Microalgae are frequency versatile organisms. Some strains, for instance, furnish vast quantities of omega-3 greasy acids that have critical health-giving properties, and are therefore used in a combination of food supplements. Many reduction in cosmetic products are also subsequent from algae, such as a red colouring astaxanthin that is extracted from a algal aria Haematococcus pluvialis. Other strains of microalgae furnish oils or starch that can be used to make biodiesel, ethanol or biogas. But a microalgae from that all of these products are subsequent are grown roughly exclusively by American, Israeli or Asian companies – there are usually few blurb prolongation comforts in Europe. In Asia, a nautical organisms are especially cultivated in open ponds. But a apportion of algae that can be harvested from these ponds is singular since they need light to grow, and object frequency penetrates over a initial few inches low in a H2O body. Finally, there is a consistent risk that a algae competence be infested by other microorganisms.
Fully programmed prolongation – underneath particularly tranquil conditions
The entirely programmed plant during a Fraunhofer Center for Chemical-Biotechnological Processes CBP in Leuna was designed to furnish microalgae on an industrial scale. It was built by Subitec GmbH palm in palm with researchers from a Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB and Fraunhofer CBP. “The commander plant enables us to furnish microalgae underneath defined, particularly tranquil conditions,” says Fraunhofer IGB group personality Dr. Ulrike Schmid-Staiger. “We are means to grasp concentrations of algae that are adult to 5 times aloft than those in other forms of sealed reactor – not to discuss open ponds.” As a result, a furnish of algae is significantly incomparable than that of other blurb plants.
The categorical reason for this is light – a primary flourishing condition for algae. To safeguard that sufficient light reaches all of a algae, a researchers chose to build their commander plant regulating flat-panel reactors. These include of arrays of panels measuring 3 or 5 centimeters in thickness, commissioned plumb to a ground. Over a slotted tube during belligerent turn a reduction of atmosphere and CO2 is blown into a nutritious middle in that a algae are suspended. This has dual effects: Firstly, a gas froth arise upward, provision a algae with a CO dioxide they need to grow, and secondly a upsurge of gas stirs adult a algae and causes them to pierce about. In this way, any alga is propelled during unchanging intervals to a aspect of a reactor, where it comes into hit with a light it needs to feed a store of energy. This light comes from a sun: The reactors are commissioned possibly outdoor or in a greenhouse.
From laboratory to industrial scale
Before a sold aria of algae is cultivated in a reactor, a Fraunhofer IGB researchers control laboratory tests to establish a conditions that inspire a growth. Their colleagues during Fraunhofer CBP afterwards imitate these conditions in a full-scale commander plant. “This competence sound easy, though in fact it’s a vital plea that requires a lot of expertise since a plant consists of several companion reactors,” explains Schmid-Staiger. “The algae have to be introduced into all of them during a same time, and it’s also critical that a algae grow during a same rate in each reactor, so that they can be harvested during a same time.” The researchers start out with small, 6-liter reactors, that they bond in series, and afterwards scale adult a formula to incomparable reactors with a volume of 30 and finally 180 liters.
“The plant in Leuna is now producing sufficient biomass for us to be means to control serve experiments on a commander scale,” says Fraunhofer CPB operative Gordon Brinitzer. “This will also concede a handling group to accumulate hands-on knowledge of using a plant of this size. One day this could give arise to a new profession: algae farmer.” In total, a commander plant comprises 65 reactors with a ability of 3.6 cubic meters commissioned in a greenhouse, and 45 reactors with a ability of 8.1 cubic meters commissioned outdoors.
The harvested algae are eliminated to an descent section to remove a fat-soluble substances they contain, such as omega-3 greasy acids. Alternatively, a biomass is sent to plan partners and business for serve processing. Organic farmers, for instance, use a algae to strengthen their crops opposite fungal infections or for harassment control. When algae are churned in with a fertilizer, their fragrance repels insects such as a cabbage base fly, that cite to lay their eggs elsewhere. As Schmid-Staiger explains, “an critical aim of a plan is to find as many uses for a microalgae as possible, since they are still comparatively costly to produce.” The researchers will be exhibiting a 180-liter reactor procedure of their commander plant during a ACHEMA uncover (Hall 9.2, Booth D64).