The Impact of Elevated SHP Energy Levels on Ethylene Plant SEC and Critical Duty Steam Turbines

 The steam pressure in both petrochemical plants and power generation facilities has increased though the years. Recent ethylene plant projects have been designed and build with the highest steam pressure, or super high pressure (SHP), at 1700 psig/120 bar with a superheat temperature of 960°F/515°C. The power industry has long since moved past ethylene plant SHP levels to super-critical steam systems that operate in excess of 4400 psig/300 bar. The power industry has successfully proven higher energy steam conditions increase the overall efficiency of the power cycle.

This paper addresses the application of elevated steam pressure and temperature levels to ethylene plants in the range of 2200 psig/150 bar. Improvements in overall plant specific energy are presented. The technical impact on operations and critical duty equipment, specifically the mechanical drive steam turbines and the ethylene process driven steam generation system, is discussed versus capital cost increases required to meet the elevated super high pressure steam level.