Hydrothermal carbonization of sewage digestate at wastewater treatment works: Influence of solid loading on characteristics of hydrochar, process water and plant energetics

RENEWABLE ENERGY

卷:157

Article

Aragon-Briceno, C. I.^1,5  Grasham, O.²  Ross, A. B.³  Dupont, V.³  Camargo-Valero, M. A.^1,4 

[1] Univ Leeds, Sch Civil Engn, BioResource Syst Res Grp, Leeds LS2 9JT, W Yorkshire, England

[2] Univ Leeds, Fac Engn, Ctr Doctoral Training Bioenergy, Leeds LS2 9JT, W Yorkshire, England

[3] Univ Leeds, Sch Chem & Proc Engn, Leeds LS2 9JT, W Yorkshire, England

[4] Univ Nacl Colombia, Dept Ingn Quim, Campus Nubia, Manizales, Colombia

[5] Univ Twente, Drienerlolaan 5, NL-7522 NB Enschede, Netherlands

关键词: Digestate;    Hydrothermal carbonization;    Sewage sludge;    Process waters;   

DOI  :  10.1016/j.renene.2020.05.021

来源: Elsevier

【 摘 要 】

Nowadays the sludge treatment is recognized as a priority challenge to the wastewater industry due to the increasing volumes produced and tighter environmental controls for its safe disposal. The most costeffective process for sewage sludge is the anaerobic digestion but raw digestate still contains high levels of organic matter that can be transformed into an energy carrier by using processes like Hydrothermal Carbonization (HTC). In this work, the influence of solid loading (2.5, 5.0, 10.0, 15.0, 17.5, 20.0, 25.0 and 30.0% solids w/w) on the composition of hydrochar and process water was studied, together with an evaluation of product yields, solubilisation of organic carbon and biomethane potential of process waters from HTC processing (250 degrees C, 30-minute reaction time). Hydrochar yields ranged from 64 to 88%wt, whereas the concentration of soluble organic carbon increased from 2.6 g/L in the raw digestate to a maximum of 72.3 g/L in the process water following HTC at the highest solid loading. Furthermore, process modelling with Aspen Plus shows that the integration of AD with HTC to wastewater treatment works provides a significant positive energy balance when process water and hydrochar are considered as fuel sources for cogeneration. (C) 2020 The Authors. Published by Elsevier Ltd.

【 授权许可】

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