Material Flow Analysis of End-of-Life Vehicles in South Korea
Article information
Abstract
The increase in end-of-life vehicles (ELVs) has highlighted the need for more advanced ELV dismantling and recycling processes. To understand the flow of ELVs after disposal, this study conducted a material flow analysis of ELVs by dividing the ELV recycling process into the stages of discarding, collection, treatment, resource recovery, and sales/export. According to our analysis, the recycling rate of ELVs in South Korea was 88.7%. Losses in liquid waste, airbags, waste refrigerants occurred due to their destruction or releasement into the atmosphere during the recycling process, and losses in the heat energy produced by formal sectors occurred at the final stage of ELV recycling. Valuable scrap metal, reusable parts, and ferrous and nonferrous metals were relatively well-recycled, pointing to the need to promote the recycling of less valuable materials, such as plastic, glass, rubber, and sheet foam. Metals recovered through shredding and automotive shredder residue (ASR) recycling are sold to steel mills and refineries, and the heat energy recovered through ASR recycling is supplied to nearby industrial facilities. Additional material flow analysis of ELVs will help identify the obstacles hindering the improvement of Korea’s ELV recycling rate and develop appropriate policies.
Abstract
Graphical Abstract
1. Introduction
The number of end-of-life vehicles (ELVs) has been growing significantly due to the increased production and use of automobiles worldwide. In the case of South Korea, the number of registered vehicles has jumped more than 100 times compared to 40 years ago, from 193,000 in 1975 to 24.4 million in 2020 (MOLIT, 2021), while approximately 970,000 ELVs were discarded in 2019 [1]. ELVs contain elements that are detrimental to the environment if not treated properly, however, drops in scrap metal prices and the consequent changes in automotive recycling industry’s profit structure have been causing companies in the industry to seek profits and cut costs by recycling those parts with high economic value and disposing of the remaining ELV waste without proper treatment [2]. For instance, one ELV generates about 300 g of waste gas, such as air conditioner refrigerants made of chlorofluorocarbons (CFCs, freon gas) and hydrogen fluorocarbons (HFCs) which have up to 11,700 times larger greenhouse effect than carbon dioxide [3, 4]. However, although most ELV recycling companies have the facilities to recover and store waste refrigerants, due to the burden of processing costs and for convenience reasons, the reality is that most waste refrigerants from ELVs are discharged into the atmosphere. In the case of Korea, only 11 tons (4.5%) of waste refrigerants were recovered out of the 242 tons that were generated in 2013, and only 134 tons (11.2%) were recovered out of the 1,191 tons generated over the five years from 2009 to 2013 [5].
Although ELVs contain a large number of harmful substances, they are a source of abundant resources that can be recycled and recirculated, including ferrous and nonferrous metals and rare earth metals. Thus, the recycling of ELVs is a must, both economically and environmentally. The European Union (EU) and Japan have recognized the importance of ELV recycling ahead of Korea and implemented policies for recycling and recirculating resource gained from ELVs [6, 7]. Korea has also been promoting ELV recycling since the enactment of the Act on Resource Circulation of Electric and Electronic Equipment and Vehicles on January 1, 2008. However, from 2013 to 2020, Korea’s ELV recycling rate has stayed between 88% to 89%, which is lower than the country’s targeted rate of 95% as well as the ELV recycling rates of Germany and Japan [8]. Understanding the flow of waste resources is vital for enhancing resource circulation, but previous studies have mostly looked into the flow of certain materials such as Ni, Co, Cu, Pd, Ti, and rare-earth metals, and few studies have so far attempted an MFA of an end-of-life product on the case of Korea or on the retrieval of useful resources and the flow of potentially-pollutant residues generated from the ELV recycling process in Korea [9–11].
Since advanced resource circulation requires a comprehensive understanding of how a product, after its disposal by the end-user, is processed and recycled, as opposed to looking at the flow of individual materials, this study conducts a material flow analysis (MFA) of ELVs to identify the flow of valuable resources which can be recovered from ELV recycling, and the residues generated during this process which may adversely affect the environment. Generally, MFA is conducted on the stages undergone by a product at its end-of-life. In this study, the material flow of ELV recycling is examined in terms of five stages, which are the discarding stage, collection stage, treatment stage, resource recovery stage, and sales and export stage, to provide new insight into the flow of recoverable resources and residues in each stage of ELV recycling.
