Algae are a group of photosynthetic organisms that are a group of important primary producers at the base of the food chain. They are mostly adapted to aquatic habitats. The cellular construction of algae may be simple unicellular to large multicellular eukaryotes. Its classification is controversial; they are classified under plants as they are autotrophic and can synthesize their own food by photosynthesis. Whereas, in some studies they are not considered as plants, as they lack certain complex structures of plants like true leaves, rhizoids, and roots.
They play a major role in the functioning of ecosystem (food chain). They serve as food for small fish and other aquatic organisms. They are used as a source of food for animals and humans since ancient times. The highly proteinaceous supplement of spirulina (a type of algae) is used for the treatment of malnutrition in children. In present day scenario, the issue of oil crisis has led to the discovery of using algae for the production of biofuel.
Use of Algae as Biofuel
Biofuel refers to fuel, produced from living or recently dead organisms. It may be in the form of solid, liquid, or gaseous states. Biofuel is used for running vehicles, supplying electricity for household appliances, cooking, etc. Due to the presence of large biomass of algae in fresh and marine water, extensive studies have been conducted for their use as a potential source of biofuel. The important fuels synthesized from algae are vegetable oil, biogas, biodiesel, biomethanol, bioethanol, biobutanol, and dry fuel (similar to coal). Moreover, many countries have implemented highly sophisticated techniques for enhancing mass-scale cultivation of algae.
Advantages and Disadvantages
The rapid growth of algae without spending extra resources is the reason why it is used as a cheap source of energy. Some species of algae can double their mass within a day. In comparison to traditional fossil fuels and other biofuel sources such as soybeans or jatropha, there are certain advantages of using this plant as a source of energy, which are highlighted here.
- One of the major benefits of this biofuel is that many algal species can be used for extraction of biofuel.
- The yield of vegetable oil from this plant species is comparatively much higher (about 30 times) than other land crops.
- Marine water as well as waste water can be used for its cultivation.
- Unlike fossil fuels, biofuels are biodegradable which thus reduces the chance of environmental pollution.
- In case there is spillage of algal biofuel in water sources, there are no significant adverse effects on the ecosystem.
- Algal biofuel does not affect the natural freshwater sources.
In spite of the benefits of this biofuel, there are some drawbacks. The performance of algal biodiesel is lower than other alternatives like biodiesel extracted from rapeseed and soybean. The production of biodiesel from this plant species also results in several other unstable compounds. Since biofuel production from algae is a relatively new technology, more research is required to develop standardized protocols for cultivation and production of biofuel.