煤的模型化合物混合燃料气流床气化中N的迁移研究

Release of fuel-N during entrained-flow gasification of fuel mixed with model compound

将吡啶配入柴油中模拟煤中氮的存在形式,考察了混合燃料在四喷嘴对置式气化炉中,轴径向位置HCN、NH3、NO和N2的浓度分布。结果表明:氮污染物(HCN、NH3、NO)在喷嘴平面处即产生且浓度最高,远离喷嘴平面时其浓度大幅降低,N2也裂解参与了气化反应,且出口浓度N2>HCN>NH3>NO;氧燃料比增高,NO、N2增加;氧燃料比1.3时HCN、NH3浓度最高,0.9和1.7时浓度较低;流场的分布使靠近出口处径向浓度基本一致,而上部各平面位置浓度靠近炉壁处最低;水汽的加入使HCN、NH3浓度增高而NO浓度降低。

Model compound pyridine was added to diesel oil to simulate the existence of coal-N. A laboratory opposed multi-burner （OMB） gasifier was used to investigate the axial and radial concentration distribution of HCN, NH3, NO and N2. The maximum concentrations of nitrogen pollutants （HCN, NH3 and NO） are produced at the nozzle plane and these concentrations decrease away from the plane. Moreover, N2 participates in gasification and the order of concentrations of nitrogen compounds in exit is N2 〉 HCN 〉 NH3 〉 NO. NO and N2 increase as O2/ fuel ratio increases. HCN and NH3 reach maximum when O2/fuel ratio is 1.3, but largely decrease at 1.7 and 0.9. Flow field distribution make radial concentration profiles uniform toward the exit region and low near the sidewall in other axial position. The steam addition leads to increased formation of HCN and NH3, whereas decreased formation of NO.