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.