The ELV Plastics Puzzle

European facilities are finding both problems and potential in recycling the shredded plastics from end-of-life vehicles—and that material stream is likely to evolve.

By Allard Verburg

Researchers have focused intensively over the past 30 years on developing industrial processes to separate plastics from shredded end-of-life vehicles, and such processes have been commercialized over the last decade. The idea seems promising: Plastics use has almost tripled since the mid-1980s, and, until recently, higher oil and chemicals prices had led to increased values. Recyclers have yet to successfully market large volumes of such plastics, however. Without a regulatory push—be it a tax stimulus or a landfill ban—there still seems to be no strong business case for retrieving polyolefins and styrenics from automobile shredder residue. Simply put, recovering plastics from ELVs is complex and costly.

Nowadays, half of automotive plastics are polypropylene, talc-filled polypropylene, polyethylene, and acrylonitrile butadiene styrene. The remaining half consists of a wide array of other, cross-polymer compounds that offer a high engineering value but are difficult to recycle. Of an average vehicle’s weight of 1,300 kilograms, more than 120 kg (9.2 percent) is plastic. Although this share has stabilized in recent years, it has surged since the 1960s, when the average was 10 kg. Today, nearly a thousand parts in a passenger vehicle are made of plastic, including an increasing share of high-performance engineering plastics.

Incentives for Recycling

Although it is much younger than its metals recycling counterpart, the plastics recycling sector is growing rapidly. The main source of supply is postproduction scrap, as well as postconsumer packaging and construction and demolition scrap. Automobiles are a larger piece of the metals market—both their production and their recycling—than they are of the plastics market. Only 6.8 percent of the world’s polymer production ends up in automotive subassemblies, as opposed to 22 percent of steel, 15.2 percent of aluminum, and 9.5 percent of copper.

One incentive in Europe for recycling ELV plastics is European Union regulations that require a weight-based material recovery rate of 85 percent of the car. At best, recyclers can achieve this rate economically by shredding the vehicle, recovering ferrous and nonferrous metals, and intensely sorting metals and valuable plastics out of the automobile shredder residue. Theoretically, separation of plastics from ASR could add roughly 8 percentage points to the 75-percent recovery achieved through metal extraction. Currently used best available technology can only add about 5 percentage points to the recovery rate, however.

Shredder Inputs and Outputs

Pure automotive shredder residue is less complex than mixed shredder residue, which arises where shredders commingle ELVs at the source with electronics and other scrap. ASR is distinct from MSR because it has less wood content and lower chemical contamination, such as from brominated or antimony flame retardants and PCBs. The automotive industry phased out the use of mercury, lead, and (with minor exceptions) nickel some years ago—much earlier than the electronics or aviation sectors. PCBs could be a serious source of contamination, but with strict recycling chain controls in place, content levels are far below Europe’s 50 parts-per-million limit.

Low-Quality Applications

Most shredder companies in Europe and the United States operate an integrated or outsourced ASR recovery process, either targeting only the shredder heavy fraction (i.e., that containing larger amounts of metals) or that plus the shredder light fraction (plastics, rubber, glass, textiles, etc.). In some cases, these investments receive financial or regulatory support.

Manufacturers can convert different grades of plastic regranulate into new plastic components via injection molding and thermoforming. Although this attracts plenty of positive marketing attention, most of the plastics end up in low-quality applications or need to be extensively blended with virgin grades. For ASR plastics, a park bench might be considered a high-quality application; other examples include the production of composite panels and structures such as railway ties. The recycler might be able to redirect any fractions that are unsuitable for material recycling to co-combustion within cement kilns or to energy recovery, depending on their chlorine level.

Fields of Innovation

There are plenty of fields of innovation within the ASR processing chain, especially in the recovery of plastics. With spectral imaging, innovation is taking place to improve the speed and quality of sensor-based X-ray, color, near-infrared, and laser sorting. The latest developments are combining several sorting tasks.

The key innovation—and the one that will improve the recycling rate and quality of plastics from ASR—relates to the production of plastics in the automotive product supply chain. Product designers currently lack a true incentive and the essential knowledge to create materials and products that, at the very least, will not dent overall vehicle recyclability. Synergy with other complex waste streams also is essential to reach a true market scale.

