Some microalgae are really attractive for biofuel production. (Image: Embrapa)
Suitable microalgae identified to produce biofuels
Tuesday, March 07, 2017, 00:50 (GMT + 9)
After three years of research, Embrapa Agroenergía (DF) has identified microalgae species that can be grown in liquid waste from agroindustry processing, and that generate renewable raw material for biofuels, food and cosmetics, among other products.
The effluents used in the studies were vinasse - formed in the production of cane sugar and ethanol -, and waste water generated in the processing of palm oil, used for irrigation purposes. The use of these products as a means to produce microalgae will add value to sugarcane and palm oil supply chains by producing more biomass and energy oils and bioproducts.
Microalgae reproduce very quickly, and provide large amounts of oil and biomass. Its productivity can be between 10 and 100 times greater than traditional agricultural crops, which is attractive for sectors that require large amounts of raw material, such as biofuels.
The oil produced by certain species often contains highly valuable compounds, such as omega-3 fatty acids and carotenoids. Therefore, they can also be used in industries that supply market niches and pay more for raw material with uncommon properties. This is the case in the cosmetics and food supplement industries.
There are at least four companies producing microalgae in Brazil: two in the Northeast, with a focus on human and animal nutrition, and two in São Paulo, which supply cosmetics and food industries, as well as sewage treatment projects.
However, there is still a lot to do in order to progress in knowledge and development of technology to boost the sector. The reduction in production cost is a major concern, especially when the aim is to reach markets that require large volumes and lower prices, such as biofuels.
The first work by EMBRAPA scientists was aimed at knowing the species capable of growing in vinasse, in industrial environments and biomes (Amazonia, Pantanal and Cerrado). Two species were identified that can be stocked in the effluents, with a good yield (one of them has not yet been described in the literature). The analysis of the components of the biomass of these two microalgae indicates a higher concentration of carbohydrates and proteins to the lipids and carotenoids, which make them more suitable for biodiesel for ethanol production, when what is sought is to produce biofuels. They can also be used for food.
The two species selected carry out photosynthesis but also use the organic matter of the vinasse to grow. They are not able to significantly reduce the organic load and therefore, they can not be used only to treat effluents, but they allow the vinasse to be used for sugarcane irrigation after the microalgae are removed.