New Jenbachers Make Ottersberg Plant Largest Biogas Complex In Germany

BENAS GmbH has added two Jenbacher J620 gas engines with a capacity of 3.05 MW each to its plant in Ottersberg near Bremen, making it the largest single biogas engine complex in Germany.

The update also increases the electrical efficiency of its plant by 7.2 percentage points and reduces its raw material needs and cuts the required crop acreage and transport costs by 19.5%, the company said. In absolute terms, BENAS’ energy corn demand, which provides part of the plant’s biogas supply, has been cut by around 15 500 tonnes per year and the area cultivated for this purpose by around 370 hectares. As was originally the case, the Ottersberg plant is operated solely using renewable raw materials and dried poultry manure.

“Twenty-five years ago, we were among the first farmers to build a biogas plant,” said Jürgen Heitmann, the BENAS GmbH founder. “And now as then, we wish to contribute to the energy transformation, make our company more environment-friendly and naturally enough, earn a little money as well.”

With a workforce of 45, BENAS grows energy plants at three locations on a total of 3300 hectares. The biogas plant, which was designed and built by the company itself, currently disposes over a fermentation volume of 43 000 m³, gas storage capacity of 33 000 m³ and net installed electricity output of 11.35 MW. In addition, BENAS operates a gas treatment plant in which 1200 m³/h of biogas is upgraded to natural gas quality.

The investments in the new plant mean that Ottersberg can now generate 28 000 MWh of electricity annually. This will be both fed into the grid and employed to heat a fiber processing plant, which has been developed jointly with Gesellschaft für Nachhaltige Stoffnutzung mbH in Halle.

“The decisive reason for the investment was the enormous improvement in the efficiency of combined heat and power plants during the past 15 years,” According to Christoph Heitmann, the BENAS CEO, who was responsible for the planning and construction of the new CHP plant.

In the course of the building work, the heat supply emanating from both cooling water and exhaust was fully automated and adapted to match the new overall system. As a result, the output of the fiber treatment plant was raised by 50% and simultaneously, a high degree of safety was achieved by means of linked process control technology.

Owing to the operational flexibility that it offers, bioenergy is seen as being of major importance to the energy turnaround. Biogas plants can start up quickly and are therefore able to compensate for grid fluctuations.

“As opposed to solar or wind power, biogas is an energy source with storage capabilities that can be used to produce power or heat at any time of the day and year regardless of whether the sun is shining, it is raining or it is storming,” said Norbert Hetebrueg, general manager for Central and Northern Europe at INNIO Jenbacher. “Consequently, INNIO’s fuel-flexible Jenbacher gas engines constitute an integral part of the global energy transformation and can contribute to power supply security.”