Influence of the Ni-Co/Al-Mg Catalyst Loading in the Continuous Aqueous Phase Reforming of the Bio-Oil Aqueous Fraction

Abstract

The effect of catalyst loading in the Aqueous Phase Reforming (APR) of bio-oil aqueous fraction has been studied with a Ni-Co/Al-Mg coprecipitated catalyst. Because of the high content of water in the bio-oil aqueous fraction, APR could be a useful process to convert this fraction into valuable products. Experiments of APR with continuous feeding of aqueous solution of acetol, butanol and acetic acid as the only compound, together with a simulated and a real aqueous fraction of bio-oil, were carried out. Liquid products in the liquid effluent of the APR model compounds were quantified and the reaction pathways were revised. The increase of catalyst loading produced an increase of gas production and a gas with higher alkanes content. Acetol was the compound with the highest reactivity while the conversion of acetic acid was very low. The presence of acetic acid in the feed caused catalyst deactivation.

Aqueous-phase reforming of water-soluble compounds from pyrolysis bio-oils

“…Comparing the results obtained in the current work with those reported in literature, Lozano et al [35] observed CCgas values of 45-50 % and hydrogen content in the gas of 33.7 % using different catalyst load and similar operating conditions. Callison et al [55] reported lower hydrogen production values (0.4 mmol H 2 and 0.2 mmol CH 4 vs 5.75 mmol H 2 and 1.96 mmol CH 4 ), using similar reaction conditions but much higher initial hydroxyacetone concentration (10 vs 1% wt.…”

“…Some studied have reported that catalyst deactivation in the APR of acetic acid and ethanol is not relevant [39]. However, Lozano et al [35], found low reactivity of acetic acid in APR using Ni-Co/Al-Mg catalysts, especially compared to ethanol, due to catalyst deactivation.…”

“…Hydroxyacetone has been one of the most studied model compounds. Some works showed carbon yield to gases of up to 50 % in the APR of hydroxyacetone using Ni-Co/Al-Mg catalysts and H 2 content in produced gas higher than 30 % [35]. However, hydroxyacetone can also undergo aldol condensation reactions leading eventually to catalyst deactivation by coke formation in Pt/AlO(OH) and Pt/ZrO 2 catalysts [36].…”