In this blog we will discuss some interesting aspects of microalgae, advantages and what barriers are necessary to cross in order to use these microorganisms as a sustainable energy source. Microalgae are unicellular microorganisms capable of photosynthesis. That is, they are capable of generating organic biomass from CO2 (as an inorganic source of carbon) and light (as an energy source). It is a 3G energy source.It is important to know that not all species of algae are suitable for the production of biodiesel. There is currently no known algae strain that can be considered the best in terms of oil yield for obtaining biodiesel, but the Porphyridium cruentum strain is a good example of the potential that some strains have [1].
The research that has been carried out over the last 50 years has shown that microalgae are capable of producing a wide range of chemical intermediates and hydrocarbons that offer the possibility of replacing petroleum or natural gas products. Three main components can be extracted from the biomass of the microalgae: lipids (including triglycerides and fatty acids), carbohydrates, and proteins. The bioconversion of these products into alcohols, methane, hydrogen, organic acids and the catalytic conversion of paraffins, olefins and aromatic compounds, make the exploitation of microalgae a true biorefinery industry.
Pros: [2],[3],[4]
It has many advantages over its competitors obtained from crops for food consumption:
-Independent of arable land.
-High productivity per unit area. Unlike other oil crops, algae grow exponentially (doubling every 8 hours or so).
-High levels of production under controlled conditions; which implies the possibility of being cultivated throughout the year.
-It is not a food resource. Therefore, it does not compete with agricultural activities.
-Use of a wide range of water sources. Water used for algae cultivation can include sewage and non-potable brackish water that cannot be used for either conventional agriculture or domestic use.
-Mitigation of the release of GHG into the atmosphere. Algae have enormous potential to reduce greenhouse gas emissions through the use of CO2-rich gas streams from thermal power plants and natural gas recovery operations.
Cons: [5]
-No competitive cost. It requires technological development to lower the current price of biodiesel. The Cyclag project, in which 6 research centers in France and Spain have participated, estimates that biodiesel could be obtained from cultivated microalgae for a value of 3.3 $ / l.
-Lack of aid. It requires incentives or subsidies from governments for the development of techniques that lowers the cost.
-A joint cooperation between the research centers of these crops is necessary, since at present the lack of transparency of these centers is slowing down their development.
Conclusion: [6]
Microalgae are an alternative for obtaining biodiesel due to its high lipid yield and its fatty acid profile. This would mean extending the useful life of diesel vehicles, reducing the pollution caused by fossil fuels.
Sweden has an advantage over other countries, it has many aquifers that can be used for both closed and open systems. This energy source provides another possibility to achieve an independent national transport of fossils by 2030.
As we have seen, the advantages outweigh the disadvantages. However, the economic barrier (achieving lower production costs) makes this fuel unfeasible at present.
References:
[1] Tredici, M.R., Biotechnology and Applied Phycology (2004)
[2] Biofuels from algae: Technology options, energy balance and GHG emissions. Insights from a literature reviem EUR 27582
[3] U.S.DOE 2010: “National Algae Biofuels Technology Roadmap”. U.S Department of Energy, Office of Energy Efficiency and Renowable Energy, Biomass Program
[4] I.Priyadarshani, B.Rath: ”Commercial and industrial applications of micro algae – A review” . J.Algal Biomass Utln. 2012, 89-100
[5] www.innovadores.larazon.es/es/cientificos/microalgas
The Environmentalization 