~1H-NMR Study of Relaxation Behaviours of Asphaltene Aggregates in Solvents

摘要

It is essential to understand the aggregation behaviours of asphaltene for the efficient upgrading process of heavy oil. In this study, relaxation behaviour of asphaltene aggregates in several solvents has been evaluated in terms of molecular mobility. Changes in the aggregate structure of asphaltene in solvents were investigated with in-situ ~1H-NMR relaxation measurement. Spin-spin relaxation time, T2, and spin-lattice relaxation time, T1, was employed to monitor the change in molecular mobility of asphaltene induced by relaxation of aggregate structure. It has been confirmed that the relaxation behaviours for asphaltene aggregate structure are affected with the nature of solvent. The results have indicated that the differences in relaxation behaviours of asphaltene aggregates based on the nature of solvents can be evaluated with molecular mobility obtained from in-situ ~1H-NMR relaxation measurement.