Scientists from NSU presented a method to extract lithium using gas hydrates at a conference in Kaliningrad

The II Russian Gas Hydrate Conference was held at the Museum of the World Ocean on the Peter the Great Embankment in Kaliningrad from September 9 to 13, 2026. The venue brought together scientists from various fields: geology, geophysics, chemistry, and thermophysics. Specialists in subsoil use, oceanologists, and engineers from oil and gas companies also participated. The event was organized by the Federal State Budgetary Institution “VNIIOkeangeologia,” the Museum of the World Ocean, and Skoltech. The conference organizing committee was headed by the scientific secretary of VNIIOkeangeologia. Tatyana Matveyeva.

The honorary committee of the conference included the head of the Laboratory of Thermophysical Foundations of Gas Hydrate Technologies, Doctor of Physical and Mathematical Sciences Physics Faculty of Novosibirsk State University Vladimir Belosludov. He is a co-author of one of the Novosibirsk papers presented at the conference by the researchers of the laboratory he heads. They delivered two reports on gas hydrate concentration of lithium.

The report on the experimental part was presented by a senior research fellow of the laboratory, Candidate of Technical Sciences Anton Meleshkin. The discussion was about concentrating lithium chloride (LiCl) and lithium hydroxide (LiOH) from aqueous solutions.

— Can you imagine “carbonated ice”? It looks like ordinary ice, but it fizzes when melting! In cold and under pressure, water molecules arrange themselves into tiny three-dimensional cavities, each containing a gas molecule. For our purpose, another point is important: only gas fits inside such a cage. Salt does not get there and remains in the water that has not yet become a hydrate., — explained Anton Meleshkin.

This is the principle on which the entire idea is based. The solution is poured into a steel reactor designed for 10 MPa, cooled almost to zero, and then hydrate-forming gas is supplied. At some point, the pressure in the reactor suddenly drops, which indicates that the hydrate has started to grow. The water goes into the crystals, while the salt finds no place there and remains in the non-crystallized solution. In the laboratory, they compared how different lithium salts behave: in LiOH solutions, gas is absorbed 3.5–3.7 times faster than in LiCl solutions. The chloride ion noticeably hinders hydrate growth more. After one cycle, the residual solution becomes roughly four times richer in lithium than the original.

The calculational part was presented by a senior research fellow of the laboratory, candidate of physical and mathematical sciences Yulia Bozhko. The report was titled “The Effect of Lithium Chloride on the Phase Equilibrium of Mixed Gas Hydrates CO2–CH4 and CO2–H2S.” Thermodynamic modeling explains why salt interferes: in a saline solution, the hydrate forms either at higher pressure or at lower temperature than in pure water. One percent LiCl by mass raises the equilibrium pressure for the CO2–CH4 mixture by about five percent. These are quite workable numbers for technology. They show under what conditions the installation should operate and how the regime will have to be adjusted as the solution becomes enriched with lithium.

— Lithium today is primarily about batteries: phones, electric vehicles, and energy storage systems. Technological development fuels demand, but extraction from brines is done by evaporation: the brine is poured into huge ponds and waits for months until the water evaporates in the sun. This is slow, and a lot of water is lost. We propose the opposite: not to evaporate the water, but to bind it into a hydrate. Importantly, the hydrate can form at positive temperatures, so this is energetically more efficient than freezing the solution. — said Yulia Bozhko.

Both reports were made under the project of the Russian Science Foundation No. 25-19-00816. The data obtained in the laboratory will be used to select operating modes for the lithium concentration setup.