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Abstract Title: Using GC-VUV for the Evaluation of Pyrolysis Oils from Mixed Waste Plastics
Abstract Type: Seminar
Session Choice: Recycling
Presenter Name: Dr Melissa Dunkle
Company/Organisation: Dow
Country: Netherlands

Abstract Information :

The issues around waste plastic have gained global attention, and many Value Chain Partners are working towards a plastics’ circular economy. Dow has evaluated multiple pyrolysis oil samples produced around the world from waste plastics as a potential circular feedstock. Typically, these have been found not suitable to be used as a drop-in replacement of fossil-naphtha to produce circular plastics. To facilitate application of such oils as a circular feedstock, a much better understanding of the pyrolysis oil composition is required. This calls for the development of more advanced characterization techniques to identify a variety of hydrocarbons as well as organic molecules with hetero-atoms such as Cl, O, and/or N.

Pyrolysis oils originating from waste plastic are complex and contain unsaturated hydrocarbons which are not present in fossil feedstocks. Therefore, detailed hydrocarbon analysis (DHA) or GCxGC with FID detection is inadequate to fully characterize the hydrocarbon composition of such samples, especially when peaks are closely eluting, or even co-eluting. In this study, the GC-VUV method previously described for the analysis of liquid hydrocarbon streams has been applied to the analysis of pyrolysis oils. While GC-VUV can provide superior PIONA quantification based on the UV spectra, little information was obtained for the heteroatoms.

Pyrolysis products are also rich in heteroatom containing hydrocarbons, especially oxygen, where commercially available methods are restricted within C1 and C5 oxygenates. To obtain a better understanding of the heteroatom composition, GCxGC coupled to Time of Flight Mass Spectrometry (TOF-MS) was used and preliminary results will be highlighted.