Science Friday

Flame Retardant Could Be Made From Discarded Cocoa HusksOn cocoa farms around the world, cocoa beans are pulled from their pods, and the hard husks are discarded, leaving 20 million tons of plant waste to biodegrade and potentially harm future crops. These husks are a source of lignin, a substance that gives plants their rigidity. It’s extremely abundant—but often wasted.A new study published in the journal ACS Sustainable Chemistry and Engineering found that the lignin processed from leftover cocoa pod husks could have a new use as an ingredient in flame retardant.“Lignin is pretty special, as it is very soluble in organic solvents,” said study co-author Dr. Nicholas Westwood, a professor of chemistry and chemical biology at St. Andrews University in Scotland, in an email. This means lignin can be chemically manipulated to create a number of useful substances relatively easily.Because of lignin’s malleability, Westwood and his coauthors were able to add a flame-retardant molecule to the processed substance,