2. Literature Review
The number of vehicles produced worldwide has grown significantly, from approximately 38 million vehicles in 1980 to 80 million vehicles in 2021 [11, 12]. As a result of this expanded production and use of vehicles, the number of ELVs discarded in countries worldwide have surged over time as well. For instance, the total number of ELVs reported in the EU was 6.1 million in 2019, which is a sharp rise from 4.8 million in 2016 and 5.3 million in 2017 [13]. Due to the hazardous quality of automotive wastes and shredder residue, growing attention is being given to the proper management of ELVs at global, regional, and national levels. Although ELVs fall under the category of waste that is difficult to process due to the complexity in their structure and composition, they are also important sources of resources and are vital for realizing circular economy and sustainable development [14]. Accordingly, along with the implementation of legislations and policies on the reuse, recycling, and proper treatment of ELVs, such as the EU’s ELV Directive, Japan’s Vehicle Recycling Law, etc., considerable research has also been conducted to understand the current status of ELV management and optimize ELV recycling and treatment processes. The scope and depth of the research related to ELVs can be grasped from the handful of review papers published on ELV management, which cover diverse topics such as automotive wastes [15, 16], comparative analysis of ELV management practices [17], and others. More recently, Karagoz, Aydin, and Simic [18] provided an extensive overview of ELV management research spanning over a total of 232 studies published from 2000 to 2019.
Concerning the material flow during ELV recycling, Hiratsuka et al. [19] analyzed the material, information, and financial flows of ELVs in Japan, including the flows of reuse, recycling, and energy recovery. Yano et al. [20] focused on the dynamic substance flow of lead in ASR generated in Japan, excluding the lead in lead-acid batteries, based on the number of ELVs from 1990 to 2010 estimated using statistical data and from 2010 to 2020 estimated using prospective data. Fuse et al. [21] conducted an interesting study which analyzed the material flow of base metals from ELV recycling across borders, quantifying the global movement of these resources through used passenger car trade.
Several previous studies have adopted the life cycle assessment (LCA) method, which extends MFA to further analyze and quantify the environmental impacts of ELV recycling processes, including resource recovery and waste generation. Ciacci et al. [22] focused on ASR management and analyzed five scenarios of treating ASR using LCA to highlight the development of post-shredder technologies and eco-design strategies that reflect end-of-life treatment. Chen et al. [23] conducted an LCA of passenger ELV recycling in China using a mathematical model to compare the environmental burden against the benefits. Fonseca et al. [24] looked at the case of Portugal and conducted a field experiment and an LCA of three scenarios representing different degrees of resource recovery through ELV recycling to investigate their environmental impacts in terms of abiotic resource depletion, climate change, photochemical oxidant creation, acidification, and eutrophication. Liu et al. [25] integrated dynamic MFA and LCA to construct a model for a recycling decision system and computed the material flow and carbon emission of ELV recycling in China.
On the Korean situation, Jeong et al. [26] provided a thorough examination of Korea’s ELV treatment system using LCA, life cycle impact assessment (LCIA), and life cycle inventory (LCI) analysis methods, which considers the environmental burdens from the dismantling and recycling of end-of-life passenger vehicles as well as the environment benefits including avoidance effects, and found that the recycling of ferrous metals had the most significant environmental impact in Korea’s ELV treatment system. However, as the study was conducted more than a decade ago, at which time Korea’s ELV recycling rate was 78%. A recently published study by Jang et al. [8] provides an update on the Korea’s ELV recycling situation through an MFA performed to quantify the amount of resource recovery, with particular focus on identifying the substance flow of polybrominated diphenyl ethers (PBDEs) in automobile shredded residues (ASR) during ELV recycling. The present study presents a fuller description of Korea’s ELV recycling and resource recovery, including contextual information to provide a better understanding of the ELV treatment system in Korea.
