Furnace Reliability: The Cornerstone of Ethylene Plant Success

Cracking furnaces’ reliability, in simplistic yet effective terms, can be measured by looking at the actual production relative to their overall capability. Many factors, from design/engineering/fabrication/construction through operation and maintenance, contribute towards overall availability and reliability. The furnaces typically determine the total ethylene plant capacity limits and require significant attention, throughout their lifecycle, to achieve best-in-class performance and availability expectations.
Key factors during project development and execution:

• Selection and design of main components – radiant coils, convection coils, transfer-line exchangers, burners, fans, SCR, etc.
• Process controls, monitoring, and safety systems
• Engineering specifications
• Fabrication details, inspection
• Quality of construction

Operation and Maintenance (a lot depends on operation and maintenance strategies along with discipline):

• Working knowledge of fundamentals on the process side (feeds, yields/severity, selectivity, coking/fouling/run-length, decoking, corrosion, erosion, etc.) and fireside (combustion, burners, SCR, emissions, fouling/corrosion/erosion, etc.)
• Design limits, process safety
• Operating variables/interactions, controls, performance monitoring
• Operating modes and procedures
• Predictive and preventive maintenance, frequency (relationship of operating parameters, failure modes, etc.)
• Equipment monitoring
• Personnel training and competency

Many of these factors are interconnected and require a deep understanding to develop a holistic approach for maintaining high reliability and availability to achieve maximum utilization of cracking furnaces.