Pyrolysis of biomass and biorefinery residual materials for production of advanced biofuels

Abstract

The work carried out throughout this project has helped to further advance the area of biomass pyrolysis for the production of bio-oil. During the early stage of the project, the focus was on investigating the effect of different processing parameters and feedstock composition on the pyrolysis products. A major part of this work involved studying the effect of pressure during conventional pyrolysis. Pyrolysis was also carried out on the residue which remained after the biomass acid hydrolysis process, this is primarily lignin. This investigation has shown that thermal treatment alone is not an adequate method for converting acid hydrolysis residue to valuable products. Following on from this work biomass hydropyrolysis with catalytic conditioning of the product vapours was investigated as a possible method of producing a high grade bio-oil and to increase the level of biomass conversion. For this work various Ni supported catalyst were utilised for vapour upgrading. Furthermore a study was carried out to examine the effect of hydrogen pressure during hydropyrolysis. This work looked at pressure ranging from ambient to 30 bar. At elevated pressure major improvements of the vapour composition were achieved. The resulting vapours in the presence of the Ni catalyst at 30 bar were highly deoxygenated and also contained no carboxylic acids. This investigation has shown that hydropyrolysis at elevated pressure has many advantages over conventional pyrolysis as a large amount of oxygen is removed from the bio-oil, thus increasing the stability of the product. Furthermore a large portion of the aromatic compounds were either fully or partially hydrogenated