Science News
from research organizations

Laundering money -- literally -- could save billions of dollars

Date:
January 8, 2014
Source:
American Chemical Society
Summary:
A dollar bill gets around, passing from hand to hand, falling on streets and sidewalks, eventually getting so grimy that a bank machine flags it and sends it to the shredder. Rather than destroying it, scientists have developed a new way to clean paper money to prolong its life. The research could save billions and minimize the environmental impact of banknote disposal.
Share:
       
FULL STORY

A new money-cleaning technique can remove years of oil build-up.
Credit: American Chemical Society

A dollar bill gets around, passing from hand to hand, falling on streets and sidewalks, eventually getting so grimy that a bank machine flags it and sends it to the shredder. Rather than destroying it, scientists have developed a new way to clean paper money to prolong its life. The research, which appears in the ACS journal Industrial & Engineering Chemistry Research, could save billions and minimize the environmental impact of banknote disposal.

Nabil M. Lawandy and Andrei Smuk point out that replacing old currency is a growing problem. When bills become too dirty, central banks take them out of circulation and replace them with crisp new bills. As a result, the world's treasuries print nearly 150 billion new banknotes every year at a cost approaching $10 billion. And about 150,000 tons of old bills become destined for shredding and disposal. The main culprit for this costly turnover is human sebum, the oily, waxy substance the body produces to protect skin -- also the bane of acne-prone teenagers. Over a bill's lifetime of about 3 to 15 years depending on the denomination, sebum accumulates on its surface, reacts with oxygen in the air and turns a yellowish hue. To delay a banknote's retirement, Lawandy's team decided to see if they could just clean it, removing the accumulated sebum.

They turned to "supercritical" CO2, which acts like both a gas and a liquid and is commonly used in other cleaning applications. When they tested it on banknotes from around the world, they found that it effectively removed oxidized sebum and motor oil while leaving intact security features such as holograms and phosphorescent inks.


Story Source:

The above post is reprinted from materials provided by American Chemical Society. Note: Materials may be edited for content and length.


Journal Reference:

  1. Nabil M. Lawandy, Andrei Y. Smuk. Supercritical Fluid Cleaning of Banknotes. Industrial & Engineering Chemistry Research, 2013; 131217133109000 DOI: 10.1021/ie403307y

Cite This Page:

American Chemical Society. "Laundering money -- literally -- could save billions of dollars." ScienceDaily. ScienceDaily, 8 January 2014. <www.sciencedaily.com/releases/2014/01/140108112702.htm>.
American Chemical Society. (2014, January 8). Laundering money -- literally -- could save billions of dollars. ScienceDaily. Retrieved August 31, 2015 from www.sciencedaily.com/releases/2014/01/140108112702.htm
American Chemical Society. "Laundering money -- literally -- could save billions of dollars." ScienceDaily. www.sciencedaily.com/releases/2014/01/140108112702.htm (accessed August 31, 2015).

Share This Page: