Algae: Future Fuel

With depleting petroleum resources around the world, the search for alternate fuel is in constant progress since many decades. According to an estimate the world’s fossil fuel will be exhausted in few decades at the present rate of population growth and fuel consumption. So, scientists as well as government agencies are taking up researches in the avenues which have the potential to replace the fossil fuel. An algal species with right properties could be immensely valuable in this regard!!

Algae are microscopic organisms, which like plants through photosynthesis convert light into chemical energy while at the same time absorbing carbon dioxide from the atmosphere. Algae turn the carbon they take into sugars and then into oil which can be made into fuel. There are nearly 3000 algal species and very few strains are rich oil producers. An algae which could thrive on polluted or salty water, reproduce rapidly and make copious amount of oil could be a viable one.

Bio fuels can also be made from Jatropha and other vegetable crops. But algae has an upper hand over these succulent plants because they grow faster and produce more oil than terrestrial plants under minimum conditions for survival. They require water, sunlight, a few nutrients and carbon dioxide from air. They grow prolifically and accumulate large amount of oil when they experience environment stress particularly when they are deprived of nutrients and sunlight. Unlike corn or soyabeans which can be harvested only once a season, algae can be reaped continuously.

A recently conducted research at the National Renewable Energy laboratory in colorodo revealed that a hectare of soyabean typically produces only about 500 litres of oil each year, whereas a hectare of algae growing in a shallow pond can easily generate 9000L oil and also as much as 47000L annually. Algae can be cultivated in open shallow ponds with paddle wheels, in undesirable land, in saline water or brackish groundwater. They can be grown even in photobioreactors or fermentors similar to stainless steel tank used to produce ethanol. Algae take up carbon dioxide and they can do that much more readily when it’s highly concentrated, such as in the flue gases from a power plant. Using emissions to grow algae can thus cut down on the release of greenhouse gas while producing the oils that are so sorely needed for biodiesel. After the oil has been extracted, the remaining residue can be burned to generate heat and power, or it can be turned into animal feed or nutritional supplements as omega-3 fatty acids and antioxidants.

With legally binding commitments for carbon emissions becoming important highlights in the agenda of every climate change summits at international levels, these microscopic oil factories would be a viable option for developing economies like India which reduces the greenhouse gas emissions into the atmosphere. India also has a large part of its land uncultivated in Rajasthan desert and in Rann of Kucchh of Gujarat which can be efficiently used for algal culture. Recent advances in technology are trying to make algal oil extraction cost effective bringing it on par with petroleum fuels. Future of these tiny oil factories looks positively golden.

Source: spectrum.ieee.org