Hydrogen-methane production from pulp & paper sludge and food waste by mesophilic–thermophilic anaerobic co-digestion

• Published in: International journal of hydrogen energy Vol. 38; no. 35; pp. 15055 - 15062
• Main Authors: Lin, Yunqin, Wu, Shubin, Wang, Dehan
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 22.11.2013; Elsevier
• Subjects: Alternative fuels. Production and utilization; Applied sciences; Co-digestion; Energy; Exact sciences and technology; Food waste; Fuels; Hydrogen; Methane; Pulp & paper sludge; Methane; Food waste; Hydrogen; Co-digestion; Pulp & paper sludge; Anaerobic digestion; Hydrogen production
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2012.01.051

The present study focused on the mesophilic anaerobic bio-hydrogen production from PPS (pulp & paper sludge) and FW (food waste), and the subsequent anaerobic digestion of the effluent for the methane production under thermophilic conditions by a two-stage process. The maximum hydrogen yield of 64.48 mL g−1 VSfed and methane yield of 432.3 mL g−1 VSfed were obtained when PPS and FW were applied with 1: 1 VS ratio as the feedstock. No VFA were cumulated in the reactor during the period of hydrogen - methane fermentation, as well as no NH3–N and Na+ inhibition were found in the process. 71%–87% removal efficiencies of SCOD were attained for hydrogen and methane co-production. pH 4.8–6.4 and alkalinity 794–3316 mg CaCO3 L−1 for H2 fermentation, as well as pH 6.5–8.8 and alkalinity 4165–4679 mg CaCO3 L−1 for CH4 fermentation, were achieved without any adjustment. This work showed that anaerobic co-digestion of PPS and FW for hydrogen-methane co-production was a stable, reliable and effective way for energy recovery and bio-solid waste stabilization by the two-stage mesophilic–thermophilic process. ► H2–CH4 co-production from PPS and MGWL was efficient by a two-stage process. ► Maximum H2 yield and CH4 yield were obtained with 1: 1 VS ratio. ► 71%–87% removal efficiencies of SCOD were attained for hydrogen-methane production. ► No VFA, NH3–N and Na+ inhibition were found in the process.