ResolVe

ResolVe

Recycling of Polystyrene by Raw Material Recovery
Coordinator

Dr. Hannes Kerschbaumer
INEOS Styrolution Group GmbH
Mainzer Landstraße 50
60325 Frankfurt am Main
Phone: +49 69 509550-1322
e-mail: hannes.kerschbaumer@ineos.com

Duration Period
August 2017
July 2020
Beschreibung

In view of climate change, environmental pollution, population growth, and resource dependency, the transition from a linear economy to a closed-loop economy is both ecologically and economically necessary. Within the ResolVe project, a logistics and an industrial plant concept for the economic use of polystyrene waste as a raw material for high-quality new plastic products were developed. Thermally-induced depolymerisation as material recycling of waste plastics can lead to the production of new polymers. In this process, the polymer is split thermally into low-molecular substances such as monomers and oligomers. Compared to the thermal utilisation or mechanical recycling of plastic waste that has been common up to now, this project aimed to actually close a cycle. Since the depolymerisation process does not lead to a "downcycling" of the recyclable materials and only makes moderate demands on the purity of the waste streams, many post-consumer waste streams can be used.

INEOS Styrolution managed the joint research project with the aim of using the styrene monomer, which is the main component of depolymerisation, in its own production process. To this end, the overall process was subjected to an intensive evaluation and the prerequisites for an investment were examined, too.

Main areas of work

  • Logistical and economic evaluation
  • Preconditioning in processing technology
  • Depolymerisation of polystyrene wastes on a laboratory scale
  • Depolymerisation of polystyrene in the twin screw extruder
  • Distillative treatment
  • Investigations on the influence of impurities on the depolymerisation process of polystyrene
  • Ultilisation of by-products through steam cracking

WP 1 Project leadership

Contact person
Dr. Hannes Kerschbaumer, INEOS Styrolution Group GmbH, Mainzer Landstraße 50, 60325 Frankfurt am Main, e-mail: hannes.kerschbaumer@ineos.com

Short description
The successful implementation of the project required a regular exchange of information between the partners and with the project management. The consortium consisted of five partners and other subcontractors and thus required careful management to ensure targeted and result-oriented cooperation. The individual tasks included: coordination of the project partners; thematic summaries of the developed results; reporting (including meeting minutes, milestone report and regular reports); organisation of project meetings and regular telephone conferences; organisation of the dispatch of hazardous substances between Aachen, Bayreuth and Cologne; and observation of parallel approaches to the raw material recycling of polystyrene.

WP 2 Procurement of waste samples and development of a recycling concept

Contact person
Prof. Dr. Thomas Pretz, RWTH Aachen University, Department of Processing and Recycling, Wüllnerstraße 2, 52056 Aachen, e-mail: pretz@ifa.rwth-aachen.de

Project partner
INEOS Styrolution

Short description
In dialogue with relevant waste disposal companies, the most important material flows were detected and samples procured. These were examined, processed and evaluated with regard to their suitability for chemical recycling. Specific logistics concepts were developed for these material flows so that a high recycling rate could be achieved. In addition, existing contacts with other research groups dealing with the collection of marine plastic waste were used. Other contacts were established to integrate the availability of material flows from the environment into the logistics concept.

WP 3 Depolymerisation of pure polystyrene granules with targeted variation of relevant material parameters

Contact person
Prof. Dr. Hans-Werner Schmidt, Neue Materialien Bayreuth GmbH, Gottlieb-Keim-Straße 60, 95448 Bayreuth, e-mail: hans-werner.schmidt@uni-bayreuth.de

Project partner
RWTH Aachen University IKV, INEOS Styrolution, INEOS Köln

Short description
The aim was to gain basic knowledge about the type of products resulting from the depolymerisation of polystyrene. For this purpose, depolymerisation was carried out on model substances on a laboratory scale. Parallel to this, a suitable extruder arrangement with separator was set up and depolymerisation was carried out in order to determine achievable yields and parameter influences. The reaction products were investigated by means of GC-MS. First experiments with real samples were carried out and the distillative separation of styrene was demonstrated. The by-products were evaluated for their suitability for the cracking process and the process parameters were optimized in both depolymerisation plants.

WP 4 Depolymerisation of pure polystyrene granules with targeted variation of relevant impurities

Contact person
Maximilian Adamy, RWTH Aachen University, Institute of Plastics Processing, Seffenter Weg 201, 52074 Aachen, e-mail: maximilian.adamy@ikv.rwthaachen.de

Project partner
RWTH Aachen University I.A.R., INEOS Styrolution, Neue Materialien Bayreuth

Short description
The material to be recycled generally contained a wide range of different impurities. These were characterized and their influence on the depolymerisation process of PS was investigated. Possible sources of polystyrene waste are: the polystyrene fraction from household waste (dual system), polystyrene from commercial waste collection, and samples of marine plastic waste. The next steps included: pre-sorting, conditioning of the waste, depolymerisation process in the piston and in the extruder, adaptation of the real samples to the optimum process conditions, and determination of the optimum operating mode depending on the material source.

WP 5 Fractionating distillation and utilisation of styrene monomers and by-products

Contact person
Dr. Ralf Gesthuisen, INEOS Köln GmbH, Alte Straße 201, 50769 Köln, e-mail: ralf.gesthuisen@ineos.com

Project partner
Neue Materialien Bayreuth, INEOS Styrolution

Short description
Depolymerisation does not produce a pure monomer stream, but rather a mixture of monomers, oligomers and other volatile components. For repolymerisation, the monomers must be separated from this mixture by fractionated distillation. Further fractions remain, which can be converted into recyclable substances by a suitable steam cracking process. The resulting products were examined qualitatively and quantitatively. Based on this, the cracking process was optimised by adjusting the process parameters and possibly adding naphtha and/or hydrogen.

WP 6 Economic and ecological considerations of the recycling concept

Contact person
Dr. Hannes Kerschbaumer, INEOS Styrolution Group GmbH, Mainzer Landstraße 50, 60325 Frankfurt am Main, e-mail: hannes.kerschbaumer@ineos.com

Project partner
RWTH Aachen University I.A.R.

Short description
The knowledge gained in the project was used to adapt the logistics concept developed in WP 2. The costs of the entire value chain, including collection and recycling, were determined. The question of the location of a depolymerisation plant had a major influence on the overall calculation: the provision of raw materials in sufficient quantity and quality could be realized with varying ease regionally and nationally. A special case took into account whether collected plastic from the environment is also suitable for economic use. An ecological assessment (CO2 footprint) of the depolymerisation was carried out.

( top of page )( zum Seitenanfang )