End-of-Life in the railway sector: Analysis of recyclability and recoverability for different vehicle case studies

Abstract

The railway system represents one of the most resource-efficient answer to our ever-growing demand for transport service and the development trends for the following years forecast a substantial increase in this sector. Considering the European Union, rolling stock realizes a significant share of both goods and passengers carriage while it is responsible for a derisory quota of environmental impact and energy consumption involved by transportation. Contrary to the low environmental impact, the amount of End-of-Life (EoL) waste generated by rolling stocks in relation to the number of vehicles is notable, much greater than in the case of road vehicles. As railway vehicles are built from many heterogeneous components, the EoL rolling stock is a precious source of materials, whose recycling brings measurable economic benefits and needs to be appropriately debated. The paper performs the calculation of recoverability/recyclability rate for different typologies of representative railway vehicles on the basis of primary data and according to the recyclability and recoverability calculation method issued by UNIFE in the context of Product category Rules (PCR). The typologies of railway vehicles taken into account are electric metro, diesel commuter train and high-speed electric train. The analysis envisages also to repeat the calculation in case innovative materials and manufacturing technologies are adopted in the construction of car-body structure. Results show that recyclability/recoverability rates are abundantly over the quota of 90% for each one of the three trains, these latter being made in major part of metals which benefit from very efficient recovery processes. The adoption of innovative materials and manufacturing technologies for car-body structure involves a scarce reduction of recyclability and recoverability rates (about 2% and 0.2% respectively) due to the introduction of components and materials characterized by critical dismantlability and low efficiency recovery processes; recoverability results less affected by lightweighting because post-shredding thermal recovery treatments are roughly independent with respect to dismantlability. A sensitivity analysis based on different dismantling scenarios reveals that the effectiveness of dismantling has a moderate influence on recyclability/recoverability rate (the variation does not exceed 3%). The low variability of recyclability/recoverability rate can be explained by the following reasons: material composition of trains shows a predominance of metals; the efficiency of metals separation processes is close to 100%; post-shredding recycling processes of metals are characterized by recovery factors equal to the ones of post-dismantling recycling processes. Keywords:Train, Railway, Rolling stock, Recyclability, Recoverability, End-of-Life, Dismantling Highlights:Overview on railway vehicles End-of-Life; Assessment of recyclability and recoverability for three trains representative of current railway vehicle categories "urban, high-speed and commuter" ...

Recycling of Rolling Stocks

“…The materials, which are derived from rail vehicles, can be divided into seven main categories: metals; glass; fluids (lubricants, oils, chemical fluids); polymers, excluding elastomers, i.e., polymer compounds, reinforced polymers; modified organic natural materials (MONM-cotton fleece, wood, leather); elastomers (rubbers); and others, such as components not built using a unique or predominant constituting material (e.g., composites) and/or made by different subparts, for instance, electronics and electrics as stated in ISO 22628 [4][5][6][7][8][9][10][11][12][13][14].…”

“…In addition, there is no current recycling technology economically efficient enough to recover composite materials, such as carbon fibers (Carbon Fiber Reinforced Polymer) or glass fiber reinforced polymer, as new technological solutions [1]. As such, the residual waste of composite materials remains considerable in practice [14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31].…”

Recycling of Rolling Stocks

“…composites) and/or made by different subparts, for instance, electronics and electrics [1,[6][7][8][9][10][11][12][13][14].…”

“…In this process, the large pieces of rolling stock material are milled and grinded into smaller pieces for further processing. These smaller prices of materials can then be sorted into different material fractions using magnetic properties and eddy current separators [14]. Consequently, the waste is segregated in ferrous metals (steel and irons), non-ferrous metals (aluminium, zinc, copper, magnesium) and light shredder residue (a mixture of different substances and materials, for instance, fibers (textiles, wood), plastics (including foam and textiles), elastomers, glass and ceramics, residue (dust, paint coatings, rust) and remaining minerals (soil, sand).…”

Lightweight Design Solutions in the Automotive Field: Environmental Modelling Based on Fuel Reduction Value Applied to Diesel Turbocharged Vehicles

“…Many LCA studies already exist in the transportation sector [35][36][37][38][39] and interest is continuously growing, particularly in the automotive field [11,36,[40][41][42][43][44][45].…”