在烟道中脱除NOx并生成HNO3的方法

A method for NO_x removal and HNO_3 production in a flue

为了解决目前气体电离放电脱硝方法存在的等离子源体积庞大、能耗高、NOx脱除率低以及需要依靠传统脱硝方法的协同作用等问题,拟用小流量、高浓度的氧活性粒子[O2+,O(1D),O(3P),O3]、引发剂HO2-分别注入烟道中,与烟气中水反应生成.OH,在无吸收剂、催化剂、氧化剂及其他技术协同作用下,实现了烟道中.OH快速氧化脱除大烟气量中的微量NOx并生成HNO3溶液的整个反应过程,等离子体反应管道长度为1～8m.实验结果表明,氧活性粒子与NOx摩尔比值决定了脱除率,摩尔比选择在2～3为宜,此时NOx脱除率将达到95%左右,回收酸液中NO3-回收率达到58.1%;NOx脱除率随着实验气体温度增高而下降;O2含量增加对脱硝效果有20%左右的影响;H2O含量大于4%时脱硝率处于最高值.可见本方法不但解决气体电离放电脱硝存在的问题,同时又为大气污染治理提供一种绿色新方法.

New methods for denitration that are compatible with traditional methods are required to overcome problems with denitration by gas ionization discharge,including the large size of the plasma source,high energy consumption and low NOx removal.Active oxygen species（e.g.O2＋,O（1D）,O（3P）,O3） and HO2-initiator were injected under low-flow and high-concentration conditions into a flue to react with the H2O molecules in the flue gas to generate.OH radicals,which can oxidize NOx and generate HNO3 liquid as a resource substance.This whole reaction took place in a 1 to 8 m flue without catalyst or reductant and eliminated environmental pollution and waste emission.Experimental results show that the optimal molar ratio was between 2 and 3,at which point the NOx removal efficiency was 95% and the NO3-recovery efficiency in the recovered acid liquid was 58.1%.Furthermore,the NOx removal efficiency decreased as gas temperature increased,the influence of O2 content in.OH radicals denitration was around 20% and the NOx removal efficiency was maximized when the H2O concentration exceeded 4%.This method not only resolves the denitration problems of gas ionization discharge but also provides a new,green method for atmospheric pollution control.