TY - JOUR
T1 - Towards solvothermal upcycling of mixed plastic wastes
T2 - Depolymerization pathways of waste plastics in sub- and supercritical toluene
AU - Saha, Nepu
AU - Banivaheb, Soudeh
AU - Toufiq Reza, M.
N1 - Funding Information:
The research is partially funded by the National Science Foundation grant ( 1856058 ). The authors acknowledge Dr. Andrew Wagner from Mainstream Engineering Corporation for his assistance with GCMS. Special thanks to Dr. Mariefel Olarte, Dr. Michael Thorson, and Mr. Andrew Schmidt from Pacific Northwest National Laboratory for meaning discussions on solvothermal liquefaction. The authors would also like to acknowledge Md Tahmid Islam, Thomas Quaid, Aaron Portell, and Laura Guidugli from the Biofuels lab at the Florida Institute of Technology for their valuable inputs on STL experiments and product characterization.
Funding Information:
The research is partially funded by the National Science Foundation grant (1856058). The authors acknowledge Dr. Andrew Wagner from Mainstream Engineering Corporation for his assistance with GCMS. Special thanks to Dr. Mariefel Olarte, Dr. Michael Thorson, and Mr. Andrew Schmidt from Pacific Northwest National Laboratory for meaning discussions on solvothermal liquefaction. The authors would also like to acknowledge Md Tahmid Islam, Thomas Quaid, Aaron Portell, and Laura Guidugli from the Biofuels lab at the Florida Institute of Technology for their valuable inputs on STL experiments and product characterization.
Publisher Copyright:
© 2021 The Authors
PY - 2022/1
Y1 - 2022/1
N2 - Solvothermal liquefaction (STL) is a thermochemical conversion process, where a waste feedstock is treated with sub-and supercritical solvents. The key objective of the study was to investigate how a one-step STL using toluene as a solvent can degrade hard-to-recycle waste plastics (#5–#7). Three different plastic wastes namely, polypropylene (#5), polystyrene (#6), and polyurethane (#7), and their equal mixture (by weight, also referred here as mixed plastic wastes) were solvothermally liquefied by toluene in a 7 mL pressure bomb at 300, 350, and 400 °C for 3, 6, and 9 h in order to determine the effect of temperature and time, respectively. The liquid products were separated from the solid residue and further analyzed in terms of the STL conversion, change in elemental compositions via ultimate analysis, boiling point distribution via thermogravimetric analyzer (TGA), alteration of chemical bonds via proton nuclear magnetic resonance spectroscopy (1H NMR), and degradation products via gas chromatography mass spectroscopy (GCMS). The results showed that the STL conversion increase with the increase of reaction temperature and time. From the elemental analysis, it can be predicted that the higher heating values of the crude products are between 30 and 45 MJ/kg. Boiling point distribution showed that the production of lower hydrocarbon (C8–C20) increased significantly from about 10% at 300 °C to 80% at 400 °C. Additionally, product distribution showed that the aromaticity increased with the increase of residence time where the main products are benzene and styrene like products. Overall, it was observed that mixed plastic wastes have a synergistic effect on the degradation products.
AB - Solvothermal liquefaction (STL) is a thermochemical conversion process, where a waste feedstock is treated with sub-and supercritical solvents. The key objective of the study was to investigate how a one-step STL using toluene as a solvent can degrade hard-to-recycle waste plastics (#5–#7). Three different plastic wastes namely, polypropylene (#5), polystyrene (#6), and polyurethane (#7), and their equal mixture (by weight, also referred here as mixed plastic wastes) were solvothermally liquefied by toluene in a 7 mL pressure bomb at 300, 350, and 400 °C for 3, 6, and 9 h in order to determine the effect of temperature and time, respectively. The liquid products were separated from the solid residue and further analyzed in terms of the STL conversion, change in elemental compositions via ultimate analysis, boiling point distribution via thermogravimetric analyzer (TGA), alteration of chemical bonds via proton nuclear magnetic resonance spectroscopy (1H NMR), and degradation products via gas chromatography mass spectroscopy (GCMS). The results showed that the STL conversion increase with the increase of reaction temperature and time. From the elemental analysis, it can be predicted that the higher heating values of the crude products are between 30 and 45 MJ/kg. Boiling point distribution showed that the production of lower hydrocarbon (C8–C20) increased significantly from about 10% at 300 °C to 80% at 400 °C. Additionally, product distribution showed that the aromaticity increased with the increase of residence time where the main products are benzene and styrene like products. Overall, it was observed that mixed plastic wastes have a synergistic effect on the degradation products.
KW - Plastic wastes
KW - Polypropylene
KW - Polystyrene
KW - Polyurethane
KW - Solvothermal liquefaction
KW - Sub-and supercritical toluene
UR - https://www.scopus.com/pages/publications/85121154716
U2 - 10.1016/j.ecmx.2021.100158
DO - 10.1016/j.ecmx.2021.100158
M3 - Article
AN - SCOPUS:85121154716
SN - 2590-1745
VL - 13
JO - Energy Conversion and Management: X
JF - Energy Conversion and Management: X
M1 - 100158
ER -