Hydroprocessing of Low-Molecular Weight Fraction of Bio-Oil Over in Situ Moox Catalyst in Sub- and Supercritical Ethanol

Abstract

The approach for producing alkylphenols from a renewable resource and their further conversion into jet fuel components (alkylcyclohexanes) was proposed. The hydroprocessing of low-molecular weight (LMW) fraction of bio-oil was studied in the presence of an in situ formed MoOx catalyst and using ethanol as a solvent. The effect of the presence and absence of the external hydrogen pressure on the characteristics of the catalyst was found. The reaction products obtained during hydroprocessing of the LMW fraction of bio-oil were analyzed by various methods (GC-MS, NMR, elemental analysis). The influence of the various reaction parameters (the presence of catalyst, the effect of external hydrogen pressure, and reaction temperature) on the product composition was studied. Conversion of LMW fraction using in situ MoOx at 350°C (5 MPa H2, 6 h) was shown to contribute to the highest yield of alkylphenols (70%) and the greatest decrease in O/C ratio (from 0.309 in LMW to 0.104). In addition, it was shown that the obtained alkylphenols can be converted into alkylcyclohexanes, components of jet fuel, over commercial Pd/C catalyst.

Keywords: bio-oil, alkylphenols, jet fuel, molybdenum oxide, oxygen vacancy sites, Pd/C.