Technical Recycling and Waste Solutions

• Mechanical Recycling
• Thermal Processes
• Landfill Disposal
• Exports of waste

Mechanical Recycling

BSEF promotes the adoption of a flexible approach to BFR-plastics waste management, encompassing an optimal balance of technical, environmental, economic and regional market factors. The goal is to ensure that natural resources are used wisely and efficiently. E&E equipment uses many different types of plastics, designed with special properties for producing high-specification products as efficiently as possible. To mechanically recycle post-user plastic waste, it has to be collected, sorted, separated, ground, washed and reprocessed before it can be mixed with virgin plastics of the same type for molding new products, or used on its own for alternative lower value products. Thus, the availability of consistent waste streams with known characteristics is a key criterion for successful recycling. Only in a limited number of cases are the overall plastics recycling operations economically viable because of the relatively low cost of new, virgin plastics.

Experience shows that for material recycling to be viable, there must be homogenous plastics and a large constant waste stream. The markets for recycled plastics are limited due to technical feasibility and economics. Small impurities from different plastics or other materials can easily occur during the recycling processes and drastically decrease the electrical and mechanical performance or safety of recycled plastics. Virgin plastics are usually cheaper and always of higher quality than recycled plastics after collection, dismantling, sorting and remelting.

Due to the ban on PentaBDE and OctaBDE (in August 2004) and PBBs (in 2006), BSEF does not promote mechanical recycling of historic plastics containing BFRs from open loop waste streams. However, recycling within a closed loop system, where E&E manufacturers receive their own original plastics, is considered a viable option in terms of offering practical opportunities for the mechanical recycling of WEEE plastics containing BFRs.

Studies of interest

• "Comparison of the recyclability of flame-retarded plastics"; Environ Sci Technol. 2003 Feb 1;37(3):652-6; Imai T, Hamm S, Rothenbacher KP. Techno Polymer Co., Ltd., 100 Kawajiri-cho, Yokkaichi, Mie 510-0871, Japan
  • Conclusion: ABS Plastics containing BFRs proved to be the most suited to mechanical recycling. Indeed, "the tested plastic materials containing BFRs showed superior recycling properties compared to the tested halogen-free plastic grades" as they were able to retain important properties such as colour and fire safety rating. Also none of the materials tested showed potential to form dioxins and furans, thus fully respecting the strictest environmental limits set by the German Dioxin Decree.
• "Determination of Polybrominated Diphenyl Ethers and PBDD/Fs during the Recycling of High Impact Polystyrene Containing Decabromodiphenylether and Antimony Oxide". Chemosphere, 44/6 (2001) 1353-1360 Hamm, S.,Strikkeling, M.,Ranken, P.,Rothenbacher, K.P, 2001.
  • Overview: High impact polystyrene (HIPS) plastic containing Deca-BDE and antimony oxide was recycled five times.
  • Conclusion: The study showed that even after such exhaustive recycling no debromination of Deca-BDE into lower brominated diphenyl ethers takes place. Furthermore, the five times recycled product was fully compatible with the German legislation on dioxin/furans limits in products.
• "Workplace measurements for PBDF/Ds during recycling of HIPS/Sb2O3/DecaBDPO plastic at an extruder at the Technical University of Erlangen-Nuernberg"; Workplace assessment, GfA Gesellschaft fuer Arbeitsplatz- und Umweltanalytik mbH Report No. 60425-002 B01. Kieper, H., 2000.
  • Overview: In a pilot project, HIPS/Deca-BDE plastic was recycled by grinding, extruding and injection molding.
  • Conclusion: Workplace exposure during the extrusion and the injection molding phases were monitored and found to comply with the strict German legislation on dioxin/furans limits in air at the workplace.
• "TV case study, a life cycle analysis", SP TV LCA data. Simonson, M., Blomqvist, P., Boldizar, A., Moeller, K., Rosell, L., Tullin, C., Stripple, H., Sundqvist, J.O. Fire-LCA model, 2000. Interscience Communication Ltd., London, ISBN 91-7848-811-7.
  • Conclusion: The study demonstrated full compliance with fire safety standards after aged televisions were recycled and concluded that HIPS plastics containing Deca-BDE carry better physical properties than plastics without BFRs.

Plastic producers for E&E may decide if they wish to set up a "closed loop" system to ensure their products are returned to their manufacturing plant and then carry out the necessary treatment, recycling and recovery of their products themselves.

