烧结烟气臭氧氧化 半干法吸收脱硫脱硝实践

以梅钢7×105 m3/h烧结机烟气的脱硫脱硝为背景，研究了实际工程应用中臭氧对烟气的氧化和半干法对氧化产物(NOx和SO2)的吸收等问题。结果表明，臭氧喷入点位置对烟道内NOx氧化影响不大，喷射格栅保证了臭氧和烟气的均匀混合。吸收塔出口烟气温度对脱硝影响显著，NOx的吸收效率会随着温度的升高而降低，当温度高于95 ℃时，脱硝效率为0；而脱硫塔出口烟气温度变化对SO2吸收几乎没有影响。优化后的烧结烟气脱硫脱硝系统连续运行数据表明，出口SO2质量浓度均值为16.83 mg/m3，出口NOx质量浓度均值为72.33 mg/m3，均达到了系统设计要求。系统运行成本为10～11元/t，与活性炭烟气净化技术、循环流化床＋SCR工艺技术相比，臭氧氧化 半干法吸收协同脱硫脱硝工艺具有明显的优势。

Practice of desulfurzation and denitrition of sintering waste gas #br# with method of ozone oxidation and semi dry absorption

Based on the desulphurization and denitration for sintering flue gas of 7×105 m3/h sinter machine, the oxidation of ozone to flue gas and absorption of oxidation products (NOx, SO2) by the semi dry process in the practical engineering applications were studied. The results indicated that the location of ozone injection had little effect on the oxidation of nitrogen oxides in duct and the injection grille guaranteed the uniform mixing of ozone and flu gas. The temperature of flu gas at the exit of the absorption tower had a great effect on the denitration, and the absorption efficiency of NOx decreased with the increasing of temperature. When the temperature was higher than 95 ℃, the denitration efficiency was zero. However, the change of temperature at the exit of the desulphurization tower had nearly no effect on SO2 absorption. The continuous operation data obtained of the optimized desulphurization and denitration system for sintering flue gas indicated that the average values of the outlet SO2 and NOx were 16.83 and 72.33 mg/m3, respectively, which both achieved the requirement of system design. The system operating cost was 10 11 yuan/t. Compared with the activated carbon flue gas purification technology and circulating fluidized bed＋SCR technology, the ozone oxidation semi dry absorption synergistic desulfurization and denitration process had obvious advantages.