Techno-Economic Evaluation of Clathrate Hydrate Desalination Leveraging LNG Cold Energy Utilization: Progress toward Commercialization

Produced water from oil and gas operations contains extremely high salinity (100,000–300,000 mg/L), far exceeding the treatment limits of conventional reverse osmosis systems. This study presents a techno-economic analysis of four clathrate hydrate-based desalination (CHD) configurations treating 750 ton/h of produced water (10 wt % salinity, 40% recovery): (1) Methane (No Recycle), (2) HFC-152a (No Recycle), (3) HFC-152a (Recycle), and (4) HFC-152a Recycle with Cold Energy Integration. Substituting HFC-152a for methane reduces the fixed capital investment (FCI) from $227.44 million to $96.80 million (−57.4%) due to a decrease in formation pressure from 8.0 to 0.25 MPa. Incorporating gas recycling further lowers the FCI to $71.93 million (−25.7%) by eliminating the need for fresh gas compression. Integrating LNG cold energy yields the largest reduction, achieving an FCI of $17.97 million (−75.0%) by replacing mechanical refrigeration with passive cryogenic heat exchange. The levelized cost of water (LCOW) decreases from $28.74/m3 to $1.66/m3 (92% reduction), approaching costs typical of seawater desalination despite treating water with triple the salinity. Equipment-level analysis reveals that compression systems dominate capital costs (72–79%) in conventional CHD configurations. LNG cold energy integration eliminates 21,282 kW of refrigeration compression, reducing total compression power by 99.6%. This work provides the first comprehensive techno-economic assessment of produced-water desalination using HFC-152a, establishing a realistic cost basis for commercialization. The findings demonstrate that integrating CHD with existing LNG regasification facilities can dramatically reduce the energy demand and operating costs, positioning hydrate-based desalination as a scalable and economically competitive alternative to conventional technologies.