Description du projet :
Plastic waste is one of the biggest current environmental problems. Plastics products are produced from fossil hydrocarbons as C-supplier by energy-intensive high-temperature cracking. These plastics, which are CO2-intensive
in production, are not recycled despite improved waste separation, which is advancing, but remains insufficient and costly. Thus, plastic waste will continue ending up in the environment or (as in Switzerland) in waste incineration
plants and thus contribute to global warming, since all C atoms are oxidized to CO2. Most innovation approaches today aim at improving the energy balance of the cracker and not at replacing the feedstock.
Our project aims to replace the supply of raw material gases from high-temperature cracking of hydrocarbons in a first step by breaking down plastic waste into its individual molecular parts by means of a soft and tunable hydrogen plasma (de-polymerization). In a second step, product gases will be separated and the resulting short-chain molecules (CH4, CxHy, i.e. alkanes, alkenes, others) returned as raw materials to the production process in chemical
and pharmaceutical industry. While the first step represents the main innovation in this project the second step takes advantage of the existing knowledge of gas separation and cleaning already practiced in high-temperature
cracking systems, which need however be adapted to the particular gas composition leaving the plasma dissociationprocess (first step).
Environmental impact
1. Plastic waste is no longer landfilled or released into the environment.
2. Elimination of CO2 release from Incineration of plastic waste.
3. The plasma process is also suitable for mixed plastic waste.
4. C-cycle is closed, as product gases will be separated & purified for use in chemical and pharmaceutical industry.
Energy relevance
5. Replacement of the high-temperature cracking process by the tunable soft hydrogen plasma process.
6. Required hydrogen is produced from solar driven electrolysis at peak times in summer. Plastic waste can be
collected in the winter months, partially reducing the summer/winter electricity storage problem.
7. The plasma reactor for decomposition of the plastic waste with admixture of the solar generated ("green")
hydrogen is run at peak times and thus also stabilizes the electric power grids. The plasma process can be started up and shut down quickly, since no large thermal masses have to be heated up (in contrast to thermal gasification at over 1000°C).
Research team within HES-SO:
Ellert Christoph
, Crelier Simon
, Berthouzoz David
, Martinet David
, Zsely Schaffter Martina
, Richard Jacques
, Jobin Marc
, Schopfer Mathieu
, Reymond Lucie
, Seppey Fabrice
, Broccard Pierre-Vincent
, Pomarico Enrico
, Schmidt Cédric
, Neuenschwander Caryl
, Varone Benoît
, Bruzzo Alessia
, Masserey Romain
Partenaires académiques: VS - Institut Systèmes industriels; VS - Institut Technologies du vivant; hepia inSTI; Ellert Christoph, VS - Institut Systèmes industriels
Durée du projet:
15.01.2022 - 31.03.2024
Montant global du projet: 220'000 CHF
Statut: Completed
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