Full steam ahead
100,000 metric tons of CO2 – that’s how much B E B Bio Energie Baden GmbH wants to save per year at Koehler’s Kehl site. We dropped by for a visit to find out how that will work and what it has to do with the circular economy.
The flames in the 1,000-degree fire bathe the boiler interior in a dazzling light; a peek into the combustion chamber reveals an impressive spectacle. “The more oxygen there is in the boiler, the brighter the fire,” explains Plant Manager Rolf-Peter Höfer, wiping the glass window that offers a glimpse inside. The fire is so fierce that it takes a whole day to switch the boiler on or off – or to start it up and shut it down, to use the industry’s terminology. Like his father and grandfather before him, the 63-year-old power plant expert has spent almost his entire career working in coal power plants, namely in the Ruhr region, where he was born and raised. In 2019, the Gelsenkirchen native wanted to change job and swapped coal for biomass. He now lives in Kehl in Baden-Württemberg during the week, where he manages the two biomass combined heat and power plants of B E B Bio Energie Baden GmbH, a Koehler Group company. Power plants all work on the same principle, regardless of whether they use coal, gas, or biomass, explains Mr. Höfer. Fuel combustion generates heat, which is used to heat water. The steam produced in this process drives a turbine, which is connected to a generator. Besides electricity, the process steam produced is also used for the adjacent paper production plant. The plants work using the cogeneration principle, which achieves an optimal degree of utilization. Both combined heat and power plants are directly adjacent to the Koehler Paper factory in Kehl. Both the electricity and process steam generated are used there to produce paper. The Koehler Group’s biomass combined heat and power plants at other sites supply local industrial customers. This is contributing to the Koehler Group’s promise to generate more green energy by 2030 than it needs for paper production.
Unlike solar or wind, biomass is always available.
Plant Manager
B E B Bio Energie Baden GmbH owns and operates two biomass combined heat and power plants fueled by waste wood at the Kehl site.
Paper and Energy Production – Part of the Circular Economy
Burning wood is considered to be environmentally friendly because it only releases as much carbon dioxide as the tree absorbed during its growth. The CO2 released during combustion is in turn taken in by growing trees, creating a cycle. Thanks to the two biomass combined heat and power plants, the Koehler Group is saving around 100,000 metric tons of CO2 per year in Kehl. The Group is adopting a holistic approach where waste is reused. Circular thinking plays an important role here too: Besides wood and sewage sludge from local treatment plants, paper mill sludge is also used as fuel. That means a waste product from the paper factory is turned into electricity, steam, and heat for new paper. The ash produced during combustion is recycled as a filler for road construction or mining, for example. At the Kehl site, CO2 in the combustion gases is used to produce fillers through precipitation with burnt lime, which in turn are used in paper production.
years of wood chip deliveries to Kehl have already been notched up by Zollikofer.
The firewood required in Kehl is supplied by Zollikofer, a company based in Allgäu. Managing Director Stefan Zollikofer traveled to Kehl today to have a look around the power plants. He loves wood: “I’m fascinated by its versatility – and the fact that you can even obtain energy from it,” he enthuses. Besides combined heat and power plants, the company also supplies customers in the pellet and chipboard industry. Zollikofer has had a trusting business relationship with B E B for 20 years now. The two companies moved even closer together in 2021, when the Koehler Group acquired a 60 % majority stake in the Zollikofer Group.The company supplies Kehl with waste timber in the form of wood chips from the construction and demolition industry, pallets, furniture, or old chipboard. The material comes from a 180-kilometer area surrounding Kehl – in other words, the Black Forest, France, and Switzerland. Mr. Zollikofer was keen to emphasize: “Quality control is essential.” Impurities and foreign bodies such as film, fabric scraps, and metal are removed beforehand. To double check, the sorting system in Kehl inspects the wood chips again when they arrive. “The most peculiar things we have ever found were a manhole cover and a concrete pillar,” recalls Mr. Höfer with a smile. Discoveries such as these are removed and taken to the scrap yard.
The steam generated in the combustion process is conveyed to the paper factory in pipes.
The brighter the fire, the more oxygen there is in the boiler.
A Step in the Right Direction
Around 30 employees in 4 shifts ensure the boilers at both power plants run continuously – 24 hours a day, 365 days a year. “That is the advantage of biomass – unlike solar or wind, it is always available,” says Mr. Höfer. He liaises continuously with the control station team, which keeps an eye on everything using monitoring and control systems. When malfunctions or failures occur now and again, the staff can intervene directly. You can tell Rolf-Peter Höfer enjoys his work: “I like the variety; no two days are the same here.” The fact that the Koehler Group is actively promoting the energy transition in Germany is a positive thing, Mr. Höfer believes. He is a grandfather of two and would like his grandchildren to grow up in a healthy environment. He is also well aware that the Koehler Group’s efforts alone cannot stop global climate change. Nevertheless, he remains optimistic: “All companies should set ambitious sustainability goals to protect our environment.”
Plant Manager Rolf-Peter Höfer (right) and Stefan Zollikofer at the unloading site
I am fascinated by the versatility of wood and the fact that you can even obtain energy from it.
Managing Director of the Zollikofer-Group
Birgit Hagebölling
Managing Director of Bio Energie Baden GmbH and Corporate Director of Technology and Operations at Koehler Renewable Energy.
What is the Koehler Group’s sustainability strategy?
We follow the UN Sustainable Development Goals (SDG) and have identified six areas of action for the Group based on these goals. We use renewable raw materials from responsible sources to manufacture successful, future-proof products. We aim to be a climate protection visionary and use our resources efficiently to this end. We also want the company’s value to grow at the same time. All of this is only possible with committed, qualified employees, which is why people are the key to the success of our strategy. We also have our own ambitious climate goal, which we call the Koehler Promise. It is about generating more energy from renewable sources than is required for paper production operations by the year 2030.
What role do the power plant conversions play in the sustainability strategy?
A very large one. One of our goals is to reduce our direct emissions from the use of fuels by 80 % by 2030. In the future, we will run the Greiz power plant on fine wood fraction, and that alone will save around 24,000 metric tons of CO2. In Oberkirch, we are expecting the conversion to biomass to cut CO2 emissions by 150,000 metric tons. So overall, we will have a good part of the work behind us and will be contributing significantly to SDG 7, which aims to secure access to affordable, reliable, sustainable, and modern energy for all.
What are the next steps to reduce direct CO2 emissions even further?
We currently still power the boiler at our Weisenbach site with natural gas/heating oil and want to replace these fossil fuels. We are planning a system of different energy sources for this. At the moment, we are examining the cost/benefit elements of different technologies to find the most economical solution. The options include biogas, wind power, and photovoltaics. Biogas is considered to be environmentally friendly because it is produced from organic waste. Wind power uses an inexhaustible resource and does not cause any air pollution. Photovoltaic plants produce clean electricity from sunlight without releasing greenhouse gases. With this kind of energy mix, we will be in a good position to emit even less CO2.
