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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
111

An evaluation of biodiesel policies : The case of palm oil agro-industry in Indonesia

Harahap, Fumi January 2018 (has links)
Oil palm has flourished as an economically vital crop in Indonesia given its use in both food and non-food products (including biodiesel) for domestic and export markets. However, the expansion of oil palm plantations in Indonesia is controversial. While the crop generates fiscal earnings for the country, and regular income streams for farmers and companies, oil palm plantation expansion is claimed to cause deforestation, environmental degradation and biodiversity losses. At the same time, there is a national target to reduce GHG emissions from land use change and the production of palm oil. Climate change mitigation goals also include ambitious targets to blend biodiesel with fossil diesel in various economic sectors. This thesis looks at the palm oil agro-industry, from oil palm plantation to crude palm oil (CPO) production, and CPO based biodiesel production. It proposes a policy evaluation to verify policy implications in relation to the issue of land use allocation, and the poor profitability in palm oil biodiesel production. The overarching objective is to evaluate the effectiveness of prevailing policies used to promote the palm oil agro-industry for biodiesel production in Indonesia. The thesis is framed by policy research and ex-post policy evaluation. The focus is on the process of policy formulation and implementation, rather than outcome evaluation. Two specific analytical frameworks are used to answer the research questions while addressing the criteria of effectiveness in policy evaluation: (i) policy coherence analysis and (ii) life cycle cost analysis. Qualitative indicators are used to measure the coherence of biofuel policy with other sectoral policies (agriculture, climate and forestry) in relation to land allocation. Quantitative economic indicators are used to compare the costs and benefits of conventional palm oil biodiesel production with a biorefinery conceptual plant. There are valuable lessons to be learnt from this policy evaluation. The results indicate areas in which policy effectiveness can be improved. For land allocation, adjustments and improvements in policy formulation and implementation are crucial. Uncertainties when it comes to the allocation of land to meet multi sectoral policy goals are to be addressed by clarifying land use definitions and categories, which should be backed up by consistent land use definitions in various policy documents. The dual land classification presently applied should move towards a single land classification, linking actual landscape coverage and the legal status of the land. Policy information and guidance across sectoral policies should be compiled in a single database. Such a publicly available database would help enhance the efficiency of land allocation for multiple policy purposes. More importantly, the formulation of biodiesel policy has to engage various sectoral policies that compete for the same resources. The biorefinery conceptual plant allows the reduction of government subsidies, while also providing a pathway to enhance the use of renewable energy and reduce GHG emissions. Policies have been designed to enhance plant profits through the improved utilisation of biomass residues in the palm oil mill for energy generation and composting. However, the low implementation rate of policies indicates the need to improve the effectiveness of policy implementation, and therefore the need for better monitoring processes, and possibly more stringent consequences for non-compliance. / <p>QC 20180223</p>
112

Breaking the chains : A technological and industrial transformation beyond papermaking: Technology management of incumbents

