Teng Yingyue, Bian Xiaoting, Song Yinmin, Wang Bingzhi, Li Na, He Runxia, Wang Yunfei, Liu Quansheng
College of Chemical Engineering, Inner Mongolia Key Laboratory of High-Value Functional Utilization of Low Rank Carbon Resources, Inner Mongolia University of Technology, Hohhot, Inner Mongolia 010051, China.
College of Chemical Engineering, Ordos Institute of Technology, Ordos 017000, China.
ACS Omega. 2022 Aug 13;7(33):29079-29085. doi: 10.1021/acsomega.2c02931. eCollection 2022 Aug 23.
Hydrochloric acid-demineralized Shengli lignite (SL) and iron-added lignite (SL-Fe) were thermally degraded using a fixed-bed device to better understand the effect of the iron component on the microcrystalline structure transformation properties of lignite during the pyrolysis process. The primary gaseous products (CO, CO, H, and CH) were detected by pyrolysis-gas chromatography. X-ray diffraction and Raman spectra were adopted to analyze the microcrystalline structure of lignite and chars. The results indicated that the iron component had a catalysis effect on the pyrolysis of SL below 602.6 °C. The pyrolysis gases released in the order of CO, CO, H, and CH, and the addition of the iron component did not change the sequences. The iron component promoted the generation of CO, CO, and H in the low-temperature stage. During the high-temperature stage, the iron component inhibited the formation of CO and H. The formation of CH was inhibited by the iron component throughout the pyrolysis process. The evolution characteristics of -OH, C=O, C=C, and C-H functional groups were not significantly affected, and the fracture of aliphatic functional groups and C-O functional groups was inhibited by the iron component during the pyrolysis process. The iron component restricted the spatial regular arrangement tendency of aromatic rings and facilitated the decrease in the small-sized aromatic ring but inhibited the formation of large aromatic rings (≥6 rings) and the content decrease in side chains during the pyrolysis process. Notably, the effects of the iron component on the formation of gaseous products were associated with the microstructure evolution of lignite.
采用固定床装置对盐酸脱矿物质胜利褐煤（SL）和加铁褐煤（SL-Fe）进行热降解，以更好地了解铁组分在热解过程中对褐煤微晶结构转变特性的影响。通过热解气相色谱法检测主要气态产物（CO、CO₂、H₂和CH₄）。采用X射线衍射和拉曼光谱分析褐煤及其半焦的微晶结构。结果表明，在602.6℃以下，铁组分对SL的热解具有催化作用。热解气体以CO、CO₂、H₂和CH₄的顺序释放，铁组分的加入并未改变该顺序。铁组分促进了低温阶段CO、CO₂和H₂的生成。在高温阶段，铁组分抑制了CO和H₂的形成。在整个热解过程中，铁组分抑制了CH₄的形成。-OH、C=O、C=C和C-H官能团的演化特征未受到显著影响，且在热解过程中铁组分抑制了脂肪族官能团和C-O官能团的断裂。铁组分在热解过程中限制了芳香环的空间规则排列趋势，促进了小尺寸芳香环的减少，但抑制了大芳香环（≥6环）的形成和侧链含量的降低。值得注意的是，铁组分对气态产物形成的影响与褐煤的微观结构演化有关。
