Indian Journal of Chemical Technology, Vol.26, No.5, 424-430, 2019
Preparation of petroleum pitch and its application in making bitumen with improved rheological behaviour
Petroleum pitches of different types and grades have been prepared from aromatic-rich residues produced in various petroleum refining and petrochemical processes. Generally, petroleum pitches having high softening point (> 100 degrees C) have widespread applications for making industrial and advanced carbon materials such as carbon fibers, carbon anodes, graphite electrodes, carbon foam, Li-ion batteries etc. On the other hand, petroleum pitches having low softening point (< 50 degrees C) have limited applications due to their low carbon yield and low viscosity. In this paper, the new use of low softening point pitches (LSPP) ranging from 45-78 degrees C as a modifier to make bitumen with improved rheological properties have been explored. Three low softening point petroleum pitches are prepared by giving thermal treatment to aromatic rich petroleum feed stocks at 390 degrees C for varied time period under inert atmosphere and characterized as per ASTM test procedures. One of the petroleum pitches namely CSO-390-3 is used for making modified bitumen. The rheological studies show that addition of low softening point pitch (LSPP) to base bitumen improves its viscoelastic behavior. The study reveal that the petroleum pitches having a softening point (45.5 degrees C) found to be effective to improve phase angle as well as oscillation stress and shear modulus (G*/Sin delta) of base bitumen.