Appraisal – Evaluation of Alternatives
Series of process alternatives are developed at the appraisal phase, and further assessment is done to evaluate risk, value and uncertainty. Examples may include alternatives such as continuous process versus batch processing, use of different types of separation procedures ( distillation versus extraction, pressure filtration versus a centrifuge), etc. The most promising concepts proceed to the selection stage.
Selection – (Preliminary Process Design)
The objective of this phase of the project is to identify a single process concept that will progress to the detailed process design phase of the project. Once a process idea has been chosen, the team will complete the level of detail necessary to create a cost estimate and preliminary project schedule with a typical accuracy of –30% to +50%.
Deliverables at this stage often include the following:
- Preliminary Process Design Basis
- Process Alternatives Evaluations Summary
- Preliminary Process Simulation and Heat and Material Balance Data
- Preliminary Process Flow Diagrams (PFDs)
- Preliminary Equipment List
- Preliminary Major Equipment Conditions of Service List
- Preliminary Capital and Operating Cost Estimate (+50% /-30%)
- Preliminary Summary of Raw Materials and Utility Requirements
- Process Risk Summary.
DETAILED PROCESS DESIGNS
Detailed Process Design Schedule A, FEL-2 / FEL-3 / FEED, or Basic Engineering Package
As soon as the process configuration has been clearly defined a detailed process design package can be prepared. This is very critical to the long-term success of the project.