Study of methods for the improvement of the anaerobic digestion of lipids and long chain fatty acids

Anaerobic digestion is a biochemical process that transforms diverse categories of biomass feedstock to renewable energy, in the form of methane, and contributes to resources conservation and greenhouse gases emission mitigation. Lipid-rich waste and wastewaters have a high energy potential, however...

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Autor: Affes Salah, Rim
Formato: tesis doctoral
Estado:Versión publicada
Fecha de publicación:2013
País:España
Recursos:CBUC, CESCA
Repositorio:TDR. Tesis Doctorales en Red
OAI Identifier:oai:www.tdx.cat:10803/116545
Acesso em linha:http://hdl.handle.net/10803/116545
https://dx.doi.org/10.5821/dissertation-2117-94878
Access Level:acceso abierto
Palavra-chave:504
628
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repository_id_str
dc.title.none.fl_str_mv Study of methods for the improvement of the anaerobic digestion of lipids and long chain fatty acids
title Study of methods for the improvement of the anaerobic digestion of lipids and long chain fatty acids
spellingShingle Study of methods for the improvement of the anaerobic digestion of lipids and long chain fatty acids
Affes Salah, Rim
504
628
title_short Study of methods for the improvement of the anaerobic digestion of lipids and long chain fatty acids
title_full Study of methods for the improvement of the anaerobic digestion of lipids and long chain fatty acids
title_fullStr Study of methods for the improvement of the anaerobic digestion of lipids and long chain fatty acids
title_full_unstemmed Study of methods for the improvement of the anaerobic digestion of lipids and long chain fatty acids
title_sort Study of methods for the improvement of the anaerobic digestion of lipids and long chain fatty acids
dc.creator.none.fl_str_mv Affes Salah, Rim
author Affes Salah, Rim
author_facet Affes Salah, Rim
author_role author
dc.contributor.none.fl_str_mv Flotats i Ripoll, Xavier
Palatsi Civit, Jordi
Universitat Politècnica de Catalunya. Institut Universitari de Recerca en Ciència i Tecnologies de la Sostenibilitat
dc.subject.none.fl_str_mv 504
628
topic 504
628
description Anaerobic digestion is a biochemical process that transforms diverse categories of biomass feedstock to renewable energy, in the form of methane, and contributes to resources conservation and greenhouse gases emission mitigation. Lipid-rich waste and wastewaters have a high energy potential, however efficient methane recovery with conventional anaerobic digestion technology is not easy to achieve because of a wide assortment of operational problems mainly related to the accumulation of long chain fatty acids (LCFA), products of lipids hydrolysis, in the system. The objective of the present dissertation is to test and to evaluate new methodologies and strategies to improve the anaerobic digestion of high-strength lipid waste. In a preliminary approach, the suitability and the attractiveness of high-strength lipid wastes and slaughterhouse wastes for biogas production was confirmed, suffice to control the applied organic load. The obtained results reinforced the existing knowledge describing the flotation and wash-out of substrate/biomass and the inhibition phenomena affecting the microbial population, as the main process drawbacks. The results of studies submitting anaerobic reactors to increasing concentrations of lipids/LCFA underlined the importance of the adsorption of LCFA onto the microbial cell membrane as limiting factor, guiding further research to found new technical approaches in order to control the biomass-LCFA adsorption dynamics. The use of inorganic adsorbents to capture LCFA prior to the anaerobic digestion process or the application of sequential low-energy ultrasonic pulses in order to control the adsorption-desorption kinetics were tested with interesting results. However, the effectiveness of these strategies was limited by the proportion of inorganic adsorbent/LCFA and the cumulative damaging effect of ultrasonic treatment over biomass, respectively. Further studies are thus required to optimize the efficiency and the applicability of these strategies. Efficient conversion of complex high-strength lipid waste to methane was proved to be possible in a novel reactor system configuration combining saponification pre-treatment and digested solids recirculation to the anaerobic digestion process, to increase solids retention time. A start-up step consisting on pulse-feeding cycles of the fatty waste prior to the semi-continuous process promoted an adapted microbial community for LCFA mineralization. The feasibility of this system configuration for solid slaughterhouse fatty waste was evidenced at lab scale reactors, reaching organic matter removal efficiencies higher than 90%. The comparison of this configuration with systems without saponification or without digested solids recirculation confirmed the synergistic effect of both strategies. The use of high throughput sequencing approach (454-pyrosequencing) to characterize the evolution of the biodiversity and the phylogenetic structure of the microbial community during the operation of the tested configurations concluded that a selection of a defined functional acidogenic population (ß-oxidizers) was induced by substrate pretreatment. Contrary, the solids recirculation resulted in an enrichment of the methanogenic biodiversity, mainly of hydrogenotrophic archaea. Based on the satisfactory results obtained with the strategies studied in the present dissertation, it is expected that lipid-rich waste valorization will be a real alternative to increase renewable energy production through anaerobic digestion process.