3. Methods
3.1. Research Scope and Method
This study limits its scope of research to look at ELVs that are passenger vehicles and light- and small-type freight motor vehicles only, which is one of the items regulated by the Act on Resource Circulation of Electric and Electronic Equipment and Vehicles. The range of ELVs considered in this Act are passenger vehicles which can transport up to 9 passengers and light- and small-type freight motor vehicles which weigh less than 3.5 tons.
The research data for the key outcome of this study, which is to draw up an MFA chart for ELV recycling, was collected through literature reviews, site visits, and consultations with experts. The Act on Resource Circulation of Electric and Electronic Equipment and Vehicles requires businesses in the ELV recycling industry (e.g., ELV dismantlers, shredders, ASR recycling facilities, and waste gas treatment facilities) to input reports detailing the collection, transportation, and recycling of ELVs in the Eco-Assurance System of Electrical and Electronic Equipment and Vehicles (EcoAS system) provided by the Korea Environment Corporation (KECO) [28]. Fig. 1. provides a flow chart of the operation reports required of the companies that transport or recycle ELVs and the procedures through which the information is input in the system throughout the material flow of ELVs. The MFA conducted in this study primarily utilized the statistical data compiled through the EcoAs system. Field research was also conducted through site visits to ELV dismantlers, shredders, and ASR recycling facilities in Korea, as well as through interviews and consultations with members of the ELV recycling industry and relevant government ministries and agencies (e.g., the Ministry of Environment, Korean Environment Corporation) to gain a deeper understanding of the actual flow of materials in each ELV treatment stage.
Operation Reporting procedure required of ELV recycling businesses
3.2. The Stages of the Material Flow Analysis of ELVs and Their Concepts
The material flow of products after their end-of-use can generally be classified into the five stages of discarding or import, collection, treatment, resource recovery, and production or sales and export. The discarding/import stage refers to the state where the product has met its complete end-of-use or the end-of-use in terms of its original usage and also includes the import of end-of-life products (waste products) from overseas for the purpose of resource recycling. However, in the case of ELVs in Korea, vehicles are not imported for the purpose of dismantling and recycling, so the import was not considered in our MFA. After an ELV is discarded, it enters the collection stage for waste treatment. ELV dismantlers are the first to receive the waste vehicles, generally by purchasing them to resell their parts and components. We also included the concept of disposal in this stage, as there are materials which are finally disposed at this stage due to their low economic value.
The treatment stage refers to the process of separating, sorting, and treating the waste vehicles, while the resource recovery stage refers to the process of converting the waste resources obtained from the treatment stage into usable forms as materials (input) for production. There are largely four processes involved for the treatment of ELVs: dismantling, shredding, automotive shredding residue (ASR) recycling, and waste gas treatment. These processes are undertaken by ELV dismantlers (who are also involved in the depollution of ELV components including waste gas treatment), shredders, and ASR recycling facilities. Resource recovery and sales are also conducted at each of these businesses. Dismantlers receive ELVs from the end-user (last owner of the vehicle) and separate and recycle valuable scrap metal, reusable parts, fuel, liquid waste, waste refrigerants and gas, batteries, tires, airbags, etc. Waste refrigerants are required by law to be sent to waste gas treatment facilities, and the car body-shells which remain after taking away the recyclable and reusable parts are transferred to ELV shredders. Shredders, after receiving the car body-shells, recycle the ferrous and nonferrous metals and send the remaining residues (i.e., ASR) to ASR recycling facilities. At the ASR recycling facilities, metal resources are further recovered from the ASR, then, the remaining residues are processed for energy recovery. We defined the resource recovery stage for ELVs as the stage in which recyclable or reusable materials are recovered after the treatment processes and analyzed the resource recovery during ELV dismantling (including the recovery of waste gas), shredding, and ASR recycling.
Lastly, the production/export stage, named as such in a previous MFA study [27], refers to the stage of exporting the recovered resources or utilizing them as raw materials for production. In the case of ELVs, the parts and components which can be recovered have value as products as is and can be reused or recycled immediately after treatment. In the case of Korea, most ELV recycling companies do not differentiate the recovered resources based on their base elements but separate them into reusable parts, valuable scrap metal, nonferrous metals, etc. Thus, it was found to be more appropriate to define this stage as the sales/export stage rather than production/export stage. Table 1 summarizes the stages of the MFA of ELVs and the conceptual definitions of the stages adopted in this study.
