气相臭氧深度氧化协同湿法吸收脱硝工艺的氮平衡研究:以某钢铁公司300 m^(2)烧结烟气脱硫脱硝系统为例

NITROGEN BALANCE OF OZONE A COMBINED DENITRATION PROCESS OF DEEP OXIDATION AND LIQUID-PHASE ABSORPTION:A CASE STUDY ON A 300 m^(2)SINTERING FLUE GAS OF AN IRON&STEEL COMPANY

目前,气相臭氧深度氧化协同湿法吸收脱硝技术已成功应用于多套大型烧结烟气超低排放治理工程。然而,有关氧化产物通过吸收系统时能否从气相高效传递至液相,能否实现氮平衡等问题尚未形成共识。为此,针对某钢铁公司300 m^(2)烧结烟气气相臭氧深度氧化协同湿法吸收脱硫脱硝系统,建立了具有清晰的氮平衡边界和明确的氮输入、输出和累积项,并且尽可能减少动态变化参数的氮平衡研究方法。在此基础上开展了氮平衡研究,结果表明:脱硫脱硝系统的氮转化率为96.4%,表明烟气中的NO_(x)经臭氧深度氧化后可高效吸收。随着烟气进入和排出脱硫脱硝系统的气态NO_(x),随着冲洗水进入和随着石膏排出脱硫脱硝系统的NO^(-)_(3),以及吸收塔、缓冲池中累积的NO^(-)_(3)是最主要的氮输入、输出和累积项,也是针对实际工程开展氮平衡研究应重点考虑的氮组分项。

Ozone deep oxidation combined with wet absorption technology has been successfully applied to many sets of ultra-low emission treatment projects for large-scale sintering flue gas,and running stably for many years.However,there is no consensus on whether the oxidation products can be efficiently transmitted from the gas phase to the liquid phase,and whether the nitrogen balance can be realized when the flue gas passing through the absorption system.Therefore,one ozone deep oxidation combined with wet absorption project for 300 m^(2)sintering flue gas in an iron and steel company was taken as an example,and this study established a nitrogen balance research method with clear nitrogen balance boundary,specific nitrogen input,output and accumulation items,and less dynamic parameters.Based on this method,the nitrogen balance was studied.The results showed that the nitrogen conversion rate of the system was 96.4%,which showed that NO_(x)in flue gas could be efficiently absorbed after ozone deep oxidation.Gaseous NO_(x)entered and discharged from the desulfurization and denitration system with flue gas,NO^(-)_(3)entered the desulfurization and denitration system accompanying flushing water or discharged accompanying gypsum,NO^(-)_(3)accumulated in the absorption tower and buffer tank were the most critical nitrogen input,output and accumulation items,which were also the main items to be considered in the actual project.