Abstract: In an ethylene plant where naphtha is used as the feedstock, naphtha is gradually replaced with ethane while maintaining the ethylene production unchanged. The analysis on the overall material balance of feedstock, products and by-products shows that only the yields of a few components such as hydrogen and recycle ethane increase while the other components, feedstock and cracked gas decrease. The modification direction of ethane preheating exchanger and cracking furnace is pointed out, and the bottleneck of ethylene recovery is predicted. Through statistical comparison of process simulation results, the trends of fuel, steam, cooling water, power and energy consumption are summarized.

Key words: ethane, replacement of naphtha, ethylene plant, lighter cracking feedstock