The stages of the material flow analysis of ELVs and their concepts
4. Results
According to our analysis, Korea’s ELV recycling rate was 88.7%, and the final residues from ELV recycling was thermal energy loss in the formal sector and final sludge. Additionally, there also existed losses from the improper treatment or release of liquid waste, air bags, waste refrigerants. The following sections provide the detailed findings on the MFA of ELVs in Korea by stage.
4.1. Discarding Stage
The average number of passenger vehicles and light- and small-type freight motor vehicles, as per the scope of this research, discarded each year was calculated to be 709,099 vehicles. The number of discarded vehicles was highest in 2011, when 81,141 vehicles were de-registered. According to the EcoAS data on ELVs, the number of ELVs reported was 71,1347 vehicles, and their weight was 928,622 tons.
At the discarding stage, the final owner often left various wastes within the vehicle when handing over the vehicle to the ELV dismantler, which relays the waste treatment disposal costs of such external waste to the dismantlers. A yearly average of 7,601 tons of external waste were disposed of by ELV dismantlers, of which 6,603 tons were estimated as the amount of waste abandoned in the vehicles by their final owners. There are also instances where vehicles are customized and tuned by their owners, which adds unspecified weight to the vehicles. Since ELV recycling rates are computed based on the weight provided by manufacturer, the external waste left by vehicle owners and the additional vehicle weight arising from vehicle customization and tuning can negatively impact the ELV recycling rate.
4.2. Collection Stage
At the collection stage, ELVs were taken over to dismantlers to be dismantled (or put on stand-by for decommissioning) or exported overseas. Therefore, the number of ELVs at this stage was compiled based on the number of ELVs acquired and processed by dismantlers. The average number of recycled ELVs was 643,499 vehicles per year, and their volume increased 21.1% from 522,391 vehicles to 633,028 vehicles over 7 years. The ELVs that were not processed by dismantlers were considered to be exported or on stand-by for decommissioning, which amounted to 71,650 vehicles/year on average, and 78,319 vehicles (42,422 exported and 35,897 ELVs on stand-by). In terms of weight, 928,622 tons of discarded vehicles were collected by dismantlers, of which 809,928 tons were taken to the treatment stage.
4.3. Treatment Stage
According to our field research at ELV dismantlers, shredders, and ASR recycling facilities in Korea, in general, ELVs were disassembled into parts and components in the following order. First, liquid waste, such as anti-freezers, engine oil, and fuel, is removed and stored separately by type for treatment or reuse. The collection of liquid waste is required to be reported daily in the EcoAS system, and the collected liquid waste is required to be treated by an EcoAS-registered company. Then, the basic parts, such as tires, batteries, and airbags, are separated. Among these, airbags are destroyed in the process and, thus, are disposed of as waste. After the separation of the basic parts, waste gas or refrigerants are recovered. LPG gas is mostly incinerated, and waste refrigerant is recovered from the compressor using a suction device. However, for reasons of convenience, the waste refrigerant recovery process is often omitted by dismantlers, resulting in their release into the atmosphere.
Next, the reusable components and parts are separated. These components and parts are not defined by law, and they are recovered and reused as much as possible depending on their condition or the demand for used parts. Plastics, rubber, glass, cat seats, etc., from ELVs, which account for about 8–10% of the vehicle weight, are not required to be recycled by law and are usually unrecycled during the dismantling process due to their low economic value. Instead, they are generally left in the ELV to be compressed along with the car body-shell. After the separation of reusable parts, the scrap metal located in the bottom of the ELV is removed, leaving the car body-shell and the aforementioned unrecycled components. These remains are compressed and handed over to ELV shredders.
