Converting Organic Matters from European urban and natural areas into storable bioenergy

The utilization and development of environmentally friendly technologies are key factors for the achievement of the ambitious aims of EU to increase the share of renewable energies. The energetic utilization of biomass has an important role, as in contrast to other renewables (wind/PV), biomass is storable and it is possible to produce storable bio-fuels.


However, currently the energy production from biomass is often economically inefficient, e.g. through an insufficient utilization of waste heat in conventional biogas plants. The conventional production of biomass for biogas plants often is eco-inefficient, for example due to the dominance of maize and the increased risk of soil erosion and nutrient losses. The competition with food production on fertile land and the resulting increase of prices for land and agricultural products causes ethical and socio-economic problems.


Therefore COMBINE aims at opening up abandoned urban, Harvesting at Wollmatinger Ried, © Volker Kromreynatural and agricultural areas for the energy production. This target is important for the region of Lake Constance since protected landscapes like the Wollmatinger Ried with its nearly 800 ha and the large energetic potential of its landscape management materials could be used for decentralized energy production.


IFBB - Integrated Generation of Solid Fuel and Biogas from Biomass

COMBINE is based on the IFBB technology, which has been developed at the University of Kassel in the early 2000s and tested on laboratory scale up to the year 2008. It has been successfully up-scaled (to 1:20) between 2009 and 2012 in the forerunner project PROGRASS.

 The IFBB process, © University of Kassel

This technique aims at dividing the grassland silage into a solid part for combustion and a liquid fraction for biogas production. In addition, the separated solid fraction (press cake) is used to provide a storable biofuel.


By adding an IFBB process to existing biogas or waste water treatment plants the waste heat is used for drying the press cake and consequently stored in a solid fuel which increases the efficiency of the integrated process. One example of a so-called add-on device is located at the environment service provider Environment Technique Baden-Baden, which is used to improve the environmental-friendly process of bioenergy production of a neighboring biogas- and sewage water plant.



At the project COMBINE-project, we have partners from Germany, Wales, Belgium and France:University of Kassel (DE), BUPNET (DE), Environment Technique Baden-Baden (DE), SWEA (GB), National Trust (GB), CWM Harry (GB), University of Gent (B), Inagro (B), Pronatura (B), Aile (F) und CG22 (F). Its leading partner is the University of Kassel.



The project COMBINE is sponsored by Interreg IV B.




If you're interested in further information, visit our COMBINE homepage ( or contact:

Volker Kromrey

++49 (0) 7732/999548