Application of microbial electrolysis cells to treat spent yeast from an alcoholic fermentation. (January 2016)

• Record Type: Journal Article
• Authors: Sosa-Hernández, Ornella; Popat, Sudeep C.; Parameswaran, Prathap; Alemán-Nava, Gibrán Sidney; Torres, César I.; Buitrón, Germán; Parra-Saldívar, Roberto
• Is Part Of: Bioresource technology. Volume 200(2016)
• Page Start: 342
• Page End: 349
• Publication Date: 2016-01
• Subjects: Spent yeast -- Microbial electrolysis cell -- Coulombic efficiency -- COD removal -- 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.2015.10.053
• Languages: English
• ISSNs: 0960-8524

Abstract

Highlights: Electron recovery from spent yeast was improved by ethanol addition in a MEC. Current density and hydrogen production increased with higher organic loads. Spent yeast treatment was mostly fermentative explaining the drift of electrons. Ethanol and experimental conditions could have induced spent yeast autolysis. This is the first study, as far as we know, of spent yeast treated in a MEC. Abstract: Spent yeast (SY), a major challenge for the brewing industry, was treated using a microbial electrolysis cell to recover energy. Concentrations of SY from bench alcoholic fermentation and ethanol were tested, ranging from 750 to 1500 mg COD/L and 0 to 2400 mg COD/L respectively. COD removal efficiency (RE), coulombic efficiency (CE), coulombic recovery (CR), hydrogen production and current density were evaluated. The best treatment condition was 750 mg COD/L SY + 1200 mg COD/L ethanol giving higher COD RE, CE, CR (90 ± 1%, 90 ± 2% and 81 ± 1% respectively), as compared with 1500 mg COD/L SY (76 ± 2%, 63 ± 7% and 48 ± 4% respectively); ethanol addition was significantly favorable ( p value = 0.011), possibly due to electron availability and SY autolysis. 1500 mg COD/L SY + 1200 mg COD/L ethanol achieved higher current density (222.0 ± 31.3 A/m 3 ) and hydrogen production (2.18 ± 0.66 L H 2 / day / L Reactor ) but with lower efficiencies (87 ± 2% COD RE, 71.0±.4% CE). Future work should focus on electron sinks, acclimation and optimizing SY breakdown.