Life Cycle Assessment. Life cycle Assessment of 9 recovery methods for end-of-life tyres

Transcription

1 Life Cycle Assessment Life cycle Assessment of 9 recovery methods for end-of-life tyres

2 Aims of the study There are three main aims for life cycle assessment of ELT* To evaluate the environmental advantages of each of the 9 recovery methods used in the sector. To compare the environmental impacts generated and avoided for each method. To identify the key points that require vigilance in the field s economic optimisation phase. * End-of-life tyres. The 9 recovery methods that are representative of LCA The study was carried out in the course of a complete year of activity was chosen as the reference because it was representative of Aliapur s current and future activities (300,309 tonnes of tyres collected and recovered in 2008). A Storage used tyres B Collecting / sorting C Storage at the transformation site Part-worn tyres Whole tyres 1 Retention basin Civil engineering recovery Energy recycling Material recycling Substitute products 1 - Retention basin 2 - Infiltration basin 3 - Cement works 4 - Urban heating 5 - Steel works 6 - Foundry 7 - Moulded objects 8 - Synthetic floors 9 - Equestrian floors Concrete block / plastic block D Shredding Shredded tyres 3 Cement works 2 Infiltration basin 4 Urban heating 5 Steel works 6 Foundry E Granulation Granulates Wire 5 Wood, coal, gas, fuel Steel works Gravel, miscellaneous Wood, coal, gas, fuel 7 Moulded objects Anthracite 8 Synthetic floors Foundry coke 9 Equestrian floors Textile fibres Landfill 2 Scrap metal Elastomers EPDM elastomers Sand

3 Introduction Definition of Life cycle Assessment (ACV) Life cycle Assessment is a method for assessing the overall environmental impact of a product from the production of its raw materials to the waste processing at the end of the product s life. The method is the subject of the ISO and standards. Context Aliapur decided to conduct the Life Cycle Assessment of End-of-Life Tyres (ELT) at a time when the sector had reached a degree of maturity, making it possible to have consistent data available : Creation of Aliapur 2004 : Start of collection, sorting and recovery operations. The R&D department implemented a flow and environmental impact study : Stabilisation of the activity The data available make it possible to draw up a preliminary report. Aliapur orders from Ecobilan PwC a Life Cycle Assessment in accordance with the ISO and ISO standards. >12-month study 2010 : Publication of the results How does the used tyre recovery field work? How is a Life Cycle Analysis carried out? Defining the aims Collecting tangible data (limited use of bibliographic data) Modelling / calculation of impacts Interpreting the results + Critical review by renowned, independent experts

4 Methodology Selecting the 9 representative methods The Life Cycle Assessment of ELT is based on 9 recovery methods that are representative of the sector. The aim of choosing these methods is to understand the sector in the totality of its components, as defined on the basis of 3 criteria: type of recovery method: public works, energy, material the level of maturity of the recovery method: - mature method: with a high contribution to recovery in terms of tonnage - emerging method: with considerable potential eliminating ELT or giving them a second life: destructive or non destructive methods Public works recovery 1 - Retention basin - mature method 2 - Infiltration basin - mature method Energy recycling 3 - Cement works - mature method 4 - Urban heating - emerging method Material recycling 5 - Steel works - mature method 6 - Foundries - emerging method 7 - Moulded objects - mature method 8 - Synthetic floors - mature method 9 - Equestrian floors - emerging method destructive method / non destructive method Defining an appropriate functional unit for the study For each recovery method, the environmental impact is calculated for the same service rendered: recovering one tonne of ELT from a given collection point. LCA is based on calculations per tonne, which: - guarantees that the results can be compared method by method, - makes possible future weighting in relation to the tonnages recovered. Choosing the limits of the system In order to provide the analysis with a framework, a choice was made to define the limits of the study: Collection Sorting Transfer* Granulation * or Shredding* Transfer Recovery * if necessary Determining the substitution rate The solutions based on ELT and alternative solutions are compared for a given service rendered, that is, in particular for identical life spans. Example: - Average life span of synthetic turf using ELT granulates = 10 years - Average life span of synthetic turf using granulates from EPDM (ethylene propylene diene Monomer) = 4 years > 1 ELT turf 2.5 EPDM turfs