Novotny, Michael January 2016 (has links)
In recent years, the necessity and opportunity for transforming pulp and paper mills into integrative units for large-scale output of biochemicals, biomaterials, and biofuels have come up in discussions of industrial renewal in the Northern hemisphere (mainly in Canada, Sweden and Finland). This transformation is related to technology shifts as well as changing business models based on new bioproducts due to profoundly new market conditions. The aim of this dissertation is to analyse how wood-based biomass industries – with an emphasis on incumbent pulp and paper industries (PPIs) – are managing this industrial and technological transformation that is taking place beyond the papermaking paradigm. Innovation theories on mature industries, their incumbents, and their propensity for technological lock-in and inertia are well-known. How new entrants and incumbents manage these large shifts is seen as central in understanding the dynamics of new, large-scale sustainable technologies on the one hand and the renewal of large, mature process industries on the other. Three research questions are addressed. First, where are the knowledge and technology frontiers developing in this transformation? Second, how are incumbents of PPIs are managing large market and technology shifts based on existing capabilities and knowledge bases? Third, what are the key mechanisms behind the transformation of PPIs from a process-industry perspective? The hermeneutical insights into the system of biomass technologies in general and the PPI industries in particular were gained by using a qualitative case-study approach, which formed the basis for four research articles and for outlining the empirical context and key words search of the quantitative bibliometric methods in a fifth research article. The research findings and main contributions address an identification of the, analytical, “formal”, science-based technology frontiers from a knowledge base perspective.  Old industrialised forest/PPI nations tended to specialize in rather slow growing, forest-based frontiers. They seem to have stayed close to the research trajectories of their woody raw material and knowledge base with the exception of North America. However, this not the entire explanation of transformation and technology development. Chemical pulp mills, in several cases developed into biorefineries, are the nexus of the emerging development block. They are contributing with products in a bioeconomy that is actively moving away from fossils and polluting materials (such as cement, cotton, plastics). In addition, demo plants (potentially nurturing hundreds of bioproducts) that are present at mill sites and involve different stakeholders, can act as the interface between analytical and synthetic knowledge bases that otherwise are difficult to combine in the upscaling phases of process industries. The response of PPI organizations to shifts in both technology and business models is also explained by the concept of diverging innovations of non-assembled products. These are part of a diversification of an industry from a forest industry perspective, and also of a diversification that may enter trajectories of several by-products and side-streams of the pulp “biorefinery” mill, and have analogies to a product-tree and to the material transformation flow of its production systems. But it is also a phenomenon of synergies in a broader multi-sectorial perspective, i.e. new sets of related products/processes that are able to replace industries of non-assembled products under the above-mentioned, new market conditions. The phenomenon of diverging innovations can be regarded as both an empirical contribution – the breaking up of a closed integrated process industry into something new with several emerging and integrative industries as a response to the large shifts in papermaking and sustainable needs in society – and as a theoretical remark on the model for non-assembled products presented by Utterback (1994). / Under de senaste åren har nödvändigheten och möjligheten att omvandla massa- och pappersbruk till integrerade produktionsenheter för storskalig produktion av biokemikalier, biomaterial och biobränslen uppkommit i diskussioner om industriell förnyelse på norra halvklotet - främst i Kanada, Sverige och Finland. Denna omvandling är relaterad till teknikskiften samt förändrade affärsmodeller baserade på nya bioprodukter och kraftigt ändrade marknadsförutsättningar. Syftet med avhandlingen är att analysera hur vedbaserade industrier – med betoning på befintliga massa- och pappersindustrin - hanterar denna industriella och tekniska omvandling utanför det traditionella papperstillverkningsparadigmet. Innovationsteorier om mogna branscher, deras benägenhet för teknisk inlåsning och tröghet är välkända. Hur nya och etablerade aktörer hanterar dessa stora förändringar ses som central för att förstå dynamiken i ny, storskalig, hållbar teknik å ena sidan och förnyelse av mogna processindustrier å andra sidan. Tre forskningsfrågor behandlas. Först, var utvecklas kunskaps- och teknikfronter i denna omvandling? För det andra, hur hanterar etablerade aktörer i massa- och pappersindustrin  stora marknads- och teknologiskiften baserade på befintliga kunskapsbaser? För det tredje, vilka är de huvudmekanismerna bakom omvandlingen av massa- och pappersindustrin ur ett processindustriellt perspektiv? Förståelsen för det biomasseteknologiska systemet i allmänhet och massa- och pappersindustrin i synnerhet erhölls genom att använda kvalitativa fallstudier och metoder. De låg till grund för fyra forskningsartiklar och utmejslade den empiriska kontexten för kvantitativa, bibliometriska metoder i en femte forskningsartikel. Forskningsresultaten utgörs bl a av en identifiering av analytiska, "formella", vetenskapligt baserade teknikfronter. Äldre skogsindustriländer tenderar att specialisera sig i långsamväxande, skogsbaserade teknikfronter. De följer forskningsbanor närmare deras vedråvaru- och kunskapsbaser (med undantag av Nordamerika). Men det är inte hela förklaringen till teknikutvecklingen och dess omställningspotential. Kemiska massabruk, i flera fall utvecklade till bioraffinaderier, kan utgöra hävstången för ett framväxande utvecklingsblock. De bidrar med produkter i en bioekonomi som aktivt rör sig bort från fossila och resursineffektiva material och processer (såsom cement, bomull, plast). Dessutom kan demonstrationsanläggningar härbärgera en storskalig testmiljö för hundratals bioprodukter som är placerade i närheten av massafabriker och som involverar forsknings-, industri- och samhällsintressenter. De kan ävenfungera som gränssnitt mellan analytiska och syntetiska kunskapsbaser som annars är svåra att kombinera i uppskalningsfaser. Massa- och pappersindustrins omvandling förklaras också av begreppet divergerande innovationer av icke-sammansatta produkter. Dessa är delvis en diversifiering av en bransch ur ett skogsindustriellt perspektiv, delvis en diversifiering som kan generera i biprodukter och sidoströmmar, som har analogier med produktträd och påminner om det materiella transformationsflödet i det egna produktionssystemet. Divergerande innovationer kan ge ett synergifenomen ur ett bredare sektoriellt perspektiv, dvs nya uppsättningar av produkter och processer som kan ersätta industrier med icke-sammansatta produkter under de nya marknadsförhållandena som ovan beskrivits. Fenomenet med divergerande innovationer kan betraktas som både ett empiriskt bidrag - att bryta upp en sluten, integrerad processindustri till något nytt med flera framväxande och integrerande näringar som ett svar på de stora förändringarna i industrin och i samhället – och också som en kritik av modellen för icke-sammansatta produkter som tidigare presenterats av Utterback (1994). / <p>QC 20160829</p>
113

