Abstract: Disclosed are methods of and means for producing ethylene by chilling the ethylene plant demethanizer heat exchange train with a refrigerated stream or streams from a cryogenic natural gas plant effective to provide ethylene level refrigeration, by condensing the ethylene distillation tower overhead with ethylene level refrigeration stream or streams from the cryogenic natural gas plant, by refluxing the ethylene plant demethanizer distillation column with a predominantly liquid methane mixture from the cryogenic natural gas plant, and by combinations thereof. Significant advantages in capital and operating costs associated with ethylene production.