液相络合-铁粉还原酸吸收回收法脱除烟气中NO_x的机理研究

Mechanism study of NO_x removal from flue gas with the recovery process of absorption with acid following complex in aqueous solution and reduction with iron powder

提出了“Fe2 + 螯合剂吸收 铁粉还原 酸吸收”回收法脱除烟气中NOx 的新工艺.通过对脱氮后气、液相组成的分析,重点研究了脱氮的反应机理.结果表明,处理后气体中没有产生N2 O ,脱氮液中也没有NO- 2 和NO- 3形成,脱氮过程中NO全部被铁粉还原成了氨;在无氧的条件下,脱氮量与铁粉消耗量的比值(摩尔比)为2 1,在有氧的条件下,脱氮量与铁粉消耗量的比值为1 2 .在此基础上提出了脱氮的化学反应.

A novel recovery process for removal of NO_x from flue gas with the sequence of absorption with acid following the complex in aqueous solutions of ferrous chelates and reduction with iron powder is proposed. The constituents of gas and liquid phases after NO_x removal are analyzed, and the reaction mechanism of the NO_x removal is investigated emphatically. The results show that there is no N_2O formed in the exhaust and no NO^-_2 and NO^-_3 ion formed in the denitrification liquid. All of the NO in the flue gas is reduced into NH_3. The molar ratio of denitrification amount to the consumption of iron powder is 2/1 without oxygen in the simulated flue gas, and that is 1/2 when the oxygen content is 5%. The chemical reactions of the process are developed. The equilibrium concentration of ammonia in the denitrification liquid is determined under the experimental conditions.