Evolution of gas phase sulfur during gasification of black liquor

The evolution of sulfur during gasification of black liquor was studied in a laminar entrained-flow reactor at 700-1000degreesC The aim was to determine the impacts of CO2 and H2O on the split of sulfur between the gas and condensed phase as well as on the gas phase sulfur species. The fraction of sulfur in the gas phase decreased as temperature was increased, At low temperatures, the gas phase sulfur was below the equilibrium values but exceeded the equilibrium values at high temperatures. H2S was the predominant gas phase sulfur species at all conditions. Organic compounds were present at significant concentrations at 700degreesC (up to 40% of the gas phase sulfur) but at 900-1000degreesC, their contents rapidly became negligible. In CO2, COS and CS2 were formed as well.