Title : Catalytic impact of Red Mud and metal oxides on the upgrading of fast pyrolysis vapour of biomass
Abstract:
Renewable bio-oil constitutes a more sustainable and long term solution to the world energy needs. Bio-oil is a complex mixture of oxygenated organic compounds derived from the depolymerisation of cellulose, hemicellulose, and lignin. Its high oxygen content, acidic nature, instability, and immiscibility with petroleum derived fuels make the bio-oil a low grade liquid fuel. Catalytic fast pyrolysis is the efficient way to remove these oxygenated compounds by converting them into useful products that fall into the fuel range or by selective conversion to valuable compounds. Red mud is a industrial solid waste residue formed during the production of alumina and is a complex mixture of oxides such as Fe2O3, Al2O3, TiO2, SiO2 and other minor inclusions. Thermal pre-treatment of Red Mud at 950 °C was found to be effective in catalysis, as during the thermal treatment unstable components (FeO(OH), α-AlO(OH) and hydrous aluminium silicates) of the initial Red Mud transformed into more stable oxide phases, resulting in a higher selectivity of pyrolysis products. Red Mud catalysis increased the yield of valuable chemicals, such as furfural and acidic compounds. Alkaline earth oxide promoted ketonisation reactions. Ketones are highly stable, higher energy and desirable molecules since they can easily couple with other bio-oil products (via aldol condensation and hydrogenation/alkylation) to create longer chain molecules that fall into the fuel range. Phenols yield was decreased in both of the catalysis. Catalysis by Red Mud and Alkaline earth oxide can provide signi?cant economic and ecological bene?ts. The effect of catalysts on the fast pyrolysis vapour upgrading was analysed by Pyrolysis-Gas chromatography-Mass spectrometry technique. X-ray powder diffraction (XRD), Scanning electron microscopy with Energy Dispersive X-ray analysis (SEM/EDX), IR-spectroscopy, Brunauer-Emmett-Teller (BET) and Thermogravimetric analysis (TGA) were applied for catalyst characterisation.