Shredders, after receiving the compressed body-shells, recover valuable metals from the ELVs by putting the body-shells through a shredder to make 25cm × 25cm pieces. Generally, about 60–65% of the shredded body-shells are recyclable ferrous or nonferrous metals. Depending on the pressure applied when compressing the body-shell, the recyclable amount can be increased up to 68–80%. Ferrous and nonferrous metals are sold to steel mills and refineries. The plastics which were not separated at the dismantling phase become included in the ASR, since a great variety of plastics are used in an average vehicle (polypropylene, polyurethane, polyethylene, polyamide, etc.), making them difficult to sort and recycle [29]. As the only recyclable resources left after the dismantling process are ferrous, nonferrous metals, and shredded residues (ASR), there is usually little room for shredding and ASR recycling processes to contribute to enhancing the ELV recycling rate.
Our field research confirmed that the remaining residues from the shredding process contained a large volume of plastics and rubber, as well as external waste, which should have been removed or recovered from ELVs at earlier processes. At present, there are 14 ELV shredders in Korea, whose combined capacity is about one million ELVs/year assuming 100% operation. However, as there are only about 600,000 to 700,000 vehicles discarded each year in Korea, it could be presumed that dismantlers have a larger voice over the shredders. Thus, even if the dismantlers include waste or leave plastics, rubber, glass, and sheet foam, etc. in the compressed body-shells, the shredders could not but keep silent in order to secure their livelihood. Also, we found that the drop in scrap prices has prompted the dismantlers to convert body-shells into scrap metal to sell to junkyards, which would bring them a higher profit than selling compressed body-shells to shredders. A common illegal behavior among dismantlers was to sell the car doors, bonnets, and even the trunk as scrap metal to junkyards, then including external waste in the compressed car body-shells to increase their weight when selling the body-shells to the shredders.
4.4. Resource Recovery Stage
4.4.1. Recycling rate and performance of ELV dismantling
The total amount of ELVs processed by dismantlers was 809,928 tons, of which 717,917 tons were recycled. In detail, valuable scrap metal had the highest recycling rate at 36.4% (294,522 tons), followed by other reusable (recyclable) parts, tires, bumpers, and batteries. Other parts and components showed recycling rates below 1%, which is either because of their low proportion in ELVs or the difficulties in recycling these materials. The recycling rate at the dismantling stage was 62.3%, accounting for more than 70% of the total ELV recycling rate. Thus, it can be said that the dismantling stage is the most important stage in Korea’s ELV recycling process.
We categorized ELVs into large, medium, and small-sized vehicles to analyze the demand for their reusable parts. Tires, horns, shock absorbers, jacks, headlights, mirrors, batteries, antennas, fenders, taillights, car audio, doors, bumpers, engines, silencers, springs, and bonnets accounted for more than 80% of all used parts that were sold. Among these parts, catalysts, bonnets and tires were found to be most valuable as used parts. Notably, catalysts had 20.9 times higher value when reused than when it is materially recycled. In general, consumers are reluctant to use used parts for safety reasons, which suggests the need to change consumers’ perception of used parts to revitalize the used parts market. On the other hand, the representative components that are improperly processed by dismantlers were various oils, such as coolants, brake oil, and engine oil, and airbags. Only 2,684 tons of liquid waste and airbags were properly disposed of at the dismantling phase, which is only 0.3% of the total ELV recycling rate. The detailed recycling rates and performance at the ELV dismantling stage are presented in Table 2.
Recycling rate and performance of ELV dismantling
We further examined the EcoAS data on the treatment of waste gas at the dismantling stage, since our field research showed that most of the waste refrigerants generated during the dismantling process seem to be released into the atmosphere without undergoing proper treatment. Table 3 shows the recycling rate and performance of waste gas treatment during the dismantling phase. Assuming that 300 g of waste refrigerant can be recovered per vehicle, it can be estimated that 198 tons of waste refrigerants were generated from ELVs, however, only 13 tons were appropriately separated and stored by dismantlers and only 0.5 tons taken over to waste gas treatment facilities (0.0% recycling rate). That is, although ELV dismantlers are legally mandated to separate and store waste refrigerants, which are known to adversely affect the climate and ecosystems, then send them to EcoAs-registered waste gas treatment facilities, many dismantlers were discharging liquid waste, airbags, and waste refrigerants without adequate treatment for reasons of inconvenience, causing a detrimental effect on the environment. Thus, there is a need of an effective system for promoting the proper treatment of waste refrigerants to minimize their harmful effects on the environment.
