By 2019, the content of nitrogen oxides (NOx) in the exhaust gas of Surgutskaya GRES-2 steam boilers was reduced from the design value of 1100 mg/m3 to 448 mg/m3 (average value for all power units). Two power units out of six already meet the declared production ratio of 350 mg/m3.
As a follow-up effort to reduce emissions in the next two years, Surgutskaya GRES-2 will modify the design of the burner gas distribution pipes in the boilers and discontinue the supply of recycle gas to the peripheral channels of Level 3 burners. In 2022, the Branch will launch a gradual replacement of Category III steam turbine extraction lines. The first activity was implemented in 2019 at Power Unit No. 2. The Branch has scheduled to do the same at the other power units in 2020–2021. According to calculations, these efforts will reduce nitrogen oxide emissions by 38 mg/m3.
The second activity was implemented at Power Unit No. 6 last year. It made it possible to reduce emissions by additional 73 mg/m3. By 2022, the power engineers will need to implement these activities at all SPU-810MW power units of the plant. As a result, the plant will secure NOx content equal to or under 350 mg/m3. By 2026, subject to replacement of Category III steam turbine extraction lines, nitrogen emissions will go down to 255 mg/m3, which meets the current ratio by a wide margin.