FIELD: partial combustion of spent cellulose liquor. SUBSTANCE: spent cellulose liquor is burned in burner connected to reactor where oxygen-containing gas is fed at temperature within reactor higher than 700 C; at least half of oxygen not contained in fuel composition and required for partial combustion of black liquor introduced in reactor through burner is supplied there in the form of hot oxygen- containing gas through duct coaxially arranged about spent cellulose liquor supply pipe; weight ratio between quantity of oxygen in oxygen-containing gas and dry substance of spent cellulose liquor is between (0.1-0.7):1. In addition, oxygen-containing gas is heated prior to feeding it to temperature higher than 100 C. Pending spraying, liquor viscosity is brought down below 200 CST. Before liquor is supplied to reactor, it is heated to temperature higher than boiling point. EFFECT: improved efficiency. 5 cl, 5 dwg
