(128e) High Temperature Hydrogen Attack in Ethylene Producing Plants

The purpose of this paper is to highlight and discuss the High Temperature Hydrogen Attack (HTHA) damage mechanism in ethylene industry equipment. The paper will specifically review the equipment susceptible to HTHA in production of “on specification” ethylene product that uses high purity hydrogen to prevent catalyst poisoning in C2, C3 and cyclohexane hydrogenation reactors. This paper will concentrate on API RP 971 “Steels for Hydrogen Service at Elevated Temperatures and Pressures in Petroleum Refineries and Petrochemical Plants” recommended practices and methods to reduce the HTHA risk. The methodology also will include a description of the Layers of Protection Analysis (LOPA) to be completed on any HTHA at-risk items identified.