What Is Chemical Recycling of Plastics?

Published at 26 October 2022

We are becoming increasingly aware of the importance of efficiently managing plastic waste and its environmental impact. In this context, recycling plays a crucial role by helping reduce the consumption of natural resources and supporting the transition to a circular economy. While traditional recycling processes are effective in many cases, continued innovation is necessary to address the challenges posed by certain types of plastics and to improve their reuse.

This is where chemical recycling of plastics becomes particularly relevant—an industrial solution that makes it possible to treat complex or low-quality waste that cannot be mechanically recycled. Thanks to these technologies, it is possible to recover the value of plastic even when it has exhausted its potential within other recycling processes, preventing it from ending up in landfill or incineration.

What Is Chemical Recycling?

Chemical recycling refers to a set of industrial processes that transform plastic waste by modifying its chemical structure, producing substances that can be used as raw materials for manufacturing new products.

Unlike other treatments, chemical recycling is not intended to produce fuels or generate energy, but rather to recover material so it can be reintroduced into the plastic value chain. In this way, waste is converted into high value-added resources.

When Is Chemical Recycling Used?

Chemical recycling is primarily used when plastic waste cannot be efficiently recycled through mechanical processes, or when the material obtained does not reach the quality standards required for reuse in new industrial applications.

This type of recycling is particularly suitable when the complexity of the waste, its level of contamination, or polymer degradation prevents recovery through conventional methods.

Main Application Scenarios for Chemical Recycling

Chemical recycling is used, among others, in the following contexts:

Plastic waste with a high level of contamination, where the presence of organic residues, inks, adhesives, or other materials makes mechanical recycling difficult.
Complex packaging and multilayer structures designed to combine different technical properties and difficult to separate through physical processes.
Heterogeneous polymer mixtures, where homogeneous fractions of sufficient quality cannot be obtained.
Plastics that have lost properties after multiple cycles of mechanical recycling, such as strength, thermal stability, or optical quality.
Residues rejected by mechanical recycling processes, which can be reintegrated into the system through chemical methods.

In these cases, chemical recycling acts as a key tool to prevent waste disposal—either in landfill or through incineration—and enables recovery of its material value in the form of new raw materials suitable for reuse within the plastics industry.

Purpose of Chemical Recycling of Plastics

The purpose of chemical recycling is to maximize the recovery of plastic waste, allowing materials that have exhausted their potential within mechanical recycling to be reintroduced into the production system as new raw materials.

This approach not only expands the volume of recyclable waste but also contributes to closing the plastic loop by recovering material value from complex or degraded waste streams.

Main Objectives of Chemical Recycling

Chemical recycling pursues several strategic objectives within the circular economy model:

Reduce the amount of plastic waste sent to landfill or incineration, preventing resource loss and minimizing environmental impact.
Supply raw materials with quality equivalent to virgin materials, capable of directly replacing fossil-based polymers in demanding applications.
Facilitate the production of plastics suitable for food contact from post-consumer waste, provided regulatory and safety requirements are met.
Decrease dependence on fossil fuels, contributing to the decarbonization of the plastics industry.
Improve raw material supply stability, reducing exposure to volatility in fossil resource markets.

Overall, chemical recycling positions itself as a key tool for advancing toward more efficient, sustainable, and circular plastic waste management, complementing other recycling technologies and expanding material recovery possibilities.

Advantages of Chemical Recycling

Chemical recycling offers multiple advantages within the framework of the circular economy and the transition toward a more sustainable production model:

Significantly broadens the range of plastic waste that can be recycled, including materials unsuitable for mechanical recycling.
Enables the production of very high-quality recycled plastics with properties equivalent to virgin plastic.
Reduces the carbon footprint associated with plastic production by lowering the need to extract and process new raw materials.
Decreases reliance on imported fossil-based raw materials, strengthening production system autonomy.
Contributes to reducing the overall volume of plastic waste sent to landfill or incineration.
Promotes the development of new industrial, technological, and employment opportunities linked to the circular economy.

