Project SynopsisPerform a preliminary engineering study for debottlenecking a petroleum refinery crude distillation unit and provide the process design for the improved unit configuration. Simulation Diagram
CRUDE DISTILLATION UNIT CAPACITY EXPANSION SCREENING PROCESS DESIGN
The client operates an independent petroleum refinery in the Western U.S. Process Engineering Associates, LLC (PROCESS) was contracted to execute a preliminary study of the crude distillation unit for potential revamp opportunities and then provide the process design for the identified revamp items. The crude distillation system consists of an 11-exchanger pre-heat train, desalter, pre-fractionation tower, two fired heaters, atmospheric crude distillation tower, and vacuum distillation tower. Project tasks included:
- Process simulation of the overall crude distillation unit: current configuration and proposed modifications
- Rigorous simulation of the crude preheat train exchangers
- Modeling of hydraulics and heat transfer for the trays and packing
- Hydraulic calculations for piping circuits, control valves, and pumping requirements
PROCESS‘ licensed commercial process simulation software packages were used for overall unit and heat exchanger modeling, respectively.
As a result of this project, the preheat train was modified to achieve a significant reduction in pressure drop while achieving much greater heat recovery with minimum exchanger modifications. The desalter operating temperature was increased to handle heavier crude slates. Piping and control valve size modifications greatly improved unit hydraulics. The existing atmospheric and vacuum distillation columns were evaluated and determined to have sufficient capacities for the increased rates. Furnace firing increases were minimal or neutral because of the improved modified unit heat recovery and improved pump-around capacity.
The documentation for the project submitted to the client included: modified process flow diagrams (PFDs) and piping and instrumentation diagrams (P&IDs); computer process simulation outputs; piping schedules; modified heat exchanger design specifications; modified control valve specifications; and utilities’ consumption calculations.
The resulting unit modifications resulted in a 20% capacity increase of the crude distillation unit with minimal operating cost increase.
- Petroleum Refining
- Process optimization
- Process debottlenecking