The impact of alkaline/hydrogen peroxide pretreatment on hydrogen and methane production from biomasses of different origin: The case of willow sawdust and date palm fibers

Abstract

The present study focuses on the use of two different agricultural residues of lignocellulosic origin, i.e. willow sawdust (WS) and date palm fibers (DPF), as substrates for batch methane and hydrogen production. Prior to use for biofuels production, the substrates were pretreated using dilute solutions of sodium hydroxide, hydrogen peroxide or combinations of the above. The results showed that in almost all cases the pretreatment enhanced biofuels production, leading to remarkably high yields compared with the untreated substrates. Specifically, WS optimal yields were 200.40 ± 13.49 L CH4/kg of raw TS (94% increase) and 102.43 ± 12.25 L H2 per kg of raw TS (345% increase) and they were observed after the addition of the mixture of the two chemical agents for 24 h at 80 °C. Also, DPF optimal yields were 211.55 ± 16.18 L CH4/kg raw TS (62% increase) and 110.50 ± 7.97 L H2/kg of raw TS (310% increase) while they were achieved when hydrogen peroxide was added to the substrate first for 24 h at 80 °C and then sodium hydroxide for another 24 h at 80 °C.