Advances in dry fermentation extends biowaste management possibilities

It was repeatedly and independently confirmed that processing of biowaste via dry fermentation technology is less capital demanding compared to a conventional (also known as continuous, wet and mixable) fermentation technology. However, low acquisition and running cost are redeemed by lower intensity of the fermentation process that results in small revenues. In this study, biowaste was deeply disintegrated before it entered the dry anaerobic fermentation that was followed by pyrolysis of the fermentation residues. It was revealed that the disintegration step increases the intensity of the fermentation process, therefore biogas yields are increased, hydraulic retention times could be shortened and biochar is priced higher (because of higher porosity partially caused during the fermentation process). Additional experiments on a commercial scale indicate that it is economically beneficial (reduction of the payback period by more than 7%) to perform the disintegration step later, in the middle phase of the fermentation process.