One-step transformation of biomass to fuel precursors using a bi-functional combination of Pd/C and water tolerant Lewis acid


Hao N., Alper K., Patel H., TEKİN K. , KARAGÖZ S. , Ragauskas A. J.

FUEL, cilt.277, 2020 (SCI İndekslerine Giren Dergi) identifier identifier

Özet

Direct one-pot transformation of lignocellulosic biomass has been developed as an effective and sustainable strategy to produce fuel blend stocks and high value chemical building blocks. In this wok, a bi-functional catalyst system consisting of palladium supported on carbon (Pd/C) and metal triflates (i.e., Sm(OTf)(3), La(OTf)(3), and Cu(OTf)(3) were shown to promote the biomass liquefaction in both hot-compressed water and supercritical ethanol medium, converting fir wood into oxygenated compounds. The highest bio-oil yield from hydrothermal liquefaction (HTL) was 10.47 wt% over Pd/C whereas the highest bio-oil yield of 49.71 wt% was achieved from supercritical ethanol liquefaction (SCEL) over the bi-functional catalyst system of Pd/C and La(OTf)(3). Higher heating values, carbon recovered values and boiling point distributions were further determined for elucidating the physical properties of the bio-oils. Gas chromatography mass spectrometry (GC-MS) analysis of the bio-oils revealed the chemical composition of the bio-oils. Substituted phenols and cyclopentenone/cyclopentanone type compounds consisted of more than 60 area% of the total products from HTL, whereas phenol and esters represented the major products from SCEL. The major reaction pathways are proposed based on the GC-MS results, which include depolymerizaton, isomerization, dehydration, condensation, and hydrogenation.