Modélisation et optimisation de la production de cellulases par Trichoderma reesei pour les bioraffineries lignocellulosiques

Jourdier, Etienne 19 September 2012 (has links)
Dans le contexte énergétique et climatique mondial, le coût élevé des enzymes Cellulolytiques (cellulases) freine le développement des bioraffineries lignocellulosiques, pour produire des biocarburants et composés chimiques à partir d'une matière première végétale renouvelable. L'objectif de ce travail est de caractériser et de modéliser le métabolisme du micro-organisme Trichoderma reesei, afin d'optimiser le protocole industriel de production de cellulases. Cette étude a été réalisée sur des milieux modèles représentatifs de ceux attendus à l'échelle industrielle. Tout d'abord, la stoechiométrie des réactions de croissance et de production a été établie, puis une étude cinétique a été menée pour mesurer précisément le comportement du micro-organisme à forte induction de la production de cellulases. Le modèle résultant a été utilisé pour optimiser le protocole industriel de production. Ensuite, l'intégration de cette étape dans une bioraffinerie lignocellulosique a été étudiée, avec l'effet sur le métabolisme i) des mélanges de sucres disponibles, ii) des composés inhibiteurs issus de la dégradation de la lignocellulose, et iii) du changement d'échelle. Ces travaux ont fait progresser de façon substantielle les connaissances du métabolisme de T. reesei en ce qui concerne la production de cellulases, et les modèles développés sont des outils d'aide rationnelle à la définition d'un procédé de production de cellulases intégré dans une bioraffinerie lignocellulosique. / In the global energetic and climatic context, the high cost of the cellulolytic enzymes (cellulases) postpones the development of lignocellulosic biorefineries, dedicated to produce biofuels and chemical compounds from renewable vegetable feedstocks. The aim of this work was to measure and model the metabolism of the micro-organism Trichoderma reesei, in order to optimize the industrial protocol for the production of cellulase. This study was carried out using synthetic media representative of industrial ones. First, the stoichiometries of growth and protein production reactions were determined. Then, a kinetic study was conducted to precisely measure the specific rates of T. reesei at high induction of cellulase production. The resulting model was used to optimize the industrial production protocol. Finally the integration of this step in a lignocellulosic biorefinery was studied by determining the impacts on the metabolism of i) available sugar mixtures, ii) inhibitory compounds from lignocellulosic biomass degradation, and iii) scale-up. These results significantly contributed to improve the knowledge of T. reesei metabolism on cellulase production. The developed models are rational tools for the optimization of a cellulase production protocol suited to lignocellulosic biorefineries.
114

