Comparing asphaltene adsorption with model heavy molecules over macroporous solid surfaces

The adsorption behavior of Athabasca bitumen C-7 asphaltene (AB-C-7-A) over a macroporous silica-alumina, kaolin, at room temperature is described by comparison with three model molecules such as Xylenol Orange (amine modified, XYO), Violanthrone-78 (VO-78), and Violanthrone-79 (VO-79). The results show that adsorption uptake at equilibrium of these model molecules is independent up to a certain initial concentration limit on the structure, the nature, and the total content of heteroatoms present. The final uptake and the dynamics of the adsorption seem to be more determined by the nature and specific content of heteroatoms, which allow them to interact stronger and faster with the macroporous solid surface.