| Along with the rise of wastewater treatment ratio, the sludge output is increasing continually. Facing with the serious problem of sewage sludge, it has become the common goal to find safe, efficient and economical treatment technology with the reduction, stabilization and reclamation of sludge. High-temperature pyrolysis of sewage sludge received wide attention for its rapid heating-up,high conversion, huge potential as resource, minor-hazard by-products, low energy cosumption and so on, has been regarded as an alternative technology for burning.Taken the sewage sludge as the main object, this article has studied nitrogen's distributing rules among the gas, liquid, solid phase during the process of pyrolysis; analysed the specific existence form of nitrogen-containing gaseous product using GS-MS and FTIR; analysed the transformation rule of NH3 and HCN using TG-FTIR, and then speculated their ways of generation; studied the influence on the production of NH3 and HCN by final pyrolysis temperature, microwave absorbing material, sludge moisture, catalyst(Fe) and the the way of its addition.For the N in the three-phase distribution and existing form in the gas when the microwave pyrolysis of sewage sludge. The results show that: the percentage of the N in the gas accounted for total N in the sludge increases with the the final temperature, while the percentage of N in the oil and solid residues correspondingly reduce as final temperature rising. Using GC-MS and FTIR technology analysis: the nitrogen-containing gas obtained from high-temperature pyrolysis of sewage sludge mainly in the form of NH3, HCN, and N2, also a small amount of HNCO, and didn't detect any NOX.Using TG-FTIR combined technique on the NH3 and HCN obtained from high-temperature pyrolysis of sewage sludge and then analysis the law of their generation. The results show that: when the microwave pyrolysis of sewage sludge, NH3 and HCN are from the thermal decomposition of protein and nitrogen heterocyclic aromatic ring material. In addition, NH3 also comes from the heated sludge adsorption of volatile ammonium salt. The results showed that: NH3 and HCN production of both the transient increase with temperature first and then decreased, and the peak value at 800℃. Compared to the traditional pyrolysis, NH3 production peak occurred in the instantaneous movement of the right. while the instantaneous HCN production peak is the same as the traditional pyrolysis.In order to study the production rules NH3 and HCN, the paper also studied the final temperature of pyrolysis, microwave absorbing material, the sludge water content, the catalyst (iron) and iron way NH3 and HCN to join the cumulative yield . The results showed: (1) NH3 and HCN with the final pyrolysis temperature of different products have different rates of accumulation. The cumulative yield of NH3 with the temperature then decreased, while the cumulative yield of HCN with increasing final pyrolysis temperature increases. (2) Incorporation of four absorbing substances, NH3 and HCN on the sludge yield of the total cumulative impact of the size of the order: activated carbon> SiC> graphite. But the incorporation of reuse as a microwave absorbing material and substances is rather special, it contains residual metal can promote the accumulation of NH3 and HCN in the total yield. (3) The higher the water content of sludge, NH3 and HCN in the cumulative production rate is higher. (4) Iron on the yield of NH3 cumulative impacts and the temperature at 800℃before, for NH3 production, at 800℃, the can catalyze the conversion of NH3 to N2, causing the cumulative production rate. Accumulation of iron on the yield of HCN influence on temperature, when the temperature is below 800℃, a disincentive to the HCN, when the temperature is higher than 800℃, the iron can promote the conversion of HCN to the other gases, causing the cumulative yield of HCN lower. (5) Plus iron as the catalyst, the catalyst and the dispersion of iron in the sludge has a great relationship, the higher the dispersion, the stronger the catalytic effect.
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