PRODUÇÃO DE ÁCIDO LÁCTICO A PARTIR DA CASCA DE ARROZ / LACTIC ACID PRODUCTION FROM RICE HUSK

Montipó, Sheila 16 November 2012 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / Lignocellulosic agroindustrial wastes, such as rice husks (RH), are abundant, low cost, renewable sources, available to biotransformation in value-added products. Thus, the main objective of this study was to investigate the use of RH with the purpose of its biotransformation in lactic acid (LacA) starting from hydrolysates of this residual biomass. At the same time, aiming to contribute to the mitigation of the growing environmental concern about the illegal disposal of this waste in the State of Rio Grande do Sul the biggest Brazilian rice producer. For this, a central composite rotational design (CCRD) of the hydrolysis experiments of RH in pressurized conversion system with diluted HCl and H2SO4, revealed that experiments conducted at 175 °C, for 46 min, with acid concentrations of 2.2% v v-1, generate the highest glucose contents. For hydrolysis involving HCl, 17.8 g glucose L-1, with an yield of 106.6 mg glucose g-1 RH; for hydrolysis with H2SO4, 14.1 g glucose L-1, with an yield of 84.5 mg glucose g-1 RH. Previous fermentative experiments were carried out with the aim to select resilient and efficient micro-organisms for the LacA production and, also, to evaluate the need of supplementation of the RH hydrolyzate with specific nutrients. L. rhamnosus, in this study, was the most suitable bacteria for the lactic fermentation, among all the Lactobacillus tested, being able to to produce 5.6 g LacA L-1, with a yield of 33.8 mg LacA g-1 RH (hydrolysed with HCl, without nutrient addition, 96 h fermentation). The acid hydrolysis, in this particular case, was carried out at 160 °C, for 70 min, using 4.0% HCl v v-1, generating 14.7 g glucose L-1. The lactic fermentation via CCRD was batch conducted in 4 mL vials, at 37 °C, pH 6.0, using L. casei subsp. rhamnosus ATCC 10863, specialized in catabolization of both hexoses and pentoses (except arabinose). Experiments with RH hydrolysates containing nutrients added produced up to 18.8 g LacA L-1 (maximum yield of 997,1 mg LacA g-1 sugars) in substrate hydrolyzed with HCl, after 52 h fermentation; and 14.6 g LacA L-1 (maximum yield of 999.8 mg LacA g-1 sugars) in substrate hydrolyzed with H2SO4, after 24 h fermentation. Therefore, in this study, the choices of most influence in the LacA production were fermentation with sulfuric acid and employment of L. rhamnosus. / Resíduos lignocelulósicos agroindustriais, como a casca de arroz (CA), são fontes renováveis, abundantes e de baixo custo, disponíveis para a biotransformação em produtos com valor agregado. O principal objetivo deste trabalho foi investigar o aproveitamento da CA com vistas à sua biotransformação em ácido láctico (ALac), partindo-se de hidrolisados desta biomassa residual. Ao mesmo tempo, objetivou-se contribuir para a mitigação do crescente problema ambiental decorrente da disposição irregular deste resíduo no estado do Rio Grande do Sul, maior produtor brasileiro. Para tanto, o delineamento composto central rotacional (DCCR) do planejamento experimental da hidrólise ácida da CA em sistema de conversão à pressão, com HCl e H2SO4 diluídos, revelou que, experimentos conduzidos a 175 °C, por 46 min, com concentração de 2,2% (v v-1) de ácido, produziram os teores máximos de glicose. Para hidrólises envolvendo HCl, teor de 17,8 g de glicose L-1, com rendimento de 106,6 mg de glicose g-1 CA; para hidrólises com H2SO4, teor de 14,1 g de glicose L-1, com rendimento de 84,5 mg de glicose g-1 CA. Ensaios fermentativos prévios foram feitos com o intuito de selecionar micro-organismos resilientes e eficientes para a produção de ALac e, também, para avaliar a necessidade de suplementação do hidrolisado da CA com nutrientes específicos. L. rhamnosus, neste trabalho, foi a bactéria mais apropriada à fermentação láctica, dentre os Lactobacillus testados, sendo capaz de produzir 5,6 g ALac L-1, com rendimento de 33,8 mg ALac g-1 CA (hidrolisado com HCl, sem adição de nutrientes, 96 h de fermentação). A hidrólise ácida, neste caso específico, foi feita a 160 °C, por 70 min, com 4,0% HCl v v-1, gerando 14,7 g L-1 de glicose. A fermentação láctica via DCCR foi conduzida em vials de 4 mL, em batelada, a 37 °C, pH 6,0, empregando-se L. casei subsp. rhamnosus ATCC 10863, cepa especializada em catabolização de hexoses e pentoses (exceto arabinose). Experimentos com hidrolisados da CA adicionados de nutrientes produziram até 18,8 g ALac L-1 (rendimento máximo de 997,1 mg ALac g-1 açúcares) em substrato hidrolisado com HCl, após 52 h de fermentação; e 14,6 g ALac L-1 (rendimento máximo de 999,8 mg ALac g-1 açúcares) em substrato hidrolisado com H2SO4, após 24 h de fermentação. Portanto, neste trabalho, as escolhas de maior influência na produção de ALac foram a fermentação com hidrolisado sulfúrico e emprego de L. rhamnosus.
115

