A Review of CO2 Clathrate Hydrate Technology: From Lab-Scale Preparation to Cold Thermal Energy Storage Solutions
Sai Bhargav Annavajjala, Noah Van Dam, Devinder Mahajan, Jan Kośny
Abstract
Carbon dioxide (CO2) clathrate hydrate is gaining attention as a promising material for cold thermal energy storage (CTES) due to its high energy storage capacity and low environmental footprint. It shows strong potential in building applications, where space cooling accounts for nearly 40% of total energy use and over 85% of electricity demand in developed countries. CO2 hydrates are also being explored for use in refrigeration, cold chain logistics, supercomputing, biomedical cooling, and defense systems. With the growing number of applications in mind, this review focuses on the thermal behavior of CO2 hydrates and their environmental impact. It highlights recent efforts to reduce formation pressure and temperature using chemical promoters and surfactants. This paper also reviews key experimental techniques used to study hydrate properties, including Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), high-pressure differential scanning calorimetry (HP-DSC), and the T-history method. In lifecycle comparisons, CO2 hydrate systems show better energy efficiency and lower carbon emissions than traditional ice or other phase-change materials (PCMs). This review also discusses current commercialization challenges such as high energy input during formation and promoter toxicity. Finally, practical strategies to move CO2 hydrate-based CTES from lab-scale studies to real-world cooling and temperature control applications are discussed.