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Research article2015Peer reviewed

Comparison of pasteurization and integrated thermophilic sanitation at a full-scale biogas plant - Heat demand and biogas production

Grim, Johanna; Schnürer, Anna; Nordberg, Åke; Malmros, Peter

Abstract

Sanitation is required for biogas plants handling slaughterhouse and food waste according to EU legislation. The standard method is pasteurization at 70 degrees C for 60 min, but integrated thermophilic sanitation (ITS), requiring 52 degrees C for 10 h in the digester, has been approved by the Swedish Board of Agriculture. This work compares pasteurization and ITS regarding heat demand and biogas production, using a full-scale plant in Uppsala, Sweden, as a case study. The plant currently uses pasteurization and thermophilic (52 degrees C) digestion. The impact of pasteurization on biogas production and process performance was examined at laboratory-scale. The heat demand for pasteurization was surveyed at the full-scale plant, while for ITS a process design was developed and the heat demand was theoretically calculated. The results showed that pasteurization had no significant effect on process performance or biogas production. The heat demand of pasteurization was measured to be 1.92 +/- 0.29 MJ (kg VS)(-1) (64.7 kWh t(-1)), while ITS was calculated to require 1.04 MJ (kg VS)(-1) (35.1 kWh t(-1)). This represented 9% and 5% of biogas energy production, respectively. Changing sanitation method to ITS would hence reduce the heat demand at the plant by 46%, corresponding to annual savings of 4380 GJ (1.22 GWh). (C) 2014 Elsevier Ltd. All rights reserved.

Keywords

Anaerobic digestion; Sanitation; Pasteurization; Heat demand; Biogas production; Process performance

Published in

Energy
2015, Volume: 79, pages: 419-427
Publisher: PERGAMON-ELSEVIER SCIENCE LTD

        SLU Authors

        • Sustainable Development Goals

        SDG7 Ensure access to affordable, reliable, sustainable and modern energy for all
        SDG12 Ensure sustainable consumption and production patterns

        UKÄ Subject classification

        Energy Systems
        Microbiology
        Bioenergy

        Publication identifier

        DOI: https://doi.org/10.1016/j.energy.2014.11.028

        Permanent link to this page (URI)

        https://res.slu.se/id/publ/65874