Alkaline pyrolysis of anaerobic digestion residue with selective hydrogen production.

Hydrogen (H 2) production from biomass has attracted the research attention as it is renewable and clean. This work investigates the alkaline pyrolysis (AP) of corn stover digestate (CSD) with sodium hydroxide (NaOH) to promote the production of H 2 and suppress carbon dioxide (CO 2) at moderate conditions. It is observed that the H 2 production is affected by the mass ratio of CSD to NaOH and reaction temperature. The H 2 yield is enhanced from 1:1 to 1:2 ratio of CSD to NaOH (10.9–25.9 mmol g−1) with the purity of 81.21–84.98% at 500 °C, whereas a slight increase in H 2 production at 1:3 ratio of CSD to NaOH is observed which may attribute to the mass transfer matter. The possible mechanism of AP is identified. Through the thermogravimetric analysis (TGA), distributed activation energy model (DAEM) was applied which evidences the catalytic ability of NaOH via the reduced activation energies. • NaOH considerably enhanced H 2 production and suppressed CO 2 as a result of Na 2 CO 3. • High purity (~84%) and yield (~25 mmol g−1) was attained at 500 °C. • The possible reaction pathways of AP were identified. • DAEM was applied to study the kinetics of AP. • Activation energies were considerably declined in the presence of NaOH. [ABSTRACT FROM AUTHOR]