Towards energy neutral microalgae-based wastewater treatment plants

The aim of this study was to assess the energy balance of a hypothetical microalgae-based wastewater treatment plant (10,000 PE) located in the Mediterranean Region, where harvested microalgal biomass and primary sludge would be co-digested to produce biogas and bioenergy. The assessment was based o...

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Detalhes bibliográficos
Autores: Passos, Fabiana Lopes del Rei|||0000-0001-7501-988X, Gutiérrez Martínez, Raquel, Uggetti, Enrica|||0000-0001-6919-485X, Garfi, Marianna|||0000-0001-9234-5580, García Serrano, Joan|||0000-0003-1258-8174, Ferrer Martí, Ivet|||0000-0002-4568-4843
Tipo de documento: artigo
Data de publicação:2017
País:España
Recursos:Universitat Politècnica de Catalunya (UPC)
Repositório:UPCommons. Portal del coneixement obert de la UPC
Idioma:inglês
OAI Identifier:oai:upcommons.upc.edu:2117/112489
Acesso em linha:https://hdl.handle.net/2117/112489
https://dx.doi.org/10.1016/j.algal.2017.11.006
Access Level:Acceso aberto
Palavra-chave:Biogas
Wastewater treatment and reuse
Anaerobic co-digestion
Energy balance
High rate algal pond
Microalgal biomass
Wastewater
Biogàs
Aigües residuals -- Aprofitament -- Plantes de tractament
Àrees temàtiques de la UPC::Energies::Recursos energètics renovables::Biogàs
Àrees temàtiques de la UPC::Desenvolupament humà i sostenible::Enginyeria ambiental::Tractament de l'aigua
Descrição
Resumo:The aim of this study was to assess the energy balance of a hypothetical microalgae-based wastewater treatment plant (10,000 PE) located in the Mediterranean Region, where harvested microalgal biomass and primary sludge would be co-digested to produce biogas and bioenergy. The assessment was based on experimental results obtained over one year in pilot high rate algal ponds followed by anaerobic digesters for biogas production from harvested microalgal biomass and primary sludge. The energy balance compared four scenarios: 1) anaerobic co-digestion of microalgal biomass and primary sludge, and cogeneration from biogas in a combined with heat and power (CHP) unit; 2) co-digestion with thermal pretreatment of microalgal biomass, and cogeneration from biogas in a CHP unit; 3) co-digestion and heat generation from biogas in a boiler; and 4) co-digestion with thermal pretreatment of microalgal biomass, and heat generation from biogas in a boiler. According to the results, when biogas was used to cogenerate electricity and heat (scenarios 1 and 2), the electricity balance was always positive, and the best results were obtained with pretreated microalgal biomass (scenario 2). Similarly, the heat balance was always positive when biomass was thermally pretreated (scenario 2). On the other hand, when biogas was only used to produce heat (scenarios 3 and 4), heat requirements were covered during the whole year. The sensibility analysis of the scenarios with pretreatment (2 and 4) confirmed that the microalgae-based WWTP would be energy neutral or even net energy producer.