Closed-loop recycling

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Closed-loop recycling is the process by which a product or material can be used and then turned into a new product (or converted back to raw material) indefinitely without losing its properties during the recycling process. [1] [2] [3] [4]

Contents

By reducing the production and use of raw materials, closed-loop recycling minimizes harm to the environment and discourages resource depletion. [5] In contrast, open-loop recycling is the process by which a product is recycled but has to be mixed with raw materials to become a new product, typically leading to downcycling. [1]

Ideal closed-loop systems produce no waste. They are called "closed" because products have a circular life cycle, beginning as raw materials and either being recycled into replacement products, returning to the original raw materials, or being returned to the environment as biodegradable waste. [2] This reduces the amount of (non-biodegradable) waste disposed, as recyclables are recovered and reused, rather than ending up in a landfill or as a pollutant.

Description

In order to grow an economy while preventing depletion of natural resources, a given amount of a resource must be used as much as possible with as little waste as possible. Closed-loop recycling systems attempt to maximize the amount of time a given amount of a resource is available to an economy. In ideal systems, materials are recycled indefinitely with practically no net change in quality or properties. This allows the same bits of a resource to be extracted, manufactured, used, and recycled back into the same product forever. [6] Waste is considered a resource in itself, closing the loop of resource production. [7]

Recycled resources require less labor and energy to convert into new products, which reduces environmental pollution and production costs. Therefore, closed-loop recycling may be considered part of environmental sustainability programs. [8]

One goal of closed-loop recycling is to reuse materials in an identical role as before recycling. [3] [5] In contrast, open-loop recycling systems do not reclaim all of a resource. Whether by design or due to the physical and chemical properties of the materials recycled, some amount of resources is wasted, used to manufacture different materials, or degraded in quality. [4] [8] The degradation of material such that it is only used to make goods that do not require the higher-quality material is called downcycling. [4]

Some biodegradable waste may also be considered part of a closed-loop recycling system if it can be broken down into natural materials and disposed of without polluting the environment or causing other negative impacts. [5]

Process

Closed-loop recycling involves: collecting and sorting recycled materials, extracting resources from the materials, and using those resources as inputs in the manufacturing of products practically identical to the original. Recycled materials are collected from homes, businesses, and recycling banks. [4]

The most suitable materials for closed-loop recycling are aluminum and glass. These are known to maintain their quality throughout many cycles of extraction, production, use, and recycling. [5] For example, aluminum cans can be recycled and turned into new cans with practically no material degradation or waste.[ citation needed ]

Economic considerations

The demand for products and efficiency of closed-loop supply chains are affected by the value of reclaimed resources. [9]

Closed-loop recycling is common in specialized industries, such as the computer and battery industries. These industries use expensive or complex materials that are not easily broken down into constituent resources. [5]

Closed-loop recycling systems may reduce landfill contributions, allowing landfill plots to last longer. For example, recycling one ton of plastic in a closed-loop system saves about 7.4 cubic yards of landfill space. Since the grocery industry demonstrated[ when? ] that consumers use at least 690,000 tons of plastic in a year, universal implementation of ideal closed-loop recycling systems could save at least 5.1 million cubic yards of landfill space each year. [10]

See also

Related Research Articles

<span class="mw-page-title-main">Recycling</span> Converting waste materials into new products

Recycling is the process of converting waste materials into new materials and objects. This concept often includes the recovery of energy from waste materials. The recyclability of a material depends on its ability to reacquire the properties it had in its original state. It is an alternative to "conventional" waste disposal that can save material and help lower greenhouse gas emissions. It can also prevent the waste of potentially useful materials and reduce the consumption of fresh raw materials, reducing energy use, air pollution and water pollution.

<span class="mw-page-title-main">Waste management</span> Activities and actions required to manage waste from its source to its final disposal

Waste management or waste disposal includes the processes and actions required to manage waste from its inception to its final disposal. This includes the collection, transport, treatment, and disposal of waste, together with monitoring and regulation of the waste management process and waste-related laws, technologies, and economic mechanisms.

<span class="mw-page-title-main">Zero waste</span> Philosophy that encourages the redesign of resource life cycles so that all products are reused

Zero waste, or waste minimization, is a set of principles focused on waste prevention that encourages redesigning resource life cycles so that all products are repurposed and/or reused. The goal of the movement is to avoid sending trash to landfills, incinerators, oceans, or any other part of the environment. Currently 9% of global plastic is recycled. In a zero waste system, all materials are reused until the optimum level of consumption is reached.

