Cellulose nanofibers from eucalyptus pulp and their coproduction with biobutanol through enzyme-mediated treatment
Nanocellulose has potential applications in various sectors ranging from biomedical to environmental fields. The possibility of developing a wide range of potential applications could be attributed to the abundance and sustainability of its resources. Even though this emerging biomaterial has many o...
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| Materyal Türü: | doctoralThesis |
| Dil: | İngilizce |
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2023
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| Online Erişim: | https://hdl.handle.net/20.500.12008/37054 |
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| _version_ | 1868890191832285184 |
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| author | Cebreiros, Florencia |
| author_browse | Cebreiros, Florencia |
| author_facet | Cebreiros, Florencia |
| author_role | author |
| collection | COLIBRI |
| dc.contributor.none.fl_str_mv | Cebreiros Florencia, Universidad de la República (Uruguay). Facultad de Ingeniería. |
| dc.creator.none.fl_str_mv | Cebreiros, Florencia |
| dc.date.none.fl_str_mv | 2023-05-10T17:29:41Z 2023-05-10T17:29:41Z 2023 |
| dc.format.none.fl_str_mv | 176 p. application/pdf |
| dc.identifier.none.fl_str_mv | Cebreiros, F. Cellulose nanofibers from eucalyptus pulp and their coproduction with biobutanol through enzyme-mediated treatment [en línea] Tesis de doctorado. Montevideo : Udelar. FI. IIQ, 2023. https://hdl.handle.net/20.500.12008/37054 |
| dc.language.none.fl_str_mv | en eng |
| dc.publisher.none.fl_str_mv | Udelar. FI. |
| dc.rights.none.fl_str_mv | info:eu-repo/semantics/openAccess Licencia Creative Commons Atribución - No Comercial - Sin Derivadas (CC - By-NC-ND 4.0) |
| dc.source.none.fl_str_mv | reponame:COLIBRI instname:Universidad de la República instacron:Universidad de la República |
| dc.subject.none.fl_str_mv | Nanocelulosa Biobutanol Eucalipto Enzimas Biorrefinería |
| dc.title.none.fl_str_mv | Cellulose nanofibers from eucalyptus pulp and their coproduction with biobutanol through enzyme-mediated treatment |
| dc.type.none.fl_str_mv | Tesis de doctorado info:eu-repo/semantics/doctoralThesis info:eu-repo/semantics/acceptedVersion |
| description | Nanocellulose has potential applications in various sectors ranging from biomedical to environmental fields. The possibility of developing a wide range of potential applications could be attributed to the abundance and sustainability of its resources. Even though this emerging biomaterial has many outstanding properties and high availability in nature, the extraction of them from renewable feedstocks such as lignocellulosic biomass or cellulosic materials is still a main challenge. Cellulose is a structural material and, due to its association with lignin and hemicellulose, it is rather resistant to decomposition. To achieve the extraction of nanocellulose, energy-intensive methods or the consumption of chemicals or costly enzymes are required for its processing, which limits the implementation of its large-scale processing. In this work, enzymatic pretreatment combined with mechanical fibrillation was proposed as an alternative strategy for the isolation of cellulose nanofibers (CNF) from eucalyptus cellulose pulp. The enzyme-mediated pretreatment allowed to relieve intrinsic recalcitrance of fibers by size reduction and partial degradation, promoting cellulose accessibility for subsequent CNF extraction. Depending on the type of enzyme used and the working conditions, the release of soluble sugars from the carbohydrate fractions (cellulose and xylan) results inevitable. When cellulase and/or xylanase complexes were used, extensive cellulose (up to 46%) and xylan (up to 85%) hydrolysis occurred, even for short reaction times (4 h). Thus, fermentable sugars such as glucose (20-40 g/L) and xylose (6-13 g/L) were available as coproducts. These fermentable sugars were recovered and completely converted to biobutanol and other solvents (up to 15 g/L) by microbial fermentation employing Clostridium strains for an integral exploitation of the raw material. Biobutanol is considered an attractive product since it has superior properties as a biofuel compared to bioethanol, as well as being an important chemical in different industries. When endoglucanase monocomponent was used, almost negligible carbohydrate degradation occurred (<5%), which limited fiber fragmentation and depolymerization for further mechanical processing. Two mechanical methods were evaluated for the extraction of CNF from enzymatically pretreated eucalyptus pulp. Ultrasonication demonstrated to be an effective mechanical method for CNF isolation