Composites Are Coming

Although their use now is limited within the automotive sector, composite materials will have significant technical, economic, and organizational impacts on the existing recycling chain. The practical recyclability of novel plastic combinations is becoming increasingly important.

For recyclers, thermosets are infamous for their irreversible characteristics. Unlike thermoplastic composites, thermosets cannot be returned to their original matrix. Such thermoset structural composites are now employed in the aviation sector and some modern car equivalents, such as electric vehicles that boast a thermoset, carbon-reinforced frame and bodywork. These lightweight vehicles have excellent environmental characteristics, such as reduced greenhouse gas emissions.

The recycling sector has always been adaptive by nature, learning to transform a threat into an opportunity. Economic value within production and recycling has always been the pillar supporting recycling chains. Therefore, all operators along the value chain should collaborate to create an ecologically and economically sustainable model for extending the life of plastics from end-of-life vehicles.

Allard Verburg is the business development manager at ARN Recycling (Tiel, Netherlands). Visit www.arn.nl/recycling. Scrap has adapted this article, with permission, from one that originally appeared in the April 2015 issue of Recycling International.

ASR Processing in Europe

These days, most medium and large shredder groups use heavy media separation plants to extract metallic fines from their automobile shredder residue. The majority of them also recover plastics—such as PP, PE, ABS, and PS—that have the most commercial value but also to satisfy European recycling targets.

--European Metal Recycling (Warrington, England), the major UK shredder group, operates a joint venture plastics separation facility with MBA Polymers (Worksop, England) in central England. This plant accepts preprocessed plastics from EMR shredding and heavy media plants across the UK.

--Axion Polymers (Manchester, England), in a strategic partnership with the S. Norton & Co. (Liverpool) shredder group, is processing ASR at its new site in Manchester. The Shredder Waste Advanced Processing Plant has the capacity to handle 200,000 mt of ASR per year. Axion’s Salford plant converts the plastics concentrate into a range of products.

--ARN (Tiel, Netherlands) is the Dutch compliance organization that runs its own post-shredder treatment, or PST, plant in the town of Tiel, Netherlands. This is capable of annually processing some 50,000 mt of ASR light fraction and shredder heavy fraction residues supplied by shredders in both the Netherlands and elsewhere.

--Derichebourg Environnement (Paris), France’s largest shredder group, runs a proprietary PST plant at Bruyères, building on its long experience in plastics from electronics. The plastics are further processed at partner company Plastic Omnium (Levallois), the largest plastics producer in France.

--TSR Recycling (Bottrop, Germany), the largest car shredder in Germany, is developing a PST plant in Brandenburg through its wholly owned subsidiary Remine. With start-up expected in 2016, it will serve TSR’s 10 shredder sites.

--Scholz Group (Essingen, Germany) could well be the PST specialist with the longest history. It was early this millennium that the family-owned German business began to explore the treatment of shredder light fraction at its Espenhain facility, SRW metalfloat. It expanded the plant hugely in 2011 to give it an annual capacity of 105,000 mt of shredder light fraction.

--Galloo Plastics (Halluin, France) has the capacity to pretreat 200,000 mt a year of ASR (both shredder light fraction and shredder heavy fraction) as well as engage in final treatment of ASR-derived plastics at a rate of 50,000 mt a year. The company, at the border of France and Belgium, also accepts pretreated ASR from other operators around Europe.

Marketing ASR Plastics

ARN (Tiel, Netherlands) has conducted extensive research into purifying ASR plastics concentrates to remove unwanted elements, especially rubber and wood. It has made investments to integrate new screening and bouncing machines that remove such contaminants.

The heaviest fraction contains valuable metals—such as copper wire and stainless steel—that can be further separated by balling the metals and using air tables for metal-plastic separation. The remaining plastic-rubber mixture is high in chlorine (10 percent) and therefore difficult to process in an incineration plant.

The lightest fraction contains the most interesting plastics for material recycling, which are the polyolefins (PP/PE) and styrenics (ABS/PS).

Specialist plastics recycling companies that have access to other plastics for blending conduct this downstream separation and compounding of plastics, thus attaining the right qualities and product specifications for a stable supply of a specified end product.