According to him, the microwave method could also be used on a variety of plant-based waste to make fuel or other products. They include straw, cashew nut shells, apple peel, coffee or rice husks, the Daily Express reported.

“Orange peel is an excellent example of a wasted resource. In Brazil, the world’s largest producer of orange juice, half the orange fruit is left as waste once the juice has been recovered. This corresponds to eight million tons a year of orange peel that can be used to produce chemicals, materials and fuels,” he said.

Prof Clark’s microwave can only treat small amounts of food waste. But soon, a model that can process 30 kg of waste an hour will be in operation.