung aus glasschmelzen. Glastechn. Ber. 59(2):34–52.

CRCT Therm Fact Inc. and GTT Technologies. (2010). Factsage® 6.2, Montreal, Aachen.

Ehrig, R. (1978). Zum problem der oberflächenverdampfung aus alkaliboro-silikatglasschmelzen. Silikattechnik, 24(8/9):296-298.

Neumann, A., Wilsmann, W., and Conradt, R. (2011). Equilibria and reactions within synthetic flue gases from the Na-H-C-O-S-N system. Glass Technol.: Eur. J. Glass Sci. Technol. A, 52(1):37-42.

Wenzel, J.T. and Sanders, D.M. (1982). Sodium and boron vaporisation from a boric oxide and a borosilicate glass melt. Phys. Chem. Glasses,23(2)7–52.