Abstract:

Comparing the composition of light hydrocarbons with that of naphtha as the raw materials to a grassroots 600 kt/a ethylene plant, it was concluded that processing light hydrocarbons has obvious advantages in terms of product yield. Since the CO₂ content of light hydrocarbons in oil fields exceeded the design processing capacity of the plant, a caustic wash tower was installed so that double caustic wash towers were used to achieve the dual purposes of enhancing the anti-CO₂ interference capability and improving the light hydrocarbon processing capacity of the plant. After the implementation, the anti-CO₂ interference capability was increased from 2000 mg/L to 4000 mg/L, the light hydrocarbon processing capacity was increased from 20,040 t/a to 430,162 t/a, and the caustic consumption per ton of light hydrocarbons was reduced from 163.87 kg to 13.70 kg.

Key words: double caustic wash towers, light hydrocarbon, carbon dioxide/CO₂