Fermentation

Fermentation is the most economically and ecologically viable treatment method for a range of organic waste. Clean energy is produced from the decomposed organic material and compost and liquid fertiliser from the fermentation residue. But packaging, contaminants and inert waste prevent direct introduction into the fermentation process.

By using the right shredding and separation technologies, heavily contaminated market waste and expired food can be recycled alongside bio-waste and food residues. Following successful treatment of the waste, the substrate is used in a wet fermentation process. In enclosed reactors, biogas is produced as an energy source.

Packaged, non-homogenous or lumpy waste necessitates pre-shredding. Slow-running shredders which break down the material thoroughly are used. Shredding with the dual-shaft shredder Crambo provides the optimum size for the largest fraction and reliable opening of packaging and containers.

The key component of the treatment stage is the transfer of the organics into the liquid phase. The pulper used performs several tasks. In batch operation, the organics are shredded further and homogenised in the process water. Packaging is emptied and cleansed by the high flow speed. At the same time, heavy material is separated off through a sluice.

Raw substrate exits the pulper onto a Multistar star screen, connected downstream. The liquid with the solubilised and suspended organic material flows through the star screen and is collected in a tray from where it is pumped, via sand separation, into the collection tank. Oversized particles (depending on source material, contaminants or organic residual fraction) are discharged via the star screens and water is removed in a press connected to the main apparatus.

After sand separation and hygenisation the fermentation substrate exhibits ideal properties for simple fermentation. Adding of additional liquid waste is possible. The ideal reactor system is based upon the on-site conditions and kind and quality of the processed waste.