(237g) Aqueous-Phase Hydrogenation of Model Bio-Oil Compounds Under Mild Condition Over CNTs Supported Catalysts

Abstract:

Bio-oil is an attractive bio-fuel in view of the development of renewable energy sources, which could offer sustainable resources and reduce our dependence on limited fossil fuels in the future. However, the quality of bio-oil should be improved by the partial or total elimination of the oxygenated functionalities. In general, bio-oil upgrading can be accomplished in three steps: water extraction, low temperature hydrogenation of the water-soluble phase, and aqueous-phase reformation (to prepare H₂) or dehydration/hydrogenation (to alkanes). In this work, hydrogenation of four model compounds of the bio-oil in aqueous phase, including furfural, hydroxyacetone, cyclopentanone and acetaldehyde, was carried out under mild reaction conditions (T≤473K) in a high-pressure autoclave. A series of nickel-based catalysts(La, Co,Mo, etc. as additives) with HNO₃-pretreated CNTs as support were synthesized using impregnation and calcination methods, which were successfully applied for the upgrading of model compound in bio-oil. The investigated compounds were accordingly converted to alcohol, such as cyclopentanol, 1,2-propanediol, ethanol and so on. Effects of nickel loading amount, reaction temperature, reaction time and hydrogen pressure on conversion rate as well as selectivity for desired products were investigated in detail, which could provide possible alternatives for the upgrading of bio-oil.