Aragón-Briceño, C, Ross, AB and Camargo-Valero, MA orcid.org/0000-0003-2962-1698 (2017) Evaluation and comparison of product yields and bio-methane potential in sewage digestate following hydrothermal treatment. Applied Energy, 208. pp. 1357-1369. ISSN 0306-2619
Abstract
In recent years, sewage sludge management has been considered one of the biggest concerns in the wastewater industry for the environmental impacts linked to its high content of pollutants. Hydrothermal Treatments are a good option for converting wet biomass such as sewage sludge into high-value products. The digestate following anaerobic treatment of sewage sludge has high organic matter content despite initial conversion into biogas and is normally spread on land or composted; however, this does not fully harness its full potential. In fact, the digestate is a potential feedstock for hydrothermal processing and this route may produce higher value products. In this study, the potential of hydrothermal processing as a novel alternative to treat the digestate has been be evaluated. The effect of temperatures is evaluated with respect to product yields, biomethane potential and solubilisation of organic carbon. Three different temperatures were evaluated: 160, 220 and 250 °C at 30 min reaction time. The hydrochar yields obtained were 73.42% at 220 °C, 68.79% at 250 °C and 56.75% at 160 °C treatment. The solubilisation of carbon was increased from 4.62% in the raw feedstock to 31.68%, 32.56% and 30.48% after thermal treatments at 160, 220 and 250 °C, respectively. The thermal treatment enhanced the potential methane production in all products up to 58% for both, the whole fraction (hydrochar + processed water) and processed waters. The Boyle’s and Buswell’s equation were used to calculate theoretical methane yields for all hydrothermal products. Theoretical methane yields were compare with experimental data from biomethane potential (BMP) tests and it was found that the Boyle’s equation had closer agreement to BMP values.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2017, Published by Elsevier Ltd. This is an author produced version of a paper published in Applied Energy. Uploaded in accordance with the publisher's self-archiving policy. This manuscript version is made available under the Creative Commons CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/ |
Keywords: | hydrochar; hydrothermal process; sewage sludge; process waters; digestate |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Chemical & Process Engineering (Leeds) The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Civil Engineering (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 15 Sep 2017 09:29 |
Last Modified: | 08 Aug 2019 15:01 |
Status: | Published |
Publisher: | Elsevier |
Identification Number: | 10.1016/j.apenergy.2017.09.019 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:121228 |