Application des électrotechnologies pour une valorisation optimisée de la betterave à sucre dans un concept de bioraffinerie / Application of electrotechnologies for an optimized valorization of sugar beet in biorefinery concept

Almohammed, Fouad 24 January 2017 (has links)
Ce travail de thèse concerne l’utilisation des électrotechnologies pour une valorisation optimisée de la betterave à sucre conformément au concept de bioraffinerie. Les électro-technologies appliquées sont les champs électriques pulsés (CEP) et les décharges électriques de haute tension (DEHT). L’étude s’attache d’une part à l’optimisation d’un procédé alternatif pour l’extraction du sucre par pressage alcalin à froid assisté par CEP. D’autre part, elle propose des nouvelles voies pour la valorisation de deux coproduits de l’industrie betteravière qui sont les radicelles et la pulpe de betterave. Dans la première partie, le traitement électrique par CEP couplé au chaulage permet une meilleure désintégration du tissu betteravier. Il permet d’accélérer les cinétiques du pressage, d’améliorer le rendement ainsi que la qualité du jus et d’alléger la procédure de purification en aval de l’extraction. Une étude paramétrique d’optimisation a permis d’identifier le meilleur itinéraire d’application de ce nouveau procédé d’extraction. Les cossettes fraîches de betterave sont prétraitées par CEP à 600 V/cm pour 10 ms (Q = 2,7 Wh/kg). Les cossettes électroporées sont ensuite pressées à froid pour extraire 75 % du jus. Les cossettes pressées subissent un pressage alcalin avec 10 % du lait de chaux. Afin d’extraire le sucre résiduel dans le gâteau de pressage obtenu, deux étapes de pressage supplémentaires avec une étape intermédiaire d’hydratation sont nécessaires. Ce procédé optimisé permet de bien épuiser les cossettes en sucre (perte en sucre de 0,23 % et matière sèche de pulpes de 39 %) pendant une courte durée d’extraction (30 min) avec un faible soutirage (108 %) par rapport au procédé de diffusion. Il permet ainsi des économies significatives de matière et d’énergie surtout pour les étapes d’extraction du jus et de séchage de pulpes. Par rapport au procédé conventionnel, le gain énergétique s’élève à 91,96 × 106 kWh pour une usine traitant 10 000 t/j de betteraves pendant une campagne de 110 jours. De plus, le procédé proposé permet de simplifier la procédure de purification et de réduire de 50 à 60 % la quantité de chaux utilisée. Dans la deuxième partie de cette étude, deux procédés de transformation ont été proposés et optimisés à l’échelle laboratoire pour la valorisation des radicelles et de la pulpe de betterave à sucre. Les radicelles ont été utilisées pour produire du bioéthanol. Le jus brut de radicelles a été extrait par pressage à froid assisté par CEP. La production du bioéthanol a été achevée par fermentation alcoolique. Le prétraitement par CEP (450 V/cm, 10 ms) a permis d’accélérer la cinétique de pressage, d’augmenter le rendement en solutés (79,85 % vs. 16,8 %) et d’obtenir un jus plus concentré (10 % vs. 5,2 %). Le procédé optimisé permet de produire environ 41,75 L de bioéthanol par tonne de radicelles lorsque l’on applique un prétraitement par CEP contre seulement 8,2 L de bioéthanol sans prétraitement électrique confirmant ainsi le potentiel de ce nouveau schéma de valorisation. La pulpe de betterave déshydratée ayant une matière sèche de 92,8 % a été utilisée pour l’extraction de pectines. L’étude réalisée a montré que l’application d’un prétraitement par DEHT permet d’intensifier l’extraction des pectines. Le gain relatif de rendement en pectines est de 25,3 % pour une énergie consommée de 76,2 kJ/kg. Le schéma de bioraffinage proposé pourra aider au maintien de la filière