RSC - Advancing the Chemical Sciences

Chemistry World


9 September 2005: Powerful promise for grass that's as high as an elephant's eye

Katharine Sanderson/Dublin, Ireland


So-called elephant grass could be the long-promised biomass fuel tipped to solve the world's energy problems, according to researchers in the US and Ireland.

Steve Long from the University of Illinois advocates the use of elephant grass, Miscanthus giganteus, to fuel power stations. 'Biomass crops are not just a minor potential operation, they can really meet very significant amounts of our energy requirements,' said Long.

'If you're thinking about mitigating rising carbon dioxide you need crops that are going to yield a lot of material but with very small input,' said Long. And he says the perennial grass is a contender. If 80 per cent of land in Illinois was given over to elephant grass, he claims, the dry matter produced would provide enough electricity for the entire state - including the city of Chicago. 

Mike Jones, from Trinity College Dublin, has used a model to determine how much grass would be needed to power different areas of Europe. Jones claims that if 10 per cent of Ireland's arable land were given over to the grass, taking into account different growing conditions and climates, 'as much as 30 per cent of the energy requirements for the country could be provided.'

Miscanthus has been trialled throughout Europe, and Long based his US work on these trials. Climatic conditions in the US mean that the grass can grow up to 14 feet high and can produce up to 60 tonnes of dry fuel per hectare. Hayfever sufferers need not worry about fields of sneeze-inducing grass, the hybrid plant is sterile so produces no pollen. Aside from this, the major benefit of a sterile plant is that it does not spread to surrounding land.

For countries looking to reach their Kyoto carbon dioxide limits, elephant grass could help. 'In terms of Kyoto it would be considered carbon neutral,' said Long. 'As the plant grows it's pulling carbon dioxide out of the air, when you burn it you put that carbon dioxide back, so the net effect on atmospheric CO2 is zero.' Long presented his data at the British Association festival of science in Dublin.