Patent ID: 9651244
Date: 2017-05-16
CPC Classifications: B01D,F01K,F22B,F23C,F23L,Y02E

Claim:
1. A method of operating an oxycombustion circulating fluidized bed (CFB) boiler that includes a furnace having a grid at its bottom section, a solid material separator connected to an upper part of the furnace, and an external solid material handling system, the method comprising steps of: arranging a circulating fluidized bed in the oxycombustion CFB boiler; introducing an oxidant gas into the CFB boiler through the grid as fluidizing gas, the fluidizing gas comprising recirculating flue gas; introducing fuel material into the circulating fluidized bed; introducing sulfur reducing agent comprising CaCO circulating solid material out of the furnace and providing an external circulation of the solid material via the external solid material handling system; fluidizing the solid material in the external solid material handling system by introducing a fluidizing medium comprising the recirculating flue gas into the external solid material handling system; introducing a predetermined amount of steam into the external solid material handling system as a component of the fluidizing medium; and controlling the predetermined amount of steam so that CO