Simulation and optimization of a condensate stabilisation process

• An industrial scale of condensate stabilisation unit was simulated using Aspen Hysys® and PRO/II.
• The simulation was validated by the plant data.
• Effects of feed flow rate, temperature and pressure and the reboiler on the product were reported.
• Product specifications are RVP and sulphur content.

A simulation was conducted using Aspen HYSYS® software for an industrial scale condensate stabilisation unit and the results of the product composition from the simulation were compared with the plant data. The results were also compared to the results obtained using PRO/II software. It was found that the simulation is closely matched with the plant data and in particular for medium range hydrocarbons. The effects of four process conditions, i.e. feed flow rate, temperature, pressure and reboiler temperature on the product Reid Vapour Pressure (RVP) and sulphur content were also studied. The operating conditions which gave rise to the production of off-specification condensate were found. It was found that at a column pressure of 8.5 barg and reboiler temperature of 180 °C, the condensate is successfully stabilized to a RVP of 60.6 kPa (8.78 psia). It is also found that as compared to the other parameters the reboiler temperature is the most influential parameter control the product properties. Among the all sulphur contents in the feed, nP-Mercaptan played a dominant role for the finishing product in terms of sulphur contents.