Improving NGL recovery process with dividing-wall column for offshore applications

Abstract

Fractionation process within natural gas processing facility is an essential step that allows to obtain liquid light hydrocarbons that are often used as feedstocks in petrochemical industries. In this article, a process scenario that includes a heat integrated distillation column is proposed for natural gas liquids (NGL) recovery and assessed through multiscale simulations. Aspen HYSYS software was used to develop steady state process models whose results were used to estimate capital and utility costs. It was noticed that the proposed process has the highest capital cost and lower operating cost which reduces remarkably the total annual cost, this process can also achieve 60 % ethane and 97 % propane recoveries with no additional of external refrigeration. Heat integration, low TAC, separation efficiencies for ethane and propane components, self-refrigeration and more importantly a possibility of operating the process in ethane recovery and ethane rejection modes are the main highlights of the proposed NGL recovery process.