from local eucalyptus pulp, allowing to achieve CNF extraction yields of up to 98% from cellulase-treated pulp. Physicochemical and microscopic characterization of extracted CNF revealed significant uniformity of sizes in the nanometer scale (531-992 nm) with diameters in the range of 3 to 10 nm. Highly transparent and flexible nanocellulosic films were produced, which results attractive for potential applications. However, considering that the industrial application of ultrasonication is still limited, ball milling treatment was investigated as an alternative mechanical method for CNF extraction. Ball milling allowed to obtain CNF suspensions at higher consistency, but the high solid concentrations limited the effectiveness of the CNF extraction process and lower extraction yields (up to 35%) were obtained compared to ultrasonication. A sequential ball milling treatment configuration (up to 5 stages) allowed to improve up to 48% the CNF extraction yield from cellulase-treated pulp. CNFs with diameters in the range of 4 to 14 nm and aspect ratios of 220-230 were obtained by ball milling treatment, with enhanced thermal properties and crystallinity. Flexible nanocellulosic films were produced, even though they were not highly transparent compared to ultrasonicated CNFs. In summary, this work highlights the feasibility of coproducing CNF and biobutanol as high value-added products using eucalyptus cellulose Kraft pulp from a local pulp mill. This work provided insights into the coproduction of biomaterials and value-added chemicals in a forestry biorefinery concept, which could increase the overall revenue of the process. In addition, it intends to contribute to the knowledge of new techniques for obtaining nanocellulose derived from renewable sources, and its potential application. |
| eu_rights_str_mv | openAccess |
| format | doctoralThesis |
| id | anni_ca01e84bd6a9a285ddd27e62cbfd83bd |
| identifier_str_mv | Cebreiros, F. Cellulose nanofibers from eucalyptus pulp and their coproduction with biobutanol through enzyme-mediated treatment [en línea] Tesis de doctorado. Montevideo : Udelar. FI. IIQ, 2023. |
| instacron_str | Universidad de la República |
| institution | Universidad de la República |
| instname_str | Universidad de la República |
| language | eng |
| language_invalid_str_mv | en |
| network_acronym_str | anni |
| network_name_str | oai-lr-anni |
| oai_identifier_str | oai:colibri.udelar.edu.uy:20.500.12008/37054 |
| publishDate | 2023 |
| publishDateSort | 2023 |
| publisher.none.fl_str_mv | Udelar. FI. |
| reponame_str | COLIBRI |
| repository.mail.fl_str_mv | |
| repository.name.fl_str_mv | |
| repository_id_str | |
| rights_invalid_str_mv | Licencia Creative Commons Atribución - No Comercial - Sin Derivadas (CC - By-NC-ND 4.0) |
| spelling | Cellulose nanofibers from eucalyptus pulp and their coproduction with biobutanol through enzyme-mediated treatmentCebreiros, FlorenciaNanocelulosaBiobutanolEucaliptoEnzimasBiorrefineríaNanocellulose has potential applications in various sectors ranging from biomedical to environmental fields. The possibility of developing a wide range of potential applications could be attributed to the abundance and sustainability of its resources. Even though this emerging biomaterial has many outstanding properties and high availability in nature, the extraction of them from renewable feedstocks such as lignocellulosic biomass or cellulosic materials is still a main challenge. Cellulose is a structural material and, due to its association with lignin and hemicellulose, it is rather resistant to decomposition. To achieve the extraction of nanocellulose, energy-intensive methods or the consumption of chemicals or costly enzymes are required for its processing, which limits the implementation of its large-scale processing. In this work, enzymatic pretreatment combined with mechanical fibrillation was proposed as an alternative strategy for the isolation of cellulose nanofibers (CNF) from eucalyptus cellulose pulp. The enzyme-mediated pretreatment allowed to relieve intrinsic recalcitrance of fibers by size reduction and partial degradation, promoting cellulose accessibility for subsequent CNF extraction. Depending on the type of enzyme used and the working conditions, the release of soluble sugars from the carbohydrate fractions (cellulose and xylan) results inevitable. When cellulase and/or xylanase complexes were used, extensive cellulose (up to 46%) and xylan (up to 85%) hydrolysis occurred, even for short reaction times (4 h). Thus, fermentable sugars such as glucose (20-40 g/L) and xylose (6-13 g/L) were available as coproducts. These fermentable sugars were recovered and completely converted to biobutanol and other solvents (up to 15 g/L) by