Formation of phase composition of petroleum bitumen according to data of temperature modulated differential scanning calorimetry

Abstract

© 2017, Akadémiai Kiadó, Budapest, Hungary. The analysis of structural and thermal properties of petroleum bitumen is carried out by temperature modulated differential scanning calorimetry. The technique allows to separate equilibrium and non-equilibrium thermal events and makes it possible to identify and observe structure transition invisible or overlapping on curves of conventional differential scanning calorimetry. It is shown that bitumen is a dispersion system only in specific time–temperature conditions. The dispersed phase can be represented by two types of aggregates. Saturates form aggregative solid, structural crystalline phase in accordance with thermodynamic law of structural phase transitions and nucleation thermodynamic mechanism of phase separation. The asphaltenes form for a relatively long time, an aggregative solid structurally amorphous phase as a result of thermokinetic structural relaxation glass transition by spinodal thermodynamic phase separation mechanism.