Simulation einer zweistufigen Sauerwasserstrippung

Abstract:
The aim of this thesis was to set up a simulation for a new sour water stripping process in an oil refinery. Three different simulation tools (Aspen Hysys®, Aspen Plus® and ProMax®) were tested to find out if they had any limitations concerning the calculation of sour water systems. Of the three simulation tools Aspen Hysys® is the only one with real limitations. The empirical sour water model in Aspen Hysys® can only calculate the major sour water components but cannot depict additional acids or bases which is essential for the simulation of a two stage sour water stripper. For a single stage sour water stripper all three simulation tools provide similar results. Only the number of required theoretical stages differs between them. Aspen Hysys® always requires the most and ProMax® always the least number of theoretical stages. An existing single stage sour water stripper was calculated with all three simulation tools. All three programs reproduced the existing stripper with a high accuracy. The results from these simulations were used to calculate the stage efficiency for the different simulation tools. In a sensitivity analysis the main parameters with influence the simulation were determined. They are the steam to feed ratio, the column pressure and the overhead temperature. With these in formations a single and a two stage sour water stripper simulation was set up and the results were compared. Due to similar stripping performance and because of the higher energy demand and investment costs of a two stage sour water stripper it is recommended to construct a single stage stripper. The developed simulation can be used to further optimize the stripper design.

Keywords:
Sourwater, stripping, Aspen