Study of Oxygen Isotope Distillation for Applications in Medical Diagnostics

The production of rare isotopes is difficult and carried out only in few sites in the World, though being of interest. For instance, the production of ¹⁸O and ¹⁷O is relevant for medical diagnostics, in particular to promote largescale application of breakthrough methods for early diagnostics for cancer, neurodegenerative diseases and lung diseases. ¹⁸O and ¹⁷O can be produced by cryogenic distillation, operating with a very high number of theoretical stages. On this topic a PRIN 2022 project has been funded by the Ministero dell’Università e della Ricerca, with the aim of designing a distillation plant for increasing the amount of the isotopes of interest in the final product from the natural abundance up to 10%. The project is based on Aria, a major cryogenic distillation infrastructure in Nuraxi-Figus (South Sardinia), where a 350-meter-tall cryogenic distillation column is being installed to purify argon isotopes for dark matter searches. Extending 350 meters underground into a mineshaft of a former coal mine, Aria is today the only facility capable of producing stable light isotopes via cryogenic distillation in the European Union and has the potentiality to become the most powerful production plant of its kind in the world. This work focuses on the study of the cryogenic distillation column for treating a binary mixture of ¹⁶O2 and ¹⁶O¹⁸O with the aim of producing a stream richer in ¹⁶O¹⁸O. The simulation of the process has been performed and sensitivity analyses on the main operating parameters have been carried out to define the best operating conditions of the column.