(566g) Energy Optimization By Installation of Heat Recovery Steam Generator at Exhaust Gases of Gas Turbine Driven Compressor

This paper encompasses operational experience of Energy Efficiency project at ammonia plant of Engro Fertilizer Pakistan. The plant is a Becthel corporation design built up in 1967. The plant was relocated to Daharki (Pakistan) from Pascagoula (USA) in 1992. The unit capacity is 1550 MeT/Day (Ammonia Production)

There were two parallel combination of gas driven centrifugal compressor (2 x Taurus 60 Compressor Sets) installed for compression of natural gas for ammonia plant. The exhaust gases were vent into atmosphere resulted in wastage of useful energy

A study was conducted to recover this heat energy by installation of heat recover steam generator at exhaust gases of compressors. A state of the art HRSG (M/S DESCON as EPC vendor) was proposed for heat recovery. The new HRSG comprised of de-aerator, BWF pumps, flash vessel, economizer, super heater, and chemical dozing facility. The steam produced by the new HRSG was integrated with the existing steam circuit

The multiple improvisation steps have been taken to develop the operations strategy for integration of new HRSG with existing steam network. Owing to the complexity of steam and gas network, an in depth process hazard analyses and review was conducted for development of commissioning procedures and emergency handling

A flawless execution of the project was accomplished by the team. A total estimated steam produced by installation of new HRSG = 21 TPH (without auxiliary or duct burner) with pressure = 50 kg/cm2. (Based upon 100% load on both compressors) HRSG is designed for turndown ratio 3:1

The intent of this paper is to share the operation experience & to gauge the key learning’s during this energy efficiency project. This energy optimization is a classic example of operating a process unit with higher efficiency and improving the overall energy index. This would be beneficial for the industries across the globe