Use of pre-oxidized ilmenite in fluidized bed boilers
AssigneeImprobed AB
InventorsBengt-Ake Andersson, Fredrik Lind, Henrik Thunman
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Abstract
The invention relates to a method for starting up a fluidized bed boiler, such as a circulating fluidized bed (CFB) or a bubbling fluidized bed (BFB) boiler, for operation with a predetermined concentration of ilmenite particles in the bed material. The invention also relates to a method for pre-oxidizing ilmenite, to pre-oxidized ilmenite and to the use of pre-oxidized ilmenite in a fluidized bed boiler.
Claims15
A method for starting up a fluidized bed boiler for operation with a predetermined concentration of ilmenite particles in the bed material, characterized in that pre-oxidized ilmenite particles are used for reaching the predetermined concentration of ilmenite particles in the bed material.
The method of claim 1, comprising:
- providing pre-oxidized ilmenite particles to the boiler, wherein said pre-oxidized ilmenite particles have preferably been pre-oxidized using the method of any one of claims 9 to 13;
- and/or
- comprising providing fresh ilmenite particles to the boiler and pre-oxidizing said fresh ilmenite particles in the boiler.
A method for producing pre-oxidized ilmenite particles inside a furnace, comprising the steps of:
- a) heating the furnace to a predetermined temperature;
- b) maintaining an oxidizing environment inside the furnace;
- c) continuously feeding fresh ilmenite particles to the furnace;
- d) pre-oxidizing the ilmenite particles by subjecting the ilmenite particles to the oxidizing environment inside the furnace at the predetermined temperature;
- e) continuously removing pre-oxidized ilmenite particles from the furnace.
Dependencies are inferred from the claim text.