Visbreaking is a well-established thermal cracking process which is used in petroleum refineries for producing valuable products like Gas, Naphtha and Diesel from Vacuum tower bottoms. Maximization of yield of such valuable products from Visbreaking unit is limited by stability of its bottom product i. e Visbroken Tar which is generally measured by P-value (ASTM 7112). Typical conversion (weight % of Gas + Naphtha + Diesel) in visbreaker unit ranges between 15-20wt% and rest of the unconverted product goes to Fuel oil. Due to lower conversion, Visbreaker technology is becoming obsolete and need of hour exists to exploit different pathways for maximizing the profitability from existing Visbreaker unit. One such approach is by utilization of catalyst.
In the current work, different homogeneous catalyst formulations were developed in lab scale and experimental studies were conducted at different concentrations of catalysts with Vacuum residue feed. Based on promising results from the lab studies, one catalyst formulation was scaled-up to commercial level and effect of catalyst was demonstrated in a commercial visbreaking unit of 17000Barrels/day capacity which shows increase in conversion by 4.5wt% and thereby improving economics of visbreaking unit by 2 million USD.
