MechReVOC: Innovative processes for VOC reduction in the mechanical recycling process for PO recyclates
| Year: | 2026 |
| Funding: | Deutsche Bundesstiftung Umwelt (DBU) |
| Duration: | 03/2026 to 02/2028 |
In the 24-month project “MechReVOC” – “Development and optimization of processes and methods for reducing the VOC content in plastic recyclates in mechanical recycling”, scientists from the IKK - Institute for Plastics and Recycling Technology at Leibniz University Hannover and WIS Kunststoffe GmbH are researching new methods for reducing volatile organic compounds (VOCs) in plastic recyclates in mechanical recycling for use in contact-sensitive applications.
The project aims to significantly improve the quality of plastic recyclates and thus expand the potential for substituting virgin material in contact-sensitive applications with high-quality recyclates. The project is thus making a significant contribution to climate and resource protection.
Challenge: Limitations due to volatile organic compounds in recycled material
The use of polyolefin (PO) recyclates in contact-sensitive applications, such as food and cosmetics packaging and automotive interior products, is currently severely limited due to high regulatory requirements and process-related constraints. As a result, these products must be manufactured largely from virgin material, which contradicts the goal of a resource-efficient and functioning circular economy. This is also shown by the figures from a Conversio study on the use of recyclates in packaging applications in Figure 1. According to this study, the combined recyclate rate from post-consumer (PCR) and post-industrial recyclates (PIR) for contact-sensitive PO packaging in Germany in 2023 was only 3.6%.
The main cause of this is volatile organic compounds that migrate from the contact products into the polymer matrix during the usage phase or are produced in the plastic as a result of degradation processes. If these substances are not removed during the recycling process, there is a risk that they will diffuse back into the contact medium or the ambient air. In the worst case, they can pose a health risk to consumers or cause an unpleasant odor. For this reason, there are strict regulatory requirements and industry standards (e.g., EU Regulation 10/2011, DIN SPEC 91521, VDA 278) that specify migration and emission limits for a wide range of substances.
Research approach and methodology: Optimization of decontamination processes and inline analytics
The aim of the project is therefore to improve the properties of recycled materials in terms of their chemical composition and harmful VOC content through the innovative combination and optimization of existing decontamination processes in mechanical recycling. The research project focuses on the extrusion and downstream deodorization processes. The methods to be used in the extrusion process are based on the optimized use of stripping media, which increase the degassing efficiency in the recycling process, or the use of adsorbent media, which physically bind the VOCs in the recyclate and prevent subsequent emissions. To further reduce the VOC content, the aim is to optimize the post-degassing process by removing the VOCs using thermal post-treatment. In addition to increasing decontamination performance, this should also reduce the energy required and the dwell time, among other things. These further developments can (or could) enable the sustainable use of PO recyclates in sensitive and/or approval-requiring applications by complying with the necessary limit values.
Another crucial component of the project is seamless quality assurance. Until now, only a few grams of material have often been tested retrospectively on behalf of batches weighing tons, a procedure that is risky, especially with inhomogeneous recyclate input streams. For this reason, a continuous inline emission analysis is being developed as part of the project. This monitors VOC values in real time directly during the recycling process, thus guaranteeing consistently high material quality.
The technological development is accompanied by a comprehensive life cycle assessment. Based on real primary data such as electricity, water, and gas consumption, the environmental impact of the optimized processes is analyzed in detail. This provides solid evidence of the ecological and technical potential of the new processes.
