Effect of pasteurisation on methane yield from food waste and other substrates in anaerobic digestion
Effect of pasteurisation on methane yield from food waste and other substrates in anaerobic digestion
The effect of pasteurisation and co-pasteurisation on biochemical methane potential values in anaerobic digestion (AD) was studied. Pasteurisation prior to digestion in a biogas plant is a common hygienisation method for organic materials which contain or have been in contact with animal by-products. Tests were carried out on food waste, slaughterhouse waste, animal blood, cattle slurry, potato waste, card packaging and the organic fraction of municipal solid waste (OFMSW); pasteurisation at 70 °C for 1 h was applied. Pasteurisation had increased the methane yields of blood (+15%) and potato waste (+12%) only, which both had a low content of structural carbohydrates (hemi-cellulose and cellulose) but a particularly high content of either non-structural carbohydrates such as starch (potato waste) or proteins (blood). With food waste, card packaging and cattle slurry, pasteurisation had no observable impact on the methane yield. Slaughterhouse waste and OFMSW yielded less methane after pasteurisation in the experiments (but statistical significance of the difference between pasteurised and unpasteurised slaughterhouse waste or OFMSW was not confirmed in this work). It is concluded that pasteurisation can positively impact the methane yield of some specific substrates, such as potato waste, where heat-treatment may induce gelatinisation with release of the starch molecules. For most substrates, however, pasteurisation at 70 °C is unlikely to increase the methane yield. It is unlikely to improve biodegradability of lignified materials, and it may reduce the methane yield from substrates which contain high contents of volatile components. Furthermore, in this experimental study, the obtained methane yield was unaffected by whether the substrates were pasteurised individually and then co-digested or co-pasteurised as a mixture before batch digestion.
anaerobic digestion, animal by-products regulation, food waste, methane yield, pasteurisation
1-22
Zhang, Yue
69b11d32-d555-46e4-a333-88eee4628ae7
Kusch-Brandt, Sigrid
d48e7631-618c-45a2-9db4-0dbdd9701f97
Heaven, Sonia
f25f74b6-97bd-4a18-b33b-a63084718571
Banks, Charles
d3196d6c-9a51-4f2f-b257-3d75e9a11cea
November 2020
Zhang, Yue
69b11d32-d555-46e4-a333-88eee4628ae7
Kusch-Brandt, Sigrid
d48e7631-618c-45a2-9db4-0dbdd9701f97
Heaven, Sonia
f25f74b6-97bd-4a18-b33b-a63084718571
Banks, Charles
d3196d6c-9a51-4f2f-b257-3d75e9a11cea
Zhang, Yue, Kusch-Brandt, Sigrid, Heaven, Sonia and Banks, Charles
(2020)
Effect of pasteurisation on methane yield from food waste and other substrates in anaerobic digestion.
Processes, 8 (11), , [1351].
(doi:10.3390/pr8111351).
Abstract
The effect of pasteurisation and co-pasteurisation on biochemical methane potential values in anaerobic digestion (AD) was studied. Pasteurisation prior to digestion in a biogas plant is a common hygienisation method for organic materials which contain or have been in contact with animal by-products. Tests were carried out on food waste, slaughterhouse waste, animal blood, cattle slurry, potato waste, card packaging and the organic fraction of municipal solid waste (OFMSW); pasteurisation at 70 °C for 1 h was applied. Pasteurisation had increased the methane yields of blood (+15%) and potato waste (+12%) only, which both had a low content of structural carbohydrates (hemi-cellulose and cellulose) but a particularly high content of either non-structural carbohydrates such as starch (potato waste) or proteins (blood). With food waste, card packaging and cattle slurry, pasteurisation had no observable impact on the methane yield. Slaughterhouse waste and OFMSW yielded less methane after pasteurisation in the experiments (but statistical significance of the difference between pasteurised and unpasteurised slaughterhouse waste or OFMSW was not confirmed in this work). It is concluded that pasteurisation can positively impact the methane yield of some specific substrates, such as potato waste, where heat-treatment may induce gelatinisation with release of the starch molecules. For most substrates, however, pasteurisation at 70 °C is unlikely to increase the methane yield. It is unlikely to improve biodegradability of lignified materials, and it may reduce the methane yield from substrates which contain high contents of volatile components. Furthermore, in this experimental study, the obtained methane yield was unaffected by whether the substrates were pasteurised individually and then co-digested or co-pasteurised as a mixture before batch digestion.
Text
Accepted manuscript Methane Yield Pastuerisation
- Accepted Manuscript
Text
processes-08-01351
- Version of Record
More information
Submitted date: 10 September 2020
Accepted/In Press date: 23 October 2020
e-pub ahead of print date: 26 October 2020
Published date: November 2020
Additional Information:
Funding Information:
Funding: This research received funding from the Department for Environment, Food and Rural Affairs, London, UK (Defra) under contract WR0212, which is gratefully acknowledged.
Publisher Copyright:
© 2020, MDPI AG. All rights reserved.
Keywords:
anaerobic digestion, animal by-products regulation, food waste, methane yield, pasteurisation
Identifiers
Local EPrints ID: 444609
URI: http://eprints.soton.ac.uk/id/eprint/444609
ISSN: 2227-9717
PURE UUID: b35d9eb7-dcee-40cc-b259-b70af3811e89
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Date deposited: 27 Oct 2020 19:55
Last modified: 17 Mar 2024 02:56
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Author:
Sigrid Kusch-Brandt
Author:
Charles Banks
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