publishDate 2013
dc.date.none.fl_str_mv 2013
2013
2013
dc.type.none.fl_str_mv info:eu-repo/semantics/doctoralThesis
info:eu-repo/semantics/publishedVersion
format doctoralThesis
status_str publishedVersion
dc.identifier.none.fl_str_mv http://hdl.handle.net/10803/116545
https://dx.doi.org/10.5821/dissertation-2117-94878
url http://hdl.handle.net/10803/116545
https://dx.doi.org/10.5821/dissertation-2117-94878
dc.language.none.fl_str_mv Inglés
language_invalid_str_mv Inglés
dc.rights.none.fl_str_mv http://creativecommons.org/licenses/by-nc-sa/3.0/es/
info:eu-repo/semantics/openAccess
rights_invalid_str_mv http://creativecommons.org/licenses/by-nc-sa/3.0/es/
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv 208 p.
application/pdf
application/pdf
dc.publisher.none.fl_str_mv Universitat Politècnica de Catalunya
publisher.none.fl_str_mv Universitat Politècnica de Catalunya
dc.source.none.fl_str_mv TDX (Tesis Doctorals en Xarxa)
reponame:TDR. Tesis Doctorales en Red
instname:CBUC, CESCA
instname_str CBUC, CESCA
reponame_str TDR. Tesis Doctorales en Red
collection TDR. Tesis Doctorales en Red
repository.name.fl_str_mv
repository.mail.fl_str_mv
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spelling Study of methods for the improvement of the anaerobic digestion of lipids and long chain fatty acidsAffes Salah, Rim504628Anaerobic digestion is a biochemical process that transforms diverse categories of biomass feedstock to renewable energy, in the form of methane, and contributes to resources conservation and greenhouse gases emission mitigation. Lipid-rich waste and wastewaters have a high energy potential, however efficient methane recovery with conventional anaerobic digestion technology is not easy to achieve because of a wide assortment of operational problems mainly related to the accumulation of long chain fatty acids (LCFA), products of lipids hydrolysis, in the system. The objective of the present dissertation is to test and to evaluate new methodologies and strategies to improve the anaerobic digestion of high-strength lipid waste. In a preliminary approach, the suitability and the attractiveness of high-strength lipid wastes and slaughterhouse wastes for biogas production was confirmed, suffice to control the applied organic load. The obtained results reinforced the existing knowledge describing the flotation and wash-out of substrate/biomass and the inhibition phenomena affecting the microbial population, as the main process drawbacks. The results of studies submitting anaerobic reactors to increasing concentrations of lipids/LCFA underlined the importance of the adsorption of LCFA onto the microbial cell membrane as limiting factor, guiding further research to found new technical approaches in order to control the biomass-LCFA adsorption dynamics. The use of inorganic adsorbents to capture LCFA prior to the anaerobic digestion process or the application of sequential low-energy ultrasonic pulses in order to control the adsorption-desorption kinetics were tested with interesting results. However, the effectiveness of these strategies was limited by the proportion of inorganic adsorbent/LCFA and the cumulative damaging effect of ultrasonic treatment over biomass, respectively. Further studies are thus required to optimize the efficiency and the applicability of these strategies. Efficient conversion of complex high-strength lipid waste to methane was proved to be possible in a novel reactor system configuration combining saponification pre-treatment and digested solids recirculation to the anaerobic digestion process, to increase solids retention time. A start-up step consisting on pulse-feeding cycles of the fatty waste prior to the semi-continuous process promoted an adapted microbial community for LCFA mineralization. The feasibility of this system configuration for solid slaughterhouse fatty waste was evidenced at lab scale reactors, reaching organic matter removal efficiencies higher than 90%. The comparison of this configuration with systems without saponification or without digested solids recirculation confirmed the synergistic effect of both strategies. The use of high throughput sequencing approach (454-pyrosequencing) to characterize the evolution of the biodiversity and the phylogenetic structure of the microbial community during the operation of the tested configurations concluded that a selection of a defined functional acidogenic population (ß-oxidizers) was induced by substrate pretreatment. Contrary, the solids recirculation resulted in an enrichment of the methanogenic biodiversity, mainly of hydrogenotrophic archaea. Based on the satisfactory results obtained with the strategies studied in the present dissertation, it is expected that lipid-rich waste valorization will be a real alternative to increase renewable energy production through anaerobic digestion process.DOCTORAT EN ENGINYERIA AMBIENTAL (Pla 2007)Universitat Politècnica de CatalunyaFlotats i Ripoll, XavierPalatsi Civit, JordiUniversitat Politècnica de Catalunya. Institut Universitari de Recerca en Ciència i Tecnologies de la Sostenibilitat201320132013info:eu-repo/semantics/doctoralThesisinfo:eu-repo/semantics/publishedVersion208 p.application/pdfapplication/pdfhttp://hdl.handle.net/10803/116545https://dx.doi.org/10.5821/dissertation-2117-94878TDX (Tesis Doctorals en Xarxa)reponame:TDR. Tesis Doctorales en Redinstname:CBUC, CESCAInglésL'accés als continguts d'aquesta tesi queda condicionat a l'acceptació de les condicions d'ús establertes per la següent llicència Creative Commons: http://creativecommons.org/licenses/by-nc-sa/3.0/es/http://creativecommons.org/licenses/by-nc-sa/3.0/es/info:eu-repo/semantics/openAccessoai:www.tdx.cat:10803/1165452026-06-14T12:46:07Z
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