2008 Spring Meeting & 4th Global Congress on Process Safety
(28e) Updating Heavy Oil and Upgrading Vacuum Simulation and Design Considerations
Author
Presentation focusses on and shares updates to design considerations on operating feedback from numerous Upgrading and heavy oil vacuum units.
First, a more appropriate cracking correlation is presented that is based on actual heavy oil and Upgrader operating feedback. The correlation is derived from the readily available plant variables (Heater outlet temperature, crude rate to the column, overhead gas flow downstream of hot well, and API of feed to vacuum column). The quantity of cracked gas differs significantly and drastically impacts the sizing and operation of the ejector system.
Secondly, an update to the simulation topology proposed by Golden et al and successfully used in many designs is illustrated. The stripping section is modelled as a multi-stage absorber versus a flash, so the impact of pressure drop and internal selection on yield can be better appreciated.
Thirdly, the difference in flash zone feed device performance is illustrated to support a claim that the choice of flash zone feed device impacts short-term yield and long term crude processing objectives.