Home – Home – Jornals – Chemistry for Sustainable Development 2023 number 4

The influence of low molecular weight nitrogenous bases (by the example of quinoline) on the composition and colloidal stability of asphaltenes in solutions and oil dispersed systems is investigated. The objects of study were model oil systems with the basic nitrogen content of 1.0-3.0 wt. %, obtained by mixing the original oil and quinoline. The content of basic nitrogen (N_bas) was determined using the method of non-aqueous potentiometric titration. Analysis of the colloidal stability of asphaltenes in solutions and oil systems was carried out by spectrophotometry. It is shown that the content of asphaltenes in oil systems is reduced by 0.22 wt. % with an increase in the content of basic nitrogen (quinoline) up to 3 wt. %. At the same time, the content of resins increases by almost 8 wt. %. With an increase in the content of quinoline in oil systems, the proportion of basic nitrogen in the asphaltenes isolated from them increases from 1.71 to 3.60 wt. %, which indicates the active participation of quinoline in the formation of supramolecular structures of asphaltenes during their precipitation with n-hexane. The presence of low molecular weight nitrogenous bases (quinoline) in oil contributes to a significant increase in the growth rate of aggregates and a decrease in the colloidal stability of oil systems.