Abstract: The reduction of diesel fuel as ethylene feedstock by enterprises have led to the trend of heavier feedstock for ethylene plants, posing severe challenges to the operation of the quenching system. Taking an 800 kt/a ethylene plant as an example, this paper investigates the impact of heavy feedstock on product distribution, heat balance of the quenching system and equipment operation. The results indicate that as the feedstock becomes heavier, the ethylene yield decreases; the total heat content of the cracked gas at the outlet of the Transfer Line Exchanger (TLE) increases; and the heat extraction from quench oil, section oil and quench water system increases significantly. The flow rates of heavy byproducts and internal recirculation streams within the quench system also show substantial increases. The adaptability verification of associated equipment needs to be performed.

Key words: cracking feedstock, heaviness, quench system, operational adaptability