Styrene Unit Needs Retrofit to Reduce NOx Emissions
In September 2020, the Order No.1 of the General Manager of China Petrochemical Corporation was officially issued, and the document put forward higher requirements for the NOx emission index of the heating furnace. The NOx emission concentration of key enterprises should be controlled at 60mg/m³, and the NOx emission concentration of key areas should be controlled at 70mg/m³.
Sinopec Qilu Petrochemical Branch’s plastic plant RTO unit and styrene heating furnace environmental protection upgrading project, the styrene unit steam superheating furnace F-301 burner NOx emission is about 80mg/m³. In response to the latest environmental protection requirements of the general manager of Sinopec, Qilu Petrochemical is determined to transform the styrene plant to reduce nitrogen oxides.
Ruichang takes the interests of customers as the starting point and proposes the best solution
The technical team of the heating furnace business department learned about the actual operation of the styrene furnace and collected various data. After investigation: the customer hopes to replace the burner on the basis of the original product, so as to reduce the amount of transformation and construction as much as possible. Foreign technical solutions need to change the original square burner into a circular burner to ensure that the NOx emission requirement is less than 60mg/m³, otherwise, it cannot be transformed.
Facing the arduous task, the heating furnace technical team conducted in-depth research and discussions on various solutions, combined with flue gas circulation, fuel grading, and other means to reduce nitrogen oxides, from the optimization of the refractory brick structure to the adjustment of the opening of the gas gun head. And then to the coordination of the various relative positions of the two, taking the convenience and interests of customers as the starting point, without changing the flame shape of the original burner, the temperature field in the furnace, and the installation size of the original burner, the shortest transformation period, The retrofits solution with the lowest retrofit cost and the most reliable performance and emission indicators.
On-site calibration, effect is remarkable
Through this low-NOX burner renovation, the Qilu styrene steam superheater F-301 renovation effect is obvious:
- 1 NOx emission is reduced from the original 80mg/m³ to 35~50mg/m³, and it can be controlled within 60mg/m³ under the condition of fluctuating on-site working conditions.
- 2. In the state of low oxygen content (the average oxygen content is 1.5% to 3%), the flame still burns stably to ensure the stable operation of the heating furnace.
After the success of this project, it represents that the ultra-low NOx burner of Ruichang Environment has achieved remarkable results in the high-temperature furnace styrene plant, and also lays a solid foundation for the transformation of other low-NOx burners in the high-temperature furnace in the future.