Warwick Manufacturing Group (WMG) at the University of Warwick in the UK has published a peer-reviewed Life Cycle Assessment that analysed the environmental impact of using hydrothermal treatment to recycle waste plastics into a feedstock suitable for producing new plastics - the technology Mura Technology calls HydroPRS.
HydroPRS utilises supercritical water to convert post-consumer flexible, multi layered and rigid plastics into high yields of petrochemical feedstocks.
Among others, the study compared the use of hydrothermal treatment to dispose of plastic waste to incineration, the most common disposal route today for the hard-to-recycle films and flexibles that HydroPRS targets. It was found that, tonne for tonne, hydrothermal treatment of plastic waste yields an approximate reduction in carbon impact of 80%, compared to incineration. Furthermore, unlike incineration, chemical recycling via HydroPRS conserves the material within the system, leading to a reduction in consumption of fossil-based resource.
The LCA also shows a clear pathway to net zero carbon emissions for Mura’s process.
“The study adds to the growing body of evidence that HydroPRS is uniquely placed to help achieve a low-carbon and global circular plastics economy by replacing incineration and substituting fossil-based naphtha feedstocks,” said Steve Mahon, CEO of Mura Technology. “Our goal is to use our scalable technology to substitute fossil-based naphtha and other hydrocarbons for more sustainable feedstocks.”
The study also showed that the impact - in terms of climate change - of the hydrocarbon products produced via HydroPRS is currently comparable to current fossil chemical feedstock production processes for future plastics, opening up presenting circularity options for plastics manufacturing with HydroPRS as an end-of-life treatment option.
It also points out the main contributor to global warming in the hydrothermal treatment process is electricity consumption. This will "naturally decrease over time as the grid is made greener through planned improvements", the authors of the study write, reducing the global warming potential of the process "to equivalent or better than fossil naphtha". They go on to states that "it could therefore be reasonably assumed that if it is not already, in the future use of HTT [hydrothermal treatment] to produce steam cracker feedstocks will be less environmentally damaging than extraction of virgin materials".
