(32cd) Establishing Safe Operating Limits: A Case Study in Operational Discipline and Process Safety at an Ammonia Synthesis Plant

Safe Operating Limits (SOL) are critical parameters for maintaining the safe operation of chemical processes, providing the "guardrails" for operational safety. While the concept is widely accepted, its practical implementation at a facility often lacks clear industry guidance. This paper will present a case study from an ammonia synthesis plant that trialed a vision for establishing an SOL program designed to enhance operational discipline and process safety.

The program was built on combining the principles of Conduct of Operations with a systematic approach to identify what parameters should be considered safe operating limits. Consistent determination and documentation of safe operating limits enables operators to maintain the highest level of operational discipline when making knowledge-based decisions. Automated communication processes allow operators to focus on bringing the plant to a safe state while other work groups are notified of any safe operating limit exceedance.

This paper proposes a three-step approach for the identification of safe operating limits, coupled with robust conduct of operations guidelines to ensure a successful SOL program. A case study highlighting the impact of utilizing the approach on an existing operating facility is provided along with an analysis of potential issues that exist if safe operating limits are not set in a consistent manner.