Recycling rate and performance of waste gas treatment during the ELV dismantling process
4.4.2. Recycling rate and performance of ELV shredding
The recycling rate at the shredding stage was computed to be 23.7%, accounting for about 27% of the total ELV recycling rate, which is lower than that of dismantling. Ferrous and nonferrous metals were the two major materials recycled through shredding, which are, and ferrous metals took up 99.4% of the materials that were recycled at this stage. The detailed recycling rates and performance at the ELV shredding stage are given in Table 4.
Recycling rate and performance of ELV shredding
4.4.3. Recycling rate and performance of ELV ASR recycling
The recycling rate at the ASR recycling phase was 2.7%, as shown in Table 5. In Korea, ASR recycling was mostly done in the form of energy recovery, however, less than 10% of the maximum energy that could potentially be recovered was being achieved. The ASR generated at ELV shredders in Korea was composed of about 80% combustible materials (such as plastics, fibers, and sponges), 10.5% soil matter, and 2% each of metals, wires, and glass [30], although some differences existed in the number of metals, wires, and soil matter depending on the equipment and machinery used for treatment and the quality of the car body-shell supplied by the dismantlers at earlier stages. The final residues (sludge) of ASR recycling consisted of soil matter or fine particulates from materials, which are difficult to recycle and, thus, are sent to landfills. The amount and properties of the final residues sent to landfills after ELV recycling depend on the ASR recycling rate. For instance, in 2010, Germany’s ASR recycling rate was 91%, meaning that only 9% of the ASR were final residues sent to landfills, while Spain, Belgium, and France sent 96%, 63%, 88% of the ASR generated from the ELV recycling process to landfills, respectively [31]. Meanwhile, in the case of Japan, resource recovery from ASR was achieved through thermal recovery (69%) and material recovery (27.1%), and only 3.9% of the ASR were sent to landfills for final disposal [32].
Recycling rate and performance of ELV ASR recycling
The growing demand for higher fuel efficiency and safety have been leading to considerable changes in the materials used in automobile manufacturing, particularly the increase in the use of light alloys and plastics. As such trend is expected to continue, ASR recycling may require greater attention in the future for enhancing the overall ELV recycling rate. As an example, in Japan, the amount of steel used in passenger cars have been showing a decreasing trend, while the use of nonferrous metals and plastics have been increasing to reduce the vehicle weight for better gas mileage [17]. Therefore, the number of plastics and nonferrous metals in the ASR generated in Japan has been increasing and is expected to increase further in the future. This trend is already being reflected in the composition of the ASR in Japan, which is composed approximately of 37% plastics, 23% of substances smaller than 5 mm, 13% textiles, 8% rubber, 8% urethane, 4% ferrous and nonferrous metals, and 2% wires, etc. [30, 33]. No soil matter is found in the ASR characterization, showing that vehicles are discarded in clean conditions.
4.5. Sales and Export Stage
The sales and export stage is the stage in which the resources recovered from ELVs are utilized as is or for manufacturing specific products. The size of the used automobile parts market is about 240 million USD with 70% of the sales made from foreign exports and 30% from domestic sales. 42,422 ELVs (56,156 tons) were exported as used vehicles as is, without further treatment or processing. Domestically, used parts from ELVs are sold to intermediary sellers (20%), car repair shops (7.2%), and individuals (4.2%). The buyers of the recovered resources from ELVs are diverse. Valuable scrap metals recovered through dismantling are sold to steel mills; reusable parts are sold to individuals, car maintenance companies, used parts retailers, foreign buyers, etc.; recovered fuel is used by the dismantlers; and batteries, catalysts, and waste refrigerants are processed by designated recycling companies to be converted into raw materials for new products. A part of the waste refrigerants is treated with a waste refrigerant renewing process to be supplied to businesses that use renewed waste refrigerants. Ferrous and nonferrous metals recovered through shredding and the small number of metals recovered through ASR recycling are sold to refineries and iron companies, while the heat energy recovered through ASR recycling is supplied to nearby industrial facilities. As the EcoAS system does not require industry participants to report on the exact destinations of the recovered resources, it is difficult to gain specific data on how the resources are used, however, it seems reasonable to assume that all recovered resources are used as is or for manufacturing products in various ways.
