The constantly increasing world population is increasing fuel consumption at a much faster rate than ever before. With many oil wells and coal resources depleting around the world, algae fuel seems to be a plausible solution. Although algae farming is at its infancy, it is likely to become a positive method of producing renewable energy in the future.
Algae farming or alga culture is being commercially researched for producing numerous biofuels such as vegetable oil, biodiesel, biogasoline, biomethanol, bioethanol, biobutanol on lands that are not arable.
Companies such as Solix Biosystems, owned and operated by an Indian tribe known as Southern Utes in Colorado, have begun working towards algae farming at a large scale. This tribe has already made a name for themselves by investing in different types of renewable energy. Although Solix Biosystems faced difficulties in farming algae, the company has not veered far from the concept. Today it sells equipment to algae farmers.
What is Algae Fuel?
Algae fuel, also referred to as Algal biofuel, is an innovative alternative to fossil fuel that uses naturally available algae to form fuel. Not only is this easier to source but also environment-friendly. It is considered as third generation fuels.
The first and second generation fuels are based on terrestrial plants and require arable lands for cultivation. Biofuel is sourced from ordinary microscopic organisms found in water and grow hydroponically in any type of water.
The chief benefits of algae fuels are listed below:
- Harvested algae release CO2 when burnt, but it is absorbed from the air by the new growing algae, which is not the case with fossil fuels
- Harvesting of algae has less impact on fresh water resources
- Ocean water and even waste water can be used for growing algae
- Non-toxic as it contains no sulfur
- Biofuel spills are comparatively harmless to the environment
- Although very expensive to grow, the fuel yield is 10 to 100 times more per unit area compared to other second-generation biofuel crops such as rapeseed and palms
- After oil is extracted, the algae residue can be either used as an animal feedstock or as a soil fertiliser
Algae require abundant sunshine so as to photosynthesise organic matter from organic nutrients available in the water they grow in as well as from CO2 in the air. This process enables them to double their mass many times in one day. In many of the algae species, almost half their mass is made up of lipids, which can be extracted and used as algal ‘crude’, or refined to higher-grade hydrocarbon commodities. These can be used to make biodiesel as well as biojet fuel.
Similarly, certain strains of algae tend to produce more carbohydrate than oil and can be fermented to produce biobutanol and bioethanol.
Algae farming is a long drawn and expensive venture. Apart from the costs involved, the challenge of identifying the right species of algae out of almost 30,000 algal species is huge. This task, however, has been started long ago by the US Department of Energy (DoE) with its Aquatic Species Program.
In order to grow the most lipid-rich algae, they must be grown in greenhouses or ponds covered with translucent membranes. Growing them in open ponds will not give the best results. Closed environments promote healthier and productive algae strains that are free of atmospheric contamination. It is easier to monitor and control the growth factors such as temperature of water, amount of sunlight, acidity/alkalinity, nutrients, and concentration of CO2 in closed ponds.
A probable scenario for algae farming - desert farms - has been suggested in the U.S. The design provided has several shallow salt water algae ponds that have water flowing around it. This design makes it easier to harvest the algae. The desert heat causes evaporation which increases the level of salinity. To solve this issue, fresh water procured via desalinating seawater is introduced into the ponds to dilute it and maintain the salinity level constant. The pond thus requires aqueducts supplying seawater, and the desalination equipment can be powered by the sun. The excess salt and minerals that are procured during desalination can be used by nearby companies. To further enhance this desert farm model, it is recommended that solar ponds be constructed close by so as to provide the algae ponds heat during the cold desert nights.
Researchers state that algae can yield 5,000-20,000 gallons per acre per year.
Biomass and Biodiesel
A common sentiment that is reflected across the U.S. is that the American transportation should be powered by fuels produced within the country, thereby giving it energy independence. In 2003, the US spent $100-150 billion to purchase petrol from other countries, and in order to secure its fuel resources, the country has had to get into conflict situations with oil-rich nations, thus gaining a negative image. Hence developing alternative fuels should become one of the main priorities for the country.
Research has proved that biodiesel is an excellent alternative for automobiles, as this fuel can be used in the already existing diesel engine without having to upgrade or alter it. Biodiesel is made from vegetable oils or animal fats. This fuel can be mixed in at any ratio with petroleum diesel as well. Thus biodiesel can be sold either wholly or in combination with diesel, making it a feasible alternative. Automobile manufacturers can continue producing the conventional diesel vehicles without any problem as biodiesel can be used to operate them. It also gives the much needed time for biodiesel manufacturers to make it available on a larger scale.
The focus is now on the two major steps required to produce biodiesel on a large scale. They are growing the feedstocks and processing them into biodiesel. Biogasoline can be produced from biomass such as algae. Just like the conventional gasoline, biogasoline contains between 6 (hexane) and 12 (dodecane) carbon atoms per molecule. This biofuel can be used in internal-combustion engines.
Biomethanol is used for internal combustion and other engines. It can be used directly or in combination with gasoline. It is already in use in China, and also in racing cars. Similarly, butanol can be made from algae using a solar-powered biorefinery. This biofuel has an energy density that is 10% lesser than gasoline but greater than that of ethanol or methanol. Butanol can easily replace gasoline, as gasoline engines require no alterations to use butanol.
Renewable energy is the subject of a lot of research, discussions, and debates these days. With the soaring fuel prices, countries will have to look for alternative sources sooner than later. One of the readily available renewable resources is algae, and with a number of researches proving its viability as an alternative fuel, countries need to commercialize this concept, and encourage further studies in this field.
Gardening has been given a unique twist by ecoLogicStudio, a London-based design organization.In February 2012, they developed H.O.R.T.U.S., an algae- powered, interactive ‘cyber-garden’ installation. Hydro Organisms Responsive To Urban Stimuli or H.O.R.T.U.S. is a way to revolutionize urban gardening with a blend of renewable energy, computational technology, agriculture, and city lifestyle. There are no plants in this garden prototype but around 300 ‘photobioreactor’ transparent plastic bags that are hung from the ceiling in a wave pattern. Each bag contains numerous species of algae meant to generate biomass, energy, and oxygen. The room also has several bags of bioluminescent bacteria. And the real twist to this project is that people visiting this place are allowed to exhale into these bags, thus feeding the algae with CO2.
The high-tech technology comes in the form of QR code, which is attached to each bag. ‘Cyber gardeners’ can scan the code and collect information and tweet the information about the growth of the algae using their smartphones. Experts believe that this futuristic concept will likely spearhead other such innovative and green projects in the years to come.
Sources and Further Reading