Plastic recycling: 3 cases of circular economy
Plastic recycling: 3 real cases of circular economy
To get into plastic recycling it is good to know that most plastics are made from petrochemicals, such as crude oil or natural gas. During the manufacturing process, monomers combine to form long polymer chains through a process called polymerization. This resulting polymer chain can be modified and processed to obtain different types of plastics with specific properties.
Although plastics offer many advantages in terms of versatility and durability, they have also generated environmental concerns due to their persistence in the environment and the problems associated with plastic waste management.
However, plastic recycling is a practice that brings many benefits to the communities that use it. Many communities see this as an opportunity to preserve the environment while generating a positive social and economic impact.
Some plastics can be recycled
Plastics are classified into different categories according to their chemical composition, and not all are recyclable in the same way. Identification of types of plastics is commonly done through a recycling code, which is a number surrounded by a triangle of arrows.
Some of the most common plastics are:
- PET (Polyethylene Terephthalate): Commonly used in beverage packaging, water bottles and food packaging and widely recyclable. It is re-used to manufacture textile fibers and packaging again.
- HDPE (High Density Polyethylene): Found in dairy packaging, detergent bottles and cleaning product packaging. It is recyclable and used to make bottles, pipes, and garden products.
- PVC (Polyvinyl Chloride): Used in pipes, clothes, toys and other products. However, PVC may contain additives that make it difficult to recycle. Recyclability of PVC may vary and in some cases recycling is not recommended.
- LDPE (Low Density Polyethylene): Common in plastic bags, films and flexible packaging. It is recyclable and used to make bags, containers and flexible plastic products.
- PP (Polypropylene): Present in yogurt containers, bottle caps and food containers. It is recyclable and used to make automotive components, kitchen utensils and other products.
- PS (Polystyrene): Used in food packaging, meat trays and foam packaging. Polystyrene recycling may be limited, and its use is being reduced due to environmental problems.
- Others: This code includes several types of plastics, such as biodegradable PLA (polylactic acid). Not all plastics classified as #7 are recyclable in the same way.
Plastic recycling. How does it work
Plastic recycling is a process that involves collecting, sorting, cleaning, crushing, melting and forming new products from recycled plastic materials. In summary the recycling process includes:
- Collection: Recyclable plastics are collected through recycling programs, specific plastic containers or recycling facilities.
- Classification: Plastics are classified according to their type using recycling codes. These codes are identified by a number found inside the recycling symbol on plastic packaging.
- Cleaning: Collected plastics are washed and decontaminated to remove any residue or impurity, key to ensuring a quality standard.
- Shredding: Clean plastics are crushed into small fragments called "pellets", facilitating their handling and transport.
- Fusion and Extrusion: Plastic pellets are melted and then extruded to create sheets or threads. Some products are made from sheets or yarns, and others are directly melted and injected, such as preformed bottles.
- End product manufacturing: Recycled plastic pellets are used to manufacture new products, such as bottles, containers, pipes, textiles and more.
The recycling of plastics can be carried out on an artisanal or small scale. While industrial and large-scale recycling is more efficient and has a greater impact, artisanal recycling can be a valuable way to address plastic waste at the local and community levels.
It is essential to take into account the limitations and safety considerations when performing craft recycling. Some plastics release toxic gas when they melt, so it is crucial to perform the process in a well-ventilated environment and take proper precautions.
Case 1: Weaving bags from plastic waste in Gambia
Source: Planeta futuro, El País 2022
Millions of plastic bags flood roadsides in many towns and villages in Africa. Traces of bags, transparent or colored, are everywhere. After a market, gangs of young people organize to clean and end up burning waste. But uncontrolled burning of plastics can have serious health and environmental consequences.
This is not the case in Njau, a town in the Central River North region of Gambia, where there is a very interesting plastics recycling activity. Here the Women’s Initiative Gambia (WIG) has been working since 1997 to empower women in this area.
Women in Njau cut recycled bags and others make bags, cases, doilies, etc. with plastic strips of various colors. Others cut out bike wheels and use them to form necklaces and bracelets. The sale of these products brings them a benefit, while helping to reduce solid waste in their communities.
The example of these pioneers has gradually spread to other communities that have understood the advantages of recycling waste. Over time, a training programme had been set up to provide women with income-generating tools and environmental care.
Waste recycling is also promoted across Africa as a way to fight pollution by leaving a better world for future generations.
Case 2: Paving with plastic recycling in Ghana
In Ghana, a company converts plastic waste into pavers to cover streets and build new roads.
Nelplast Ghana was created in 2017 in the city of Ashaiman by engineer Nelson Boateng, who built an innovative recycling machine capable of processing plastic waste, except PVC. The pavers are made of 70% plastic and 30% sand which makes them more durable than the cement of a traditional asphalt.
This project has many advantages:
- It favors the removal and recycling of a large quantity of plastic waste that creates problems for the environment and for the health of citizens.
- It generates a product of great resistance that allows pave roads, streets of towns and villages at a lower cost than that incurred with traditional asphalt and reducing maintenance costs.
- It allows to create jobs for all the activity, from the collection of plastics, the manufacture and the installation of the pavers.
The manufacturing process consists of crushing bags and other plastic waste that becomes a binding agent providing resistance to pavers. To do this, the company employs 60 workers directly, while the entire production chain as a whole creates work for more than 200 people. However, improvements are being made to the plant, through new machinery, new equipment and new spaces.
In addition to building the new pavers, the company now recycles plastic waste to make tiles and bricks, which are used in housing construction. This allows a scaling of the activity that in addition to the social and economic impact facilitates a great environmental benefit.
Case 3: Fishing communities also contribute to plastic recycling
Many of the plastics that are used and thrown away on land end up in the seas. In reality every year more than 10 million tons of plastic become part of our oceans. These come from the landfills, float down our drains, end up in the rivers and then into the sea.
This problem was well known to the Greek Lefteris Arapakis who in 2016 founded enaleia, a non-profit organization focused on sea cleaning and fisheries education. His proposal was to recycle and pay fishermen to collect and bring the plastic ashore. This allows plastic waste to be collected at sea, recovering the fish ecosystem and stocks.
We must also understand that this plastic is recovered and valued, becoming products such as socks and swimwear. To this end, Enaleia has created a network for the circular economy of all this waste in addition to a certification through a blockchain platform. Some examples of this network are:
- PET from plastic bottles is transformed into jackets and shoes.
- A mixture of plastics and fishing nets ends up becoming furniture, through The Gravity Wave
- Plastic is also used to produce building materials for homes, such as through Kwaleplastics in Kenya
Enaleia might be doing many things well since every day +3,000 fishermen (more than half of Greece’s large-scale fishing fleet) collaborate and collect plastic while sailing the Mediterranean. Since 2018 they have withdrawn almost 1 million tons of plastic and plan to continue expanding globally.