Time to read: 8 minutes
The role of the waste hierarchy in the circular economy
By: Dan Andersson
With consumer interest and demand rising for sustainable products, and regulations around the globe raising sustainability standards, the move towards the circular economy is imminent. But to do so, the chemical industry needs to take on approaches that prioritize sustainability, such as the waste hierarchy.
The role of the waste hierarchy
To understand the role of the waste hierarchy, one must first understand the circular economy. Circular economy refers to an economic model of production and consumption in which final materials are reused and recycled back into the cycle as much as possible. Ultimately, waste is kept to a minimum.
The waste hierarchy is a strategy to achieve a circular economy. It ensures that, from the start, products are being designed to reduce overall waste. Additionally, the waste hierarchy prepares for a product’s end-of-life so that materials can reenter the cycle by means of reuse, recycling, and recovery.
Breaking down the waste hierarchy
Step 1: Reduce
Reduce can be achieved by:
- Generating less scrap
- Redesigning a product to use sustainable materials (without compromising quality)
- Redesigning a product to need fewer materials (without compromising the functionality)
- Reducing energy used to create
- Optimizing processes for efficiency
Designing for waste reduction, for example, means thinking of the end-product before it is even moulded. By thinking of the full life cycle (and post-life) at the design phase, challenges that emerge later can be easily overcome.
Step 2: Reuse
When designing (or re-designing a product) for reuse, every aspect must be considered, from how it will be used in the market to which raw materials can be most tailored to increase durability for the specific application.
Often, the design process includes a mix of materials; ones built to last and additives, like antioxidants, UV stabilisers, UV absorbers and polymers that are tailored towards reusability.
Step 3: Recycle
Recycling is the act of giving the material a second life, to be used again and again. And this process doesn’t happen only once. By adding additives, for example, you can continue to recycle materials over and over. There are numerous ways to recycle but there are two primary ways this is done now: mechanical recycling and chemical recycling.
Mechanical recyclingMechanical recycling is the process of collecting plastic waste from various sources, grinding it together and then washing, melting and drying into a new raw material that can be used in a new process.
Currently, it is the most common approach within the advanced materials industry. In Europe, for example, mechanical recycling currently makes up 99% of all recycling processes.
Mechanical recycling is ideal for recycling mass quantities of plastic. Why? Because even though the chemical structure of the materials degrades slightly when reworked, they can be upgraded again with antioxidants and other additives to increase the quality.
Plastics that cannot be mechanically recycled may be a valuable resource for chemical recycling.
Chemical recyclingChemical recycling involves changing the chemical structure of plastic waste to break it down into smaller molecules so it can be used for new chemical reactions. This means that there is no limit to how many times these materials can be recycled, and even more important, there are no restrictions on the type of application these materials end up in as a second life. This is particularly relevant for the food and medical industries.
The process of chemical recycling involved sorting the plastic debris for chemical processing. The chemical structure of waste is then transformed, converting it into shorter molecules that can be used for completely new reactions.
Companies around the world are beginning to use this method, with companies like Eastman at the forefront.
Step 4: Energy recovery
This process takes place in modern combined heat and power recovery plants (CHP Plants), where waste plastics and other highly calorific materials are used to generate heat and power. At such CHP plants, exhaust treatment technologies are additionally implemented to reduce gaseous emissions.
Step 5: Landfilling
In the waste hierarchy, reduce, reuse, recycle and recover are all steps to avoid landfilling; using a landfill is the last resort.
Currently, 83% of consumers think it’s important for companies to design products that can be reused or recycled to never go into a landfill. So, to meet consumer demand, the previous steps of the waste hierarchy must be considered.
The outcomes of the waste hierarchy
When businesses implement the waste hierarchy, they have the potential to save money in everything from materials used to energy consumption. A McKinsey study found that approaches to the circular economy could generate cost savings of €600 billion a year in Europe alone.
Additionally, with the strategies to reduce, reuse, recycle and recover in place, businesses across sectors can lower CO2 emissions. Companies around the world are pledging to go carbon neutral, like Apple, Amazon and Coca-Cola, in the coming years, and the strategies of the waste hierarchy will play a critical role in helping them get there.