Mechanochemical separation of hydrogen isotopes

This PhD aims to develop a new technology that uses mechanochemical reactions to separate hydrogen isotopes. The project builds on exciting new research published in Stillings, Shipton and Lunn, Nature Sustainability, 2023[1] that uses mechanochemical reactions to trap CO2. In mechanochemistry, fracturing of the chemical bonds in a solid, releases charged particles and photons, and produces an instantaneous localized temperature increase of >600 degrees C that can be used to drive a reaction such as the production of H2 gas and H+ ions in water [Stillings et al 2021].

Breaking silicate rocks results in charged silica and oxygen - depending on how the electrons are shared during breakage of the siloxane bond. These charged species can result in a range of subsequent reactions contingent on the composition of the situ fluid(s) For example, in the presence of water, the breakage of siloxane bonds can produce hydroxyl, peroxyl, hydrogen radicals, hydrogen peroxide and hydrogen.

Pilot proof of concept experiments, conducted at Strathclyde, using hydrogen and deuterium, have shown that the mechanochemical reactions that result from milling silicate rocks can be used to separate hydrogen isotopes. Without optimising the process, using only trace levels of deuterium, our pilot data show that deuterium is preferentially adsorbed onto the surface of the milled rock.

Similar pilot experiments using natural water also result in a change in hydrogen isotopes of the water samples. These experiments open the door to an exciting new technology.

Research Hypothesis: Mechanochemical reactions can provide a cheap technology for isotope separation that could be used to reduce industry requirements for more expensive methods, such as cryogenic distillation.