The pre-cutting tower(or C3 splitter) is a vital distillation column in an ethylene plant, designed to separate lighter hydrocarbons (C2 and below) from heavier components (C3 and above) in the cracked gas stream. Positioned after the quench tower and compression system, it ensures proper feedstock distribution for downstream processing. The overhead stream, rich in ethylene, ethane, methane, and hydrogen, is sent to the demethanizer for further separation, while the bottoms stream, containing propylene, propane, and heavier hydrocarbons, is routed to the depropanizer or debutanizer.

Operating at moderate pressures (typically 10–20 bar) with precise temperature control, the tower optimizes separation efficiency while minimizing energy consumption. Challenges such as fouling from heavier hydrocarbons and the need for tight process control require careful monitoring. Effective heat integration with other units enhances overall plant efficiency. The pre-cuttingColumnplays a crucial role in ensuring product purity and smooth operation across the ethylene production process.