Closed loop recycling

Closed-loop recycling "occurs when a product is recycled into a product that can be recycled over and over again, theoretically endlessly". A perfect examples to illustrate this process are aluminum cans, because they can be recycled over and over again into the same things - aluminum cans (Vigon B. W. i in. 1994, p. 91).

From an environmental point of view, the closed-loop recycling process is very much needed, albeit many countries do not have manufacturers, by implying it is logistically and economically not feasible (Khan A., Inamuddin, Asiri A. M. 2020, p. 7).

Advantages of closed-loop recycling

There are plenty of benefits of closed-loop recycling, especially for the environment, several are worth mentioning (Hamada Hiroyuki i in. 1998, p. 7-8):

• materials considered as useless can be reused without cost penalty
• products do not end their usability in the landfills
• for manufacturers - the result of closed-loop recycling is recyclate that is a way easier to formulate into a quality part than an original product.

Examples of processes in closed-loop recycling

There are many examples of products that can be recycled endlessly, however, the closed-loop recycling process includes many stages before the product will be able to use again. For example, for plastic like jugs, the stages are as following (Vigon B. W. i in. 1994, p. 91):

1. grinding
2. washing and also
3. remelting.

It should be remembered that every product requires different processes to be recycled. To picture that, consider the example of paper products - the only things that must be done before selling are (Vigon B. W. i in. 1994, p. 91):

1. repulping
2. deinking or/also bleaching.

Open-loop recycling

It is worth mentioning, that there also occurs a process called open-loop recycling. The main divergence between above and closed-loop recycling system is the fact, that in an open-loop recycling "a product made from virgin material is recycled into another product that is not recycled, but disposed of, possibly after a long-term diversion". A good example illustrating this recycling system is a plastic milk bottle changed into (for instance) flower pots that are not recycled (Vigon B. W. i in. 1994, p. 91).

Limitations of Closed loop recycling

Closed loop recycling is a form of recycling which can be used to create a product that can theoretically be recycled endlessly. However, there are several limitations to this process. These include:

• Cost - The cost of the machinery and infrastructure required to create closed loop recycling systems is often prohibitively expensive, making it difficult to implement them on a large scale.
• Availability - Some raw materials are not available in sufficient quantities to create a continuous recycling loop. For example, rare earth metals are difficult to find in sufficient quantities for efficient recycling.
• Contamination - If products being recycled are contaminated with other materials, this can disrupt the recycling process and may render the recycled material unusable.
• Durability - If the materials used in the recycling process are not sufficiently durable, they may break down over time and be unsuitable for further recycling.
• Complexity - Closed loop recycling processes often require complex machinery and processes to be successful. This can make them difficult to implement and maintain.

Other approaches related to Closed loop recycling

To complement closed-loop recycling, there are other approaches to recycling that can be used to reduce the amount of waste going into landfills. These include:

• Upcycling: This approach involves taking existing material and transforming it into something new and of higher quality than the original material. For example, old plastic bottles can be used to create coats and other clothing items.
• Recycling: This approach involves taking existing materials and transforming them into new products with the same composition and purpose. For example, aluminum cans can be melted down and shaped into new cans.
• Reuse: This approach involves using items multiple times, with no changes in composition or purpose. For example, glass jars can be reused for storing food or as craft supplies.

In conclusion, closed-loop recycling, upcycling, recycling, and reuse are all strategies for reducing the amount of waste going into landfills, and all four approaches can be employed for maximum efficiency.

Closed loop recycling — recommended articles

Clean fuel — Clamshell packaging — Recovered material — Reverse distribution — Direct material — Weep hole — Paper packaging — Life cycle of technology — Tertiary packaging

References

• Barnes K. A., Sinclair C. R., Watson D. H. (2007), Chemical Migration and Food Contact Materials, Woodhead Publishing Limited, Cambridge, p. 209
• Beukering P. J. H. (2001), Recycling, International Trade and the Environment: An Empirical Analysis, Kluwer Academic Publishers, Dordrecht, p. 32
• Ferguson M. E., Souza G. C. (2010), Closed-Loop Supply Chains: New Developments to Improve the Sustainability of Business Practices, CRC Press, Boca Raton, p. 170
• Finkbeiner M. (red.) (2016),Special Types of Life Cycle Assessment, Springer, Dordrecht, p. 253
• Hamada Hiroyuki (red.) (1998),SPI/CI International Conference and Exposition 1998, Composites Institute, New York, p. 2-8
• Khan A., Inamuddin, Asiri A. M. (2020), E-waste Recycling and Management: Present Scenarios and Environmental Issues, Springer, Cham, p. 7
• Schlesinger M. E. (2014), Aluminum Recycling, Second Edition, CRC Press, Boca Raton, p. 29
• Vigon B. W. (red.) (1994), Life-Cycle Assessment: Inventory Guidelines and Principles, CRC Press, Boca Raton, p. 91

Author: Urszula Bochenek