An experimental biorefinery turns spent coffee grounds and old pastries from Starbucks into a building block for plastic. Using food waste as fuel might improve the sustainability of biobased chemical production, the researchers say.
Oil refineries clean up crude oil to produce fuel for cars, trucks and planes. Side products from that process include building blocks for plastics, fabrics and detergents, like lactic acid, succinic acid and glycerol.
Biorefineries could reduce our dependence on fossil fuels by creating fuel from renewable sources of energy like plant biomass. Right now, many biorefineries consume sugars and starches from corn – a plant we eat as food. Should food supplies become scarce, humans and biorefineries would compete for fuel. Energy from food waste, instead of food plants, could make biobased chemical production more sustainable.
Carol Lin, at the City University of Hong Kong, and her coworkers developed a tabletop biorefinery to run on food waste from Starbucks. Fungi first break down the food into sugars. Then bacteria transform those sugars into succinic acid, a chemical building block for plastics, spandex, detergents and deicing solution.
Starbucks Hong Kong donated money to help fund Lin’s research, which she presented at a meeting of the American Chemical Society last week. The company produces nearly 5000 tons of food waste yearly in Hong Kong alone, which would normally be burned or buried in landfills.