Enhancement of mesophase formation in paraffinic-rich clarified oil using transition metal catalysts (Cr and Cu)

Abstract

In the present work, we have made attempts to prepare petroleum pitches from paraffinic-rich clarified oil (CLO) by giving thermal treatment at 370?°C in the presence of Cu and Cr catalysts. The feed CLO is predominantly paraffinic in nature, so it takes fairly large thermal soaking time (21?h) to convert into pitch having mesophase content below countable limits. To increase the mesophase content in the pitch or to make mesophase pitch, 3 wt?% transition metal catalysts (Cu and Cr) were added to CLO. Addition of transition metal catalysts not only enhances mesophase formation but also helps to reduce thermal treatment time by promoting polymerization and condensation reactions at a faster rate. The mesophase formation pattern reveals that Cu and Cr catalysts increase the mesophase content from below countable limit to 12 and 9 vol?%, respectively. This indicates that Cu and Cr showed better catalytic activity for mesophase formation growth. The effect of transition metal catalysts on physico-chemical properties (softening point, coking value, toluene insolubles and quinoline insolubles) as well as the optical texture and physical properties of mesophase pitches were investigated by optical microscope, FT-IR, SEM, NMR, TG/DTG and XRD.