Data gathering and impact assessment for a review and possible widening of
the scope of the IPPC Directive in relation to waste treatment activitiesFinal report
Factsheet E9 –Recycling of Rubber
Potential amendment e9 – Recycling of Rubber
1.Issue
Aim of the study: The present work intends to identify the issues related to the possible extension of the IPPC Directive to recycling of rubber. This analysis focuses on the scope definition and a rough estimate of the environmental impact and size of sector. The relevance to go on performing a more in-depth analysis of the related advantages and disadvantages will then be assessed. The present study is based on background literature survey and interview with experts.Background: The overall objective is to have a better definition and a clearer outline of waste activities in the IPPC Directive, taking account of the dispositions of the Waste Framework Directive. The evaluation of a possible extension of the IPPC Directive to other waste treatment activities forms the basis for reaching this objective. Recycling of rubber is a potential candidate for such an inclusion.
Issue summary:Until now, the installations for rubber recycling are not regulated under the IPPC Directive. A preliminary study [EPEC 2005] classifies these installations as installations with unknown environmental impact. The present analysis aims to focus on facilities dedicated to rubber recycling and examines their environmental impacts.
2.Products concerned
2.1Production of rubber
Each year, about 3.9 million tonnes of natural and synthetic rubbers (see Annex Afor definitions of rubber) are consumed in EU-25 (see Table 1).
Table 1: Rubber production and consumption in EU-25 for 2005
Rubber type / Production(thousand tonnes) / Consumption
(thousand tonnes)
Natural Rubber / 0 / 1334
Synthetic Rubber / 2675 / 2565
Total / 2675 / 3899
Source: [IRSG]
A wide variety of rubbersexists that are commonly classified as follow:
- Commodity rubbers: they arehighly predominant on the market
-Natural Rubber (NR)
-Styrene Butadiene Rubber (SBR)
- Engineering rubbers: they are fairly used
-Butyl Rubber (BR)
-Isoprene Rubber (IR)
-isobutylene-isoprene rubber (IIR)
-Nitrile Rubber (NBR)
-Chloroprene Rubber (CR)
-ethylene propylene diene monomer rubber (EPDM)
- Specialty rubbers: they have very specific applications. It includes:
-chlorosulfonated polyethylene (CSM)
-Chlorinated Polyethylene (CPE)
-Fluorocarbon (FKM)
-perfluorocarbon FFKM
-silicones
-Epichlorohydrin (CO, ECO)
-Polyacrylate (ACM)
Figure 1 provides the market shares of the various rubbers for an industrialised country.
Figure 1: Market shares of the rubber types
2.2Manufacture of rubber goods
Natural and synthetic rubbers are used to manufacture goods as diversified as medical gloves, tyres, bridge bearings, etc.
Generally, rubber alone is not suitable for industrial applications and several ingredients are essential:
-Some are highly consumed as carbon black, more than 30 % of the consumed rubber. Mineral fillers and plasticizers are also commonly used.
-Others have very specific properties such as vulcanising effect. In the most common case, the vulcanising agent is sulphur that does not disappear in the end-of-life goods and can contribute to vulcanising during recycling.
-Certain additives can result in environmental hazards, soluble salts of zinc for example.
In a first approach, rubber goods can be classified in two categories:
-Tyres: produced at 280 million units in Europe each year [ETRMA] that is to say more than 2.6 million tonnes accounting for more than €14 000 M. After use, some are collected by the garages; the others are included in the end-of-life vehicles (ELV).Their lifetime is in a medium range, generallyseveral years.
-Industrial goods: from disparate sizes, their number of units is unknown, their weight is more than 3 million tonnes accounting for more than €20 000 M. These rubber goods are difficult or impossible to collect because of their scattering.
This category is highly heterogeneous in term of size and lifetime.Sizes of rubber goods vary from less than a gram to tonnes, from millimetre to hundred meters or kilometres for conveyor belts. Moreover, their lifetimes vary from few minutes to more than a century.
Figure 2 displays the scattering of applications of industrial rubber goods.
Figure 2: Market shares of the identified industrial rubber goods
3.Current recycling practice
3.1 Scope of the sector
Preliminary remark: for the purpose of clarification, “recycling of tyre” is understood here as the use of tyres to make granulates, shred, chips, powder that can further substitute for virgin materials in the manufacture of goods such as sport surfaces, footwear, children’s play areas.
