Energy and phosphorous recovery through hydrothermal carbonization of digested sewage sludge

This work evaluates the potential of hydrothermal carbonization (HTC) to valorize the digestate derived from the anaerobic digestion of sewage sludge into useful materials for P and energy recovery. The hydrothermal treatment of digestate at 180–240 ºC did not lead to high-rank hydrochars. On the ot...

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Detalles Bibliográficos
Autores: Marin-Batista, J. D., Fernández Mohedano, Ángel, Rodríguez Jiménez, Juan José, Rubia Romero, María de los Ángeles de la
Tipo de recurso: artículo
Fecha de publicación:2020
País:España
Institución:Universidad Autónoma de Madrid
Repositorio:Biblos-e Archivo. Repositorio Institucional de la UAM
Idioma:inglés
OAI Identifier:oai:repositorio.uam.es:10486/696899
Acceso en línea:http://hdl.handle.net/10486/696899
https://dx.doi.org/10.1016/j.wasman.2020.03.004
Access Level:acceso abierto
Palabra clave:Anaerobic digestion
Digestate
Hydrothermal carbonization
Phosphorus recovery
Química
Descripción
Sumario:This work evaluates the potential of hydrothermal carbonization (HTC) to valorize the digestate derived from the anaerobic digestion of sewage sludge into useful materials for P and energy recovery. The hydrothermal treatment of digestate at 180–240 ºC did not lead to high-rank hydrochars. On the other hand, inorganic P concentration did not change with the temperature, while as the carbonization temperature increased, the organic P retention yield in hydrochar became lower, increasing the total P in the process water obtained at the highest temperature, up to 25.3%. P recovery from acid leaching of the hydrochar obtained at 180 ºC, via precipitation with CaO at pH up to 9, led to a brown solid precipitate with total P content close to 42 mg g-1 , in the range of low grade phosphorus ores. Moreover, acid leaching reduced by 50% the ash content, yielding lignite-like upgraded hydrochars with higher heating values in the range of 20.5–23.1 MJ kg-1 , fairly interesting as solid fuels. Anaerobic digestion of the process water enabled additional energy recovery in form of biogas (325 and 279 mL CH4 g-1 VS -at standard temperature and pressure; STP- from the process water resulting at 180 and 210 ºC, respectively)