microbial fermentation employing Clostridium strains for an integral exploitation of the raw material. Biobutanol is considered an attractive product since it has superior properties as a biofuel compared to bioethanol, as well as being an important chemical in different industries. When endoglucanase monocomponent was used, almost negligible carbohydrate degradation occurred (<5%), which limited fiber fragmentation and depolymerization for further mechanical processing. Two mechanical methods were evaluated for the extraction of CNF from enzymatically pretreated eucalyptus pulp. Ultrasonication demonstrated to be an effective mechanical method for CNF isolation from local eucalyptus pulp, allowing to achieve CNF extraction yields of up to 98% from cellulase-treated pulp. Physicochemical and microscopic characterization of extracted CNF revealed significant uniformity of sizes in the nanometer scale (531-992 nm) with diameters in the range of 3 to 10 nm. Highly transparent and flexible nanocellulosic films were produced, which results attractive for potential applications. However, considering that the industrial application of ultrasonication is still limited, ball milling treatment was investigated as an alternative mechanical method for CNF extraction. Ball milling allowed to obtain CNF suspensions at higher consistency, but the high solid concentrations limited the effectiveness of the CNF extraction process and lower extraction yields (up to 35%) were obtained compared to ultrasonication. A sequential ball milling treatment configuration (up to 5 stages) allowed to improve up to 48% the CNF extraction yield from cellulase-treated pulp. CNFs with diameters in the range of 4 to 14 nm and aspect ratios of 220-230 were obtained by ball milling treatment, with enhanced thermal properties and crystallinity. Flexible nanocellulosic films were produced, even though they were not highly transparent compared to ultrasonicated CNFs. In summary, this work highlights the feasibility of coproducing CNF and biobutanol as high value-added products using eucalyptus cellulose Kraft pulp from a local pulp mill. This work provided insights into the coproduction of biomaterials and value-added chemicals in a forestry biorefinery concept, which could increase the overall revenue of the process. In addition, it intends to contribute to the knowledge of new techniques for obtaining nanocellulose derived from renewable sources, and its potential application.La nanocelulosa tiene aplicaciones potenciales en varios sectores que van desde el campo biomédico hasta el medioambiental. La posibilidad de desarrollo de una amplia gama de aplicaciones potenciales se ve favorecida por la abundancia y sostenibilidad de los recursos necesarios. Aunque este biomaterial emergente presenta propiedades excepcionales y alta disponibilidad en la naturaleza, su extracción a partir de materias primas renovables como la biomasa lignocelulósica o los materiales celulósicos sigue siendo un desafío importante. La celulosa es un material estructural y, debido a su interacción con la lignina y la hemicelulosa, resulta ser bastante resistente a la descomposición. Para lograr la extracción de nanocelulosa, se requieren métodos energéticamente intensivos o el consumo de productos químicos o enzimas costosas, lo que limita la implementación de su procesamiento a gran escala. En este trabajo, se propuso una combinación de pretratamiento enzimático seguido de fibrilación mecánica como estrategia alternativa para la extracción de nanofibras de celulosa (CNF del inglés cellulose nanofibers) a partir de pulpa de celulosa Kraft de eucalipto de una planta de celulosa local. El pretratamiento mediado por enzimas permitió disminuir la recalcitrancia intrínseca de las fibras mediante reducción del tamaño y degradación parcial, promoviendo la accesibilidad de la celulosa para la posterior extracción de CNF. Según el tipo de enzima utilizada y las condiciones de trabajo, la liberación de azúcares solubles de las fracciones de carbohidratos (celulosa y hemicelulosa) resultó inevitable. Cuando se utilizaron complejos de celulasa y/o xilanasa, se alcanzó una extensiva hidrólisis de celulosa (hasta 46%) y xilano (hasta 85%), incluso para tiempos de reacción cortos (4 h). Por lo tanto, azúcares fermentables como glucosa (20-40 g/L) y xilosa (6-13 g/L) resultaron disponibles como coproductos. Estos azúcares fermentables fueron recuperados y convertidos completamente a biobutanol y otros solventes (hasta 15 g/L) por fermentación microbiana empleando cepas del género Clostridium para un completo aprovechamiento de la materia prima. El biobutanol es considerado un compuesto atractivo ya que tiene propiedades superiores como biocombustible en comparación