(409d) Application of Plant-Wide Dynamic Simulation for Safety Operation of An Ethylene Oxide Plant

The manufacturing of Ethylene oxide (EO) involves critical exothermic reactions at high temperature and high pressure.  EO is flammable and toxic gas In addition, the mixture feed of ethylene and oxygen has potential explosive dangers. It was reported a lot of fires and explosions occurred on EO Plants during the past decades, and most of those accidents were caused by the reactor entering explosive range, which were caused by equipment malfunctions, process failures, air/electricity/signal failure, etc. The EO manufacturing process is highly integrated process, where un-reacted reactants are recycled and reused in the reactors and lean water is recycled from downstream units to EO scrubber to knock down EO.  Thus, the downstream process failures/upsets will propagate to the upstream reactions and affect the EO reactions.  Therefore, EO plant operation needs sufficient dynamic investigation for its safety operation.

This work develops a plant-wide dynamic simulation model for EO manufacturing to study the safety impacts on the entire plant operations under various failure/upset scenarios. The model includes two reaction subsystems and one recovery subsystem. It gives a comprehensive understanding of how the failures would affect the overall process. Decision-making information is provided so as to prevent dangerous accidents from occurrence.  This information includes, but not limited to, the time duration between a failure/upset occurrence and resultant accident.  The significance and benefits of this study are demonstrated through multiple case studies.