Thermophilic anaerobic digestion of cheese whey: Coupling H2 and CH4 production. (October 2015)

• Record Type: Journal Article
• Authors: Fernández, C.; Cuetos, M.J.; Martínez, E.J.; Gómez, X.
• Is Part Of: Biomass and bioenergy. Volume 81(2015:Oct.)
• Page Start: 55
• Page End: 62
• Publication Date: 2015-10
• Subjects: Cheese whey -- Hydrogen -- Thermophilic anaerobic digestion -- Biogas production -- 1H NMR -- FTIR; Biomass energy -- Periodicals; Biomass -- Periodicals; Energy-Generating Resources -- Periodicals; Bioénergie -- Périodiques; 333.9539
• DOI: 10.1016/j.biombioe.2015.05.024
• Languages: English
• ISSNs: 0961-9534

Abstract

Abstract: The thermophilic anaerobic digestion of cheese whey was evaluated using a single and two stage configuration (H2 –CH4 ) in a sequencing batch reactor (SBR). The single stage process presented stable performance with a specific methane production (SMP) of 314.5 ± 6.6 L CH4 kg −1 CODfeed (Chemical oxygen demand) at a hydraulic retention time (HRT) of 8.3 days. On the contrary, the two stage process presented instabilities at an HRT of 12.5 days with acid accumulation being observed in the methanogenesis phase at an earlier stage. This behaviour was indicative of process inhibition by high concentrations of sodium and potassium ions as a consequence of pH control during the H2 producing stage. In spite of this phenomenon, this condition attained the highest SMP value (340.4 ± 40 L CH4 kg −1 CODfeed ). The performance of the anaerobic digestion process was also analysed by means of Fourier transform infrared (FTIR) and 1 H nuclear magnetic resonance ( 1 H NMR) spectroscopy. The two stage process showed higher content in triacylglycerol groups probably associated with changes in archaeal lipid complexes as a microbial response to a higher salinity environment. Highlights: Digestion of cheese whey at thermophilic conditions was successful at an HRT of 8.3 d. Two-stage process (H2 – CH4 ) was affected by salinity problems due to pH regulation. Methane yield was higher in two-stage process than in single-stage at an HRT of 25 d. VFA build-up was observed in the methanogenic reactor with two-stage configuration.