Storage of Food Waste: Variations of Physical–Chemical Characteristics and Consequences on Biomethane Potential

• Published in: Waste and biomass valorization Vol. 11; no. 6; pp. 2441 - 2454
• Main Authors: Degueurce, Axelle, Picard, Sylvie, Peu, Pascal, Trémier, Anne
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.06.2020; Springer Nature B.V
• Subjects: Ammonia; Anaerobic digestion; Biogas; Carbon dioxide; Engineering; Environment; Environmental Engineering/Biotechnology; Ethanol; Food; Food waste; Gases; Industrial Pollution Prevention; Lactic acid; Liquefied gases; Liquid phases; Methane; Original Paper; Renewable and Green Energy; Substrates; Waste Management/Waste Technology; Kitchen waste; Gaseous emissions; Lactic acid; Biomethane potential; Anaerobic digestion
• ISSN: 1877-2641; 1877-265X
• DOI: 10.1007/s12649-018-00570-0

Food waste (FW) storage influences its physical–chemical characteristics and anaerobic digestion (AD) performance. In this work we present the results of two weeks long experiment where two types of FW were stored in dedicated cells (10 L and 300 L). Air was evenly flushed on the top surface of the substrates and then analyzed to identify and quantify possible gaseous emissions. Solid and liquid fractions were also periodically sampled and analyzed for total solid, volatile solid, ammonia and VFA contents. Results showed that storage initiated a hydrolysis process that modified the physical structure of FW, leading to the production of gases (CH 4 , CO 2 and ethanol) and a partly liquefied FW. Depending on experimental conditions, a fraction between 61 and 70% of the initial substrate remained solid at the end of the storage period. In the liquid phase, a large proportion of lactic acid was measured with maximum contents of 5.9 and 14.8 g/kg vs for the small-scale experiments with two different FW types and 3.0 g/kg vs for the large-scale experiment, leading to inhibition of the biomethane potential (BMP) tests. In conclusion, this work showed that when storage of FW is needed before AD, the optimal time recommended to keep a high methane yield is one week.