The global production of plastics increased twenty-fold in the past half-century, reaching almost 360 million tonnes in 2018. The extensive use of plastics has become a pre-eminent environmental problem due to the leak of long-lasting plastic waste into natural ecosystems. In a planet with limited resources, it becomes crucial to develop new technologies that boost the transition towards a circular plastic economy and protect the environment by promoting the correct collection of plastic waste.
In this context, chemical recycling comes into play as a new recycling technology able to cope with both contamination and degradation of plastic waste. Hot compressed water has already proved to be an outstanding medium for chemical reactions and so it is for chemical recycling of plastic waste. Hydrothermal processing (HTP) of plastics uses hot compressed water to recover monomers and chemicals from plastic waste so they can be used in plastic production and other sectors over and over again.
In this project, the chemistry behind HTP of plastics will be experimentally studied in batch and continuous operation, followed by product separation and purification processes that will be crucial unit operations to deliver marketable recycled products. Experimental data will be used in software modelling and simulation, techno-economic feasibility studies and LCA methodology implementation, which will prove the profitability and environmental benefits of HTP.
The development and commercialization of the HTP technology could drastically reduce plastic CO2 emissions by enhancing plastic circularity and decoupling plastics’ production from fossil feedstock. Moreover, HTP would provide a green plastic recycling route that could monetize plastic waste and therefore give incentives for better waste management systems.
Funding: Urban Waste Hydrofaction, EUDP