Third generation of biofuels from microalgae
Using fossil fuels resulted in various environmental problems. With the increasing energy demands the world start focusing on renewable sources to meet the growing needs. First and second-generation biofuels are appropriate option to replace the fossil fuels but as a result of producing these fuels “food versus fuel” problem occur worldwide. To overcome this problem researchers start focusing on algal based biofuels.
In 2008 , about 88% of the world’s expenditure of energy was attained by fossil fuels. However, fossil fuels are restricted in supply and will depleted in near future. Moreover, consuming non-renewable energy sources have raised various ecological concerns, including greenhouse gas (GHG) emissions which altogether leads to global warming. Due to the depletion of fossil reserves, climate change, growing energy consumption and other financial problems, there is an overall need to begin alleviation methods and start focusing on natural resources for fuel production.
A biofuel is a fuel produced from renewable biological resources. At present, biodiesel is accepted as inexhaustible diesel fuel as it is eco-friendly, safe and has reduced emission of GHG. There are three generations of biofuels. The first generation of biofuel relies on oil crops (palm oil, sunflower, soybean) and food, the second generation comprises on wastes and inedible parts of the plants (lignocellulosic) and the third generation focuses on microorganism (microalgae) for the production of energy.
Using food crops for fuel production may resulted in ‘food vs fuel’ problem around the globe and consequently there is an increase in biodiesel and edible oil prices. The 2nd generation has higher energy production and can reduce the problem of food shortage however, there are many problems associated with it includes fuel produced is not of good quality, biosafety issues in using animal fat for biofuel production and required complex technologies.
Why third generation biofuels are better?
Since third generation produces biofuel from microalgae, is an exceptionally encouraging hotspot for sustainable energy. The ability of algae to photosynthesize lies in the range from 3%-6% which is greater than many other crops having 0.5% efficiency. The outrageous photosynthetic capability of microalgae makes them excellent source of lipids for the production of biodiesel. Besides their rapid proliferation, they have increase yield and easier to grow than various plants and also have the ability to grow on infertile land. The yield of oil produced by microalgae is 25 times greater than the conventional crops. Additionally, microalgae can produce 121,104 kg of biodiesel annually by utilizing 0.1m2 of land.
Algae also helps in reducing pollution by consuming N and P from wastewater. They are like small factories utilizing atmospheric CO2 and as a result producing fuel for various purposes. Therefore, algae make third generation biofuels are better as they are not competing with human food sources and also the yield is greater as compared to conventional strategies.
There are several types of biofuel produced by various species of algae includes biodiesel, bioethanol, biomethane and biogas by different conversion technologies.
Current research and future prospects
At present microalgae is only produced at small level, over the globe production is only of 6000 tons annually. Technologies that are used to produce algal biofuels include photobioreactors and open ponds system. The open pond system is cheap but they can’t be operated in the absence of sunlight and have less production. However, in photobioreactors there is more yield but they are costly to build.
A short time ago, few organizations in the US were trying to lower down the price of PBR’s. There are several countries like Israel, cultivating algae from long time for therapeutic purposes and also for food and recently they start producing fuel from different species.
There are several companies in US and Europe that are utilizing algae for biofuel production includes originOil Inc, PetroSun, Ingrepo, Neste oil, Blue marble industry and Neptune industries. It is anticipated by the US business that in about 4 to 5 years the commercial production of algal oils will start to happen in the US.
There is not a single industrial unit for algal biofuel production yet develop because several strains of microalgae are not appropriate to use in industrial process and large amount of energy and high cost is also required to start the process. Along these lines, production of algal biofuels is not able to maintain at a certain level. There is not a single strain of algae for the production of biofuel which can be designated as “algal crop”.
Microalgae is capable of producing biofuel but due to high energy input it is still not a practical option. There is no single strategy that can give ideal extraction of lipids for a wide range of microalgae. There is a need to develop a system which require less energy and cost for the production and easily applicable in developing countries.
However, this can be achieved by research and development programs on large scale for efficient production of biofuel and classify the appropriate species of algae with greater yield. This might be attained by genetically modifying the algal species that have more carbohydrates and lipid content. By developing these strains, we can replace the fossil fuels with biofuels.
This article is jointly written by Esha Mehmood and Nida Habib from Kinnaird College for Women, Lahore.