<span class="mw-page-title-main">Downcycling</span> Recycling waste into products of lower quality

Downcycling, or cascading, is the recycling of waste where the recycled material is of lower quality and functionality than the original material. Often, this is due to the accumulation of tramp elements in secondary metals, which may exclude the latter from high-quality applications. For example, steel scrap from end-of-life vehicles is often contaminated with copper from wires and tin from coating. This contaminated scrap yields a secondary steel that does not meet the specifications for automotive steel and therefore, it is mostly applied in the construction sector.

<span class="mw-page-title-main">Plastic recycling</span> Processes which convert waste plastic into new items

Plastic recycling is the processing of plastic waste into other products. Recycling can reduce dependence on landfill, conserve resources and protect the environment from plastic pollution and greenhouse gas emissions. Recycling rates lag behind those of other recoverable materials, such as aluminium, glass and paper. From the start of plastic production through to 2015, the world produced around 6.3 billion tonnes of plastic waste, only 9% of which has been recycled and only ~1% has been recycled more than once. Of the remaining waste, 12% was incinerated and 79% was either sent to landfills or lost to the environment as pollution.

<span class="mw-page-title-main">Glass recycling</span> Processing of turning glass waste into usable products

Glass recycling is the processing of waste glass into usable products. Glass that is crushed or imploded and ready to be remelted is called cullet. There are two types of cullet: internal and external. Internal cullet is composed of defective products detected and rejected by a quality control process during the industrial process of glass manufacturing, transition phases of product changes and production offcuts. External cullet is waste glass that has been collected or reprocessed with the purpose of recycling. External cullet is classified as waste. The word "cullet", when used in the context of end-of-waste, will always refer to external cullet.

<span class="mw-page-title-main">Biodegradable waste</span> Organic matter that can be broken down

Biodegradable waste includes any organic matter in waste which can be broken down into carbon dioxide, water, methane, compost, humus, and simple organic molecules by micro-organisms and other living things by composting, aerobic digestion, anaerobic digestion or similar processes. It mainly includes kitchen waste, ash, soil, dung and other plant matter. In waste management, it also includes some inorganic materials which can be decomposed by bacteria. Such materials include gypsum and its products such as plasterboard and other simple sulfates which can be decomposed by sulfate reducing bacteria to yield hydrogen sulfide in anaerobic land-fill conditions.

<span class="mw-page-title-main">Biodegradable plastic</span> Plastics that can be decomposed by the action of living organisms

Biodegradable plastics are plastics that can be decomposed by the action of living organisms, usually microbes, into water, carbon dioxide, and biomass. Biodegradable plastics are commonly produced with renewable raw materials, micro-organisms, petrochemicals, or combinations of all three.

<span class="mw-page-title-main">Landfill diversion</span>

Waste diversion or landfill diversion is the process of diverting waste from landfills. The success of landfill diversion can be measured by comparison of the size of the landfill from one year to the next. If the landfill grows minimally or remains the same, then policies covering landfill diversion are successful. For example, currently in the United States there are 3000 landfills. A measure of the success of landfill diversion would be if that number remains the same or is reduced. In 2015 it was recorded that the national average of landfill diversion in the United States was 33.8%, while San Francisco had implemented the most effective policies and had recorded a landfill diversion rate of 77%.

Precycling is the practice of reducing waste by attempting to avoid buying items which will generate waste into home or business. The U.S. Environmental Protection Agency (EPA) also cites that precycling is the preferred method of integrated solid waste management because it cuts waste at its source and therefore trash is eliminated before it is created. According to the EPA, precycling is also characterized as a decision-making process on the behalf of the consumer because it involves making informed judgments regarding a product's waste implications. The implications that are taken into consideration by the consumer include: whether a product is reusable, durable, or repairable; made from renewable or non-renewable resources; over-packaged; and whether or not the container is reusable.

<span class="mw-page-title-main">Textile recycling</span> Method of reusing or reprocessing used clothing, fibrous material and rags

Textile recycling is the process of recovering fiber, yarn, or fabric and reprocessing the material into new, useful products. Textile waste is split into pre-consumer and post-consumer waste and is sorted into five different categories derived from a pyramid model. Textiles can be either reused or mechanically/chemically recycled.

<span class="mw-page-title-main">Upcycling</span> Recycling waste into products of higher quality

Upcycling, also known as creative reuse, is the process of transforming by-products, waste materials, useless, or unwanted products into new materials or products perceived to be of greater quality, such as artistic value or environmental value.

Recycling can be carried out on various raw materials. Recycling is an important part of creating more sustainable economies, reducing the cost and environmental impact of raw materials. Not all materials are easily recycled, and processing recyclable into the correct waste stream requires considerable energy. Some particular manufactured goods are not easily separated, unless specially process therefore have unique product-based recycling processes.

Products made from a variety of materials can be recycled using a number of processes.

