流化床燃烧工况下N_2O生成机理的试验研究

An Experimenta1 Study on Nitrous Oxide Formation under Fluidized Bed Combustion Conditions

在一个小型固定床反应器上对流化床煤燃烧温度下Ｎ＿２Ｏ均相和多相生成机理进行了试验研究。研究表明，ＮＨ＿３氧化形成的Ｎ＿２Ｏ量很少，其主要产物是ＮＯ，当增加Ｏ＿２浓度时，Ｎ＿２Ｏ略有增加，在９５０℃左右时，Ｎ＿２Ｏ量最大，而在８８０℃时，ＮＯ量最大。焦炭直接燃烧能形成一定量的Ｎ＿２Ｏ，ＮＯ能在焦炭表面还原成Ｎ＿２Ｏ，氧化性气氛下，焦炭的还原能力降低。最后，对煤焦生成Ｎ＿２Ｏ的多相反应机理进行了讨论。

An experimental study on N2O formation under fluidized bed combustion conditions hasbeen carried out in a small fixed bed reactor of laboratory scale,N2O formations from bothhomogeneous reaction of NH3 oxidation and heterogeneous reaction of char and NO have beeninvestigated. It is found that only a small amount of N2O is formed from oxidation of NH3while NO is the main product. The increase of O2 concentration can result in a slight increaseof N2O formation. The direct combustion of char can produce a certain amount of N2O andNO can be reduced to N2O on the char surface, However,the atmosphere will weaken thereduction of NO. The mechanism of N2O formation from heterogeneous reaction on the charsurface is discussed.