Abstract: During the startup of ethylene plant, emissions mainly come from front-end cold box system and deethanization system. This paper introduces the basic process flow of the front-end cold box system and the deethanization system and the possible emission points during operation, analyzes the reasons for the unreasonable emission in combination with the actual situation on site and the startup experiences of other ethylene plants, and proposes some rectification measures to achieve the successful low-emission startup of ethylene plant on the first try. Through analysis of the basic process flow of cold area, some processes are optimized and modified. Startup lines are added without changing the existing process flow, so as to achieve the goals of emission reduction, energy saving and consumption reduction, reduce the total emissions of the system during startup, and reduce the material loss and energy consumption of the ethylene plant.

Key words: ethylene plant, technical modification, startup line；emission reduction