At Kansas State University, researchers have applied the laws of physics in order to get a better understanding of the 'sustainability' of algae-based bio-diesel production. They concluded that although this method of producing fuel is certainly more sustainable than fossil fuels, it wasn't entirely sustainable and could still deplete world resources.
Moreover, it would be difficult to produce enough of it to replace diesel. The suggestion from Dr Phromm and his team is that not examination has gone into the physics, microbiology and chemistry of the process to back up what the economists are saying.By tracing the flow of carbon through the process of creating biofuel from algae, the researchers concluded that the production of biofuel from algae was not balanced. Dr Phromm said: 'The inflow must equal the outflow if we are to be sustainable. Without this, our production cycle won't last decades - or even centuries - and will instead deplete resources that can't be renewed and degrade our planet.'
Furthermore, the study showed that the amount of algae produced was vastly lower than the predictions of many algae scientists. Dr Phromm said that estimates of 200 to 500 grams of algae per square metre of pond were unrealistic, as there is simply not enough sunlight to achieve these levels. 50gms per square metre was a much more accurate figure, meaning it would take it would take 11 square miles, making 14,000 tonnes of algae per day just to fulfil 0.1% of US annual diesel consumption. In addition, he identified other problems in biomass production, such as preventing algae-eating organisms from attacking the crop.
It could all have a massive impact on the incentive for algae farming for fuel production, particularly if the profit simply isn't there. Dr Phromm believes it could be another 20 years before the process of making bio-diesel from algae is economically viable. In which case, few investors will back any plans to develop the technology.
'Right now the fundamentals are the problem', says Phromm, 'It doesn't matter how well we engineer our production machine, the engine under the hood just isn't that good. The best option right now is to invest in fundamental research and design so that the yield can hopefully reach above the 50 grams per square meter per day on our most optimistic assumption.'
If the research is correct, then it could see more and more scientists moving away from research into algae biomass for fuel production to genetically engineered cyanobacteria, whose DNA is easier to access and manipulate.