Using process simulators for steady-state and dynamic plant analysis - An industrial case study

Process simulation tools are widely adopted for the design and optimization of chemical processes. However, for quite a long time their use has been confined within research centres and highly specialized technical groups. This is especially true for dynamic simulation software, long regarded as a very specific tool requiring considerable expertise. In this work we intend to demonstrate the benefits that process engineers working on the plant may receive from an appropriate use of commercial software currently available for steady-state and dynamic simulation. A case-study concerning the purification section of an industrial plant for vinyl chloride monomer production will be considered. First of all, a steady-state simulation will be considered. Primarily, the simulation will allow a better judgement of the plant operating conditions; then it will be illustrated that sensitivity studies may produce great benefits in the general economy and productivity of the plant. Secondly, it will be shown how a dynamic model suitable for practical needs can be derived from the steady-state model. This model can be used as a powerful tool to assess the performance of the control system in handling standard operational disturbances as well as abnormal events. Simple improvements of the control system design will be also simulated and commented on.