According to a representative of the European Tyre Recycling Association (ETRA), the quantities of industrial rubber goods such as moulding and toys that are recycled are far smaller than the quantity of tyres that are recycled. In addition, industrial rubber goods can be very variable in material content and not sufficient in quantity for separate collection. Moreover, some rubber goods such as conveyor belts can be contaminated with substances that they transport. As a result, the recycling of other rubber goods is generally non-profitable and tyres can be considered the only rubber fraction that is effectively recycled today.
Consequently, the rest of this fact sheet focuses on the recycling of tyres.
However, it should be noted that a market seems to exist for the recycling of rubber other than tyres. As a matter of fact, euro.recycle.net, theEurope's Recycling Marketplace, lists more than 20 different grades of rubber recycling (non tyre) [ERecycle]:
-Used/Reusable Rubber Belting
-Heavy Rubber Belting Scrap
-Light Rubber Belting Scrap
-Rubber Hose Scrap
-EPDM Scrap
-EPDM Regrind
-EPDM Repro
-SBR Rubber Scrap
-SBR Regrind
-SBR Repro
-PolyButadiene Rubber Scrap
-Butyl Rubber Scrap
-Nitrile Rubber Scrap
-Neoprene Rubber Scrap
-Fluorocarbon Elostomer Scrap
-Silicone Rubber Scrap
-Silicone Rubber Regrind
-Silicone Rubber Repro
-Latex Rubber Scrap
-Latex Rubber Regrind
-Latex Rubber Repro
-Foam Rubber Scrap
-Other Non Tire Rubber
According to the European Tyre Recycling Association, these markets are small. However, no other information has been identified to confirm this statement.
Summary of key elements about the scope of the study useful for this exerciseThe sector of the recycling of rubber covers the recycling of tyres.
3.2 Size and structure of the sector
Quantity of waste produced and existing end-of-life routes
Estimates are that around 3 million of post-consumer tyres are accumulated each year in EU25 [ETRMA]. Historic stockpiles[1] are estimated to be well over 1,000,000,000 within the EU25. For many years new accumulations are added to the billions that had been stockpiled or buried in designated landfills as well as the uncounted millions found in illegal dumping sites, warehouses, and through-out mountains and valleys, worldwide.
According to the European Tyre Recycling Association [ETRA], tyres have a four-phase life-cycle:
1. New: those which meet national manufacturing standards for road or special purpose use.
2. Part-worn, road-worthy tyres: those which meet national standards (i.e., tread depth, non-injured carcass) for continued road use.
3. Re-treadable/Casings suitable for re-treading: as defined by the re-treading industry
4. Recyclable: those which are not re-useable or re-treadable but suitable for recovery by material recycling or energy recovery.
Tyres that do not meet national standards for road use are collected from a range of sources:
-Private individuals (cars, vans, 4 x 4, farm equipment, etc.);
-Government fleets (cars, buses, lorries, construction, maintenance, delivery vehicles, etc.);
-Commercial enterprises which include all of the above;
-Automobile and truck concessionaires;
-Tyre importers and distributors;
-Tyre fitters, garages and automobile repair shops;
-Vehicle dismantlers and shredders.
Today, a wide variety of practices exist in Europe. They include:
-Re-use of newer tyres, subject to legal standards on tread
-Re-use for landfill engineering (whole tyres can be used in construction of landfill sites)
-Re-treading
-Recycling through grinding (crumb is used in sports and play surfaces, brake linings, landscaping mulch, carpet underlay, absorbents for wastes and shoe soles, and in rubberised asphalt for roads; some crumb is also used in tyre manufacture, along with virgin rubber)
-Other recycling techniques include cryogenic fragmentation, de-vulcanisation, microwave technology, and are subject to continuing development
-Energy recovery (through burning, pyrolysis, or incineration in cement kilns for instance).
Quantity of waste recycled
In Europe, tyre recycling represents about 950 thousand tonnes, i.e. about 30% of the end-of-life management of tyres (see “material recovery” in Table 2).
Table 2: End-of-life tyre management in EU25 in 2005
Quantity(thousand tonnes) / Percentage of total
Part-worn tyres / Reuse / 129 / 4%
Export / 126 / 4%
Re-treading / 350 / 12%
End-of-life tyre recovery / Material / 953 / 32%
Energy / 979 / 33%
Landfill and unknown / 430 / 15%
Total Arising / 2 967
Source: [ETRMA], for an analysis per country, seeAnnex B.
According to a representative of ETRA, the quantity of tyres that are recycled per year is not expected to increase significantly in the next years for two reasons. The first one is that the share of tyre arisings that are recycled is not expected to increase (currently 32%) and the second is that the aging of the European population will probably lead to smaller vehicles on the market and less car trips, and consequently less post-consumer tyres.
