Burner

[0105] The combustion process is as Figure 1a According to the invention and connected to a burner of an industrial refractory boiler represented in . The burner is used at 100% of its thermal power (100% load). The fuel supplied is natural gas (about 95% methane, 2.5% ethane, 0.2% propane, 0.06% butane, 0.02% pentane + C 10 h 22 mixture, 1.6% nitrogen, 0.7% CO 2 、H 2 O trace and H 2 S). The oxidizer is atmospheric air at room temperature.

[0106] The air supply pressure is 12000 Pa. Gaseous fuel is supplied downstream of the injector 1 via an injection system 8 . The fuel supply pressure is 250000Pa.

[0107] Air excess is 1.5%. The oxygen contained in the flue gas is 0.3% by volume, calculated on a dry gas basis. The temperature of the flue gas output from the boiler was 1320°C.

[0108] The volume ratio of recycled flue gas / combustor is 45%. CO exhaust pipe emission ≤ 20 ppmv and NO x ≤15ppmv.

[0110] Example 1 was repeated, but the injection of natural gas was carried out upstream of injection section 1 via injection system 5 .

[0111] CO exhaust pipe emission ≤ 10 ppmv and NO x ≤10ppmv.

[0118] The combustion process takes place in a burner connected to an industrial boiler according to the invention. The burner is used at 100% of its thermal capacity. A fuel oil with a nitrogen content of 0.2% by weight was used. The combustor used is the same as in Example 1.

[0119] The air supply pressure is 12000 Pa. Fuel is supplied upstream of injection section 1 via injection system 5 . The fuel supply pressure is comprised between 10 and 15 bar (10000-15000 KPa). Air excess is 5%. The oxygen contained in the flue gas is 1% by volume of the dry gas. The temperature of the flue gas output from the boiler was 1250°C.

[0120] The volume ratio of recycled flue gas / combustor is 42%. Tailpipe emissions of CO are ≤40 ppmv and NO x ≤80ppmv.