(564e) A Conceptual Design of Shale Gas Condensate Recovery Process for Maximum Energy Savings

Shale gas condensate refers to the light liquid hydrocarbons recovered from lease separators at natural gas or shale gas wells.  It primarily consists of pentanes and heavier hydrocarbons.  By definition, condensate is lighter than crude oil, but heavier than natural gas liquids.  The API gravity of condensate is typically higher than 50 degrees.  It is a valuable mixture that can be converted to different petroleum products like naphtha, jet fuel, and diesel etc.  Plenty of new condensates show up at the Gulf Coast from production in the Eagle Ford and other shale basins.  Forecasters predict that total Eagle Ford condensate output will reach 250,000 and 400,000 barrels per day (BPD) by 2020.  However, increasing the production from shale gas condensate is not easy for existing refineries, especially those in the Gulf Coast of Mexico. This is because condensates contain too many components belonging to the light naphtha range that can overwhelm most Gulf Coast refineries that are mostly designed to process heavier crudes.  Thus, a novel conceptual design for shale gas condensate recovery is developed in this paper to enable the production activity and meanwhile to maximize energy savings during the production.

A four-columns process system including pre-flash column, debutanizer, condensate splitter and vacuum distillation column is investigated for condensate recovery process.  To optimize the process, a superstructure is constructed first considering many alterative operation conditions.  Next, a simulation-assisted mixed-integer linear programming (MILP) model is developed and solved to derive the optimal process synthesis.  In order to maximize the energy savings, heat exchanger network (HEN) design is taken into account in conjunction with the superstructure optimization.  Finally, rigorous plant-wide simulations are conducted to validate the feasibility and capability of the entire conceptual design coupling separation and heat integration.