Sócrates Acevedo

The physical chemistry of the heavyweight fraction of crude oil is still a subject of vivid discussions due to the complications which arise from the tendency of this fraction to aggregate and finally hinder the refining processes. Asphaltene molecules, that compose the largest part of this fraction, can be separated into two subfractions, A1 and A2, through a treatment with p-nitrophenol. In this paper, starting from the molecule models suggested by Acevedo et al. (Acevedo et al.

Super high-molecular-weight (SHMW) asphaltene aggregates, hereafter called asphaltene clusters, have been observed for the first-time using gel permeation chromatography with inductively coupled plasma mass spectrometry (GPC-ICP HR MS). Presumably these clusters are composed by nanoaggregates joined by physical interactions such as polar and dispersion forces.

Effects of pressure on thermo-oxidative decomposition of different sources of n-C7 asphaltenes were investigated at high pressure using a thermogravimetric analyzer under an air atmosphere.