Research Finds Microalgae That Grow in Waste and Generate Biofuels

(Embrapa (Google translation)) Embrapa Agroenergia (DF) was able to identify species of microalgae that can be cultivated in liquid waste from agroindustrial processes, effluents. This crop can generate renewable raw material for biofuels, feed, cosmetics and various other products. The research, which lasted three years, also resulted in the discovery of previously unknown species in Brazilian biodiversity.

The effluents used in the studies were vinasse, formed in the production of sugar and ethanol from sugarcane, and Pome ( palm oil mill effluent ), which is generated in palm processing. They are used, today, for fertirrigation of the plantations. Using them, however, as a means to produce microalgae, can add value to the sugar cane and palm production chains, generating more biomass and oil for energy and bioproducts.

Microalgae are unicellular and microscopic organisms that live in aquatic environments and have a curious feature: although they are not plants, they are capable of photosynthesis and develop using sunlight and carbon dioxide. They reproduce very quickly, generating large amounts of oil and biomass in a short time. Productivity can be ten to 100 times greater than traditional agricultural crops. This has caught the attention of sectors that require large amounts of raw material, such as biofuels.

At the same time, the oils produced by some species almost always contain very valuable compounds such as omega 3 and carotenoids. As a result, they also find space in industries that serve niche markets and pay more for raw materials with rare properties. This is the case with cosmetics and food supplements.

There are already at least four companies in Brazil producing microalgae: two in the Northeast, focusing on human and animal nutrition, and two in the interior of São Paulo, already serving cosmetics and feed industries, or effluent treatment projects. However, there is still much to advance in the knowledge and development of technologies to boost the sector. Reducing the cost of production is a major concern, especially if you want to reach markets that require large volumes and low prices, such as biofuels.

Vinasse is rich in nitrogen, phosphorus and potassium (NPK), nutrients as necessary to microalgae as to plants.Using it as a cultivation medium, however, has its challenges , explains researcher Bruno Brasil, Embrapa Agroenergia. If, on the one hand, the concentration of nutrients favors the growth of organisms, on the other hand the dark color makes it difficult to pass light without which there is no photosynthesis. To minimize this problem, the Embrapa Agroenergy team used low cost chemical clarification methods or simply diluted the vinasse in water. Another challenge associated with vinasse is the high load of organic material. It favors the proliferation of bacteria and yeasts, which become contaminants in the culture medium and impair the growth of microalgae.

The two species selected by the Embrapa Agroenergy team are mixotrophic. This means that they perform photosynthesis, but also use the organic matter of the vinasse to grow. READ MORE and MORE (Fish Information & Services)