How Your Coffee Grounds Can Help Save the World
Heating used grounds with potassium hydroxide enables methane storage
By Elizabeth Armstrong Moore,  Newser Staff
Posted Sep 3, 2015 8:24 AM CDT
This undated publicity photo provided by Birdsandblooms.com shows coffee grounds that can be sprinkled on the ground at the base of certain plants.   (AP Photo/Birds & Blooms)
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(Newser) – As if coffee isn't amazing enough already. A team of researchers—who, yes, got the idea over a cup of coffee—are reporting in the journal Nanotechnology that soaking spent coffee grounds in potassium hydroxide and then heating the grounds in a furnace creates a material that can store up to 7% of its weight in methane, a greenhouse gas that Popular Science calls both "incredibly potent" and "much stronger than carbon dioxide." Further, the scientists write they were able to create their carbon capture material in fewer than 24 hours—"a fraction of the time" it normally takes. Trapping and storing methane is a double win for the environment: Not only does doing so remove the harmful greenhouse gas from the atmosphere, but it can also be used as a cleaner alternative to fossil fuels that can, say, power cars.

In their paper, the scientists explain that traditional methane storage methods involve compressed gas cylinders, a storage system they describe as "dangerous and heavy." That's shifted attention to "low-weight" alternatives, and the researchers think theirs stands out. "The waste material is free compared to all the metals and expensive organic chemicals needed in other processes—in my opinion this is a far easier way to go," coauthor Christian Kemp of Pohang University of Science and Technology in South Korea tells Nanotechnology Now. The absorbency, he adds, turns out to be key: "It seems when we add the sodium hydroxide to form the activated carbon it absorbs everything. We were able to take away one step in the normal activation process—the filtering and washing—because the coffee is such a brilliant absorbent." (More news about our planet: Earth has 3 trillion trees ... and that's not good.)