Treatment of digestates

Digestates or fermentation residues are fluid or solid residues which rest in the biogas plant after the fermentation of biomass. WEHRLE developed pioneering technologies in terms of the processing of fermentation residues. 

Digestates need to be specially treated before being thermally processed. Therefore the digestates are drained first.

Fluid digestates can be used as fertilisers by the agriculture on the one hand. On the other hand, WEHRLE's technologies can provide receiving water quality after processing the digestates. Solid digestates are used for composting or can be dried for thermal use. 

Due to persistent carbonhydrates (cellulose and lignocellulose) dried digestates are also interesting fuels since the ashes are easily transportable inputs for the fertiliser industry. Solid residues need to reach a calorific value of 4,5 MJ/kg to process an independent incineration. 

The digestates with a particulate grain size up to edge length of 250 mm can be processed by the fluidised-bed combustion plants of WEHRLE depending on the size of the plant. WEHRLE's fluidised- bed combustion technology can cope with high proportion of mineral, sulphur and nitrogen compounds due to WEHRLE's expertise regarding construction and combustion control system technology.

WEHRLE's know-how in terms of construction as well as WEHRLE's special regulation system which have been gained by the experience in the waste sector, are the main reasons for the advantages of strongly reduced corrosion and conservation of low NOx-value of the flue gas. 

We provide small and middle sized incineration plants (1-10 MWth) for digestates. All small and middle scale plants are completely standarised fluidised-bed combustion plants including fuel feed, firing, boiler plant, flue gas cleaning plant as well as chimney.  Besides the small and middle sized incineration plants, we offer individually designed plants up to 30 MWth together with our partners. You may find further information regarding fluidised-bed combustion plants here:

Firing/ Fluidised-Bed Combustion plant

Contact us! We are happy to analyse your specific requirements with you and well-advice you accordingly!