large Machine Electric Drives – How Experience in LNG Can be Applied to Ethylene Plants

The decarbonization of ethylene plants via electrification is gaining prominence both for existing facilities as well as for future expansions and grassroots projects. The cracking heaters are the major source of emissions in an ethylene plant and emission reductions can be achieved through the use of air preheat and ultimately through the electrification of Stream Cracking Heaters. The cracking heaters generate the Super High Pressure Steam that is used to drive the ethylene plant compressors. As a result of lower firing there will be less steam available necessitating switching the compressor drivers from steam turbines to electric drivers. While electric drivers have been applied for the smaller machines, such as the ethylene refrigeration compressor and, at times, for the other compressors, such as the charge gas, propylene, binary refrigeration or similar compressors, they have not been utilized to the size and scale associated with world scale crackers.

McDermott has unparalleled experience utilizing large variable speed electric drivers in LNG facilities of up to 75 MW. We will discuss the experience associated with the design, start-up and operations of such electrically driven compressors and then relate this to the implication of implementing similar electric drive systems in an ethylene plant.