Patent ID: 8052803

Claim:
Method for preventing chlorine deposition on heat-transferring surfaces of a boiler, in which boiler a fuel with a chlorine content is burned, said method comprising the steps of: feeding a compound with a sulphate content to the boiler, said compound forming a reagent that fixes alkali compounds, and said compound being ferric(III) sulphate, Fe 2 (SO 4 ) 3 and/or aluminium(III) sulphate, Al 2 (SO 4 ) 3 ; spraying said compound in a drop size of 1-100 μm close to and on the front side of a thermal surface of the boiler to be protected, as a water solution, wherein heat causes said compound to thermally decompose into a metal oxide and sulphur trioxide (SO 3 ) such that the sulphur trioxide reacts with said alkali compounds to destroy said alkali compounds and to capture chlorine from said alkali compounds, thereby preventing the deposition of said chlorine content of said fuel.