Introducing Auto Shredder Residue
The vehicle recycling process makes use of over 75% of a vehicle by weight. There is not a consumer product in the world with these types of material recovery rates. Because of this, many are looking toward the automotive sector for what could be the first industry to achieve a closed loop recycling process, a so-called ‘circular economy’.
The idea of a circular economy is in opposition to the traditional ‘linear economy’ in which we make, use, and then dispose of products. This is already happening in the auto industry, where on average 20% of a vehicle’s makeup consists of recycled metals. Lately, as companies build batteries for EVs, they are simultaneously creating plans for managing the disposal and recycling of used EV batteries at the end of their useful life.
As mentioned earlier, 75 percent of a car can be recycled, as in either parts refurbished for reuse or material transformed for new purposes. This is all good and fine but what about the non-recyclable elements in cars, that remaining 20-25% of a vehicle?
These materials, a combination of plastics and metals, are destined to become auto shredder residue (ASR). Understanding the composition of ASR is crucial for effective waste management and resource recovery. It will also be crucial if automakers hope to be the first to achieve a fully circular industry.
How it’s made
ASR is produced during the vehicle recycling process. This occurs after end-of-life vehicles have been dismantled for potential reuse. Typically, these vehicles are then compacted and transported to secondary recycling facilities, which could include shredding plants or metal recycling facilities equipped with shredding capabilities. The residual left behind is what is referred to as ASR.
ASR consists of glass, fiber, rubber, automobile fluids, plastics and dirt. It is a challenging waste stream due to its diverse composition, making it difficult to handle and recycle efficiently and economically.
Fate of ASR
So what exactly do these facilities do with the ASR? It depends. The management of ASR depends on local regulations and the specific practices of each shredding facility. In the past, a significant portion of ASR ended up in landfills, which raised environmental concerns due to the potential for hazardous materials being introduced into the environment. Recently, the recycling industry has been making efforts to find more sustainable solutions for ASR, such as mechanical separation, which is employed to extract additional recyclables from ASR such as plastics and foam that can be reused. There is also thermal conversion, which includes technologies like incineration or pyrolysis to convert ASR into energy or useful materials including fuel. Regardless, a great deal of ASR materials are likely to end up in landfills despite recyclers’ best efforts.
As previously mentioned, ASR presents environmental challenges due to its complex composition and potential for hazardous materials. The disposal of ASR in landfills can lead to contamination, resource depletion, and increased energy consumption which poses risks to ecosystems and human health. Evidently, the impacts of ASR go far beyond a simple barrier between the auto sector achieving a more circular economy.
ASR from less environmentally-conscious auto recyclers often contains hazardous substances such as heavy metals, oils, and chemical additives from automotive components. The improper disposal of ASR in landfills then results in the displacement of these substances into the soil, overtime, contaminating groundwater. This contamination can pose significant environmental risks and health concerns.
ASR also contributes to air pollution. When ASR is stored or landfilled, it can release volatile organic compounds (VOCs). These compounds have a high vapor pressure and low water solubility. These pollutants cause respiratory problems and other health issues in humans and wildlife. High levels of VOCs in the air can also harm vegetation, leading to reduced crop yields and damage to forest ecosystems.
Resource depletion is another big problem when it comes to ASR; ASR contains valuable resources such as metals and plastics, that could otherwise be recovered and recycled. Failing to extract these resources in a pure form means a missed opportunity for resource conservation and a greater reliance on virgin materials. This will cause increased energy consumption, a spike in environmental impacts associated with resource extraction, and an increase in greenhouse gasses released into the atmosphere. But, with proper management and treatment methods that focus on a larger degree of resource recovery, energy consumption can be minimized and can also reduce the amount of ASR as well as its impacts.
Achieving a Circular Economy
In conclusion, ASR is a complicated waste stream generated during the recycling process of ELVs and a large barrier to achieving a circular economy. Its diverse composition, containing materials like glass, fiber, rubber, automobile liquids, plastics, and metal, poses challenges for efficient handling and recycling. Despite its potential for resource recovery, we’ve yet to find a way to make the material within ASR useful again. As we move forward, it is imperative to prioritize end-uses and recoverability during the design process. With this strategy, in addition to the widespread adoption of advanced separation techniques and adherence to stricter regulations, the recycling industry can pave the way for a more circular future that is better for all, environmentally and economically.