催化水热裂解对重油沥青质ζ电势的影响

Influence of catalytic aquathermolysis on ζ potential of heavy oil asphaltenes

关键词:  催化裂解  重油  沥青质  环烷酸铁  胶体粒径  ζ电势

Key words:  catalytic cracking  heavy oil  asphaltenes  iron naphthenate  diameter of colloidal granule  ζ potential

摘要:

从辽河重油中分离出沥青质,以环烷酸铁作催化剂,考察沥青质在不同反应温度下的催化水热裂解反应;用元素分析、VPO平均相对分子质量、¹H和¹³C—NMR等手段评价沥青质反应前后的性质变化,用纳米粒度及ζ电势分析仪考察沥青质的胶体粒径和ζ电势的变化。结果表明:催化水热裂解反应后,沥青质的氢、碳摩尔比(nH/nC)减小,相对分子质量增大,沥青质的芳香度增大,极性增强,沥青质的ζ电势为负值,随着反应深度的增加,沥青质的ζ电势绝对值增大;经轻微催化水热裂解反应后,沥青质的胶体粒径减小,随着反应温度的升高,胶体粒径增大。

Abstract:

Asphaltenes were separated from Liaohe heavy oil. Catalytic aquathermolysis of asphaltenes was investigated using iron naphthenate as catalysts at different temperature. Before and after aquathermolysis, the properties of the asphaltenes were compared by means of elemental analysis, VPO averaged relative molecular mass, ¹H and ¹³C—NMR. Changes of diameter of colloidal granule and ζ potential of the asphaltenes were measured by the apparatus of nano granule and ζ potential tester. The results show that after the reaction, the mole ratio of H and C in asphaltenes decreases, and the relative molecular mass of the asphaltenes increases. From the results of averaged structural parameters, it is found that the aromaticy of the asphaltenes is augmented. ζ potential of the asphaltenes is negative, whose absolute value increases with the reaction degree increasing. The colloidal granule diameter of the asphaltenes decreases after slight aquathermolysis, but it increases with the reaction temperature rising.