摘要
利用沉降炉和管式炉结合X射线光电子能谱仪(XPS),分析研究了不同升温速率和环境压力下热解煤焦表面含氮和含硫官能团的赋存形态。结果表明:升温速率和环境压力对煤焦表面含氮和含硫官能团的转化规律均有比较明显的影响;与慢速热解相比,快速热解使煤焦中吡啶型氮(N-6)更难分解,但是却促进了季氮(N-Q)的分解与转化;对于含硫官能团,快速热解降低了硫铁矿和硫化物的稳定性,却抑制了亚砜和硫酸盐的分解;环境压力的提高,促进煤分子结构外部的氮结合到芳香结构中,但吡咯型氮(N-5)向N-6的转化被抑制,最终使二者更多地转化为煤分子结构内部的N-Q,同时氮氧化物(N-X)的稳定性也有所提高;对于有机硫而言,环境压力的提高加速了硫化物和亚砜的分解,同时使噻吩和砜更加稳定,但对无机硫的赋存形态无显著影响。
The characterization of nitrogen-and sulfur-containing functional groups on pyrolytic char surface at different heating rates and pressures was studied by X-ray photoelectron spectroscopy(XPS) analysis in the drop tube furnace and the tube furnace. Results show that the heating rate and the pressure obviously affect the transformations of nitrogen-and sulfur-containing functional groups on the char surface. Compared with the slow pyrolysis, the rapid pyrolysis with high heating rate restrains the decomposition of pyridine(N-6), but the decomposition and transformation of quaternary nitrogen(N-Q) is promoted. For the sulfur-containing functional groups, the rapid pyrolysis reduces the stability of pyrite and sulfide. However, the decomposition of sulfoxide and sulfate was inhibited. With the increasing of pyrolysis pressure, nitrogen in the interior-molecular structure bound to the aromatic structures, but the transformation of pyrrole(N-5) to N-6 is inhibited. Finally, both N-5 and N-6 transform to N-Q in the interior-molecular structure, and the stability of nitrogen oxide(N-X) is improved. For the organic sulfur, the increase of pressure enhances the decomposition of sulfide and sulfoxide, and improves the stability of sulphone and thiophene, but has an insignificant influence on the occurrence of inorganic sulfur.
作者
张燕超
雷鸣
ZHANG Yanchao;LEI Ming(Department of Power Engineering,North China Electric Power University,Baoding 071003,Hebei Province,China)
出处
《动力工程学报》
CAS
CSCD
北大核心
2021年第5期350-357,共8页
Journal of Chinese Society of Power Engineering
基金
国家重点研发计划资助项目(2016YFB0600701)。
关键词
煤焦
升温速率
含氮官能团
含硫官能团
XPS
coal char
heating rate
nitrogen-containing functional group
sulfur-containing functional group
XPS
