Jim Gilmour of Sheffield University asks, ‘Can algal biofuels play a major role in meeting future energy needs?’ The link I’ve just given will take you to an open-access review of research by Dr Gilmour and others.
There are great possibilies in microalgae, says Dr Gilmour. These tiny plants need carbon dioxide (CO2) to grow. The same CO2 that causes such worry when it’s emitted after burning fossil fuels. Other plants, including all our familiar crops, use CO2 to make themselves by photosynthesis. But microalgae are particularly exciting because they can be fed on CO2 from an industrial source such as a power station.
Microalgae also need other plant nutrients, including nitrogen (N) and phosphorus (P). N and P are common elements. Can they be brought in from industrial sources too? Yes they can. Dr Gilmour’s team is developing methods to do this cost-effectively.
Once your microalgae are well fed and growing well, you can make them into ethanol or biodiesel. If you make biodiesel you can run diesel engines on it and do whatever you want a diesel engine to do.
To grow microalgae in the right way to make them into biodiesel, you have to stress them. Poor little dears. But these aren’t furry animals, they’re microscopic plants! I don’t see a movement for algal welfare. You can stress them by keeping them low on nitrogen rations and by giving them plenty of salt and light.
All of this can be done in an open pond or in an enclosed ‘photobioreactor’ like this one. Which is better? That depends on which climate you’re in. There are more questions about the technology for growing microalgae – how best to stir the algal soup, how to make the right kind of bubbles in it, how to scoop from the soup – but it looks promising.
Not too far into the future, we can hope that microalgae will be used to make biofuels in a cost-effective, sustainable way.