The AD Plant Zell am See is planned complementary to the already existing composting step in the MBT Zemka, where the rather wet biowaste could not be treated optimally. The Client looked for a concept that allowed him to treat not only this fraction but as well new substrates like food waste, sewage sludge, commercial waste, fat separator contents and liquid waste. For this reason, the main focus of this plant is its flexibility for diverse types of input materials. This is also the reason why the BTA® Process was chosen as basic concept for this plant.

The diversity of the substrate mix presents particular challenges to the waste reception, the pre-treatment and the anaerobic digestion step of the new plant. For this purpose in the reception area different reception lines are foreseen. The proven BTA® Hydromechanical Pre-treatment will be applied to cope with the high flexibility required to treat these different types of waste.

The Customer expects the production of approx. 14 GWh/year energy equivalents in the biogas. This corresponds to the natural gas consumption of  about 930 households and to a CO2 saving of about 2.680 tons per year.

The digestate is dewatered. The solid phase is stabilized in the neighboring MBA Zemka while the liquid phase is recirculated to a very high percentage in the process for mixing and rinsing purposes. The excess water is internally treated before it is discharged to the wastewater treatment plant Zell am See.

Within the Executing Consortium BTA International is responsible for the turnkey supply, assembly and start-up of the equipment of the complete plant excluding the excess water treatment as well as for the control unit of the overall installation.