Project meeting of STEP at the site of the company ATS - Agro Trading & Solutions in Hardegsen (Photo: DBFZ)

Heat Power Biogas

Project ID 03EI5403

KoSaTZ - Treatment and combined use of straw and residual materials from grain processing for a biogas technology chain with a future

Recording of the flow conditions when mixing straw (pellets) in the wet fermenter (source: IKTS)


  • 01.01.2020 – 31.12.2021


Fraunhofer Institute for Ceramic Technologies and Systems IKTS
Biomass Technologies and Membrane Process Engineering
Winterbergstraße 28
01277 Dresden

Dr. Burkhardt Faßauer – project leader
Telephone: +49 (0)351 2553-7667
E-mail: burkhardt.fassauer‍@‍

Björn Schwarz – direct contact person
Telephone: +49 (0)351 2553-7745


03EI5403B - ATS - Agro Trading & Solutions
03EI5403C - Agrargenossenschaft "Bergland" Clausnitz e. G.
03EI5403D - DBFZ Deutsches Biomasseforschungszentrum gemeinnützige GmbH
03EI5403E - Rückert NatUrgas GmbH

Associated partners

Cooperation partners



Planned results:

  • Plant level: process optimization
  • Concept level: system concept
  • Market level: business plan, business models


In Germany and also internationally, alternative, sustainable and affordable input materials for biogas plants are of great interest. In the long term, the industry will have to concentrate primarily on residual materials in order to achieve cost efficiency and image enhancement. The KoSaTZ project is based on important findings from the predecessor projects EFFIGEST and STEP and focuses on the improvement of biogas production from straw and residues from grain processing.


The following objectives are being pursued to achieve a significant increase in efficiency. The addition of alternative agricultural residues from grain processing is intended to reduce raw material costs. Alternatively, the use of briquetting technology instead of pelleting technology is to be tested. An intermediate use of straw or mixed pellets as bedding in animal husbandry with subsequent utilisation in the biogas plant should lead to an increase in added value. A regulation for the mixing of straw or mixed pellets in large-scale biogas plants to save energy and avoid accidents should eliminate existing uncertainties.



  • Screening, procurement, storage and testing of straw and alternative residue streams from grain processing
  • Adaptation of the pelleting process to the new mixtures of substances, experiment execution of pelleting tests
  • Large-scale production of bedding pellets, recording and evaluation of operating parameters


  • Use of the project-specific pellets in animal husbandry, adaptation of internal logistics
  • Comparison to the conventional use of chopped straw
  • Realisation of the practical use of the used bedding pellets in the 75 kW practical biogas plant (1250 m³)
  • Operational monitoring and control


  • Small-scale tests for pelletizing the substrate mixtures (use of 10 mm dies compared to 8 mm dies at ATS and evaluation of the process difference
  • Systematic experiments for briquetting of substrate mixtures (process comparison for pelletisation)
  • Analysis of the mechanical properties of the products
  • Investigation of the transferability of pilot scale pelleting to industrial scale pelleting (parameter transfer, differences in product quality, energy consumption)


  • Recording of quantity and energy potentials for the favoured material flows
  • Clarification of licensing and safety issues
  • Specification of the feeding regime and the stirring intensities during the pilot test
  • Evaluation of the operating data


  • Analysis of the material, energetic and fluid dynamic properties of pellets and briquettes
  • Balancing of energy losses along the utilisation path
  • Systematic investigations of the swelling and mixing behaviour of straw pellets, mixing pellets, briquettes and solid manure after intermediate use in a 1m³ round digester (process tomography)
  • Design of experiments and analytical monitoring of the practical fermentation



  • Raw material procurement, pelleting, product marketing


  • Practical cascade use and evaluation of the project-specific pellets in the agricultural enterprise
  • Animal husbandry
  • Biogas production


  • Briquetting, pelletizing, analysis


  • Balancing of material flows and energy
  • Licensing law


  • Analysis, mixing and stirring, fermentation


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