Upgrading of bio-oil using novel catalysts

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Keywords: Catalysis, bio-oil, biofuels, renewable energy.The quest for sustainable resources to meet the demands of a rapidly rising global population represents a major challenge. In the context of energy, despite significant growth in fossil fuel reserves, great uncertainties remain in the economics/environmental impact of their exploitation, and crucially ~65-80 % of such carbon resources cannot be burned without breaching the UNFCC targets for a 2 degrees C increase in mean global temperature relative to the pre-industrial level. Biofuels are critical in helping the UK meet its commitments of 15 % renewable energy by 2020, and greenhouse gas (GHG) emission reductions of 34 % by 2020 and 80 % by 2050 (cf. 1990 levels). They also represent drop-in fuels able to utilise existing pipeline and filling station distribution networks. Bio-oil, a form of crude oil produced from biomass via processes such as pyrolysis or hydrothermal liquefaction, will diversify UK energy, thus improving energy security and boosting agriculture, forestry, waste management and transport sectors, as well as local economies through decentralized production. However, crude bio-oil contains oxygenated molecules and requires substantial 'upgrading' to render it a suitable liquid transportation fuel. Crude bio-oils are complex and difficult to work with, as they contain a large range of different chemical components. The first step to understanding how to design a catalyst to upgrade and deoxygenate them may be better achieved by the study of model compounds typical of constituent components of real bio-oil. In order to design a reactor to process them, it is necessary to determine a kinetic model for the upgrading process. Catalyst deactivation is also a significant issue, and the use of supercritical fluids may be employed to delay coking of the catalyst and extend its lifetime. Specific objectives of the project are:- The upgrading of bio-oils using catalytic reactors such as autoclave and fixed bed. - Selection of model compounds to study, e.g. alcohol, acid, aldehyde.- Optimisation of process conditions such as temperature, pressure, residence time.- Reaction mechanism and kinetic modelling of model compounds/products.- Effect of catalyst type.- Comparison of batch, flow, sub and supercritical reaction conditions upon the product distribution.- Limited tests with real bio oil under similar conditions to model compounds. Determination of degree of deoxygenation of product oil.