Seaweeds - A source of biofuel
Not only India, but the whole world is engaged in discussing about the problem arising out of increasing energy demand for economic development. Currently due to extensive use, the energy supply has not only reduced considerably but also has become environmentally, socially and financially unsustainable. This has resulted in considering some alternate source for energy conservation, to make employment available and to restrict the carbon-dioxide emission in the environment. This consideration has put forward a new alternative called as biofuel.
Biofuel as an alternative source of energy was gracefully accepted by the whole world. Many scholars commented that biofuel will prove to be a universal remedy on energy crisis. But very soon everybody began to sense the limitations of biofuel.
Limitations of biofuel
- The production of biofuel is completely based on the process of photosynthesis. But this process is very slow and time consuming. Also it requires the usage of grasses and vegetation to a large extent. So it is not effective to produce biofuel as an alternative for mineral oil.
- For cultivation of various sources of biofuel like sugarcane, corn, vegetable oil crops etc, large land area is required. We already have less land area. Only 29% of earth has land and out of it most of the land is inaccessible, barren and not suitable for farming.
- The land which is available is either under forest or utilized for cultivation of food and cash crops. So if this land is used for cultivation of biofuel sources than it might result in starvation of the population.
- One more obstacle in the production of biofuel is the shortage of water required for growing biofuel sources.
After concentrating on these limitations once again the search began for other alternative energy sources. Then the alternative found was biofuel again but this time the source was sea. Since 71% of the earth surface has water, so sea can be widely used as a source of biofuel.
Sea has photosynthetic microorganisms called as phytoplankton. They are responsible for half all the photosynthetic activity on earth and hence produce much of the oxygen present in the atmosphere.
Some important types of phytoplankton include:
These three types of phytoplankton are commonly called as seaweeds. The seaweeds are also called as marine alga which are either attached to rock or any hard substrata as that of diatoms or are mobile like Dinoflagellates. Since the seaweeds obtain their energy through photosynthesis, so they require enough sunlight on their surface layer. Also they are dependent on minerals prominently on carbon dioxide nitrate, phosphate and iron. So, if these seaweeds are provided with enough sunlight and the required inorganic minerals then organic substances can be produced from them. These unicellular microscopic organisms have such a vast source of energy stored in them that this energy can be used to supply the chemical energy to a large population of living organisms.
During the process of photosynthesis, the seaweeds absorb carbon dioxide, radiation and water to produce oxygen and carbohydrates. The seaweeds produce 8-12 billion tons of carbohydrate every year while the total annual carbohydrates produced by the whole vegetation on the earth are only 4 billion tons. From these carbohydrates, phytoplankton produce lipids and proteins and these lipids can be used for energy supply.
There are various strains of phytoplankton which differ in their carbohydrate, protein and lipid content. Those having higher carbohydrate concentration produce starch which can be used for ethanol production. Those having higher lipid concentration can be used to produce biodiesel. Those with higher protein concentration can be used as animal grain.
India has a vast coastline of 750 kilometers and the sea water is very useful in cultivation of sea weeds. There are basically three types of seaweeds:
- Red seaweeds: They are also called as rhodophyta and their red color is due to pigment called phycoerythin.
- Brown seaweeds: They are the largest type of seaweeds. They are also called as phaeophyta and are brown or yellow brown in color.
- Green seaweeds: They are called as chlorophyta and found in marine or freshwater.
Out of these three types, red seaweed is widely used in the equatorial country like India due to its large coastline and the huge productivity from sea water. The red seaweeds are readily available in India and from the productivity point of view near about 100 ton/hector production can be made available from red seaweed which is thrice the productivity of sugarcane.
Advantages of seaweed
- Seaweeds have higher annual productivity than soybeans, sugarcane, wood, corn and other sources of biofuel.
- It can grow at any place having enough sunshine. Thus they can be cultivated on land, fresh water and sea water.
- They complete their life cycle in few days which can cause several harvests in short time throughout the year.
- The energy required to cultivate and produce biofuel from seaweeds is very low.
- Seaweeds can covert the photon with higher efficiency.
- The biofuel produced from seaweed is non toxic and biodegradable.
Sea 6 energy is formed at the renowned technology institute of IIT Chennai. The former students of the institute Nelson Wadaseri, Shailaja Nori, Saumya Balendriyan and Sayeshkumar have established this start up along with Shreekumar Suryanarayan. While doing research as a student they realized that it is not economically affordable to obtain large amount of biomass from mosses. So, they switched off to seaweeds. The Sea6 Company has developed a process for seaweed cultivation on a large scale and has future plans to take the seaweed to fuel production stage using fresh water.
The company has signed an agreement with Danish company Novozymes, one of the leading industrial biotech companies for production of biofuel from seaweed. This alliance will try to develop enzymes which will be used to convert carbohydrates in seaweed to sugar which can then be used to produce bioethanol. Since both the process of hydrolysis and fermentation will be done in saline water, the use of fresh water will be reduced. This is the basic concept of Sea6 Company for biofuel. This technique can be very beneficial to country like India which is scarcity of fresh water.
Future technical advances
The scientists are trying to fulfill the challenge of cheaper and effective biofuel from red seaweeds. They are trying to reduce the cost from 20 rupees/kg to 5 rupees/kg. Traditionally bamboos are used for cultivation of seaweeds. But they break due to its flexibility. So in order to develop the coastal agricultural methods, the scientists are trying to use marine plastic polymer. Since this new technology is easier, it will prove effective to cultivate seaweeds profoundly.
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