As our world becomes increasingly industrialized and the less economically developed countries are racing through the conventional stages of development, our consumption of energy has skyrocketed. We have yet to put a lid on population growth, and in the meantime we have been scrambling to discover new sources of energy. Our crude oil reserves are speculated to be drained by 2052, and even when the greenhouse gas emissions that comes with burning carbon is disregarded, the use of coal will only last us to 2088. Nevertheless, there still is hope; companies and governments worldwide are funding efforts towards a fairly new source of oil-based fuel – algal biofuel.
The hope resting on these photosynthetic organisms is high – although still a ways from large-scale commercial use, there is increasing incentive to exploit algae as an energy source. Algal biofuel stands as a more efficient and ethical alternative to food-crop biofuels, such as from corn and sugarcane. After all, with malnutrition and starvation rampant in the world, do we have the right to make fuel from food? Algal fuel circumvents that problem – algae farms are compact and highly efficient, known to yield up to 100 times more fuel than other biofuels. Easy to grow with mainly water and light, algae can even be cultivated successfully in polluted run-off water, minimizing the impact on freshwater supply. Algae can filter the water as they soak up nutrients, and also absorb carbon dioxide from the atmosphere as they photosynthesize. Of course, algal fuel also releases carbon dioxide when it is burnt to be used, but only as much as the algae fixed during its growth – this means that the balance of carbon dioxide in the atmosphere is maintained! And all this is without the hazard and environmental consequences that come with hydro-electric or nuclear power.
The extraction process determines the type of fuel that will be refined from the algae – lipids (fats and oils) are converted into biodiesels, while the carbohydrates undergo fermentation into bioethanol or butanol fuel. Currently, the main procedures used are dehydration and processing via chemical reactions to extract lipids, and hydrothermal liquefaction, where the algae are subjected to high temperature and pressure to yield crude oil. Here lies the main set-back of this technology– the cost of refinement is higher than the price of the fuel it yields, and this prevents its large-scale commercial production. Hopefully the research efforts going into the extraction of algal fuels will present a new and more cost-efficient method that will allow the phasing out of fossil fuels. Researchers are continually looking to find more efficient species of algae and bio-engineering species to increase fuel production and ease of extraction.
Companies such as Solazyme, Sapphire Energy, and Algenol have already begun to produce and sell algal biofuel, and government-funded projects are hard at work to make it a viable energy source. It is possible that within the next few decades the gasoline in our cars and jet fuel in our planes will be extracted from tiny micro-organisms fixing carbon dioxide for our atmosphere and purifying our waste water. So the next time you take a dip in the ocean or a lake, give a shout-out to the small green creatures swirling around you – they may just be the foundation for future civilization!
Written by Sarah Ng
Edited by Yoo Jin Bae