Abstract: The depropanizer system is one of the important process units in ethylene plants, usually composed of dual towers of high-pressure and low-pressure. The operation of the system directly affects the product specifications and the long-term safe and stable operation of the unit. This article analyzes the problems encountered during the long-term operation of the depropanizer system in domestic ethylene plants, and proposes measures to reduce the bottom temperature of high-pressure and low-pressure depropanizing towers through process optimization. At the same time, some suggestions are also provided for the long-term operation of the system. This has certain guiding significance for the process design and actual operation of the depropanizer system in the separation unit of the ethylene plant.

Key words: ethylene plant, depropanizer system, bottom temperature of tower, process optimization, process design