Fundamental studies of black liquor combustion: Report No. 2, Phase 1 (October 1984-November 1986)

Combustion properties of Kraft Black Liquors

“…In much of the work on single black liquor droplet combustion, ignition of the droplet has been taken as the point when drying is complete and devolatilization begins (e.g. Clay et al, 1988). Most of these results are for droplets burned at relatively low temperatures compared with recovery boiler environments.…”

“…A great deal of information on the swelling of black liquors during combustion has been reported over the past decade. The research results have identified swelling as occurring differently in each of the separate stages of combustion and provided useful data on the effect of liquor composition and furnace variables on the magnitude of swelling Clay et al, 1985Noopila, 1989;Frederick and Hupa, 1991). A quantitative model of the swelling process has also been presented .…”

“…It is necessary therefore in modeling to begin with experimentally measured SVma x data for the liquor of interest. Procedures for measuring swelling during devolatilization have been developed by Hupa , Clay et al (1985, 1987, and Verrill (1992). We recommend Hupa's procedure because of its simplicity and the decoupling of flow and combustion phenomena during the experiments.…”

Sodium and sulfur release and recapture during black liquor burning

“…The data include those obtained in this work together with data of Brink et al (1970) and Clay et al (1985Clay et al ( , 1987). Brink's data are for droplets sprayed into a hot gas environment, while Clay's data are for single droplets suspended in a hot radiant environment with a low gas flow past the particle.…”

“…In batch pyrolysis studies at low heating rates (-0.1 "C/s) the amounts released were almost constant over the temperature range 400"C-1000"C (Brink et al, 1970). At higher heating rates (-lOO"C/s), total sulfur release went through a maximum between 400 and 700°C (Brink et al, 1970;Clay et al, 1985Clay et al, , 1987. In flash pyrolysis experiments (heating rates -lOOO"C/s) Harper obtained a maximum in sulfur release at 480°C.…”