Autorefrigeration Near-Miss Incident at Equistar Chemicals, a Lyondell Company

摘要

During the startup of the Equistar Chemicals Chocolate Bayou Olefins Plant following an eight day outage, an autorefrigeration near-miss incident occurred involving the unit deethanizer column. Autorefrigeration, i.e., the unintentional and uncontrolled phase change from a liquid to a vapor of a hydrocarbon that results in refrigeration, occurred when the deethanizer column was being reinventoried. The column's brittle fracture minimum allowable temperature was nearly reached. This autorefrigeration caused a failure of deethanizer reboilers resulting in extended downtime. Causes and corrective actions for this incident are presented.