Hydrotreatment of Kraft Lignin to Alkylphenolics and Aromatics Using Ni, Mo, and W Phosphides Supported on Activated CarbonChowdari, R. K., Agarwal, S. & Heeres, H. J., 21-Jan-2019, In : ACS Sustainable Chemistry & Engineering . 7, 2, p. 2044-2055 23 p.
Research output: Contribution to journal › Article › Academic › peer-review
The conversion of lignin to biofuels and biobased chemicals is currently attracting a lot of attention. We here report on the valorization of Kraft lignin by a catalytic hydrotreatment using Ni, Mo, and W phosphide catalysts supported on activated carbon in the absence of an external solvent. Experiments were carried out in a batch setup in the temperature range of 400-500 degrees C and 100 bar initial H-2 pressure. The synthesized catalysts were characterized by X-ray diffraction, nitrogen physisorption, and transmission electron microscopy. The lignin oils were analyzed extensively by different techniques such as GPC, GC-MS-FID, C-13 NMR, and elemental analysis. Two-dimensional gas chromatography (GCxGC-FID) was applied to identify and quantify distinct groups of compounds (aromatics, alkylphenolics, alkanes, etc.). Mo-based catalysts displayed higher activity compared to the W -containing catalysts. The reaction parameters such as the effect of reaction temperature, reaction time, and catalyst loading were studied for two catalysts (15MoP/AC and 20NiMoP/AC), and optimized reaction conditions regarding yields of monomeric components were identified (400 degrees C, 100 bar H-2 at RT, 10 wt % catalyst loading on lignin intake). The highest monomer yield (45.7 wt % on lignin) was obtained for the 20NiMoP/AC (Ni 5.6 wt %, Mo 9.1 wt %, P 5.9 wt %) catalyst, which includes 25% alkylphenolics, 8.7% aromatics, and 9.9% alkanes. Our results clearly reveal that the phosphide catalysts are highly efficient catalyst to depolymerize the Kraft lignin to valuable biobased chemicals and outperform sulfided NiMo catalysts (monomer yield on lignin <30 wt %).
|Number of pages||23|
|Journal||ACS Sustainable Chemistry & Engineering|
|Publication status||Published - 21-Jan-2019|
- Kraft lignin, Hydrotreatment, Depolymerization, Phosphided catalysts, Biobased chemicals, NICKEL PHOSPHIDE, CATALYTIC HYDROTREATMENT, MOLYBDENUM CARBIDE, ALCELL(R) LIGNIN, FORMIC-ACID, BIO-OIL, DEPOLYMERIZATION, CONVERSION, BIOMASS, CHEMICALS