What are Algae Biofuels?

Posted on 24. Aug, 2009 by Ross in New Technologies, Oil

Algae-based biofuels, or algal biofuels, are sources of biodiesel, bioethanol and other biofuels derived from simple organisms such as algae and phytoplankton. As with plants and other photosynthetic organisms, algae use sunlight to convert water and carbon dioxide into oxygen and biomass.

Why bother with algal biofuels?

The key reasons to research biofuels are of course all pertinent to the pursuit of algae-based biofuels, which all stem from the desire to find an alternative analogous fuel supply to oil:

Avoiding high oil prices - individuals and businesses all bear the brunt of escalating energy prices, which are likely to continue their long-term rise due to ever-increasing international demand as more countries become industrialised.
Dwindling reserves - countries which have long depended upon plentiful oil supplies but whose reserves have failed to be augmented with new oil field discoveries need to find alternatives or risk the effects of higher prices on their economies.
Energy security - net importers of oil find that their foreign policies are often highly influenced by the need to maintain those imports, resulting in more conflicts in oil-rich areas or more concessions to net exporters.
Climate change - the primary aim of those governments attempting to avoid the effects of global climate change is to decrease the quantities of carbon dioxide being pumped into the atmosphere, replacing fossil fuels with carbon-neutral alternatives. All of the carbon dioxide released by burning biofuels was originally sequestered by the plants involved in the fuel’s production, leading to a carbon-neutral fuel source.

However, compared to crop-based biofuels derived from plants such as corn, palms, jatropha or tallow, algae have some significant advantages.

Algae biofuels versus the rest

Algal growth is significantly faster than that of more complex photosynthetic organisms, with a harvesting cycle of 1-10 days. This enables much faster and more prolonged turnover of product than other biofuel crops.

Compared to traditional crop-based alternatives, algal biofuels can yield a far greater supply of product per unit area, needing far less land to produce and interefering with food production less. Because strains of algae can be grown in salt water, offshore algal biofuel farms are also a long-term possibility.

The algae can be grown in closed systems, which would prevent contamination of the algal growth culture with bacteria and viruses which could potential damage the biofuel production. Traditional crops are more prone to disease and drought, requiring more energy-intensive treatments such as insecticides and herbicides to combat attacks.

As well as fresh and salt water, the algae could also potentially be grown using waste water from sources such as sewage treatment plants, absorbing extra nutrients. Algal biofuel plants could also be linked directly to the exhaust systems of power plants and industrial factories, taking waste carbon dioxide gases directly into the growth tanks for conversion into biomass, thereby directly reducing industrial waste.

Genetic engineering - maximising algae’s potential

The other major advantage of algae over other biofuel feedstocks is that most of the likely long-term candidates for the best biofuel output are simple single-celled organisms with a short lifespan. This makes it faster and easier to test and assess the effectiveness of genetic modification upon the algae’s biofuel yields, growth rates and hardiness.

As well as simply increasing the biofuel yield, faster growing algae would also enable the adoption of more efficient continuous systems rather than batch manufacture, creating even greater gains.

However, genetically-modified algae have a very strong likelihood of escaping into the wild in an uncontrollable fashion, making genetic safeguards even more imperative than with more complex crops.

Future repercussions of algal biofuel

Algae-based biofuels are likely to have a massive impact upon the world over the medium term, enabling a technologically simple solution to perpetuating the reliance on hydrocarbon-based fuels for transport. This provides a counter-balance to relying too heavily upon countries rich either with oil, or with resources such as lithium which are likely to define the next generation of energy technologies, partially decoupling the world’s economy from the effects of supply and demand of just one commodity.

Algal biofuels will also present part of a growing selection of clean technologies designed to reduce the environmental impact of a growing population and/or economy, enabling countries to industrialise at less of a cost to the health and well-being of their citizens.

They will be one of a number of energy technologies which manage to drive the world towards a carbon-neutral economy, until later technologies such as artificial photosynthesis take the process forward once more into the realm of carbon-negative industry.

Image by Ross Tucknott @ Flickr