Application of a Methodological Framework for the Development of a Hazop Study of a CSTR Reactor for the Production of Propylene Glycol from Propylene Oxide Using Process Simulation in Aspen Hysys

HAZOP analysis is a systematic and structured method used to identify operational problems and potential hazards within a process. The methodology implemented, proposed in previous research (Danko et al., 2019), is based on the incorporation of process simulation to carry out a HAZOP study, through the construction of the process operating window and the establishment of deviations in the relevant process parameters. This methodology also includes a process layer analysis (LOPA), with special emphasis on the process design layers and the basic process control system. This research uses a CSTR reactor used in the production of propylene glycol through the hydrolysis reaction of propylene oxide as a case study, and was carried out using the commercial simulator Aspen HYSYS. For the initial operating conditions, a temperature of 91.63°C, a water conversion of 95%, an outlet product flow of 10.29 mol/s, and a propylene glycol composition in the product of approximately 56% were obtained in both cases. Using dynamic simulation, the deviations corresponding to the scenarios proposed were simulated, then the consequences observed were carefully analyzed, and preventive measures (known as safeguards) were proposed for each scenario. Finally, the study report was prepared based on the information obtained in the previous phase. The results obtained demonstrate that it is possible to effectively implement the methodology within the HYSYS simulator. In the short term, this methodology can be very useful as an initial stage of simulation-based process analysis, prior to the execution of a traditional HAZOP by a multidisciplinary group of experts in this method.