(263f) Primary Reformer Revamp and Modernization of Vintage Ammonia Plant

Engro Ammonia plant Primary Reformer was commissioned in 1967 at Pascagoula, USA and was relocated to Pakistan in 1992. Over its operational life of more than 50 years, it has undergone various revamps for capacity enhancements. This primary reformer uses Turbine Exhaust Gases (TEG) as primary oxidant coming from gas turbine. During the last few years, plant load was curtailed due to unstable combustion in firebox mainly due to maldistribution of TEG/fuel resulting in structural oscillations. Detail Engineering was done including Computational Fluid Dynamics (CFD) to identify the bottlenecks.

Several modifications were proposed and implemented in 4Q-2022 turnaround including:

• Telescopic design of TEG duct with improved metallurgy
• Individual burner fuel header size upgradation
• Catalyst tubes replacement with upgraded metallurgy (micro alloy)
• Staged fuel burners installation
• Convection coils adequacy evaluation and replacement
• Forced draft (FD) fan installation along with air preheater
• Addition of trip logics as per HAZOP study

After major revamp of Primary Reformer; plant is operating well with best energy efficiency and reliability as envisaged at design stage. This paper entails impact of modifications on plant reliability and efficiency improvement.