Are microalgae a possible energy source for a sustainable world?

V. Kava, J.V.C. Vargas, A.B. Mariano, J.C. Ordonez
Federal University of Parana,
Brazil

Keywords: food supplements, biofuels, pharmaceuticals, compact photobioreactors

Summary:

In recent years, much scientific research has been directed to the search for viable alternatives to clean energy. Investments in research and development of renewable energy sources have been implemented, and the economic viability of clean energy use has become a possible reality in the near future. One of the harshest criticisms of vegetables derived biofuels is the use of food producing agricultural land for biofuel production, whilst hunger still harms many countries. In such a scenery, the development of economically viable methodologies for microalgae derived bioproducts and biofuels would be very much appreciated. Energy generation is one of the most important microalgae applications in different forms, such as biodiesel, biohydrogen, and biogas. The industry sector attention has been increasingly attracted to microalgae derived biodiesel since it is ecologically correct and potentially more productive than oil crops. Additionally, many high valued substances of interest to the pharmaceutical and nutrition industries, such as carotenoids derivatives. Microalgae could be cultivated in compact photobioreactors (PBR), thus not competing with agricultural land. Cultivation conditions could be controlled and should be adequate for each species. After reaching the best conditions, the production increase is expected to be limited, however genetic modification strategies with the recombinant DNA technology or genetic engineering could make possible a real productivity increase aiming at industrial production scale. The technical literature shows that in the past 30 years there was a substantial increase of the scientific community interest about microalgae and bioenergy, with an exponential increase in the past 10 years, mainly from the USA, China, Germany and the UK. In this paper, the essential fundamentals for facing the challenges to be overcome to turn viable microalgae industrial utilization are presented. The discussion includes the microalgae biological characteristics; possible direct and indirect applications; the search for genetic improvement based on food biophysics and other high interest products; the use of the mathematical modeling and computational simulation tool for evaluating potential results before large financial investments; perspectives about large scale microalgae production in ponds and photobioreactors, and a critical appreciation.