TY  - JOUR
AB  - The increasing demand for lightweight materials with exceptional stability and durability has resulted in a significant rise in fiber-reinforced plastic (FRP) production. These materials find applications in various fields. However, the exceptional properties and diverse compositional range of FRPs pose challenges to conventional recycling strategies. Pyrolysis has emerged as a highly promising approach for separating the fibers from the polymer matrix. In this study, we employed thermal analysis coupled with high-resolution mass spectrometry to investigate the pyrolysis process. Representative FRP showed a starting decomposition temperature of 300 °C and bisphenol A, styrene, alkenes, and phenols could be identified. The identified parameters were used to operate a pilot plant with a capacity of up to 50 kg/h FRP, and reactor products were directly analyzed with soft photoionization mass spectrometry. The findings demonstrated good agreement between the pilot plant results and laboratory experiments, particularly for smaller compounds (m/z<200). The non-condensable fraction showed a range of 17 to 22 MJ/m3 as lower heating value. Analysis of the recovered fibers (diameter between 6.20 and 8.05 μm) revealed residual coke, but no toxic fibers were detected, according to the World Health Organization's definition. Yet, the organic coating of the fibers contained small amounts of potentially harmful PAHs. A toxicological assessment using a multicellular in vitro model confirmed the low hazardous potential of the recovered fibers. The findings contribute to developing sustainable and environmentally friendly recycling strategies for FRP while addressing important aspects related to the safety and toxicological implications of the resulting chemicals and fibers.
AU  - Friederici, L.*
AU  - Koch, A.*
AU  - Martens, P.*
AU  - Pantzke, J.
AU  - Di Bucchianico, S.
AU  - Streibel, T.
AU  - Rüger, C*
AU  - Zimmermann, R.
C1  - 68763
C2  - 54973
CY  - The Boulevard, Langford Lane, Kidlington, Oxford Ox5 1gb, England
SP  - 10-21
TI  - Recycling of fiber reinforced composites: Online mass spectrometric tracing, offline physicochemical speciation and toxicological evaluation of a pilot plant pyrolytic conversion.
JO  - Waste Manag.
VL  - 173
PB  - Pergamon-elsevier Science Ltd
PY  - 2023
SN  - 0956-053X
ER  - 

TY  - JOUR
AB  - In the context of waste upgrading of polyethylene terephthalate (PET) by pyrolysis, this study presents three on-line mass spectrometric techniques with soft ionization for monitoring the emitted decomposition products and their thermal dependent evolution profiles. Pyrolysis experiments were performed using a thermogravimetric analyzer (TGA) under nitrogen atmosphere with a heating rate of 5 degrees C/min from 30 degrees C to 600 degrees C. Single-photon ionization (SPI at 118 nm/10.5 eV) and resonance enhanced multiple photon ionization (REMPI at 266 nm) were used with time-of-flight mass spectrometry (TOF-MS) for evolved gas analysis (TGA-SPI/REMPI-TOFMS). Additionally, the chemical signature of the pyrolysis products was investigated by atmospheric pressure chemical ionization (APCI) ultra high resolution Fourier Transform ion cyclotron resonance mass spectrometry (FT-ICR MS) which enables assignment of molecular sum formulas (TGA-APCI FT-ICR MS). Despite the soft ionization by SPI, the fragmentation of some compounds with the loss of the [O-CH = CH2] fragment is observed. The major compounds were acetaldehyde (m/z 44), benzoic acid (m/z 122) and a fragment of m/z 149. Using REMPI, aromatic species were selectively detected. Several series of pyrolysis products were observed in different temperature intervals, showing the presence of polycyclic aromatic hydrocarbons (PAHs), especially at high temperatures. FT-ICR MS data showed, that the CHO4 class was the most abundant compound class with a relative abundance of 45.5%. The major compounds detected with this technique corresponded to m/z 193.0495 (C10H9O4+) and 149.0233 (C8H5O3+). Based on detailed chemical information, bulk reaction pathways are proposed, showing the formation of both cyclic monomer/dimer and linear structures.
AU  - Dhahak, A.*
AU  - Grimmer, C.*
AU  - Neumann, A.*
AU  - Rüger, C.*
AU  - Sklorz, M.
AU  - Streibel, T.
AU  - Zimmermann, R.
AU  - Mauviel, G.*
AU  - Burkle-Vitzthum, V.*
C1  - 58803
C2  - 48346
CY  - The Boulevard, Langford Lane, Kidlington, Oxford Ox5 1gb, England
SP  - 226-239
TI  - Real time monitoring of slow pyrolysis of polyethylene terephthalate (PET) by different mass spectrometric techniques.
JO  - Waste Manag.
VL  - 106
PB  - Pergamon-elsevier Science Ltd
PY  - 2020
SN  - 0956-053X
ER  -