Applications of Chemical Recycling of Plastics

Products obtained through chemical recycling can be used in a wide range of industrial applications, adding value to recovered materials:

Manufacture of new plastic packaging, including those intended for demanding uses.
Production of plastics suitable for food contact, provided they comply with current regulations.
Supply of raw materials for the chemical and petrochemical industries.
Synthesis of new high-performance polymers used in technical and specialized sectors.

This approach allows recycled plastic to re-enter the market with technical and quality properties equivalent to virgin materials, supporting a more circular and sustainable production model.

Differences Between Mechanical and Chemical Recycling

Mechanical and chemical recycling are two fundamental processes in plastic waste management. Although both aim to recover value from plastic and reduce its environmental impact, they differ in operation, scope, and the types of waste they can process.

Mechanical Recycling

Mechanical recycling involves the physical treatment of plastic without altering its chemical structure. Waste is sorted, shredded, washed, and transformed into pellets that can be used to manufacture new plastic products.

This process is particularly effective when working with clean, homogeneous waste, such as single-polymer packaging.

Main characteristics of mechanical recycling:

Does not alter the chemical structure of the polymer.
Requires well-separated waste with low contamination levels.
May experience gradual property loss after multiple cycles.
Is widely implemented and efficient for suitable waste streams.

Chemical Recycling

Chemical recycling transforms plastic waste by modifying its chemical structure, breaking polymers down into simpler molecules that can be used as raw materials to manufacture new plastics.

This type of recycling is especially suitable for complex or degraded waste that cannot be treated mechanically.

Main characteristics of chemical recycling:

Alters the chemical structure of the polymer.
Can process multilayer plastics and complex mixtures.
Produces raw materials equivalent in quality to virgin materials.
Expands the volume of plastic waste that can be recycled.

Complementary Processes Within the Circular Economy

Rather than being mutually exclusive, mechanical and chemical recycling are complementary technologies. Mechanical recycling should be prioritized whenever possible, while chemical recycling enables recovery of waste that has exhausted its mechanical recycling potential.

Combining both processes is key to maximizing recycling rates, reducing dependence on fossil raw materials, and advancing toward a more efficient and sustainable circular economy model.

The Role of Chemical Recycling in the Circular Economy

Chemical recycling plays a strategic role in the transition toward a circular plastics economy, as it allows materials to remain in use for longer and significantly reduces the environmental impact associated with both their production and end-of-life management.

However, mechanical recycling remains the most common and widely used method today, mainly because it is more cost-effective, efficient, and technologically mature. It requires less energy and involves fewer complex steps, making it more accessible for many facilities. Chemical recycling, although promising, is less widespread and, due to its complexity, requires greater investment in infrastructure and energy.

By transforming complex plastic waste into new raw materials, chemical recycling complements mechanical recycling and contributes to building a more sustainable and efficient system aligned with European objectives on waste prevention, circularity, and industrial decarbonization.

Plastic Management at SINTAC

Chemical recycling expands the possibilities for recovering plastic waste that cannot be treated through conventional processes. Nevertheless, mechanical recycling remains the preferred route whenever the waste allows, due to its efficiency and its established role within the circular economy.

At SINTAC, we have been working for more than 30 years in mechanical plastic recycling, focusing on industrial processes that enable recycled material to be reintroduced into the value chain. In this way, we continue advancing toward more sustainable and efficient plastic waste management.

Frequently Asked Questions About Chemical Recycling of Plastics

What types of plastics can be recycled through chemical recycling?
Chemical recycling can process multilayer plastics, complex polymer mixtures, highly contaminated waste, and materials that have lost properties after several cycles of mechanical recycling.

Does chemical recycling produce fuels?
No. In the context of circular economy-oriented chemical recycling, the goal is to recover raw materials to manufacture new plastics, not to produce fuels or generate energy.

When is chemical recycling recommended?
It is recommended when plastic waste cannot be efficiently recycled through mechanical recycling, due to its complexity, contamination, or material degradation.

Does chemical recycling replace mechanical recycling?
No. Both processes are complementary. Mechanical recycling should be prioritized whenever viable, while chemical recycling enables recovery of waste that cannot be treated through conventional methods.