The effects of noble metal catalysts on the bio-oil quality during the hydrodeoxygenative upgrading process

Hydrodeoxygenation of Lignin-Derived Phenols: From Fundamental Studies towards Industrial Applications

“…In bio-oil HDO over noble metal catalysts supported on active carbon at 300 • C under 30 bar hydrogen, the catalyst deactivation was intensive during reuse [30]. It was also concluded that Ru/C deactivated mainly via fouling and blocking of active sites, whereas activity loss of Pt/C was attributed to extensive char deposition on the catalyst surface.…”

“…HDO of real bio-oils [4,30,35,62] have been investigated in several publications. Bio-oil derived from yellow poplar via fast pyrolysis was hydrodeoxygenatied at 300 • C in ethanol at 30 bar hydrogen [4].…”

“…HDO of the bio-oil prepared via fast pyrolysis of Miscanthus sinensis at 350 • C and 30 bar over noble metals supported on carbon, in supercritical ethanol [30] showed deoxygenation of the heavy oil fraction of the bio-oil to 78% with the heating value of the product 27.8 MJ/kg. It is also important to note that such unstable compounds, as acids, furfural, vanillin and levoglucosan were converted to esters, ketones and saturated phenols [30]. Macromolecular products in that work were also characterized [28].…”

“…Catalyst stability, activity as a function of time-onstream [31,33,36,39,42,43,47,48,58,59,61], reuse [30,54,[56][57][58]63], regeneration [34,36], origin of the catalyst deactivation [30], chemical composition of coke [31], thermogravimetrical analysis of the spent catalysts [62], modelling of deactivation [33] are also very important from the industrial point of view. Since the real bio-oils contain in addition to lignin derived compounds also water [59], acetic acid or furfural [56] as well several catalyst poisons, such as chlorine, potassium and sulphur containing compounds [47], it is very important not only to investigate HDO of model compounds but also the real feed [30] using different approaches, such as a single component feed, co-feed studies, real bio-oil [30], simulated bio-oil [40], adsorption studies [48,79] as well as continuous operation [33,36,39,42,43,48].…”

Review of Heterogeneous Catalysts for Catalytically Upgrading Vegetable Oils into Hydrocarbon Biofuels

“…The acidity of the support materials such as HZSM-5 and Al 2 O 3 affects the adsorption properties [71]. Oh et al [131] investigated the bio-oil upgrading over noble metal catalysts of Ru/C and Pt/C. The surface area, pore size, and pore volume of these two catalysts all decreased after three times of reusing.…”