沥青质分散剂对沥青质的稳定及缔合的影响

Effect of asphaltene dispersants on asphaltene concentration and asphaltene aggregation

采用紫外-可见光谱法研究了沥青质分散剂对甲苯-正庚烷-沥青质体系中沥青质的稳定作用,通过黏度法考察了沥青质分散剂对沥青质溶液中胶束缔合度的影响。结果表明,十二醇(DAL)、十二烷基苯磺酸(DBSA)、十二烷基苯酚(DP)对沥青质都有一定的稳定作用。三种沥青质分散剂的稳定作用顺序为DBSA>DP>DAL。DAL、DP及DBSA浓度较低时(1%)对沥青质甲苯溶液黏度的影响规律相似,推迟了黏度迅速增加的拐点,即可以抑制沥青质胶束的缔合。DBSA浓度较大时,沥青质胶束没有明显的聚并,同时使得沥青质溶液的相对黏度增加明显。三种沥青质分散剂都能显著降低胶束的聚集数;三种沥青质分散剂抑制沥青质胶团聚并强弱顺序为:DBSA>DP>DAL。这与其头部官能团的酸性顺序一致。

The ability to stabilize asphaltene of DBSA, DP and DAL as the asphaltene dispersants in toluene/ beptane solution was investigated by UV-Vis spectrum. A study of the dispersion and aggregation of asphaltene with different asphaltene dispersants was performed with a capillary tube viscosimeter. The aggregation number of the asphattene was determmed. The results showed that the dispersants could stabilize asphaltene in toluene solution, increased the asphaltene amount in solution. The effectiveness of these dispersants followed the order： DBSA 〉 DP 〉 DAL. It was found that the three asphaltene dispersants had the similar effect on the asphaltene aggregation. DBSA had the best effect on the asphaltene aggregation and the relative viscosity was increased with the addition. The aggregation number of asphaltene in toluene was decreased by addition of DBSA, DP and DAL. The retardation of asphaltene aggregation was found to be in the order： DBSA 〉 DP 〉 DAL. This order was matched by the acidity of these dispersants.