At the pilot plant, the CO2 that conventional power stations release in the form of fumes will for the first time be collected on a technical scale and transformed into biomass by algae. “We practically feed the algae with it. Microalgae use CO2 as a source of carbon. By raising the concentration we can also increase the growth rates”, says Kerner. “But we shouldn’t think that in doing so we could make conventional power stations CO2-free in a big way. We don’t want to compensate, we want to replace fossil fuels with biomass from algae.”
Algae offer some clear advantages: They are high in energy, providing a ten to thirty times larger yield than conventional energy plants like sugar cane, corn or rape and they also take up much less space. Further: “Biomass from algae can also be produced in places where the soil is unsuitable for growing other plants”, adds Kerner. So there are additional advantages, too: It is neither necessary to cut down rain forests, nor does a debate ensue on whether it is right to use food for producing energy if it is needed urgently for nutrition elsewhere. And because it has a relatively high oil content, microalgae can ultimately be pressed to produce biofuels.
That is why in mid-2008 a pilot plant went into operation on the site of E.On Hanse AG in Hamburg-Reitbrook. The project behind the plant is ‘TERM’ (Technologie zur Erforschung der Ressource Mikroalge – Technology for Researching the Resource Microalgae). The facility is unique in Europe. It has a new kind of bio-photo-reactor type from the company SSC. In the open-air plant and under the influence of sunlight the microalgae change the CO2 from the exhaust fumes of a block-type thermal power station into biomass. The resulting biomass can in subsequent process stages be used for the production of energy. The TERM project receives financial support from the City of Hamburg and E.On Hanse AG.
“I will be pleased if we can harvest 100 tonnes of dry microalgae per hectare in the medium term“, is the clear target that Dr Martin Kerner has set for the R&D TERM project. To achieve this, however, there is still a lot of experimental work to be done at the existing plant. “We will have to further improve the surface-volume ratio of our photo-bio-reactors and considerably reduce energy input. Apart from that, we are trying to optimize the light conditions and find out which CO2 concentrations lead to the best growth results.” Without a doubt, there is still a lot to be done.
“waste to energy“ takes place in Hall 5 of the Bremen Exhibition Centre on 10 and 11 December 2008 under the patronage of the Federal Ministry for the Environment, Nature Conservation and Nuclear Safety. The organizers are expecting 134 international exhibitors and 2,000 participants. For more information please visit www.wte-expo.de.