con el bioetanol, además de ser un químico importante en diferentes industrias. Cuando se utilizó endoglucanasa pura, la degradación de carbohidratos resultó baja (<5%), lo que limitó la fragmentación y la depolimerización de las fibras de celulosa para su posterior procesamiento mecánico. Dos métodos mecánicos fueron evaluados para la extracción de CNF a partir de pulpa de eucalipto pretratada enzimáticamente. El método de ultrasonicación demostró ser eficaz para el aislamiento de CNF de la pulpa de eucalipto local, permitiendo alcanzar rendimientos de extracción de CNF de hasta 98% a partir de pulpa de celulosa pretratada con los complejos de celulasa y xilanasa. La caracterización fisicoquímica y microscópica de las CNF extraídas reveló una significativa uniformidad de tamaños en la escala nanométrica (531-992 nm) con diámetros en el rango de 3-10 nm. Se obtuvieron films de nanocelulosa altamente transparentes y flexibles, lo que resulta atractivo para aplicaciones potenciales. Sin embargo, considerando que la aplicación del tratamiento de ultrasonicación a escala industrial es aún limitada, se evaluó también el tratamiento de molienda de bolas como un método mecánico alternativo para la extracción de CNF. El método de molienda de bolas permitió obtener suspensiones de CNF de mayor consistencia, pero las altas concentraciones de sólidos limitaron la efectividad del proceso de extracción de CNF resultando en rendimientos de extracción más bajos (hasta 35%) en comparación con el método de ultrasonicación. Se evaluó el tratamiento de molienda bajo una configuración secuencial (hasta 5 etapas), el cual permitió alcanzar un rendimiento de extracción de CNF de 48% a partir de pulpa pretratada con los complejos de celulasa y xilanasa. Se obtuvieron CNF con diámetros en el rango de 4-14 nm y relaciones de aspecto de 220-230 mediante tratamiento de molienda de bolas, con mejores propiedades térmicas y cristalinidad. Se obtuvieron films de nanocelulosa flexibles, cuya transparencia resultó menor en comparación con las CNF extraídas por ultrasonicación. En resumen, este trabajo destaca la viabilidad de coproducir CNF y biobutanol como productos de alto valor agregado utilizando pulpa de celulosa Kraft de eucalipto de una planta de celulosa local en un concepto de biorrefinería forestal, lo que podría aumentar la rentabilidad del proceso. Además, pretende contribuir al conocimiento de nuevas técnicas de obtención de nanocelulosa derivada de fuentes renovables, y su potencial aplicación.Udelar. FI.Cebreiros Florencia, Universidad de la República (Uruguay). Facultad de Ingeniería.2023-05-10T17:29:41Z2023-05-10T17:29:41Z2023Tesis de doctoradoinfo:eu-repo/semantics/doctoralThesisinfo:eu-repo/semantics/acceptedVersion176 p.application/pdfCebreiros, F. Cellulose nanofibers from eucalyptus pulp and their coproduction with biobutanol through enzyme-mediated treatment [en línea] Tesis de doctorado. Montevideo : Udelar. FI. IIQ, 2023.https://hdl.handle.net/20.500.12008/37054reponame:COLIBRIinstname:Universidad de la Repúblicainstacron:Universidad de la RepúblicaenengLas obras depositadas en el Repositorio se rigen por la Ordenanza de los Derechos de la Propiedad Intelectual de la Universidad de la República.(Res. Nº 91 de C.D.C. de 8/III/1994 – D.O. 7/IV/1994) y por la Ordenanza del Repositorio Abierto de la Universidad de la República (Res. Nº 16 de C.D.C. de 07/10/2014)info:eu-repo/semantics/openAccessLicencia Creative Commons Atribución - No Comercial - Sin Derivadas (CC - By-NC-ND 4.0)oai:colibri.udelar.edu.uy:20.500.12008/370542026-04-14T10:36:32Z |
| spellingShingle | Cellulose nanofibers from eucalyptus pulp and their coproduction with biobutanol through enzyme-mediated treatment Cebreiros, Florencia Nanocelulosa Biobutanol Eucalipto Enzimas Biorrefinería |
| status_str | acceptedVersion |
| title | Cellulose nanofibers from eucalyptus pulp and their coproduction with biobutanol through enzyme-mediated treatment |
| title_full | Cellulose nanofibers from eucalyptus pulp and their coproduction with biobutanol through enzyme-mediated treatment |
| title_fullStr | Cellulose nanofibers from eucalyptus pulp and their coproduction with biobutanol through enzyme-mediated treatment |
| title_full_unstemmed | Cellulose nanofibers from eucalyptus pulp and their coproduction with biobutanol through enzyme-mediated treatment |
| title_short | Cellulose nanofibers from eucalyptus pulp and their coproduction with biobutanol through enzyme-mediated treatment |
| title_sort | Cellulose nanofibers from eucalyptus pulp and their coproduction with biobutanol through enzyme-mediated treatment |
| topic | Nanocelulosa Biobutanol Eucalipto Enzimas Biorrefinería |
| url | https://hdl.handle.net/20.500.12008/37054 |