Development of a method for the energetic use of brewery wastes

Development of standard parameters for pyrolysis of remains and other recycling, for complete use of pyrolysis gas by methanisation and recycling of biogas in a gas motor work facility

The project idea arises out of the need for energetic use of brewery waste, mainly the spent grain, filter residues, yeast and wastewater, by means of pyrolysis and fermentation. With current energy prices as they are, this recycling process is very interesting and will be the starting point of the process to be developed within this project. The situation today: In breweries, the spent grain is usually given away as animal food, and frequently ends up as 'fertilizer' on farms. At present there is no technical possibility for treating the wet remains (spent grain with only 20 percent dry substance). The waste is stored for a short time in storage silos which have to be drained daily as the remains turn sour very quickly and smell bad. The use as animal feed or fertilizer results in low economic returns and involves the following risks: 1. If there are any animal diseases in farms of the surrounding area, farmers' vehicles are not allowed to drive onto the brewery premises because of the danger of epidemic. 2. Furthermore much of the spent grain is increasingly substituted in animal feed by residues of bio fuel production (bio diesel, alcohol, such as rapeseed cake ore molasses). Large amounts of highly nutritious feed will be put into the market. The prospect for marketing spent grain to breweries is shrinking continuously. 3. On the other hand, cattle stock numbers are decreasing permanently in Europe. 4. Since the beginning of 2005, the deposit of the spent grain into dumpsites (as fertilizer) is not allowed any longer and has to be carried out according the special guidelines. This must be documented and thus results in additional costs. This project aims to develop a new method which combines pyrolysis and fermentation. Both technology steps are currently used in many industrial processes separately, but not for this specific application and not in combination. The new method will enable complete use of the process heat arising as well as low temperature heat. The pyrolysis gas may be cleaned (washed) and applied in anaerobic process equipment. The obtained pyrolysis gas (mainly methane) will be used for drying the remains or will be used in steam vessels. The equipment will be operating continuously. The facility will be relatively small and will use the discontinuously obtained spent grains within the brewery. Pyrolysis will be a closed process together with the anaerobic treatment of the wastewater. The pyrolysis gas will be quenched not discharged into the open, however used in the fermentation process. Therefore the administrative approval process for such facilities (building license) will be quite simple. The complete treatment of the pyrolysis gas by a multistage fermentation process will enable us to use the complete heat energy content of the pyrolysis gas. This results in increased efficiency in comparison with the difficult direct use of pyrolysis in internal combustion engines. By combining pyrolysis and fermentation technologies, the addition of further biogene remains (bio waste, sewer sludge, etc.) will be possible. All excess sludge of the wastewater treatment plant can be energetically used within the brewery. Keywords: pyrolysis, fermentation, brewery.
Project ID: 
3 540
Start date: 
Project Duration: 
Project costs: 
830 000.00€
Technological Area: 
Solid biomass
Market Area: 
Wine and liquors

Raising the productivity and competitiveness of European businesses through technology. Boosting national economies on the international market, and strengthening the basis for sustainable prosperity and employment.