With an average of 45% (weight) of rubber per tyre (see Table 3), about 430 ktonnes of rubber are recycled per year in EU25 through tyre recycling, i.e. about 10% of rubber consumed in Europe.
Table 3: Average composition (in weight) of tyres in the European Union
Material / Passenger cars / Trucks/busesRubber /Elastomers / 48 % / 43 %
Carbon black / 22 % / 21 %
Metal / 15 % / 27 %
Textile / 5 % / -
Zinc oxide / 1 % / 2%
Sulphur / 1 % / 1%
Additives / 8 % / 6%
Source: [ETRA]
The most common rubber used in the production of passenger car tyres is styrene-butadiene co-polymer (SBR), which contains about 25% by weight of styrene in combination with SBR. Other elastomers such as natural rubber (cis-polyisoprene), synthetic cispolyisoprene, and cispolybutadiene are used in varied amounts.
Number of facilities and employment
ETRA count around 130 member companies, specialised in tyres recycling. 60% of these facilities employ less than 10 persons and 19 companies have 3 full time employees. The biggest facility counts 126 employees.
Outside ETRA, there are at least 30 companies, 5 of them being the biggest players in the recycling sector.
Summary of key elements about the size and structure of the sector useful for this exerciseIn Europe, about 32% of tyres are recovered for material. This corresponds to 430 thousand tonnes of rubber that are recovered for material, every year.
There are far less than 200 companies recycling rubber in Europe. In addition, more than half of the recycling facilities are rather small and employ less than 10 persons.
3.3Environmental impacts
Available data and main assumptions
As already mentioned above, rubber can be recycled through several processes, depending upon the use the recycled material is intended for.
The PRé Consultants report [PRéC 2001] quantifies the environmental impacts of four processes representative of tyre recycling. The proportion of tyres treated by each process was discussed by PRé Consultants with ETRA and BLIC[2]and are summarised inTable 4, which also provides the type of grinding associated with each process.
Table 4: Existing processes in tyre recycling
Recycling option / Share of this option / Process / Avoided productFilling materials for construction application / 22% / Coarse shredding / Stone/gravel
Additive for bitumen application in road surfaces / 8% / N/A / Regular synthetic rubber
Consumer goods / 24.4% / Fine grinding / Regular rubber
Sport surfaces and floors / 45% / N/A / Regular rubber
Other / 0.6% / Unknown / Unknown
N/A: not available
Source: [PRéC 2001]
In the present study, the focus is on the environmental impacts directly generated by the recycling facilities. The potential benefits of recycling corresponding of the saving of primary or virgin products that the recycled products substitute are of no interest here.
The PRé Consultants report provides direct impacts only for recycling into filling material and for recycling into consumer goods only. For the other processes mentioned in Table 4, the impacts inventory available in the report take into account the avoided impact of the product that the recycled tyre is intended to substitute. For example, in the case of sport surfaces, the use of the recycled material avoids the production of regular rubber. The avoided impacts generated through the regular rubber production are thus subtracted to the environmental impacts generated through the recycling of rubber and only the net impacts are displayed in the report.
For the purpose of estimating the environmental impacts of the whole tyre recycling activity, the following assumptions are made, based on the grinding type in each recycling processes:
-Assuming that the recycling of tyre into additive requires a coarse shredding, the environmental profile of this process is considered to be similar to the one of tyre recycling into filling materials.
-Assuming that the recycling of tyre into sports surfaces and floors requires a fine grinding, the environmental profile of this process is considered to be similar to the one of tyre recycling into consumer goods.
-Assuming that other recycling options requires fine grinding, the environmental profile of this recycling route is considered to be similar to the one of tyre recycling into consumer goods.
To assess the environmental impacts in this study, it is thus considered that 30% of the recycled tyres are recycled through coarse shredding and 70% are recycled through fine grinding.
Environmental impacts of tyre recycling
Table 5 below provides the environmental impacts for 1kg of tyre recycled through coarse shredding and fine grinding processes [PRéC 2001]. The last column of this table is the computed average impacts per kg of tyre recycled. Main environmental impacts associated to tyre recycling are dust and PM10 emissions to air as well as waste production (rubber, steel scrap and chemical waste, part of them being recovered, the others being landfilled).
