Alkaline pyrolysis of anaerobic digestion residue with selective hydrogen production

Abstract

Hydrogen (H2) 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 H2 and suppress carbon dioxide (CO2) at moderate conditions. It is observed that the H2 production is affected by the mass ratio of CSD to NaOH and reaction temperature. The H2 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 H2 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.