Method for treating black liquor
AssigneeA. Ahlstrom Corporation
InventorsBertel K. Hakulin, Erkki J. Kiiskila, Marjo Kuusio
Life of this patent
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Abstract
A method and apparatus for recovering black liquor chemicals and heat in a sulphate pulp process. The black liquor is concentrated in an evaporation plant, which includes a pressure heating reactor, after which the black liquor is gasified or combusted in a reactor for producing hot gases. The hot gases formed in the reactor are introduced into gas turbine power plant. The exhaust gases from the gas turbine are introduced into a waste heat boiler, where steam is generated for a steam turbine power plant. Secondary steam is led from the pressure heating reactor as injection steam into the gas turbine, to control inlet temperature.
Claims20
A method of treating black liquor from a sulphate pulp process, for recovering chemicals and heat therefrom, utilizing a gas turbine having vanes and preceded by a combustor, a waste heat boiler, and a steam turbine power plant, comprising the steps of:
- (a) evaporating black liquor from a sulphate pulp process to produce a concentrated black liquor having a higher dry solids content;
- (b) gasifying and/or combusting the concentrated black liquor to produce hot gases and molten and/or solid salts;
- (c) recovering sulphate cooking chemicals from the molten and/or solid salts;
- (d) purifying the hot gases;
- (e) introducing purified hot gases into the combustor for the gas turbine, and then into the gas turbine, in order to recover energy from the hot gases, the gas turbine producing exhaust gases;
- (f) introducing the exhaust gases into the waste heat boiler to effect generation of steam;
- (g) recovering energy from the waste heat boiler steam in the steam turbine power plant;
- (h) pressurizing secondary steam from the sulphate pulp process;
- and
- (i) introducing the pressurized secondary steam as injection steam prior to the gas turbine vanes, to regulate the gas turbine inlet temperature.
A method of treating black liquor from a sulphate pulp process, for recovering chemicals and heat therefrom, utilizing a gas turbine having vanes and preceded by a combustor, a waste heat boiler, and a steam turbine power plant, comprising the steps of:
- (a) evaporating black liquor from a sulphate pulp process to produce a concentrated black liquor having a higher dry solids content;
- (b) gasifying and/or combusting the concentrated black liquor to produce hot gases and molten and/or solid salts;
- (c) recovering sulphate cooking chemicals from the molten and/or solid salts;
- (d) purifying the hot gases;
- (e) introducing purified hot gases into the combustor for the gas turbine, and then into the gas turbine, in order to recover energy from the hot gases, the gas turbine producing exhaust gases;
- (f) introducing the exhaust gases into the waste heat boiler to effect generation of steam;
- (g) recovering energy from the waste heat boiler steam in the steam turbine power plant;
- (h) purifying secondary steam from the sulphate pulp process;
- and
- (i) introducing the purified secondary steam as injection steam in the combustor prior to the gas turbine vanes, to regulate the gas turbine inlet temperature.
Dependencies are inferred from the claim text.