Scientists have dramatically increased the efficiency of producing clean hydrogen fuel from plant waste, the Independent has reported.
A study funded by Shell Oil has shown that it is possible to convert 100% of the sugar stored in corn stover – the stalks, cobs and husks leftover in a harvested maize field – into hydrogen gas, with no overall increase in carbon dioxide emissions to the atmosphere.
The process has been perfected by mixing the raw plant matter with a watery solution containing 10 enzymes, which turn the plant sugars xylose and glucose into hydrogen and carbon dioxide, said Professor Percival Zhang of Virginia Tech in Blacksburg, Virginia.
“Previously it has only been possible to convert between 30 and 60% of the plant’s sugars into hydrogen, using either fermenting microbes or industrial catalysts,” he said.
“All the products produced by the process are gases so they can be separated and collected easily from the biomass substrate. Over its lifecycle, the process is carbon neutral and we have achieved a 17-fold increase in the rate of the reaction which makes it economically viable.”
One of the critical developments in the process is being able to directly use ‘dirty’ biomass as the fuel rather than relying on highly processed sugars as the source of hydrogen. In addition to being more efficient, this means it should also be possible to build large bioreactors the size of petrol stations near to sources of biomass.
