Page 352 - BOLA Catalogue

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Chemical recycling
Chemical recycling, also referred to as upcycling in the case of ful-
ly fluorinated fluoroplastics, is a new technology (Figure 2). It has been developed on an industrial scale since 2015 in an experimental industrial plant with a capacity of one thousand tons per year. In the meantime, it is ready for market launch. The fully fluorinated polymers, PTFE, modified PTFE, PFA and FEP, as well as some PTFE compounds can be recycled. The monomer recovery rate is around 85 percent.
Figure 2: In the upcycling process, the products are not incinerated after reaching the end of their life, but are returned to the cycle. The polymers produced again in this way polymers produced in this way show no loss of quality.
weight of the recycled fluoropolymers. The CO2 footprint („carbon foot- print“) of fluoropolymers is thus significantly reduced via the upcycling process to better values.
Figure 3: The environmental impact per 1,000 tonnes of upcy- cled monomer TFE is enormous. Unwanted by-products of the regular monomer production process, such as CO2 and hydro- chloric acid, are even completely avoided.
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Disposal by life landfill or incineration
For the upcycling process, too, the products are collected after rea- ching the end of their lives, cleaned and then mechanically shredded. This is followed by thermal splitting back into the monomers at over 600 °C. Reaction products are primarily tetrafluoroethylene (TFE) mixed with a little hexafluoropropene (HFP). After purification of the raw
gas mixture by distillation and special washing processes, high-purity monomers are recovered. These can be reused for the polymerisation of new fluoropolymers.
Polymers produced with this process show no reduction in quality compared to the original polymers. Upcycling thus transforms „old“ into „new“ materials. The quality is thereby raised to the initial level. Fears that the properties of upcycled products are inferior to those of new products do not apply.
Raw-material saving by upcycling
The raw materials for fluoropolymers are fluorspar, crude oil/natural gas, methane and common salt (NaCl). From these, first the fluorocar- bon intermediate R22 and finally tetrafluoroethylene (TFE) are produced in a multi-stage process. All fluoropolymers are made from this raw material. Besides a high energy demand, waste products are also pro- duced, especially hydrochloric acid (HCl). These have to be reprocessed or recycled in complex processes. In addition, all the raw materials mentioned are only available in limited quantities. Once these resour- ces are used up, substitute products will be in short supply.
However, if fluoropolymers that have reached the end of their useful life or machining waste are used instead of these finite resources, the raw material and waste savings that can be achieved are enormous. Figure 3 shows the environmental relief per 1,000 tonnes of fully fluori- nated polymer returned to the cycle through upcycling. The amounts
of „waste acid“ or saved carbon dioxide (CO2) are about ten times the
Two important representatives of the „standard plastics“ are polye- thylene (PE) and polypropylene (PP). Due to the comparatively low raw material prices of virgin materials, only low-cost recycling processes are used here; chemical recycling is not possible because of the comparatively high costs.
PE and PP in the production of laboratory supplies are essentially chips or remnants. These are collected, shredded, cleaned and then conver- ted back into new products via thermoplastic processing methods. The preferred recycling method for PE is film production. Recycled PP is reused by means of injection moulding mainly for technical products, for example bumpers or lamp housings for motor vehicles. In these applications, the material cycles can also be passed through several times. About 14 per cent of the plastics currently used in Germany come from such recycling processes.
Plastic mixtures collected via the „yellow bag“, for example, provide a „PE-rich fraction“ and a „PP-rich fraction“ in automated processes. These are then also suitable for further processing by extrusion or injection moulding. Non-separable municipal plastic waste ends up in so-called „energy recycling“ as substitute fuel in coal-fired power plants and thus replaces lignite or hard coal.
Re-use of PE and PP
By the way: BOLA offers custom manufacture. From 1 piece. Hotline +49 (0) 93 46-92 86-0 351
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