Performance of mesophilic biohydrogen-producing cultures at thermophilic conditions. (September 2015)

• Record Type: Journal Article
• Authors: Gupta, Medhavi; Gomez-Flores, Maritza; Nasr, Noha; Elbeshbishy, Elsayed; Hafez, Hisham; Hesham El Naggar, M.; Nakhla, George
• Is Part Of: Bioresource technology. Volume 192(2015)
• Page Start: 741
• Page End: 747
• Publication Date: 2015-09
• Subjects: Co-fermentation -- Mesophilic -- Thermophilic -- Unacclimatized -- Hydrogen; Biomass -- Periodicals; Biomass energy -- Periodicals; Bioremediation -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Bioénergie -- Périodiques; Déchets agricoles -- Périodiques; Déchets industriels -- Périodiques; Déchets organiques -- Périodiques; Déchets (Combustible) -- Périodiques; 662.88
• DOI: 10.1016/j.biortech.2015.06.047
• Languages: English
• ISSNs: 0960-8524

Abstract

Highlights: Effect of temperature shock to mesophilic anaerobic digester sludge was assessed. Co-fermentation of starch, and cellulose was assessed. Mesophilic co-fermentation of starch and cellulose increased the H2 yield by 26%. Thermophilic co-fermentation did not show any enhancement in H2 yield. Higher overall rates at mesophilic conditions than thermophilic conditions. Abstract: In this study, batch tests were conducted to investigate the performance of mesophilic anaerobic digester sludge (ADS) at thermophilic conditions and estimate kinetic parameters for co-substrate fermentation. Starch and cellulose were used as mono-substrate and in combination as co-substrates (1:1 mass ratio) to conduct a comparative assessment between mesophilic (37 °C) and thermophilic (60 °C) biohydrogen production. Unacclimatized mesophilic ADS responded well to the temperature change. The highest hydrogen yield of 1.13 mol H2 /mol hexose was observed in starch-only batches at thermophilic conditions. The thermophilic cellulose-only yield (0.42 mol H2 /mol hexose) was three times the mesophilic yield (0.13 mol H2 /mol hexose). Interestingly, co-fermentation of starch–cellulose at mesophilic conditions enhanced the hydrogen yield by 26% with respect to estimated mono-substrate yields, while under thermophilic conditions no enhancement in the overall yield was observed. Interestingly, the estimated overall Monod kinetic parameters showed higher rates at mesophilic than thermophilic conditions.