Clean energy from micro-algae

Associate Prof Ben Hankamer from the University of Queensland in Australia is attempting to engineer bioreactors that can produce hydrogen in a carbon-dioxide neutral process.

The solar bio-hydrogen process he is working on uses solar-powered bioreactors filled with single-celled algae to produce hydrogen from water. Algae naturally capture sunlight and use its energy to split water into hydrogen and oxygen; however, the process is not efficient enough to be commercially viable.

Hankamer has established a Solar Bio-fuels Consortium, which he co-directs with Prof Olaf Kruse from the University of Bielefeld in Germany, which is attempting to develop ways of enhancing the efficiency to a level where the process will be economically viable - with the help of a $286,000 Australian Research Council grant.

'We have focused on micro-algae as a source of hydrogen because they have several advantages over traditional bio-fuel crops. One major advantage, especially in drought-stricken countries like Australia, is that marine and salt-tolerant algae can extract hydrogen and oxygen from seawater and on combustion, these gases produce fresh water and electricity which can be fed into the national grid. Consequently, clean energy production can theoretically be coupled with desalination,' said Hankamer

One of the current concerns about traditional bio-fuel crops is that they will compete with food production for arable land and water. In contrast, algal bioreactors could be placed on non-arable land and use much less water than conventional bio-fuel crops.

One other major benefit of the hydrogen production process is that it absorbs carbon-dioxide. 'We are also starting to investigate whether our hydrogen producing systems can be linked to conventional power stations to sequester carbon-dioxide which would otherwise be released into the atmosphere',  Hankamer added.