Table 1: Main characteristics of polymers during the closed loop recycling process

Source: Ricoh Presentation to BSEF Tokyo Seminar, November 6, 1998

The electrical appliance in the photo below may look like an ordinary state-of-the-art photocopier. However, unlike other photocopiers, 30% of its outer plastic casing is made from recycled plastic containing BFRs. This copier was launched in the Japanese market in Spring 2000.

The plastic used in this copier is particularly suited to recycling. ABS requires brominated flame retardants to be added in order to meet the high fire safety standards of UL 5VA and 5VB. Copier manufacturers and their plastic suppliers have found that certain ABS/BFR combinations (in this case brominated epoxies or brominated epoxy oligomers) have very clear advantages in terms of recyclability. In essence, the advantage is due to the stability of the brominated flame retardants in the recycling process. Only with the ABS/BFR plastic does the flame retardancy of the polymer maintain the UL 5VA level, thus foregoing the need to add more flame retardants after recycling. This provides clear economic and environmental benefits.

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Thermal Processes

Feedstock Recycling

In principle, feedstock recycling has great potential to boost plastic waste recovery levels. However, for feedstock recycling to be viable economic considerations, as well as the availability and quantity of quality plastics waste are key. Furthermore, such conditions vary greatly depending on local situations and are often hard to find. A variant of feedstock recycling is the use of plastics as a chemical reductant which is necessary for the recovery of non-ferrous metals. In this case, the plastics not only react with the metals, but are also used for their energy value.

As an example, the Japanese Plastic Waste Management Institute (PWMI) has developed a zero emission chemical recycle technology. Waste plastics from cars and E&E products are used for electricity generation by gasification and bromine is recovered at the same time.

Studies of interest regarding the feedstock process

• "Implementation of thermal processes for feedstock recycling of bromine and antimony, with energy recovery, from plastics waste of electrical and electronic Equipment, Phase 1" Dr H. Boerrigter, Netherlands Energy Research Foundation (ECN), July 2000.
  • Overview: The study evaluated and ranked various available processes for Feedstock Recycling of plastic waste from electrical and electronic equipment (WEEE), containing brominated flame-retardants (BFRs) –including Deca-BDE-. The study aimed to recycle bromine and recover the energy content.
  • Conclusion: The study concluded that staged-gasification is a thermal process that is potentially suitable for this purpose. No increase of dioxin/furans was observed.
• "Recovery of bromine and energy from waste electrical and electronic equipment containing bromine in the European Union". May 1999, PB Kennedy & Donkin Limited.
  • Overview: The study evaluated the economical impact of bromine recovery from WEEE plastics – including Deca-BDE.
  • Conclusions: The study concluded that handling WEEE plastics containing bromine can profitably operate when recovering amounts above 500 tons/year.

Energy recovery

Energy recovery is a resource recovery method in which a part of all of the waste produced in a process is burned to generate heat or electricity. Energy recovery is a great recycling process for plastic because plastic is derived from oil. In the past, there has been much opposition to energy recovery of plastics; some opposition justified by concerns around the poor environmental performance of old incinerators. Today, however, energy recovery is more widely approved as an environmentally sound option. Modern incinerators significantly reduce emissions and waste combustion for energy recovery is embodied in European legislation. Energy recovery among material recycling plays a vital role in diverting plastic waste from landfill and maximizing environmental gain.

Incineration

Incineration tests, pyrolysis and combustion studies have shown that waste from E&E equipment can be safely added to today's municipal solid waste (MSW) to generate advantageous energy, in an environmentally friendly manner, when incinerating BFR-containing materials. During the incineration process, PBDD/F formation is not altered by the presence of the bromine-containing waste and remains well within emission standards. The Organization for Economic Cooperation and Development (OECD) also attests to the minimal risks during such incineration; they conclude there is insignificant formation of dioxin/furan when incinerating brominated flame retardant (BFRs). The OECD noted that, during laboratory experiments, the highest formation rates for brominated dioxins/furans from PBDEs were associated with low temperatures and pyrolitic conditions. Modern waste-to-energy facilities are specifically designed to avoid these conditions. A report from the European Commission came to the same conclusions.

