Influence of red mud impregnation on the pyrolysis of oil palm biomass-EFB

Red mud which enriched with various metal oxides was impregnated into oil palm biomass-empty fruit bunch (EFB) to study its effect on pyrolysis product. During impregnation, most of the biomass inherent minerals (mainly K, Ca and Mg) were removed and simultaneously red mud compounds (mainly Fe, Al and Ti) were impregnated into EFB. Biomass impregnation of red mud derived compounds was enhanced by acid pretreatment. Pyrolysis of EFB impregnated with acid pre-treated red mud increased the bio-oil yield from 39 wt% for untreated EFB to 52 wt% at the expense of char and gas yield at 400 °C in a fixed-bed reactor. With the impregnation of red mud derived metal-ions, the bio-oil chemical groups distribution was altered and large amounts of sugar and furan compounds were produced. Therefore, red mud could be used as an alternative metal-ions source to selectively catalyse biomass pyrolysis for high value added chemical feedstock.