Abstract
Thermochemical processing of lignin ends up with a major problem which is the high yield of char remained from lignin conversion, causing low yields of desired products. The ReS2/Al2O3 catalyst, used in this work, exhibited a high char-suppressing potential and high hydrodeoxygenation efficiency in the reductive liquefaction of kraft lignin. Compared to NiMo/Al2O3, as a conventional sulfide catalyst, ReS2/Al2O3 showed significantly better catalytic performance with 72.4 % lower char yield, due to its high efficiency in stabilizing the lignin-depolymerized fragments. The remarkable catalytic performance of ReS2/Al2O3 is attributed to its high oxophilicity, the metal-like behavior of rhenium sulfide and sufficient acidity. The effects of reaction temperature and different catalyst supports (Al2O3, ZrO2 and desilicated HY zeolite) were also studied. In an alkali (NaOH)-assisted depolymerization of lignin, it was revealed that ReS2/Al2O3-to-NaOH (stabilization-to-depolymerization) ratio plays a crucial role in determining the reaction pathway toward either solid char residues or liquid monomeric products.
Original language | English |
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Article number | 120449 |
Journal | Applied Catalysis B: Environmental |
Volume | 297 |
DOIs | |
Publication status | Published - 15 Nov 2021 |
MoE publication type | A1 Journal article-refereed |
Funding
The Swedish Energy Agency ( P47511-1 ), Formas ( 2017-01392 ) and Area of Advance Energy at Chalmers are greatly acknowledged for their financial support. We would also like to acknowledge the Chalmers Material Characterization (CMAL) facilities for STEM and XPS measurements.
Keywords
- Char suppression
- Lignin
- Monocyclic hydrocarbon
- Reductive liquefaction
- ReS/AlO