The program HYSYS, version 7 is used for the process modelling work as the preference unless the client has some other preference.

Peng-Robinson Equation of State is selected for the model.  This property package is generally recommended for oil, gas, refinery and petrochemical applications.  Enhancements to this equation of state enable its accuracy for a variety of systems over a wide range of conditions.  It rigorously solves most single-phase, two-phase and three-phase systems with a high-degree of efficiency and reliability.  Reasonable results at all temperatures and pressures can be expected.

In the HYSYS simulations, numbers are allocated to the major streams to identify process conditions at specific points throughout the process.  These stream numbers are in accordance with the stream numbers on the HYSYS generated Process Flow Diagram (PFD).

Based on the agreed process data provided by the client, different cases are typically developed to determine the required duty and process conditions on the outlet of the process or alternatively the input conditions required depending on the process requirements.

The results of the model output from all the different cases is normally analysed in a table to determine the sizes of all the major equipment items and also the process conditions, ie pressure, temperature, flow-rate etc.