Evaluation of asphaltene degradation using C ₃ N ₄ /TiO ₂ composite via the onset of precipitation variations

This study explores an alternative for degrading asphaltene through photocatalytic degradation using a composite of carbon nitride (C3N4) and titanium dioxide (TiO2) under visible light. While previous research has examined the photocatalytic degradation of various pollutants, investigations specifically targeting asphaltene degradation under visible light conditions are limited. The research focuses on the photocatalytic degradation of nC7-asphaltene, utilizing the onset point of precipitation as a key indicator. The findings indicate that the onset point of precipitation effectively reflects the residual asphaltene that remains capable of precipitating. Notably, all synthesized C3N4/TiO2 nanocomposites exhibited higher precipitation onset points than pure C3N4 and TiO2. Among the samples tested, the composite synthesized with a melamine to TiO2 mass ratio of 1:4 demonstrated the highest onset point of precipitation. This superior performance is attributed to its large surface area and efficient charge carrier separation within a mesoporous structure. The study further reveals that by employing 75 ± 0.5 mg of the photocatalyst under visible light for three hours, asphaltene degradation was achieved, resulting in reduced aromaticity and mineralization of the asphaltene. The results underscore the potential of using C3N4/TiO2 composites for effective photocatalytic degradation of asphaltenes in oil production and refining processes.