Now, a Swiss research team is turning leftover fruit and vegetables into hydrogen and biochar in a flash.
First banana- and orange peel, corn cobs or coffee beans are dried and ground. Next the resulting powder is heated and evaporated with a high energy Xenon flash lamp.
The 14.5 millisecond long light impulses are applied over 12 seconds in total. After 5 sessions a kilogram of biomass renders 100 litres of hydrogen and 330 grams of biochar.
The latter, stemming from lignin and cellulose, can be used as fertiliser, or stored in the earth to bind CO2.