BSEF has cooperated with Forschungszentrum Karlsruhe, a European science and engineering research institution, as well as various members of PlasticsEurope, an umbrella organization of European plastic associations, to undertake a number of research programs. The aim of the research was to investigate the co-combustion of plastic waste streams and municipal solid waste. In the experiments, a variety of plastics, including TV monitors and printed wiring boards, containing brominated flame retardants were fed to the pilot plant, TAMARA, with 250 kg/h feed to simulate full scale incinerators. In one experiment, the bromine content of the fuel was increased to approximately 10 g/kg dry waste. Results confirmed that up until a level of 3 g, no detectable amounts of elementary Br2 could be detected in the raw gas, post- incineration.

State of the art thermal processes is a dioxin sink. The example of the TAMARA study showed that > 98% of the brominated dioxins and furans had been destroyed during the controlled combustion process of WEEE.

Smelters

Smelting is an innovative approach to recycling plastics and has significant economic benefits, regarding the reduction of waste management costs. For example, producing copper from recycled material requires one-sixth percent of the energy needed than producing copper from ore. With such innovation, waste from the E&E sector can now be used as a feed stream in non-ferrous metal smelting plants.

Case studies on the smelting process

• A Swedish mining and smelting company, Boliden, has developed a recycling process for electrical and electronic equipment waste, in compliance with European regulation. Plastics provide energy for the smelting process and allmetals are recovered. BFR containing plastics have been tested in this process and fully meet emissions requirements.
• In 2004, a study was conducted at the UMICORE smelter in Belgium, in which 250 tons of WEEE plastics were used to test smelting processes. The results concluded that smelting is a practical recycling solution, economically viable and environmentally friendly.
• Plastics Europe carried out an eco-efficiency study showing that the metal smelting process provides the highest recovery rate for handling mobile phones, without high dismantling costs.

Metal smelters recycling in Europe

Further studies of interest regarding the smelting process

• "Electrical and electronic plastics waste co-combustion with municipal solid waste for energy recovery", Juergen Vehlow, Forschungszentrum Karlsruhe, Mark, Dow Europe, February 1997
• "Recycling of bromine from plastics containing brominated flame retardants in state-of the-art combustion facilities", Tamara, Vehlow, B. Forschungszentrum Karlsruhe Institut für Technische Chemie Bereich Thermische Abfallbehandlung, Plastics Europe, EBFRIP, 2002.
  • Conclusion: Pilot studies (conducted by German institute FZK and Plastics Europe) show that brominated flame retardant, including Deca-BDE, contained in WEEE plastics can be safely handled in modern household waste incinerators. Specifically, up to 3% of WEEE plastics containing BFRs can be safely added to the incinerator. In addition, the halogens have a positive cleaning effect on the heavy metals in the slag.
• "Emission measurements during incineration of waste containing brominated flame retardants" by Dag Borgnes, Bente Rikheim. 2004.
  • Overview: Three full-scale trials adding 10% waste containing brominated flame retardants on Deca-BDE includes to a modern household waste incinerator were carried out in Norway.
  • Conclusion: The report observed no increase of dioxin/furans. It even reported a decrease of dioxin/furans due to better waste burn out because of the presence of these plastics.
• "Report on incineration of products containing brominated flame retardants" OECD Waste Management Policy Group, Environment Policy Committee, ENV/EPOC/WMP(97)4/REV3, August 1998.
  • Conclusion: According to the International Programme on Chemical Safety (IPCS), properly controlled incineration of materials containing BFRs does not lead to significant emissions of brominated dioxins and furans. IPCS recommends that incineration should only be carried out in properly constituted incinerators, running at consistently optimal conditions.
• "E&HS aspects on metal recovery from electronic scrap". Sweden, Metal and Energy Recovery Conference. Lehner T., Boliden (2003).
  • Conclusion: The study concludes that plastics containing Deca-BDE demonstrate good energy recovery and are fully compatible with metal recycling.
• "Risk Assessment of Decabromodiphenylether, Deca-BDE", CAS Number: 1163-19-5, Final Environmental Draft of May 2004, pages 26 and 17-18.
  • Overview: The EU Risk Assessment on DecaBDE includes an entire section on End-of-life (EoL), a term suched to indicate a products lifetime, and on dioxins and furans. The EoL sections looks into various disposal and recovery options including recycling, recovery and landfill.
  • Conclusion: None of the sections mentioned that the disposal and recovery options posed significant risks. Regarding incineration, the risk assessment reports: "It is expected that emissions from controlled incineration processes will be near zero (…)."

