Money laundering has long been a crime and the plot to many a good mob movie. However, Nabil M. Lawandy and Andrei Smuk have published results of research in the ACS journal Industrial & Engineering Chemistry Research that suggests that money laundering might just be the ticket for countries looking to save money. A lot of money.
Lawandy and Smuk document how government are continually replacing soiled and dirty banknotes at the cost of billions. Governments around the world print nearly 150 billion new banknotes every year at a cost approaching $10 billion. Not only that, but those discarded bills produce about 150,000 tons discarded material. So, the two started to look more closely at why most of these bills are removed from circulation and they found that the chief reason is human sebum — that oily layer that protects our skin. It turns out that the bane of every teenager is also the bane of every banker. A bill in circulation for as little as 3 years will build up sebum on its surface and, once it reacts with oxygen, the mix yellows the bill.
The solution? “Supercritical” CO2. No that is not a teenage version of CO2. Supercritical CO2 works both like a gas and a liquid and has long been used in some cleaning operations It works great on bills by removing oxidized sebum and motor oil while leaving the rest of the bill crisp and clean.