Table 5: Electricity consumption, air emissions and waste per kg of tyre recycled
Coarse shredding (30%) / Fine grinding (70%) / Average impacts per kg of tyre recycleda / b / c=0.3 x a+0.7 x b
Electricity consumption / 0.028 kWh / 1.065 kWh / 0.754 kWh
Dust emissions (coarse) / 28 mg / 25.21 mg / 26.047 mg
PM10 emissions / 0 / 0.224 mg / 0.157 mg
Rubber waste (landfill) / 0 / 0.027 kg / 0.019 kg
Steel scrap (recycling of ferro metal) / 0.4 kg / 0.058 kg[3] / 0.161 kg
Chemical waste (incinerated) / 0 / 0.370 g / 0.259 g
Table 6 quantifies the environmental impacts for the 950 kt of tyres which are recycled in Europe each year.
Table 6: Annual environmental impacts of the recycling of tyre in EU-25
For EU-25 recycled(hyp.: 950 kt of tyres recycled) / Annual tyre recycling impacts
d=c x 950 kt
Electricity consumption / 718.56 GWh
Dust emissions (coarse) / 24.82 tonnes
PM10 emissions / 0.15 tonnes
Rubber waste (landfill) / 18107 tonnes
Steel scrap (recycling of ferro metal) / 153 433 tonnes
Chemical waste (incinerated) / 247 tonnes
Comparison of PM10 emission and energy consumption with other sectors
As shown inTable 7, the annual PM10 emissions due to tyre recycling activity in EU-25 is very low compared to other sources of emissions such as sectors already covered by IPPC (waste disposal, etc.) or sources of diffuse emissions (e.g. transports, agriculture).
Table 7: Annual PM10 emissions into air of some sectors in EU-25
Sectors / Annual PM10 emissionQuantity (t) / Share of tyre recycling (% of other sectors)
Tyre recycling / 0.15
Total EU-25 [EEA 2002] / 2 160 587 / 0.000007
Total IPPC / Total Industrial emissions [EPER2004] / 290 564 / 0.00005
Sectors covered by IPPC / Installations for the disposal or recovery of hazardous waste [EPER 2004] / 80 / 0.187
Installations for the disposal of non hazardous waste [EPER 2004] / 1 024 / 0.015
Installations for the disposal or recycling of animal carcasses and waste [EPER 2004] / 138 / 0.108
Total Diffuse emissions [E-PRTR 2004] / 919 238 / 0.00002
Table 8 provides the annual electricity consumption of some sectors including the tyre recycling industry. Electricity consumption of tyre recycling represents less than 1% of each other sector.
Table 8: Annual electricity consumption of some sectors in EU-25
Sector / Annual electricity consumptionQuantity (103 GWh) / Share of tyre recycling (% of other sectors)
Tyre recycling / 0.72
Iron and steel industry* / 123.52 / 0.58
Non-ferrous metal industry* / 82.21 / 0.87
Chemical Industry* / 192.63 / 0.37
Non-metallic mineral products industry* / 82.20 / 0.87
Ore extraction (except fuels) industry* / 15.07 / 4.77
Food, drink and tobacco industry* / 103.75 / 0.69
Textile, leather and clothing industry* / 35.93 / 2.00
Paper and printing industry* / 139.08 / 0.52
Engineering and other metal industry* / 150.21 / 0.48
Other non-classified industry* / 168.40 / 0.43
* Source: Eurostat, 2004
Summary of key elements about the environmental impacts of the sector useful for this exercise.
The major environmental impact generated by the recycling of rubber is the emission of particulate matters into the air. However, compared to other recycling sector, the amount of the emissions is small.
4.Summary
Rubber products and production
Every year, around 3.9 million tonnes of rubber are consumed in EU-25. Natural and synthetic rubbers are intended to manufacture either tyres or general rubber goods. Among these two categories of rubber products, tyres are the only rubber products that are recycled. The small size of general rubber goods, their little collection, their variability of content and their potential contamination make their recycling difficult, non-profitable. Therefore, general rubber goods are little recycled.
Quantity of rubber recycled
Around 950 thousand tonnes of tyre are recycled in EU-25 every year. This corresponds to an annual quantity of 430 thousand tonnes of rubber recycled,i.e. about 10% of rubber consumed in Europe. In a near future, this quantity is not expected to increase significantly.
Rubber recycling facilities
In Europe, there are around 160 recycling facilities, 60% of them count less than 10 full-time employees.
Environmental impacts of tyre recycling
The annual environmental impacts of tyre recycling have been computed at the EU-25 scale. Results show that the major environmental impact of tyre recycling is the emission of particular matters PM10. However, emission generated by the tyre recycling industry are very low compared to other sources of emission such as sectors already covered by IPPC.