Used ethylene plant using Lurgi and Linde process. Convert naphtha, propane or LPG into ethylene, propylene, and C4 olefins. The process comprises: pyrolysis (cracking), gas separation, drying, cooling and liquefaction, demethantion, depropanization and fractionation. Raw gases feed three screw compressors in which the necessary pressure is obtained to have circulation of gases through the plant. Caustic soda solution is used to eliminate sour gases contained in the naphtha or propane feed. The plant shut down recently due to overcapacity in local market. The plant underwent mothball procedure and all its equipment is maintained well.