Biogas Production from Brewer's Yeast Using an Anaerobic Sequencing Batch Reactor

• Published in: Food technology and biotechnology Vol. 55; no. 2; pp. 187 - 196
• Main Authors: Zupancic, Gregor Drago, Panjicko, Mario, Zelic, Bruno
• Format: Journal Article
• Language: English
• Published: Croatia Sveuciliste U Zagrebu 01.06.2017; Sveuciliste u Zagrebu, Prehramheno-Biotehnoloski Fakultet; University of Zagreb Faculty of Food Technology and Biotechnology
• Subjects: Alternative energy sources; Anaerobic conditions; Anaerobic digestion; Anaerobic processes; ASBR; Batch reactors; Biogas; Biomass; Breweries; brewer’s yeast; Brewing; Brewing industry wastewaters; Cattle; Cattle feeds; Chemical oxygen demand; Degradability; Energy consumption; Energy resources; Energy value; Finishes; Food industry; Food processing industry; Load distribution; Loading rate; Market value; Organic loading; Original Scientific Papers; Oxygen demand; Physiological aspects; Production processes; Raw materials; Reactors; Refuse as fuel; Renewable energy sources; Saccharomyces cerevisiae; Sequencing batch reactor; Side effects; Wastewater; Wastewater treatment; Yeast; Slovenia; Croatia; anaerobic digestion; ASBR; brewer’s yeast; biogas
• ISSN: 1330-9862; 1334-2606
• DOI: 10.17113/ftb.55.02.17.5080

Renewable energy sources are becoming increasingly important in the beverage and food industries. In the brewing industry, a significant percentage of the used raw materials finishes the process as secondary resource or waste. The research on the anaerobic digestion of brewer's yeast has been scarce until recent years. One of the reasons for this is its use as a secondary resource in the food industry and as cattle feed. Additionally, market value of brewer's yeast is higher than its energy value. Due to the increase of energy prices, brewer's yeast has become of interest as energy substrate despite its difficult degradability in anaerobic conditions. The anaerobic co-digestion of brewer's yeast and anaerobically treated brewery wastewater was studied using a pilot-scale anaerobic sequencing batch reactor (ASBR) seeded with granular biomass. The experiments showed very good and stable operation with an organic loading rate of up to 8.0 kg/(m ·day), and with a maximum achieved organic loading rate of 13.6 kg/(m ·day) in a single cycle. A specific biogas productivity of over 0.430 m /kg of the total chemical oxygen demand (COD) inserted, and total COD removal efficiencies of over 90% were achieved. This study suggests that the brewer's yeast can be successfully digested in an ASBR without adverse effects on the biogas production from brewer's yeast/wastewater mixtures of up to 8% (by volume). By using the brewer's yeast in the ASBR process, the biogas production from brewery wastewater could be increased by 50%.