Lohne -- More electricity with the same input? That's what the Organic Rankine Cycle technology (ORC) employed by the Lower Saxon biogas plant manufacturer EnviTec Biogas can do. Biogas plant operators in particular can profit from the procedure that the listed company already uses successfully throughout Europe.
ORC technology was originally developed for operation of steam turbines using an alternative working medium instead of water vapour. Today it is used to convey the waste heat generated in a co-generation plant during electricity production via a carrier medium to the ORC cycle. The heat causes the organic working medium to vaporise. The high-pressure steam thereby generated is then conducted through a turbine and converted into electrical energy by a generator. The working medium is then liquefied in a condenser and fed back to the cycle process. The electrical energy created in the process is fed into the public power grid.
'As the ORC technology is a simple closed cyclic process these plants convince in operation above all thanks to the low costs and maintenance they require', explains Jürgen Tenbrink, Chief Technology Officer of the Lohne-based biogas all-rounder.
The cost-efficient technology has won over operators of a biogas plant located in the Lower Saxon town of Bergen near Celle. Their 1,067 kWel EnviTec biogas plant with CHP which is operated with renewable raw materials and pig slurry recently has been upgraded with the ORC waste heat technology. This will result in an additional output of 96 kWel, which will be fed into the grid. In addition to the extra electricity generated in the process, there is also still enough waste heat left for the fermentation process.
For operators, an ORC plant is an investment that pays off: 'Usually, the costs have been amortised after about five years', reports Axel Faulborn, Head of the Construction Management Department at EnviTec. In addition to the financial bonus for EnviTec customers, the environment also benefits from the ORC technology used. 'Over half of the energy used worldwide by industry and agriculture is still lost as waste heat', explains Jürgen Tenbrink. Its sustainable use therefore opens up potential for the alternative generation of electrical energy, not only in Germany, but throughout Europe.
About EnviTec Biogas AG
EnviTec Biogas AG covers the entire value chain for the production of biogas, including the planning and turnkey construction of biogas plants and biogas upgrading plants as well as their commissioning. The company takes charge of biological and technical services on demand and also offers full plant and operational management. In addition, EnviTec also operates its own biogas plants. In 2011, EnviTec Biogas along with EnviTec Energy GmbH & Co. KG and its 100% subsidiary EnviTec Stromkontor GmbH & Co. KG expanded its business operations into the direct marketing of upgraded biomethane as well as the marketing of green electricity and balancing energy. EnviTec Biogas AG currently operates in more than 20 countries. In 2013, EnviTec generated revenues of €148.8 million and an EBIT of €2.4 million. The EnviTec Group currently has 350 employees. EnviTec Biogas has been listed on the Frankfurt stock exchange since July 2007.