A biorefinery waste product can be easily processed into functional powders and tough polymers, Leuven researchers show in ChemSusChem.

What tar is to petrochemical refining, humins are to the biorefinery. Humins form a black, sticky substance and contain up to 50% of the carbon atoms you start with in a biorefinery, which go to waste. They are formed by side reactions such as aldol condensation or transesterification, resulting in a varying polyaromatic structure with alcohol, aldehyde, ketone and acid groups.

Since it’s impossible to prevent the formation of humins, researchers are trying to find a way to valorise them. Dilhan Kandemir, Peter Van Puyvelde and Anton Ginzburg from KU Leuven have developed a relatively simple synthetic strategy to convert humins into functional materials that are also recyclable.