2009 Annual Meeting

(320e) Formation and Impact of Gases Sulfur Components in An Oxyfuel Combustion Process

Authors

Maier, J. - Presenter, University of Stuttgart
Al-Makhadmeh, L. - Presenter, University of Stuttgart

Formation and Impact of Gases Sulfur Components in an Oxyfuel Combustion Process

 J. Maier, L. Al-Makhadmeh, G. Scheffknecht


Institute of
Process Engineering and Power Plant Technology (IVD)

Pfaffenwaldring 23,
University of
Stuttgart, 70569
Stuttgart, Germany

Corresponding Author: maier@ivd.uni-stuttgart.de  +49 711 685 63396

The higher concentrations of sulfur components in the furnace during an oxy fuel process, compared to conventional combustion, increase the interest of studying sulfur components formation and destruction mechanisms under oxy-fuel conditions and its impacts in power stations. Sulfur components have effects on boiler corrosion, ash deposition, ash precipitation, acids dew point, and impacts during temperature changes associated with start-up and shut-down, etc.

In this investigation the formation and destruction mechanisms of sulfur components under oxy-fuel conditions in the boiler were analyzed during different combustion conditions (staged, un-staged). Experimental investigations were conducted in a once through 20 kW furnace and in a semi technical 500 kW test facility with flue-gas recirculation. Different coal qualities such as lignites and bituminous coals were used. Besides SO2, H2S has been measured in the sub-stoichiometric combustion zone. To study effects on destruction and formation of sulfurous species, the SO2 concentration in the artificial combustion gas mixture was varied between 500ppm and 6000ppm and detailed inflame measurements of gas components (SO2, H2S, NO, CO etc) have been performed. During staged combustion, the effect of burner stoichiometry on sulfur components speciation has been performed at 0.75, 0.85, and 0.95. In addition, the impact of a wet condition was studied by injecting H2O steam through the burner. Moreover, the conversion of SO2 to SO3 and the behavior of the acid dew point have been investigated. On the other hand, SO2 capture capacity of coals in the convective section of the furnace has been studied.

Keywords: Sulfur components (SO2, SO3, and H2S); Oxy-fuel combustion; Coal; SO2 capture

Axial concentration profiles for gaseous sulphur components and oxygen during Lausitz coal combustion in air and OF27