4.6. Material Flow Analysis of ELVs in Korea
The MFA of ELVs in Korea conducted in this study can be visually summarized into a chart as shown in Fig. 2. In Korea, the bulk of the resource recovery from ELVs primarily occurred at the dismantling stage, when the ELVs were dismantled, and its parts and components are separated into heavy scrap metal (36.4%), reusable parts (24.1%), and fuel (0.1%). The car body-shells were then taken to shredders to separate the non-ferrous and ferrous metals (23.8%). At the ASR recycling phase, almost all of the ASR were incinerated for thermal recovery, and only a minute portion was treated for material recovery. After ASR recycling, ultimately, about 1.3% (10,522 tons) of all ELV waste ended up as final residues disposed at landfills. Interestingly, while ASR recycling is heavily concentrated on thermal recovery in Korea, in contrast to Japan, where around 27.1% of the ASR was treated for material recovery, and 69.0% was incinerated for thermal recovery in 2020 [32].
Material Flow Analysis of ELVs in Korea
5. Conclusions
This study categorized the material flow of ELVs into the five stages and analyzed the resources that were recovered and the waste that remained at each stage. That is, instead of looking at only the ELV treatment and recycling process consisting of dismantling, shredding, ASR recycling, and waste gas treatment, our research conducted a full MFA of ELVs in Korea covering the five stages of (1) discarding, (2) collection, (3) pretreatment, (4) resource recovery, and (5) sales/export. At the discarding stage, we found that an average of around 700,000 vehicles were being discarded annually, often containing abandoned waste left by their end-users. Urgent attention is needed on addressing the abandoned waste in ELVs, as the treatment of these abandoned waste adds to the cost of recycling ELVs and affects the quality of ELV recycling. At the collection stage, the formal procedures for discarding vehicles upon the expressed intent of the end-user to do so (i.e., de-registering the vehicle and delivering the ELV to an ELV recycling company) are well-implemented, however, measures are needed to induce the proper treatment of less valuable materials such as liquid waste, air bags, and waste refrigerants, which are currently being disposed of without suitable treatment due to their low economic value.
In the treatment stage, the factors impeding ELV recycling were the dismantlers’ inclusion of irrelevant external waste in the compressed car body-shells for shredding and the difficulties in determining the amount of ELV recycling conducted in the informal sector (i.e., scrap metal dealers and general incineration facilities). In the resource recovery stage, high-value materials, such as valuable scrap metal, reusable parts and ferrous and nonferrous metals, were being recycled relatively well, pointing further to the need to induce higher recycling of low-value materials such as plastic, glass, rubber, and sheet foam, etc. to increase the overall ELV recycling rate. Lastly, at the sales and export stage, where the recovered resources are utilized for specific products, different sellers and buyers existed depending on the usage of the resources who engage actively in the market for selling and exporting recovered resources from ELVs. Since selling valuable resources recovered through ELV recycling can be quite profitable, it is reasonable to assume that all recovered resources from ELVs find their usage in the market. The insights provided by the MFA performed herein may be used to derive effective policies to improve the recycling rates at each stage for Korea to achieve the targeted ELV recycling rate of 95%. Further in-depth studies on the material flow of ELV resources using up-to-date performance data will help identify the areas requiring additional efforts for improvement. Also, future research may benefit from investigating the actual input of recovered resources from ELVs in producing goods at the sales stage, which was undeterminable from the data collected for this study.
Acknowledgement
This study developed the analysis provided in “A Study on Analysis of Waste Resources Circulation Flow of End-of-Life Vehicles (2015–06)” under the financial support of the Korea Environment Institute (KEI).
Notes
Author Contributions
S.Y. (PhD) conducted partly the analysis and wrote the manuscript. H.S.L. (PhD) conducted all the analysis and wrote the draft of manuscript.
Conflict-of-interest statement
The authors declare that they have no conflict of interest.