Dense phase CO2 cleaning: An alternative solution to the use of solvents

At the dawn of the 2000s, processes using pressurized carbon dioxide (CO ₂ ) for cleaning applications seemed to have emerged from research laboratories, while this technology was already widely used, industrially, in the extraction of natural substances. It wasn't until a decade later that American scientists (Kohli & Mittal), from NASA and IBM respectively, integrated high-precision cleaning and the use of pressurized, liquid or supercritical CO ₂ for the first time in a single journal .

Inspired by this publication on "Cleaning by dense CO ₂ under pressure", this article was constructed. The aim is to provide up-to-date information on the existence of this process for cleaning in industrial environments. To this end, it seemed essential to address the theoretical and fundamental aspects in depth, as this reflects the effort made to understand these notions of transport physics, and thermodynamics oriented towards fluids under pressure.

Solubilizing apolar and polar solutes in an apolar medium is a complex issue, due to the very nature of this type of fluid. The instrumentation needed to carry out measurements is unconventional, due to the pressure and the particular behavior of water in this medium. We will see, through industrial examples, that developments have been particularly abundant since 2010. Today, the technology has reached a high level of industrial maturity, as it is applied in a number of fields, including mechanical engineering, medical devices and certain niche markets. In each of the cases presented, we'll see how manufacturers have developed their applications, combining a viable business model with a major advance in terms of reducing or eliminating health and environmental risks.