The Northwestern filter changes color when full of carbon dioxide, then changes back after being emptied
As concerns continue to rise over man-made carbon dioxide entering the atmosphere, various groups of scientists have begun developing filters that could remove some or all of the CO2 content from smokestack emissions. Many of these sponge-like filters incorporate porous crystals known as metal-organic frameworks (MOFs). Unfortunately, most MOFs are derived from crude oil, plus some of them contain toxic heavy metals. Researchers from Illinois’ Northwestern University, however, recently announced that their nontoxic MOF sponge – made from sugar, salt and alcohol – is fully capable of capturing and storing CO2. As an added bonus, should you be really hungry, you can eat the thing.