Assessment of a Sour Water Treatment Unit Using Process Simulation, Parametric Sensitivity, and Exergy Analysis

In this work, a sour water treatment unit was evaluated combining exergetic analysis and parametric sensitivity analysis. Process simulation was performed using Aspen HYSYS 10.1 following real refinery configurations, and the results were validated with existing data. The parametric sensitivity was evaluated by varying the effect of process variables to identify an alternative case with the best technical performance. The exergy analysis was applied to both base and alternative cases. The outcomes were exergy efficiency by stages, global exergy efficiency, total irreversibilities, and exergy by industrial services. A comparison of both cases was performed to identify opportunities for improvement in real sour water treatment. Results revealed that the overall exergy efficiency for the base case was 44.28%. After improving the technical performance, the overall exergy efficiency decreased to 36.12%; the latter indicated higher irreversibilities due to the increase in the use of industrial services. This finding suggested that those process improvements may affect the performance of this refinery unit from an exergetic point of view.