煤焦油沥青质的表面官能团特性及对悬浮床加氢裂化助剂选择的影响

以煤焦油常压渣油(T AR)为原料,分离出了正庚烷沥青质(T AR HI),通过元素分析、XPS、FT IR手段对该沥青质的表面官能团进行了表征,同时考察了不同助剂作用下T AR悬浮床加氢裂化反应过程中的生焦行为,进而分析了不同助剂对T AR沥青质的稳定作用机理。结果表明,T AR HI表面官能团以C-C、C-H、C-O为主;杂原子中O含量最高,杂原子官能团以含O官能团为主,其中醚类结构(C-O-C)占大多数;含N官能团主要为吡啶、吡咯和胺类,此外含有少量亚砜等含S官能团。表面官能团中,中性官能团总相对浓度为79%,酸性官能团为001%,碱性官能团为147%,沥青质表面呈弱碱性。SDBS、OA、CTAB 3种助剂对T AR沥青质的稳定作用依次降低,稳定作用主要取决于沥青质表面官能团与助剂之间的酸碱作用和氢键作用,其中酸碱作用影响较大。宜选取具有酸性基团的阴离子型双亲分子作为T AR悬浮床加氢裂化的助剂。

Characteristics of Surface Functional Groups From Coal Tar Asphaltene and Its Influence on the Selection of Assistants in Slurry-Bed Hydrocracking

n Heptane asphaltene(HI) was isolated from coal tar atmospheric residue (T AR). Its surface functional groups characteristics were studied by Element analysis, XPS and FT IR. The coke formation in slurry bed hydrocracking of T AR in the presence of assistant and the mechanism of the stabilization of T AR asphaltene by different assistants were investigated simultaneously. The results indicated that the main surface functional groups of T AR HI were C-C, C-H and C-O, and the O content was highest in heteroatom contents. In addition, O containing groups were the main part of heteroatom functional groups and appeared mainly as ethers structure (C-O-C). N containing groups were mainly pyridine, pyrrole and amine. 〖JP2〗Sulfoxides was detected as the main S containing functional group with the smallest content in the total heteroatom functional group contents. In the surface functional groups, the relative concentrations of neutral functional groups, acid functional groups and basic functional groups were 79%, 001%, and 147%, respectively, which made the surface of T AR asphaltene being weak alkaline. The stabilization abilities of the three assistants of SDBS,OA and CTAB for T AR asphaltene decreased in turn, which depended on the acid base interaction and hydrogen bond interaction between asphaltene surface functional groups and assistants, and the acid base interaction was the most important factor. Furthermore, the amphiphile with acidic groups was the optimal assistant in T AR hydrocracking process.