The most promising technology for the production of high value products based on previous FLEXI-PYROCAT work has found that the two-stage pyrolysis-catalysis of the feedstock has the most potential in terms of flexibility.
Scale-up of the pyrolysis-catalysis process was undertaken in order to understand the implications in process development by moving from experimental bench scale reactors to larger quantities of feedstock, larger scale and further to continuous processing. Process modeling of the scale-up plastic waste pyrolysis catalysis system was undertaken. A process flow diagram of the industrial scale plastic waste catalysis pyrolysis process was developed using Aspen Plus®. A techno-economic assessment was produced based on a mass and energy balance of the process and estimated cost data.
Co-processing of waste plastics and biomass was successfully performed in a two-stage reactor with different plastics for the production of hydrogen. Adding polystyrene significantly improves the quality of bio-oil from biomass due to co-processing and improving the aromatic content and gasoline range hydrocarbons in the oil. Co-processing biomass and waste plastics however has a detrimental effect on the quality of product carbon nanotubes.
Standards and specifications of commercially carbon nanotubes, hydrogen, petroleum derived fuels (gasoline, diesel), and aromatic chemicals have been compared with the target end-products produced from the FLEXI-PYROCAT project. Carbon nanotubes produced from plastics showed the most promise in matching to commercial standards.
A WEB based learning resource related to the pyrolysis and gasification of wastes plastics for the recovery of high value products has been prepared and presented aimed at high school children and teachers and the informed general public. The three packaged learning resources contain a wealth of easily accessible information and references and are presented as ‘Open Access’ on the FLEXI-PYROCAT WEB SITE;
Articles published in high impact international journals are a highlight of the FLEXI-PYROCAT project, resulting in currently 23 papers published as OPEN ACCESS. Several of the papers are amongst the top ‘most downloaded articles’ of the journals (e.g. Journal of the Energy Institute (Impact Factor 4.2) and Journal of Analytical & Applied Pyrolysis (Impact Factor 3.4). In addition, one paper reported on work by the consortium members that has produced carbon nanotubes from waste plastics and then incorporated the collected carbon nanotubes into composite material which was tested and shown to deliver superior strength characteristics. The research was published in the journal Process, Safety & Environmental Protection (103 (2016): 107-114) which is the Official Journal of the European Federation of Chemical Engineering. The work was featured by the Institution of Chemical Engineers monthly magazine ‘The Chemical Engineer’ (November 2016, pp21) with a circulation in excess of 40,000 copies per issue.