分散型催化剂下克拉玛依超稠油常压渣油加氢裂化中沥青质变化对生焦的影响

以克拉玛依超稠油常压渣油为原料，在分散型催化剂作用下，采用高压釜考察了不同反应时间下加氢裂化反应体系的生焦率与正庚烷沥青质质量分数之间的关系，同时采用1H NMR、TEM、XRD和SEM等方法研究了反应过程中沥青质的组成结构变化，并将其与生焦状况关联。结果表明，随着反应时间延长，反应体系中沥青质质量分数和缩合度逐渐升高，少量沥青质大分子聚集体开始生成焦炭，生焦率增加缓慢，沥青质表面颗粒尺寸增大，颗粒数量和芳香片层层数增多，芳香片层间距减小；当反应时间增加至20 min时，体系中沥青质质量分数达到极大值，沥青质大量聚集，芳香片层数和间距也达到极值；当反应时间超过20 min之后，大量高缩合度的沥青质大分子聚集体迅速转化成焦炭，生焦率显著增加，焦粒的尺寸也明显增大，而反应体系中剩余的沥青质质量分数和缩合度逐渐下降，颗粒尺寸减小，颗粒数量和芳香片层层数减少，芳香片层间距增大。

Effect of Asphaltene Changes on Coke Formation During Karamay Extra Heavy Atmospheric Residual Hydrocracking Over Dispersed Catalyst

In order to study the relationship between yield of coke and quality content of C7 asphaltene in the reaction system, Karamay extra heavy atmospheric residual hydrocracking was carried out in an autoclave over dispersed catalyst at various reaction time. At the same time, the change of composition and structure of C7 asphaltene were investigated by 1H NMR, TEM, XRD and SEM, and the relevance between coke formation and C7 asphaltene properties was discussed. The results showed that the mass fraction and condensation degree of asphaltene tended to increase with the extending of reaction time, while a few of large asphaltene polymers started to convert into coke and the yield of coke increased slowly. Size and amount of particles on the surface of C7 asphaltene increased, the number of aromatic layers became more and slice spacing became short before reaction 20 min. The mass fraction of C7 asphaltene reached maximum at reaction 20 min, large amounts of C7 asphaltene gathered together, the number of aromatic layers and slice spacing reached extremum. Plenty of large asphaltene polymers converted to coke fast after reaction 20 min, the yield and size of coke increased obviously, while the mass fraction and condensation degree of remaining C7 asphaltene declined. Size and amount of particles on the surface of C7 asphaltenedecreased, the number of aromatic layers became less and slice spacing became long. 