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Landfill Disposal

Studies of interest

• "TV case study, a life cycle analysis", SP TV LCA data. Simonson, M., Blomqvist, P., Boldizar, A., Moeller, K., Rosell, L., Tullin, C., Stripple, H., Sundqvist, J.O. Fire-LCA model, Interscience Communication Ltd., London, ISBN 91-7848-811-7. 2000.
  • Overview: The study estimated no significant emissions from Deca-BDE into the environment. WEEE plastics compacted in landfills do not cause leaching of BFRs. If, by chance, leaching does persist it is in minimal quantities of no significance.
• "Risk Assessment of Decabromodiphenylether, Deca-BDE", CAS Number: 1163-19-5, Final Environmental Draft of May 2004, pages 26-27
  • Overview: The EU Risk Assessment on DecaBDE includes a entire section on End-of-life (EoL), a term suched to indicate a products lifetime, and on dioxins and furans. The EoL sections looks into various disposal and recovery options including recycling, recovery and landfill.
  • Conclusions: None of the sections mentioned that the disposal and recovery options posed significant risks. The assessment reports: "When decabromodiphenyl ether in plastic is disposed of to landfill, in theory it could leach out of the plastic and into groundwater or volatilise to the atmosphere. However, several experiments have shown that leaching of decabromodiphenyl ether from polymers is minimal and it would not be expected to leach to a significant extent from polymers in landfill, unless the polymer itself undergoes some form of degradation, thus releasing the decabromodiphenyl ether. Any released decabromodiphenyl ether is likely to adsorb strongly onto soil, thus minimising the possibility of reaching groundwater. Similarly, the low vapour pressure of the substance would limit its volatility to the atmosphere."

For more specific info on WEEE plastics with BFRs go here.

Exports of waste

Thanks to enhanced recycling techniques, old plastics and printed circuit boards are no longer perceived as waste, but rather as valuable material. Printed circuit boards are particularly efficiently recycled through the smelting process.

Many studies have verified, along with EU Risk Assessment Reports, which the most commonly used BFRs in EEE, Deca-BDE and TBBPA, are fully compatible with integrated waste management systems. These studies show that it is possible to handle E&E appliances containing BFRs in an environmentally friendly manner while also complying with the WEEE Directive standards and stringent emission regulations.

Studies on Printed circuit Boards (PCBs)

• UMICORE
  • Overview: A metal recovery study conducted at the Umicore Integrated Metal Smelter, tested PWBs containing TBBPA.
  • Conclusion: The study showed process stability in the smelter and demonstrated that PWB waste can be handled on a large scale while fully respecting stringent environmental and health standards.
• Swedish IVF
  • Overview: The Swedish IVF institute conducted a case study comparing the costs and environmental implications of halogen-free flame retardants used in the manufacturing of printed wiring boards (PWB) opposed to bromine-based fire safety systems.
  • Conclusion: The study indicates there was a cost increase ranging from zero to €10 per panel, resulting from the adoption of halogen-free flame retardant systems. Specifically, the increased costs were related to panel drilling, degreasing and materials.
  • Implications: Even though few studies have investigated the production of non-halogenated PWBs, the Swedish IVF case study indicates that costs relating to panel drilling and degreasing will remain stable, while other experiment parameters (pressing, design, and solder mask) did not change regardless of the flame retardant system used.

Studies on ABS Plastics

• "Emission measurement during incineration of waste containing Bromine" Borgnes and Rikheim. Kjelforenigne Norsk Energi, 2005.
  • Conclusion: Commissioned by The Nordic Council of Ministers, The study confirms that TBBPA in waste, decomposes in the incineration process and that increases of BFR content in the waste gave no significant increase in the emissions of chlorinated dioxins, or either brominated and chlorinated/brominated dioxins.
• "Recycling of bromine from plastics containing brominated flame retardants in state-of the-art combustion facilities," Tamara, Vehlow, B., Forschungszentrum Karlsruhe Institut für Technische Chemie Bereich Thermische Abfallbehandlung, 2002.
  • Conclusion: The study showed that WEEE plastics containing brominated flame retardants, including TBBPA in ABS, can be safely handled in modern household waste incinerators. Specifically, up to 3% of WEEE plastics containing BFRs can be safely added to the incinerator. In addition, the halogens have a positive cleaning effect on the heavy metals in the slag.

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