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The catalytic hydrotreatment of Kraft lignin using sulfided NiMo and CoMo catalysts on different acidic and basic supports (Al2O3, ZSM-5, activated carbon (AC) and MgO-La2O3) was studied in the absence of a solvent. Experiments were carried out in a batch set-up at a reaction temperature of 350 °C, 4 h and 100 bar initial H2 pressure. The catalysts before and after reaction were characterized by X-ray diffraction, temperature programmed desorption of ammonia/CO2, BET surface area and scanning electron microscopy. The liquid products were fractionated and analyzed extensively by different techniques such as GPC, GC-MS-FID, GC-TCD, FT-IR, 13 C-NMR and elemental analyses. Two dimensional gas chromatography (GCxGC-FID) was applied to identify distinct groups of compounds (aromatics, alkylphenolics, alkanes) after reaction, and product quantification was performed based on this method. Catalyst activity is a function of the support and increased in the order Al2O3 < ZSM-5 < AC=MgO-La2O3. In addition, the support also largely influenced the extent of depolymerization and monomer yield. The highest lignin oil yields were obtained using the sulfided NiMo supported on activated carbon and MgO-La2O3. The highest total monomer yield 26.4 wt.% on lignin intake, which included 15.7 wt.% alkyl-phenolics was obtained using the sulfided NiMo/MgO-La2O3 catalyst.

Efficient catalytic hydrotreatment of Kraft lignin to yield aromatic monomers was demonstrated in supercritical methanol using a variety of NiW and NiMo catalysts on acidic, basic and neutral supports.

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The direct conversion of ethanol to higher value 1-butanol is a catalytic transformation of great interest in light of the expected wide availability of bioethanol originating from the fermentation of renewable resources. In this contribution we describe several novel compositions of porous metal oxides (PMO) as highly active and selective catalysts for the Guerbet coupling of ethanol to 1-butanol in the temperature range 180−320 °C. The novel PMO catalysts that do not contain any noble metals are obtained by calcination of a series of hydrotalcite precursors synthesized through modular procedures. In particular, catalyst compositions simultaneously containing Cu and Ni dopants have shown excellent catalytic activities. Up to 22% 1-butanol yield at 56% ethanol conversion was reached in a batch mode; recycling and leaching tests showed excellent robustness of the new catalysts. An extensive characterization by means of several techniques such as powder XRD, SEM, TEM, BET, and NH 3 -and CO 2 -TPD was performed in order to understand structure−activity trends.

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