Hydraulic design of thermally coupled columns and a DWC for NGL fractionation plants

Abstract

Combining a conventional demethanizer with thermally coupled deethanizer and propane-butane recovery columns or a three-product dividing wall column (DWC) provides a realistic opportunity for natural gas liquids (NGL) fractionation complexes as encountered in floating, as well as on-land natural gas liquefaction plants, to minimize energy requirements and reduce carbon dioxide emissions accordingly, in a cost-effective way. The present paper addresses and discusses hydraulic design aspects of these two thermal coupling arrangements, including the choice of the most appropriate column internals that largely depends on important design, construction, and operating considerations that differ for floating and on-land plants.