FRACTIONATION OF MODIFIED ASPHALTENES USING N-METHYL-PYRROLIDONE

Birgit Elkjaer Ascanius and Simon Ivar Andersen*

Center for Phase Equilibria and Separation Processes

Dept.Chem.Eng. bldg. 229

Technical University of Denmark

DK-2800 Kgs.Lyngby

Denmark

Previously we have reported the fractionation of asphaltenes by NMP leading to the separation of an insoluble fraction of very low if any fluorescence in toluene solution. This was performed on 6 different oils of which one had more than 50 % w/w of this fraction. In the present study data is presented regarding the long term extraction of modified asphaltenes: methylation, silylation, reductive alkylation, reductive hydrogenation and Fridedel-Craft octylation in order to investigate the influence of the alteration on the solubility in this. NMP is in coal science seen as one of the very powerful solvents that i.e. gives excellent elution during size exclusion chromatography. The soluble fraction obtained from our different asphaltenes will be characterized by SEC using NMP as the solvent.