Entsorga's Prometheus is a flexible mechanical refinement system, allowing the production of a high quality SRF. 


After biological phase, the material has to be subjected to a mechanical separation treatment in order to discard low calorific fraction and obtain a final SRF with a suitable quality. Entsorga propose a flexible mechanical refinement system, allowing the production of a high quality SRF. This refining line is the Entsorga’s Prometheus technology.

Prometheus consist in a very efficient set of different equipment that lead to the increase of the calorific value by sorting out the unwanted fractions. The sequence and the number of machines mostly depends on the quantities and on the waste composition. 

The material is moved from the bio-drying hall to the refinement hopper by means of a bridge crane with grab. The stabilized material (Underscreen fraction from pretreatment) is loaded to an hopper that by pass the primary shredder and move the material directly to the conveyor that feed the Screening trommel. The Overscreen fraction is loaded at the primary shredder in order to reduce its size and make more efficient the following separation operations. Loading have to be done in order to feed the screening trommel with both Underscreen and Overscreen and mix them again inside the trommel. Under certain condition, it will be possible to make also the Biodried Underscreen pass into the primary shredder with the Overscreen.

Air classification
The aim of the air classifier is to split the stream into a low density and high density fraction. The low density stream contains mainly plastic, paper, card and organics, collectively having a higher calorific value and is the source of the high quality SRF. The high density stream generates a lower quality SRF or waste depending upon the SRF specification. This step can be calibrated by fine tuning the equipment efficiency in order to obtain the SRF under the required specification.

After air classification, in order to increase SRF quality and material recycling, ferrous metals are removed by magnets operating on both the light and heavy streams. Furthermore an Eddy current separator is placed on the high quality SRF line to divert residual non-ferrous metals, further enhancing both the quality of SRF and materials recycling rate.

NIR - PVC Removal
NIR optical sorter (Entsorga Falcon proprietary technology) is a great improvement of the Prometheus refining line. Its primary purpose is the one to remove chlorinated plastic in order to achieve a low chlorine content into final SRF. In addition, the Falcon is also able to estimate (by calculation algorithm managed by the software) the material composition, its humidity content and its calorific value. This additional information is especially intended to be used as feedback parameters in the plant adjustment.
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Lastly, depending on final destination, SRF can be either stored as a fluff in a covered area near the refining section, or compacted within a press container or a press baler. In case of close proximity of the final user facility, SRF can be directly transported to the burner’s feeding system by conveyors.

Three principal material streams are produced:

  • solid Recovered Fuel (SRF)
  • fines & heavies containing the undersize organic fraction and inerts
  • ferrous and non ferrous metals for recycling

The refining line is a flexible and high performing line. An analysis of the outlet and related specification may enable Entsorga to optimize the design in order to adjust the economics of the project.