Chemical recycling

How chemical recycling can turn silicone waste into a valuable resource 

Depolymerisation, a form of chemical recycling, involves breaking down the chemical bonds of silicone waste products into their key building blocks: monomers D4, D5 and D6. This process effectively transforms the waste product back into a valuable resource.  

In addition to enabling circularity in complex silicone waste streams, depolymerisation offers additional benefits:  

It significantly reduces CO2 emissions, energy consumption and resource intensity associated with silicone production.   

Around 70-80% of the energy consumed in silicone synthesis, along with its corresponding carbon emissions, is tied to the mining and refining of silicone metal. By transitioning to a circular model that uses chemically recycled silicones as secondary raw materials, we can circumvent the need for quartz extraction. This also eliminates several complex steps from quartz to D4, D5, and D6, simplifying the process and making it more environmentally friendly. Consequently, it can lead to a significant reduction in the CO2 emissions, energy consumption, and the resource intensity of silicone production. 

Capitalising on Europe’s renewed circularity focus 

The new European Commission has set out a strong focus on reducing waste and promoting recycling. The mission letters to the new Commissioners and the political priorities have given a clear mandate to build a European market for second-hand waste, especially for critical products. Currently, the majority of silicone waste is not recycled but instead ends up in landfills or is used for energy recovery – a missed opportunity for Europe’s strategic autonomy. 

Depolymerisation presents an opportunity to develop the raw materials needed to produce silicone-based products, thereby reducing Europe’s reliance on third countries.  

At present, the waste that industry uses towards chemical recycling usually comes from finished silicone polymer material from the industry itself and from by-products of other industries.  This is a preliminary step towards making the silicones industry more circular. Moreover, there is potential for this technology to be used in the future for chemically recycling end-of-life silicone materials, provided they are collected in sufficient quantities.  

 Offering the building blocks for decarbonising other sectors 

Beyond transforming silicone waste into D4, D5, and D6 for reintegration into the silicone industry’s manufacturing process of silicone polymers, it is also possible to retrieve short-chain oligomers. These can be further developed into new added value products such as semi-conductors, protective products for solar panels and other renewable energy technologies – further supporting Europe’s decarbonisation efforts. 

Considering the potential of silicone’s chemical recycling to tackle global challenges, reduce waste and foster a circular economy, members of Silicones Europe call on the EU to recognise and invest in innovative technologies that facilitate silicone recycling within Europe. A potential POP nomination would put all this at stake.