Patent ID: 8534236

Claim:
An oxyfuel combustion boiler plant comprising: an air separation unit for manufacturing oxygen by separating nitrogen from air, a boiler having a burner for burning the oxygen supplied from the air separation unit and pulverized coal and a primary system pipe for supplying the pulverized coal to the burner, an exhaust gas recirculation system pipe for supplying combustion exhaust gas discharged from the boiler to the primary system pipe, and a carbon dioxide capture unit for capturing carbon dioxide in the exhaust gas discharged from the boiler, characterized in that: the oxyfuel combustion boiler plant is further comprising: an oxygen buffer tank disposed on a downstream side of the air separation unit; an oxygen supply pipe for supplying oxygen to the primary system pipe of the burner from the oxygen buffer tank; and a nitrogen supply pipe for supplying a part of nitrogen generated from the air separation unit or an air supply pipe for supplying air from outside which is connected to the oxygen supply pipe on a downstream side of the oxygen buffer tank and on an upstream side of a junction of the primary system pipe.