<span class="mw-page-title-main">Circular economy</span> Production model to minimise wastage and emissions

A circular economy is a model of resource production and consumption in any economy that involves sharing, leasing, reusing, repairing, refurbishing, and recycling existing materials and products for as long as possible. The concept aims to tackle global challenges such as climate change, biodiversity loss, waste, and pollution by emphasizing the design-based implementation of the three base principles of the model. The main three principles required for the transformation to a circular economy are: designing out waste and pollution, keeping products and materials in use, and regenerating natural systems. CE is defined in contradistinction to the traditional linear economy.

Resource recovery is using wastes as an input material to create valuable products as new outputs. The aim is to reduce the amount of waste generated, thereby reducing the need for landfill space, and optimising the values created from waste. Resource recovery delays the need to use raw materials in the manufacturing process. Materials found in municipal solid waste, construction and demolition waste, commercial waste and industrial wastes can be used to recover resources for the manufacturing of new materials and products. Plastic, paper, aluminium, glass and metal are examples of where value can be found in waste.

<span class="mw-page-title-main">Cotton recycling</span> Reuse of cotton fabric

Cotton recycling is the process of converting cotton fabric into fibers that can be reused into other textile products.

<span class="mw-page-title-main">Economics of plastics processing</span> Economic aspects of plastic manufacturing


The economics of plastics processing is determined by the type of process. Plastics can be processed with the following methods: machining, compression molding, transfer molding, injection molding, extrusion, rotational molding, blow molding, thermoforming, casting, forging, and foam molding. Processing methods are selected based on equipment cost, production rate, tooling cost, and build volume. High equipment and tooling cost methods are typically used for large production volumes whereas low - medium equipment cost and tooling cost methods are used for low production volumes. Compression molding, transfer molding, injection molding, forging, and foam molding have high equipment and tooling cost. Lower cost processes are machining, extruding, rotational molding, blow molding, thermoforming, and casting. A summary of each process and its cost is displayed in figure 1.

<span class="mw-page-title-main">Closed-loop box reuse</span> Business practice

Closed Loop Box Reuse, is the process by which boxes or other containers are reused many times. It is a form of reusable packaging.

References

  1. 1 2 Lucy, Author (10 May 2019). "What is closed loop recycling?". The Waste Management & Recycling Blog. Retrieved 4 May 2021.{{cite web}}: |first= has generic name (help)
  2. 1 2 "5.2. Recycling: open-loop versus closed-loop thinking | EME 807: Technologies for Sustainability Systems". www.e-education.psu.edu. Retrieved 4 May 2021.
  3. 1 2 Lamanria, F.P (2010). "Closed loop recycling:A case study of films for greenhouse". Polymar and Degradation: 285–288.
  4. 1 2 3 4 Min, Huang (2013). "Analysis for strategy of closed-loop supply chain with dual-recycling channel". International Journal of Production Economics. 144 (2): 510–520. doi:10.1016/j.ijpe.2013.04.002.
  5. 1 2 3 4 5 Bruno, Lacarriere (2015). "Emergy assessment of benefits of closed-loop recycling accounting for material losses". Ecological Modelling. 315: 77–87. Bibcode:2015EcMod.315...77L. doi:10.1016/j.ecolmodel.2015.01.015.
  6. ↑ "5.2. Recycling: open-loop versus closed-loop thinking | EME 807: Technologies for Sustainability Systems". www.e-education.psu.edu. Retrieved 16 May 2019.
  7. ↑ Huysman, Sofie; Debaveye, Sam; Schaubroeck, Thomas; Ardente, Fluvio; Mathieux, Fabrice; Dewulf, Jo; DeMeester, Steven (22 May 2015). "The recyclability benefit rate of closed loop recycling and open-loop systems: A case study on plastic recycling in Flanders". Resources, Conservation and Recycling. 101: 53–60. doi: 10.1016/j.resconrec.2015.05.014 . hdl: 1854/LU-6851927 .
  8. 1 2 Tapper, Rhys J.; Longana, Marco L.; Yu, Hana; Hamerton, Ian; Potter, Kevin D. (2018). "Development of a closed-loop recycling process for discontinuous carbon fibre polypropylene composites". Composites Part B: Engineering. 146: 222–231. doi:10.1016/j.compositesb.2018.03.048. hdl: 1983/97263ff8-0235-4a01-9df2-b186dcd230a8 . S2CID   139702514.
  9. ↑ Wenxue, Ran (2016). "A study of the closed-loop recycling supply chain coordination on waste glass bottles recycling". sydney.primo.exlibrisgroup.com. Retrieved 16 May 2019.
  10. ↑ Iqbal, Marie (2012). "Closed-loop recycling of recycled concrete aggregates". sydney.primo.exlibrisgroup.com. Retrieved 16 May 2019.
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