Hydrodeoxygenation of the aqueous fraction of bio-oil with Ru/C and Pt/C catalysts

Abstract

In this paper we discuss the continuous flow hydrogenation of the water soluble fraction of bio-oil (WSBO) with Ru/C and Pt/C catalysts. Temparatures higher then 125°C lead to homogeneous reactions within the aqueous phase of bio-oil. Low temperature hydrogenation (LTH) at 125°C over Ru/C catalyst and with WHSV of 1.5-3 hr -1 was required to stabilize the bio-oil so higher temperature hydrogenation (HTH) could occur. The main products from LTH were ethylene and propylene glycols and sorbitol. At these temperatures only small amounts of acetic acid (AA), levoglucosan, furanone, phenol and phenol substitutes were hydrogenated. In the HTH step, the sorbitol was hydrogenated to mono-alcohols and diols by hydrogenolysis and secondary hydrogenation reactions. Up to 45% carbon in WSBO was converted to useful products (gasoline-cuts and diols) in the HTH step over Pt/C catalyst at 250°C and WHSV of 3 hr -1 . The reactions product distribution can be controlled by modifying operating pressure and temperature. The production of gasoline range compounds (C4-C6 alkanes and C1-C6 alcohols) is favoured at low pressure (750 psi). Increasing the reaction pressure decreased the amount of carbon that was converted into gas phase products.

Review of recent developments to improve storage and transportation stability of bio-oil

“…oxygen removal [100,107,[119][120][121]. Mild HDO refers to the first low temperature stabilization step, in which carbonyl groups were hydrogenated into more stable alcohols [107]. French et al [101] used a sulfided Ni-Mo/ƴ-Al 2 O 3 catalyst to upgrade bio-oil in a two-stage hydrotreating process.…”

“…Adapted with modification from [86]. oxygen removal [100,107,[119][120][121]. Mild HDO refers to the first low temperature stabilization step, in which carbonyl groups were hydrogenated into more stable alcohols [107].…”

Production of renewable jet fuel range alkanes and aromatics via integrated catalytic processes of intact biomass

“…Meanwhile, the elevated reaction temperature also possibly favored the scission of hydroxyl group from phenyl to form phenol through hydrogenolysis reactions. Guaiacol with adjacent methoxy and hydroxyl functional groups could readily be hydrogenated at the aromatic ring to saturated intermediates [26]. Methoxy functional group of the intermediate was hydrogenated to hydroxyl group, finally forming 1,2-cyclohexanediol.…”

“…Since advanced jet fuels from HDO process are expected to be enlarged in a biorefinery scale, high capital costs caused by tolerance of severe condition and low selectivity of liquid products render these processes uneconomical [25,26]. Accordingly, the production of jet fuels from renewable biomass resources calls for ideal technologies with efficient solid-phase catalysts to make the processes economically feasible under a mild reaction condition.…”

Development of Heterogeneous Catalysts for Thermo-Chemical Conversion of Lignocellulosic Biomass

“…One of the methods of pyrolysis oil conversion into valuable products (such as hydrocarbons) is hydrodeoxygenation. According to the literature data [53,54], during the HDO process, oxygen can be eliminated from the pyrolysis products in various ways: hydrogenation of C-C and C-O bonds, dehydration of C-OH groups, C-C bond cleavage by retro-aldol condensation, and decarboxylation or hydrogenolysis of C-O-C groups. The reaction is usually conducted at a lower temperature than in the case of pyrolysis (usually between 200 and 400 • C) and under higher pressure (10-70 atm) [53].…”