Catalytic conversion of furfural from pyrolysis of sunflower seed hulls for producing bio-based furfuryl alcohol

Abstract

Clean production of furfuryl alcohol, an industrial product used worldwide, is presented using as a raw material sunflower seed hulls, an abundant agro-industrial waste. The method involves two steps. Firstly, a fast pyrolysis of pre-treated hulls, performed washing with aqueous solutions of phosphoric acid or zinc chloride, is carried out at 400 °C under a 200 mL/min of nitrogen flow, where a bio-oil rich in furfural is obtained. In the second stage, the catalytic hydrogenation of furfural is carried out, to obtain furfuryl alcohol over palladium supported on bio-chars obtained as side products of the hull pyrolysis. High catalytic performance for the hydrogenation of furfural to furfuryl alcohol under batch conditions at 110 °C and 0.4 MPa of hydrogen is reached. A preliminary industrial scale process is presented using the laboratory data for the technical evaluation. It is concluded that it is possible to obtain furfuryl alcohol from a renewable source consisting of sunflower seed hulls.