All drying systems for digestate are designed with suitable materials (Aisi 304) in compliance with current regulations for emissions into the atmosphere. Normally, for the saturated process air at the outlet, a wet treatment with horizontal scrubbers or with double tower and / or biofilter is foreseen. Ammonium sulphate is recovered from the scrubber with a 6% nitrogen which is fully included in fertilizers.
If there is no heat to be recovered, it is possible to use fuels such as biomethane, natural gas or LPG. In this case, thermal recovery in the saturated outgoing air can be expected to be used as preheating of the incoming ambient air. The system allows to increase the thermal efficiency of the system by about 15-20%.
All our dryers meet the requirements of the European plan for Industry 4.0 and the Circular Economy. Thus it is possible to request the incentives provided for these types of plants and reduce depreciation times and costs.