5 Taking into account 8 characteristic environmental indicators The Life Cycle Assessment of ELT is based on eight fundamental indicators: total primary energy consumption contribution to the greenhouse effect consumption of non renewable resources acidifying gas emissions water consumption tropospheric oxygen formation contribution to eutrophication production of non dangerous waste In addition, toxicology and ecotoxicology studies were carried out on the ELT. These studies are available in the R&D section at Substitution effects and avoidance scenarios Environmental assessment is calculated stage by stage for each criterion. The overall impact for each criterion is: on the one hand, the sum of the results for each stage, on the other, the comparison of this overall result with the impacts generated and avoided. Overall environmental report = impacts generated by the stages needed to recover the ELT impacts avoided by substituting the ELT for traditional products Discussion points The outcome of end-of-life products For the non destructive methods, the outcome of the end-of-life products is not taken into account: this conforms to current practices, there is no feedback currently available. Limits of the stages in the system The study does not concern all used tyres, but only ELT. The collection (all products) and sorting stages are nevertheless taken into account in the overall report. Transport impact This is a key point in any recovery study. Ecobilan PwC worked on the basis of all the 140,000 transport slips from 2008 which were used and processed in their entirety. Status of ELT and accounting for material energy With regard to material energy, the hypothesis retained is as follows: - ELT are waste materials considered to have been abandoned by their users, - using their real energy potential (NCV) is considered to be free and does not result in any counting of primary energy consumption. As this choice is decisive for the results regarding primary energy, a sensitivity analysis was carried out. It was considered that 50% of the material energy consumption would be imputed to the person who abandoned the tyre and 50% to the user of the ELT, that is the recovery method studied.

6 Results 9 methods compared, 8 indicators: a wealth of data and results Ecobilan PwC chose to present the results by means of more than 100 graphs and comparative tables. A document summarising all the results is available in the R&D section at For each indicator an assessment in figures was carried out stage by stage, as was a comparison of the various recovery methods in relation to their avoidance scenarios. Example of greenhouse gas emissions: the case of synthetic turf. > Position of the gain from using ELT as substitutes in synthetic turf among the 9 recovery methods studied > Overall and comparative > Absolute data stage by stage environmental impact in relation to the avoidance scenario (EPDM) Recovery 78% Recovery 78% Recovery 78% ling act ycling pact The presence of negative values indicates that the recovery process Greenhouse effect (in kg CO2-equivalent) is more respectful of the environment. Synthetic Moulded Equestrian Retention Infiltration Cement Urban Steel Foundry Greenhouse effect (in kg CO2-equivalent) turf object floor basin basin works heating works Synthetic Moulded Equestrian Retention Infiltration Cement Urban Steel Foundry turf object floor basin basin Water worksconsumption heating (in works m3) Example of water consumption: the case of synthetic turf. Water consumption (in m3) > Position of the gain from using ELT as substitutes in synthetic turf among the 9 recovery methods studied Report Avoided impacts Recycling impact Synthetic turf Moulded object Equestrian floor Retention Infiltration basin basin > Overall and comparative > Absolute data stage by stage environmental impact in relation to the avoidance scenario (EPDM) Greenhouse effect (in kg CO2-equivalent) Urban heating Steel works Foundry Cement works Water consumption (in m3) Report Transfer for recovery 0% Sorting 0% Recovery 74% Transfer for recovery 0% Sorting 0% Recovery 74% The presence of negative values indicates that the recovery process is more respectful of the environment. In the context of the LCA of End of Life Tyres, three profiles stand out: 1 synthetic turf, moulded objects and cement works = proven benefits 2 retention basins, infiltration basins = minimal benefits 3 other recovery methods = intermediate benefits (gains that are more or less marked, depending on the indicators) These results may evolve with the emergence of new transport, shredding, granulation technology etc.

7 Conclusion Globally positive results The Life Cycle Assessment made it possible to identify that, under present conditions, all the recovery methods studied have environmental benefits, regardless of the impact taken into consideration. Justified investment in the preparation stages The study revealed that the impact of the collection, sorting and shredding/granulation stages is secondary in relation to the benefits obtained from the recovery process. The hierarchy* of recovery methods brought into doubt The LCA shows that the environmental assessment of material recycling methods is not systematically better than that of energy recycling methods. Projects and future perspectives As a result of the analysis, Aliapur s R&D department intends to continue carrying out studies, in particular: - analysis of future recovery methods, - taking into account the end of the second life of the products used in non destructive methods until their total elimination. *Hierarchy in the methods for managing waste mentioned in article 4 of the European Union directive (n 2008/98/EC) concerning waste.

8 Main contributors Members of the critical review team Henri Lecouls - LCA expert, Panel coordination Jacky Bonnemains - Robin des Bois Guy Castelan - Plastics Europe Walter Klöpffer - International Journal of Life Cycle Assessment Didier Laffaire - Association Technique Industrie des Liants Hydrauliques Lars-Gunnar Lindfors - Swedish Environmental Research Institute - IVL Jean-Sébastien Thomas - ArcelorMittal Project team Catherine Clauzade - R&D - Aliapur Philippe Osset, Charlotte Hugrel, Aude Chappert, Maxime Durande - Ecobilan PricewaterhouseCoopers February Photos : Michel Djaoui et photothèque Aliapur - All rights reserved. ALIAPUR 71, cours Albert Thomas Lyon - FRANCE Tél : +33 (0) Fax : +33 (0) contact@aliapur.fr French leader in used tyre recovery