ConocoPhillips’ Optimized Cascade LNG Liquefaction Technology: Monkey Island LNG Chooses It for Planned Louisiana Terminal

     ConocoPhillips Optimized Cascade process is a proprietary LNG liquefaction technology that is efficient and can include recovery of heavier hydrocarbons and removal of nitrogen. Nitrogen content can be high for some natural gas sources, including parts of the Midland Basin Permian. ConocoPhillips explains the technology on its website:

“The Optimized Cascade process is based on three multi-staged, cascaded refrigerant circuits using pure refrigerants, brazed aluminum heat exchangers and insulated cold box modules. ConocoPhillips has optimized the heat integration to closely approach the natural gas and refrigerant cooling curves, resulting in a highly efficient process. Pure refrigerants of propane, ethylene and methane are utilized, since their physical properties are ideal for heat integration. The refrigerant properties are also well known and predictable, contributing to unrivaled operating ease and flexibility.”

     The use of brazed aluminum for heat exchangers and cold box modules leads to efficient heat transfer. This technology can accommodate different-sized LNG plants. It can include an integrated heavies removal unit (HRU) and/or a nitrogen rejection unit (NRU). The tech can be configured into a:

“two-trains-in-one” arrangement, where one train of highly reliable heat exchangers and related process equipment is served by two parallel refrigeration turbine/compressor trains. Pioneered by ConocoPhillips, this approach was first used in the Optimized Cascade process, and has become widely accepted as a design that provides the highest plant availability, along with the widest range of turndown capability in the LNG industry.”

     ConocoPhillips licenses the technology but also uses it in its own operated LNG plants. Thus, their expertise is integrated. They also employ subject matter experts to address every part of LNG plant design, operation, and maintenance. The full plant process is explained below in the description and schematics.

     Monkey Island LNG recently announced that they have selected ConocoPhillips’ Optimized Cascade process for their planned 26-MMtpy liquefaction and export facility in Cameron Parish, Louisiana. The following is from the September 4 announcement:

“After an extensive technology selection study and analysis on multiple technologies, Monkey Island LNG selected the Optimized Cascade® process based on its operational flexibility, quick restart capabilities, high efficiency, and proven performance above nameplate capacity. The ConocoPhillips Optimized Cascade Process will enable Monkey Island LNG to provide customers with long-term, secure, and competitively priced LNG supply. The decision marks a major milestone in advancing Monkey Island LNG’s mission to deliver TrueCost LNG™- a radically transparent, cost-efficient model that eliminates hidden fees and aligns incentives across the LNG value chain,” stated Greg Michaels, CEO of Monkey Island LNG.

“Darren Meznarich, who leads ConocoPhillips LNG Technology and Licensing, added “ConocoPhillips is pleased to support Monkey Island LNG with our new, mega-module Optimized Cascade template, designed to reduce costs, plot size and overall project risks for our clients.”

 

     

 

References:

 

Monkey Island LNG selects ConocoPhillips’ Optimized Cascade process technology for $25-B LNG terminal. Gas Processing & LNG. September 4, 2025. Monkey Island LNG selects ConocoPhillips’ Optimized Cascade process technology for $25-B LNG terminal | Gas Processing & LNG

Optimized Cascade Process. ConocoPhillips. Optimized Cascade Process | LNG Technology & Licensing - Optimized Cascade Process