Influence of kiln desulfurization and delisting equipment on environment

With regard to the ultra-low emission of desulfurization and de marketing equipment in Shenyang kilns, the concept that is widely used in China now refers to that the pollutant emission specifications of coal-fired power plants basically reach the emission limits of gas turbine units (that is, under the condition of 6% of the reference oxygen content, the emission concentrations of soot, SO2, and nitrogen oxides are not higher than 10, 35, and 50mg/m3 respectively), but in this specification, the oxygen content of flue gas corresponding to the emission limits of natural gas turbine and coal-fired boiler are respectively 15% and 6%, If converted to the same oxygen content conditions, the emission limit of natural gas turbine is actually 2.5 times that of coal-fired unit. It can be seen that after the ultra-low emission transformation, the emission specification of coal-fired unit is lower than that of gas unit.

Selection of skill path

Since 2014, domestic coal-fired power plants have continuously implemented ultra-low emission transformation. From the perspective of power plants that have completed transformation, the selected ultra-low emission transformation skills are mainly electrostatic bag filter, wet desulfurization skills, selective catalytic recovery skills. With the promotion of ultra-low emission transformation in all aspects, new ultra-low emission skills will be rapidly developed, The ultra-low emission transformation skills will be continuously improved and optimized based on the experience of stacking in the field application practice. The ultra-low emission skills of desulfurization and denitrification equipment will become more sophisticated, and the cost of transformation together will gradually decrease.

A 600 mw power plant conducted a specific investigation on the technical road of transformation after the ultra-low emission transformation was launched, combined with the actual conditions of on-site equipment system, small space for reconstruction and expansion, and based on the current emission concentration of three pollutants of the unit, it was concluded that the emission requirements could be satisfied only by adding a standby layer of catalyst in the aspect of lowering nitrogen oxides. The key points were to reduce smoke, dust The technical road for SO2 transformation shall be selected based on the actual situation. After comparing the above technical roads, "desulfurization and dedusting integration+denitration catalyst plus standby layer+absorption tower expansion" has the advantages of less investment in transformation funds, short shutdown construction period, small land occupation, etc., which is determined by the power plant as the technical road for this transformation. According to the calculation, the investment for the completion of the reconstruction of a single unit is about 60 million yuan. After the completion of the reconstruction, the emission concentrations of the three major pollutants in the flue gas, soot, SO2 and nitrogen oxides, can be separately lower than 6, 25 and 35 mg/m3, which can meet the requirements of ultra-low emissions.

Benefits of transformation

The ultra-low emission transformation of coal-fired power plants will not bring economic benefits to the power plants themselves, but the environmental benefits of the transformation of desulfurization and denitrification equipment are very significant, which is of great significance for improving the regional ambient air quality.