煤焦油沥青质含量对加氢沥青质化学结构的影响

Influence of Asphaltene Content in Coal Tar on Chemical Structures of Hydrotreated Asphaltenes

以陕北中低温煤焦油的脱沥青油与粗沥青质掺兑的不同沥青质含量的煤焦油为原料,通过高压反应釜进行加氢实验,研究原料中沥青质的含量对加氢后沥青质的组成与结构的影响。实验结果表明,随原料中沥青质含量的增加,加氢后沥青质的相对分子质量及硫、氮和氧等杂原子的含量均增加;H/C原子比和芳环缩合度参数减小,芳香度增大,表明随原料中沥青质含量的增加,沥青质的缩合度增大,生焦趋势增强。当沥青质含量达17%(w)时,加氢后沥青质的总环数和芳环数均大于中低温煤焦油原料中的沥青质,说明沥青质的含量过高时沥青质倾向于脱氢缩合生成大分子。

The influence of asphaltene content in coal tar feedstock which consisted of deasphalted oil in medium and low temperature coal tar mixed with crude asphaltene on the compositions and structures of hydrotreated asphaltenes was studied in an autoclave. The results showed that, with increasing the asphaltene content in the feedstock, the average relative molecular mass and the contents of sulfur, nitrogen and oxygen in the hydrotreated asphaltenes increased, the H/C atomic ratio and condensation degree parameter of the aromatic ring system decreased, but the aromaticity factor of the hydrotreated asphaltene increased, which indicated that the condensation degree of the hydrotreated asphaltene increased and its coking reactivity was enhanced. When the asphaltene content reached 17%（w）, both the total ring number and the aromatic ring number in the hydrotreated asphaltene were more than those in the coal tar feedstock, which showed that the condensation reactions were dominating when the asphaltene content in the feedstock was excessively high.