No flight of fancy

The substitution of hydrogen fuel cells for hydrocarbon fuels or their vegetable-oil based substitutes, promises a cleaner environment with greater ecological gains. However, development and implementation is being held back by the problem of storing the dangerous gas safely and efficiently. One ingenious solution is to store the gas in a 'sponge' of carbonized keratin - the protein that forms skin, hair and ......bird feathers.

A team at University of Delaware have discovered that the protein keratin, (in the form of chicken feathers) developed interesting properties when it's heated. What happens is that the keratin creates very strong cross-links when it's carbonized, and the feather fibres become super-porous, dramatically increasing their total surface area. As a result, the carbonized feathers can absorb huge amounts of hydrogen into their structure.

Also under consideration are some very high-tech methods of creating a safe hydrogen tank. Carbon nanotubes and graphene, or complex metal hydrides formerly seemed the best options but the chicken feather tank would potentially store even more hydrogen than either of those two options, and cost enormously less to create. It is estimated the feather solution would cost about £100 - a very favourable alternative to tens of thousands for a hydride tank, and millions for a nanotube version. Though these figure could be lower as the technologies develop, neither option is likely to come close to the use of what is otherwise industrial waste.

Development to date suggests that carbonized feather technology could easily create a 65-gallon hydrogen tank, which would power a family car over 300 miles - capacity that may increase yet further as the technology develops.