Re-peptization

As indicated earlier, there is a delicate balance between the concentration of resins and asphaltenes in petroleum fractions. Any interruption in the ratio of asphaltenes resins can cause operational problems because of asphaltene precipitation (coke formation) and plant shutdown. It is therefore crucial, if coke formation is to be minimized, to monitor the ratio of asphaltenes resins during the thermal processing of bitumens and heavy oils. Clarke and Pruden developed a heat transfer analysis technique that can detect the onset of asphaltene precipitation. They showed that precipitated asphaltenes could be re-peptized using polynuclear aromatic compounds such as phenanthrene. It has been demonstrated in the 5000 bbl/d CANMET hydrocracking unit... [Pg.162]