CO₂ Refrigeration at Very Low Temperatures Using Natural Gas Expansion

Hamzaoui, Malek; Hadiouche, Ahmed; Grine, Ali

Journal of Materials and Engineering Structures
Volume 13, Numéro 2, Pages 359-368
2026-06-30

Co₂ Refrigeration At Very Low Temperatures Using Natural Gas Expansion

Authors : Hamzaoui Malek . Hadiouche Ahmed . Grine Ali .

Abstract

The pressure reduction of natural gas in distribution networks generally leads to a significant loss of available energy due to the use of throttling valves. Recovering this pressure energy represents an important opportunity to improve the global efficiency of gas infrastructures. In this study, a refrigeration system operating with carbon dioxide (CO₂) and driven by the expansion of natural gas is investigated. The proposed system replaces the conventional expansion valve by a turbo-expander able to convert the pressure energy of natural gas into mechanical energy. This energy is then used to drive the compressor of a vapor compression refrigeration cycle. A thermodynamic model of the system is developed based on mass and energy balances applied to each component. The performance of the system is evaluated for different operating conditions corresponding to pressure reduction stations used in Algeria. The results show that the integration of a turbo-expander allows simultaneous production of refrigeration at very low temperatures while recovering part of the pressure energy of natural gas. This approach contributes to improving the overall energy efficiency of gas distribution networks while reducing energy losses.