Bed management cycle for a fluidized bed boiler and corresponding arrangement

A process for bed management for a fluidized bed boiler, the process comprising the steps of:

• a) providing fresh ilmenite particles as bed material to the bed of a fluidized bed boiler;
• b) carrying out a fluidized bed combustion process with the fluidized bed boiler, wherein air is passed from below the bed through the bed material;
• c) removing at least one ash stream comprising ilmenite particles from the fluidized bed boiler;
• d) separating ilmenite particles from the at least one ash stream;
• e) recirculating separated ilmenite particles into the bed of the fluidized bed boiler, wherein a first fraction of the separated ilmenite particles is recirculated into the bed of the fluidized bed boiler, and a second fraction of the separated ilmenite particles is discharged, wherein the first fraction and the second fraction are determined based on the degree of activation of the ilmenite particles;
• wherein the average residence time of the ilmenite particles in the fluidized bed boiler is at least 75 hours;
• and wherein separating ilmenite particles comprises magnetic separation.