ENV-03-107 Refinery Acid Gas Incident Investigations and Remedies (A Success Story)

Description:

Navajo Refining Company, L.P., brought a new Claus sulfur recovery unit (SRU) online in February 2001. Numerous acid gas flaring incidents ensued during the subsequent shakedown of the SRU due to design shortcomings, instrumentation problems, power outages, and upstream factors contributing to operational upsets and shutdowns of the SRU. Navajo began an informal process to address the shakedown problems and prevent further acid gas flaring. The process involved dedicating key Navajo personnel to a problem-solving task team and enlisting SRU experts outside of Navajo to assist in identifying the factors causing the SRU outages and to aid in developing remedies. This investigative process was subsequently enhanced by the implementation of formal root cause analyses to identify and remedy acid gas flaring causal factors. This paper discusses causal and contributing factors identified or suspected in the acid gas flaring incidents and also describes the measures taken which ultimately effected a significant reduction in the frequency and duration of such acid gas flaring incidents.