Improved Refinery Margins through Feedstock Management

摘要

Abstract: Refinery profitability is linked with its ability to process bad crudes and its complexity factor. Another key factor that can boost process margin is the feedstock management (FSM), a study of low value process streams and blending them in the feeds of other units to enhance refinery economics. Propylene yielding deep catalytic cracking (DCC) units tend to fire a part of unit feed to regenerator as torch oil which badly affects the catalyst activity and unit conversion apart from being a wastage of unit feed. Blending CCR rich streams like vacuum slop or Coker gas oil can solve the heat balance issues, improve unit material balance and enhance the unit conversion by 1-2 %. Another aspect of FSM is in maintaining tighter distillation cuts to avoid feeding lower cuts to units like DCC which can instead be processed well in units like DHT. Other prime example can be of Coker unit blow down tower overhead stream, which is often rejected to slops due to its lighter distillation range (60-370 0C), higher sulfur and water content. Laboratory analysis proves its suitability for diesel hydtrotreater (DHT) feed to augment the refinery ultra low sulfur naphtha and diesel production. This has a potential to reduce refinery slop generation by 50-75 % and decreasing the slop load on crude distillation unit (CDU). This paper studies the potential usage of some low value refinery streams for enhancing margins. Keywords: Refinery profitability, vacuum slop, torch oil, slop.