Digestate post - treatment

The digestate is the remaining part of the process of anaerobic biodigestion and consists of the indigestible parts of biomass. It’s very valuable material as fertilizer soil, reducing the need for the cultivation of exogenous inputs of chemical fertilizers. It’s reuse on soil that produced the biomass is therefore very useful in order to ensure sustainability over time of production and maintain a good level of organic matter in soils, essential for agronomic fertility and reducing erosion risks.

The digestate is sent to post-treatment section. The centrifugal involves a separation of organic substances in suspension and not in solution in the slurry leaving the digestion. It is a process that operates to difference in specific weight between the substances to be separated.

The centrifugation is carried out inside a cylindrical-conical container, called a drum, which is rotated at high speed by an electric motor to raise thousands of times the force of gravity. Inside the drum there is the cochlea, the function of which is to transport to the outside the solid product, which will then be downloaded from an evacuation system. The solid part is extracted completely devoid of odors; the biodigestion in fact has characteristics to stabilize the organic material. The separated water are in part recirculated head of the plant for the dilution of the organic liquid inlet.

The bio-digestate to be treated is poured onto a bed of ligno-cellulosic material of particle size and functional characteristics. The fermentation bed, after months of work, is replaced with fresh material. The composition of this exhausted material is such as to make it suitable as highest quality compost (KEMET®). Was called Kemet, the fertile land of the Nile River, in contrast to the red desert land Decheret.