Fe基催化剂对煤热解-燃烧的NO_(x)排放控制耦合效果

Coupling effect of Fe-based catalyst on coal pyrolysis-combustion NO_(x) control

为解决民用散烧原煤中NO_(x)排放高的问题,提出了“热解减氮耦合燃烧脱硝”方法,即将煤与铁助剂混合,通过管式炉热解制备洁净燃料,并对洁净燃料燃烧过程中NO_(x)排放情况进行研究.结合表征手段,考察铁助剂对氮迁移影响规律.结果表明,铁助剂的负载比为0.5wt%,热解温度为1000℃时耦合效果最佳,相对于未负载时,焦炭燃烧NO_(x)排放量减少34.65%.热解前负载的铁助剂在焦炭中稳定存在,并可促进热解过程中含氮化合物向N_(2)的转化;在洁净焦炭燃烧过程中,铁助剂的存在利于C和CO与NO_(x)还原,进而降低燃烧过程NO_(x)的高排放.通过一步引入的铁助剂,在煤热解-洁净燃料燃烧过程中对NO_(x)控制耦合效果,最终实现了NO_(x)的超低排放.

In order to solve the problem of NO_(x)emission in civil loose-burning raw coal,a source control strategy of"pyrolysis to reduce nitrogen and couple combustion to denitrate"was put forward to realize pollutant emission.The additive was introduced into raw coal in one step to control NO_(x)emission in the process of pyrolysis and combustion.The specific research contents were as follows:coal and iron additive were pyrolyzed in a tube furnace to prepare clean fuel,The emission of NO_(x)during clean fuel combustion was studied.The influence of iron additives on nitrogen migration and the influence of surface structure and pore structure of clean coke were systematically investigated.The results showed that iron additives loaded before pyrolysis existed stably in coke and promoted the transformation of nitrogen-containing compounds into N_(2) during pyrolysis.In the combustion process of clean coke,the existence of iron additives is beneficial to the catalytic reduction of NO_(x)by C and CO,and then the emission of NO_(x)in the combustion process is controlled.The iron additives introduced in one step play a coupling effect of NO_(x)control in the coal pyrolysis-combustion process,realizing the ultra-low emission of NO_(x).