Molecular-level structures and distribution of refractory polycyclic aromatic sulfur heterocycles (PASHs) during residue hydrotreating process (RHT) are investigated. A prior atmospheric pressure photoionization (APPI) FT-ICR MS was used to obtain the distribution of refractory PASHs. Then the key refractory PASHs were further dissociated by collision-induced dissociation (CID) to identify the isomers and gain their fragment ions. During deep hydrodesulfurization (HDS), S1 class compounds detected in the RHT products was identified as the major refractory sulfur compounds. Moreover, an increase in the aromatic structure of S1 class species is present during RHT. The key refractory PASHs are these with DBE = 9–12, which also determine HDS depth during RHT process. From the CID experiments, as indicated by an increase of abundance of fragmentation of alkyl(C1-C4)-substituted DBT, alkyl(C2)-substituted DBT in particular, these key refractory PASHs have a structure of alkyl(C2)-substituted DBT, such as 4,6-DMDBT. In addition, the molecular chemical formula and molecular structure for these key refractory PASHs were proposed, shedding a light on the development of industrial HDS catalysts and optimization of RHT process

研究了渣油加氢处理 (RHT) 过程中难熔多环芳族硫杂环 (PASH) 的分子级结构和分布。先前的大气压光电离 (APPI) FT-ICR MS 用于获得耐火 PASH 的分布。然后通过碰撞诱导解离 (CID) 进一步解离关键的难熔 PASH，以识别异构体并获得它们的碎片离子。在深度加氢脱硫 (HDS) 过程中，在 RHT 产品中检测到的 S1 类化合物被确定为主要的难熔硫化合物。此外，在 RHT 期间存在 S1 类物种的芳香结构增加。关键的耐火 PASH 是 DBE = 9-12 的那些，这也决定了 RHT 过程中的 HDS 深度。从 CID 实验来看，如烷基(C1-C4)-取代的DBT，特别是烷基(C2)-取代的DBT，尤其是烷基(C2)-取代的DBT的断裂丰度增加所表明的，这些关键难熔PASH具有烷基(C2)-取代的DBT结构，例如4， 6-DMDBT。此外，提出了这些关键难熔PASH的分子化学式和分子结构，为工业HDS催化剂的开发和RHT工艺的优化提供了启示。