CFB中基于赤泥催化的N_(2)O/NO_(x)/SO_(2)协同降低技术路线

Collaborative Reduction Technology Route of N_(2)O/NO_(x)/SO_(2)Based on Red Mud Catalysis in CFB

随着污染物排放标准越发严格,为进一步发挥循环流化床污染物控制成本低的优势,需要明晰各个运行参数和因素对N_(2)O/NO_(x)/SO_(2)排放的影响规律,挖掘N_(2)O/NO_(x)/SO_(2)协同超低排放的可能性。基于“十四五”规划的要求和N_(2)O/NO_(x)/SO_(2)的研究现状,初步形成了一条或实现N_(2)O/NO_(x)/SO_(2)协同降低的技术路线:在保证燃烧效率的前提下,选择合适的床料(如赤泥)在炉内通过催化或反应脱除N_(2)O,通过平衡赤泥中的铝铁比例,实现N_(2)O和NO_(x)的双低排放,同时由于赤泥良好的吸附能力和较强的碱性,可进一步实现SO_(2)的脱除。如必要,通过流态重构或超细石灰石等将剩余的NO_(x)和SO_(2)降至合理水平,或通过SNCR和脱硫塔分别处理剩余的NO_(x)和SO_(2),使其达到排放标准,从而实现N_(2)O/NO_(x)/SO_(2)的协同超低排放。

With the increasingly strict emission standards for pollutants,to further leverage the low-cost advan⁃tage of circulating fluidized bed(CFB)pollutant control,it is necessary to clarify the impact of various operat⁃ing parameters and factors on N_(2)O/NO_(x)/SO_(2)emissions,and explore the possibility of N_(2)O/NO_(x)/SO_(2)synergis⁃tic ultra-low emissions.Based on the requirements of the“14th Five Year Plan”and the research status of N_(2)O/NO_(x)/SO_(2),a technology roadmap that may realize the coordinated reduction of N_(2)O/NO_(x)/SO_(2)has been preliminarily formed:under the premise of ensuring the combustion efficiency,select appropriate bed materials(such as red mud)to remove N_(2)O in the furnace through catalysis or reaction,and achieve dual low emissions of N_(2)O and NO_(x)by balancing the proportion of aluminum and iron in red mud.At the same time,due to the good adsorption capacity and strong alkalinity of red mud,it can further achieve the removal of SO_(2).If neces⁃sary,the remaining NO_(x)and SO_(2)can be reduced to a reasonable level through flow state reconstruction or ultra⁃fine limestone.The remaining NO_(x)and SO_(2)also can be treated separately by SNCR and desulfurization tower,thereby achieving synergistic ultra-low emissions of N_(2)O/NO_(x)/SO_(2).