By Aaron Foyer
The World of Plastics | What is Advanced Recycling?
Courtesy of ENERGYminute
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Mechanical recycling and advanced recycling are two distinct approaches to recycling materials, each with its own characteristics and processes. Here’s an overview of the key differences between these two methods:
Mechanical recycling, also known as traditional or conventional recycling, is the most common form of recycling widely practiced today. It involves collecting, sorting, and processing recyclable materials such as plastic, paper, glass, and metals. The process typically includes the following steps:
- Collection: Materials are collected from households or businesses through recycling programs or dedicated collection centers.
- Sorting: The collected materials are sorted based on their type and composition. For instance, plastics are separated by resin type, while metals are sorted by type (aluminum, steel, etc.).
- Processing: The sorted materials undergo processing, which may involve cleaning, shredding, melting, or grinding to transform them into raw materials or feedstock. These materials are then used to manufacture new products.
The primary characteristic of mechanical recycling is that it retains the original properties of the recycled material to some extent. However, it often faces limitations, such as a loss in quality or performance due to degradation during processing, contamination, or incompatibility between different types of plastics. As a result, mechanical recycling is generally limited to lower-grade applications and may not be suitable for all types of materials.
Advanced recycling, also referred to as chemical recycling or molecular recycling, encompasses a range of innovative technologies that aim to address the limitations of mechanical recycling. It involves breaking down the complex molecular structure of materials to obtain their basic building blocks, which can then be used to produce new materials or chemicals with properties similar to virgin materials. Advanced recycling techniques include:
- Pyrolysis: The process of heating materials in the absence of oxygen to break them down into their constituent molecules. The resulting pyrolysis oil or gas can be used as a feedstock for the production of plastics, fuels, or chemicals.
- Depolymerization: Breaking down the polymer chains of materials through chemical reactions, enabling the recovery of monomers or smaller molecules for subsequent use.
- Solvent-based processes: Using solvents to dissolve and extract valuable components from the waste material, which can then be used to produce new materials.
The key advantage of advanced recycling is its ability to handle a broader range of materials, including complex and mixed plastic waste that cannot be easily recycled through mechanical means. It offers the potential to produce high-quality materials with properties equivalent to or even better than those of virgin materials, thus enabling their use in more demanding applications.
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