EFFECT OF CHEMICAL ALTERATION ON THE AGGREGATION OF ASPHALTENES IN d-TOLUENE USING SANS

Simon Ivar Andersen*, Martin Vigild

Dept.Chem.Eng. bldg. 229

Technical University of Denmark

DK-2800 Kgs.Lyngby

Denmark

*corresponding author sia@kt.dtu.dk

The association of asphaltenes is believed to be an important step towards the flocculation and instability of crude oils.  In order to understand the mechanisms and balances between different possible forces involved the chemical blocking of hydrogen bonding sites such as HS, NS, COOH and OH has been performed through methylation. As reported previously amongst several chemical alterations on four different asphaltenes only methylation gave a clear trend in lowering the interaction and enhancing stability. In this work we continue this study of silylation, methylation and freidel-craft alkylation on the stability. Solubility studies are combined with investigations using SANS to investigate the effects of these changes. The data is combined with VPO and SEC measurements and previously reported data using isothermal titration calorimetry presented by Merino-Garcia, 2004 (PhD thesis) is included in the discussion.