The Müller-Guttenbrunn Group has developed a process for the 2nd stage of the recycling and treatment of the cabinets of VHC-only foamed refrigerators and freezers. Compared to the current system of treatment in encapsulated shredder systems the climate-relevant emissions reduced by more than 12% and the energy consumption reduced even by one third. At the same time, this new “Foam Capturing Process” generates a plastic fraction that contains 90% recyclable target plastics PS, PP, and ABS.
Following the stage 1 treatment in cooperation with the Niederösterreichen Kühlgeräteentsorgung (part of the Höpperger Group) an analysis takes place of the blowing-agent used in each of the refrigerator cabinets and doors.
By adapting specific process parameters in the specialized Hoffmann-Shredder the tests have shown that more than 80% of the polyurethane foam parts (PUR) can be recovered in a particle size> 20 mm.
Picture 1: Explosion Triangle VHC –>
This newly developed method is exclusively applied for the treatment VHC (or pentane) foamed refrigerators. The innovation is that the “Foam Capturing Process” does not require an encapsulated shredder nor is there a requirement for de-gassing of the PUR matrix and a subsequent recovery of the blowing agents.
“The shredder room does not need to be inserted with nitrogen to prevent explosions, as the process allows us to always stay outside the explosion triangle. The material is removed out of the shredder room immediately, allowing the pore matrix of the PU foam to remain practically fully intact.
„Up to 94% of the blowing agent-input (VHC) are thus kept within the large PUR foam particles, which subsequently are fed into thermal recovery.” explains DI Günther Höggerl Manager of Research and Development in the Müller-Guttenbrunn Group proudly.
Only about 6% of the VHC (pentane) gasses contained in the PUR foam are released as diffuse emissions during the treatment process.
These emissions are lower than the threshold of 50 mg/M3 and the climate-related effects of this release are more than offset by the savings made, as the table shows. The subsequent material recycling of the shredded material results in a recycling rate of over 80%.
In the course of a number of trials, the results (450 fridges) were verified on a practical relevant scale through extensive material flow analyses.
Because of the open shredder process, this treatment method can exclusively be applied to VHC (pentane)-foamed refrigerators and freezers. As the marking of the cabinets and doors is not always correct, as research has shown, this method requires an error-free detection analysis of the blowing agents in the cabinets and doors before the shredding takes place. An automated blowing-agent analysis method is still in the phase of development.
Picture 2: Particle size of the polyurethane foam – PUR (left) and the plastic fraction (right).
For further questions please contact:
DI Chris Slijkhuis
E-Waste & Public Affairs – Müller-Guttenbrunn Gruppe