During the last two decades, the use of biofuels has shown rapid growth,
driven mostly by policies focused on increasing energy efficiency, and replacing fossil
energy by renewable energy. There are different biomass raw materials that have been
evaluated for the production of several added-value products. These raw materials have
been classified into the first generation (agricultural and edible crops), second
generation (inedible agroindustrial residues) and third generation (algae). The interest
in the cultivation of microalgae has been increasing due to the high value products that
can be obtained. Additionally, the oils present in microalgae are used for the production
of biodiesel and the cake resulting after processing can be used for the production of
bioethanol, biobutanol or energy. Based on this, this chapter first introduces the current
uses and applications of multiple species of microalgae in terms of energy production
and describes the technologies being used for the production of bioenergy using microalgae.
Then, two specific cases are analyzed: cogeneration and biodiesel production.
The performed analysis serves to conclude that in order to establish microalgae as an
energy-producing feedstock, it is necessary to integrate their use to obtain multiple
products simultaneously: metabolites due to their high value, oils to produce biodiesel
and the dry cake for thermochemical production of energy. The extraction of multiple
products can only be made possible if a biorefinery concept is applied.
Keywords: Microalgae, Biorefineries, Bioenergy, Biofuels, Biodiesel,
Cogeneration.
