Raw materials from residues: test of sustainable and energy-efficient sewage sludge utilization
- Project consortium is testing novel process for converting organic waste into high quality raw materials. As part of the research project funded by the Bavarian State Ministry of Economic Affairs and Media, Energy and Technology with € 1.959 million, a plant for the sustainable recycling of municipal sewage sludge will be built in Schwandorf.
- Susteen Technologies GmbH supplies a system that converts daily up to 7 tons of dried sewage sludge into storable syngas, engine-friendly bio-oil and phosphate-rich biochar.
If the reorganization of sewage sludge utilization by the Federal Ministry for the Environment, Nature Conservation, Building and Nuclear Safety (BMUB) prevents the application of untreated sewage sludge in the coming years and commits to the recovery of phosphates, the operators of sewage treatment plants face major challenges. The Zweckverband Thermal sewage sludge utilization Schwandorf (ZTKS) reacts early and builds in Schwandorf a plant for the drying of sewage sludge. In addition, a globally unique, new process for the economic utilization of sewage sludge is used.
In the so-called thermo-catalytic reforming (TCR®) process, the dried sludge is split into its constituents in a special reactor under the action of heat. This produces synthesis gas, bio-oil and biochar. The process is a development of the Fraunhofer Institute UMSICHT in Sulzbach-Rosenberg and is developed to market readiness by Susteen Technologies and marketed exclusively. "We are happy to be part of the project," says Susteen CEO Thorsten Hornung. "This project provides us with optimal conditions for further developing our process for use under industrial conditions. The aim of the project is, in particular, to achieve continuous plant operation with efficient generation of electricity and heat at a combined heat and power plant. The energetic potential of sewage sludge can thus be optimally made available. "
Numerous waste materials have already been successfully tested at the laboratory scale. In addition to digestate from biogas plants, sludges from paper production, horse and chicken manure also included sewage sludge. "Nowadays sewage sludge is partially thermally recycled and converted into electricity via steam turbines," says Hornung. "Conventional incinerators can not react flexibly to the current demand for electricity and generally achieve lower efficiencies." Here, the TCR® process clearly has the advantage: it converts the sewage sludge into high-energy synthesis gas and motor-driven bio-oil. Within the scope of the project, these raw materials are to be converted into electricity and heat in a dual-fuel cogeneration plant with up to 240 kilowatts of electrical power. Adaptation and testing of the combined heat and power plant are managed by the Institute of Energy Technology (IfE) at OTH Amberg-Weiden as project partner.
"This not only increases the flexibility of sewage sludge utilization, but also increases the electrical efficiency due to modern CHP technologies," says Hornung. At the same time, a gasification of the produced biochar from sewage sludge to generate the process heat for the process is being tested. The valuable phosphorus remains in the biochar or ash and can flow back into the economic cycle.
In addition to technical and economic questions, the 34-month project will also investigate how the technology can be integrated into an overall concept for Bavaria's use of sewage sludge.
- About the Institute of Energy Technology (IfE) GmbH at OTH Amberg-Weiden
The Institute of Energy Technology (IfE) at the Ostbayerische Technische Hochschule Amberg-Weiden deals with an interdisciplinary team of scientists and engineers with applied research and development in the fields of renewable energy, energy efficiency and combined heat and power. Based on the findings from research, the IfE develops innovative energy supply concepts for industry, trade and municipalities and accompanies the implementation of new technologies into practice as a scientific partner in demonstration and pilot projects.
The IfE closely cooperates with the Competence Center for Combined Heat and Power of the Ostbayerische Technische Hochschule Amberg-Weiden (OTH), whose research focuses on emission reduction, biogenic fuels, CHP system technology, increasing energy efficiency and new CHP technologies. The IfE has received several awards for the implementation of innovative CHP and industrial projects in recent years. i.a. with the EON Environmental Award and the Bavarian Energy Award.
- About Susteen Technologies GmbH
Susteen Technologies GmbH develops and markets "Clean Technology". The company is a spin-off of the Fraunhofer Institute UMSICHT and is located in Sulzbach-Rosenberg.
Susteen has the vision to create a new generation of sustainable commodity platforms. This makes it possible to extract gas, oil and coal from all those carbonaceous residue streams that can not be recycled economically with other techniques. In this way, the carbon cycle is closed.
Susteen relies on the TCR® process, for which it has received an exclusive, worldwide license from the Fraunhofer-Gesellschaft. Based on its innovative technology, Susteen not only develops a wide variety of biomass applications, but also designs and supplies TCR® reactor systems.
- About Zweckverband Müllverwertung Schwandorf (ZMS)
Zweckverband Müllverwertung Schwandorf (ZMS) is a public corporation. As early as 1979 waste disposal bodies of the Upper Palatinate, Lower Bavaria and Upper Franconia joined together to fulfill part of the waste management tasks.
The task of the DMF is to treat the non-recyclable, combustible residual waste thermally and to use it energetically.
A total of 17 members of the association ZMS today, namely the independent cities Amberg, Bayreuth, Landshut, Regensburg and Weiden idOPf., The counties Amberg-Sulzbach, Bayreuth, Cham, Kulmbach, Landshut, Neumarkt i.d.OPf., Neustadt a.d. Waldnaab, Regensburg, Schwandorf, Tirschenreuth and the Abfallzweckverbände AZV city and district court and ZAW Straubing city and country. Association chairman is the Schwandorfer district administrator Thomas Ebeling.
The disposal area covers an area of about 15,000 km² (which corresponds to about one fifth of the area of Bavaria), about 1,850,000 inhabitants in this area are disposed of by the waste power plant Schwandorf of domestic, restricted and commercial waste.
The energy generated by waste incineration at the Schwandorf waste-to-energy plant is used in the form of steam, district heating and electricity. State-of-the-art flue gas cleaning systems ensure that waste disposal at the Schwandorf waste-to-energy plant is environmentally friendly, economical and safe.