Nitrogen Evolution during Fast Pyrolysis of Sewage Sludge under Inert and Reductive Atmospheres
2017
Wei, Fu | Cao, Jing-Pei | Zhao, Xiao-Yan | Ren, Jie | Wang, Jing-Xian | Fan, Xing | Wei, Xian-Yong
The influence of atmospheres on the product distribution and behaviors of nitrogen evolution during fast pyrolysis of sewage sludge (SS) was investigated in a drop-tube quartz reactor. The results indicated that H₂ improved the formation of gas products and gave a relatively low tar yield in comparison to an inert atmosphere. The char N yield obtained under a H₂ atmosphere is lower than that under an Ar atmosphere. Above 500 °C, H₂ further promoted the conversion of nitrogenous compounds to NH₃. The HCN yield was low under all conditions. The decomposition of nitrogenous substances in SS produced more amine N, nitrile N, and heterocyclic N under a H₂ atmosphere. The synergistic effect of a reductive atmosphere and high temperature promoted the thermal decomposition of more difficult-to-cleave N-containing heterocycles, such as piperidines, pyrroles, and pyridines. This study provides a better and deep understanding of the nitrogen transformations during fast pyrolysis of SS under a reductive atmosphere, which would benefit the environmental protection and sustainable clean use of SS.
显示更多 [+] 显示较少 [-]