Incoming MSW is pretreated mechanically (shredding, sieving, removal of metals) and split into three fractions: a high, a medium, and a low calorific fraction, with a grain size < 40 mm. The high and medium fractions are used for RDF, while the organic fraction (OF) of the low calorific fraction will be fed into the digesters of WWTPs for enhanced biogas production.
The managerial solution consists in administrating the newly generated organic fraction and the newly generated waste streams: calculation of general mass potential, distribution of required quantities to the WWTPs, optimizing transport logistics, managing biogas production, managing the predominantly mineral residues and their further processing (p.ex. separation and sale of recyclable glass cullet) and their final disposal.
processes: The mechanical waste treatment plant (MWTP) receives MSW as well as
bulky wastes, usually with little or no organic fraction (OF). Therefore, the
management of the MWTP has to make sure that only that part of the LCF which
resulted from MSW treatment is going to be further processed for the separation
of the OF. Thus, a quality control protocol needs to be in place. In Tyrol’s
case, the OF of the LCF, when fed into the digesters of WWTPs for biogas
production, will replace the organic wastes from source separate collection
commonly used for this purpose. These organic wastes usually have a very low
concentration of contaminants and therefore are more suitable for fertilizing
purposes, thus contributing to closing the loops of certain minerals, p. ex.
phosphorus, a critical resource. However, in a near future, the sludges of
WWTPs will be legally banned from being used as fertilizers, and therefore the
fertilizer potential of the clean organic wastes from source separate collection
will be most probably lost, because viable industrial processes for their
recovery are still expensive and not yet wide-spread. The proposed CE-solution
therefore replaces the outside process of clean biowaste digestion at WWTPs,
which then can be treated in mono biowaste treatment facilities. By doing so,
the CE solution enhances the local and regional biowaste treatment sector and
contributes indirectly to local and regional recycling of important plant
nutrients and carbon.
Not yet available
the technology of the proposed CE-solution is promising, its success depends on
the acceptance by the WWTPs’ operators, and their cooperation. The results achieved
with the technology until now are restricted to the physical composition of the
potential co-substrate from MSW-LCF, which indeed has a very low impurity
content. However, no reliable data on its biogas potential exist to date,
especially from a continuous biodigestion process. This is currently carried
out by a third party, and the results will be made available to the PP.
Meirer, M., Müller, W. & Bockreis, A. Österr Wasser- und Abfallw (2017) 69: 397. https://doi.org/10.1007/s00506-017-0411-2.
Leonhartsberger, C., Müller, M., Meirer, M., do Carmo Precci Lopes, A. (2018): Endbericht. Machbarkeitsstudie ENARA. Internal report.