Researchers from Fraunhofer Institute for Ceramic Technologies and Systems in Dresden have developed the first-ever biogas plant to run purely on waste instead of edible raw materials - transforming waste into valuable material. The plant generates 30 percent more biogas than its predecessors. A fuel cell efficiently converts the gas into electricity. Until now, biogas plants have only been able to process a certain proportion of waste material, as this tends to be more difficult to convert into biogas than pure cereal crops or corn, for example.
The researchers optimized the conversion of biogas into electricity by diverting the gas into a high-temperature fuel cell, with an electrical efficiency of 40 to 55 percent. By comparison, the gas engine normally used for this purpose only achieves an average efficiency of 38 percent. The fuel cell operates at 850 degrees Celsius. The heat can be used directly for heating, or be fed into the district heating network. The time for which the decomposing waste material, or silage, is stored in the plant is reduced by 50 to 70 percent.