betteravière en France après la suppression de système de quotas sucriers dans l’Union européen qui entrera en vigueur le 1er octobre 2017. / This work discusses the use of electrotechnologies for an optimized valorization of sugar beet according to the concept of biorefinery. The applied electrotechnologies are pulsed electric fields (PEF) and high-voltage electrical discharges (HVED). The study firstly aims at optimizing an alternative method for sugar extraction by PEF assisted cold alkaline pressing. On the other hand, it proposes new ways for valorizing two by-products of sugar beet industry, which are sugar beet tails and pulps. In the first part, PEF treatment combined with liming leads to a better disintegration of beet tissue. It permits accelerating of pressing kinetics, improvement of juice yield and quality, and reduction of subsequent purification procedure. A parametric optimization study identified the best application itinerary of the proposed extraction process. Fresh sugar beet cossettes are pretreated by PEF at 600 V/cm for 10 ms (Q = 2.7 Wh/kg). The electroporated cossettes are then pressed to extract 75% of intracellular juice. Compressed cossettes are subjected to an alkaline pressing with 10% lime milk. In order to extract the residual sucrose in the obtained press-cake, two additional steps of pressing with an intermediate hydration are required. This optimized process allows well exhausting the sugar cossettes (sugar loss of 0.23% and pulp dry matter of 39%) for a short extraction (30 min) and with low draft (108%) compared to diffusion method. Thus, it allows substantial saving in materials and energy especially for juice extraction and pulp drying. Compared to the conventional method, the energy saving amounted to 91.96 × 106 kWh for a sugar beet factory treating 10 000 tons per day for a campaign of 110 days. In addition, the proposed method simplifies the purification procedure of raw juice and reduces the used amount of lime from 50 to 60%. In the second part of this study, two processing methods were proposed and optimized at lab-scale for valorization of sugar beet tails and pulps. Sugar beet tails were used to produce bioethanol. Raw juice of beet tails was extracted by PEF assisted cold pressing. Bioethanol production was then done by alcoholic fermentation. Pretreatment of beet tails with PEF (450 V/cm, 10 ms) permits accelerating the pressing kinetics, increasing the yield of solutes (79.85% vs. 16.8%), and leads to a more concentrated juice (10% vs. 5.2%). The optimized process permits the production of about 41.75 L of bioethanol per ton of beet tails when PEF pretreatment is applied against only 8.2 L of bioethanol without PEF confirming the potential of this new valorization scheme. Dried beet pulp having a dry matter of 92.8% was used for pectin recovery. The present study showed that the application of HVED pretreatment leads to intensify pectin extraction. The relative gain of pectin yield is 25.3% with an energy consumption of 76.2 kJ/kg. The proposed biorefinery scheme could protect the sugar beet industry in France after the suppression of the sugar quota system in the European Union, which will take effect on 1st October 2017.
116

Valorisation de la vinasse de canne à sucre : étude d'un procédé d'extraction d'un acide organique multivalent / Valorization of sugarcane distillery stillage : study of an extractive process of a multivalent carboxylic acid

Wu-Tiu-Yen, Jenny 28 February 2017 (has links)
La vinasse de distillerie, co-produit de l’industrie canne-sucre-alcool-énergie, contient de 5 à 7 g/L d’un acide d’intérêt, l’acide aconitique, au sein d’un milieu complexe comportant d’autres acides organiques, des acides aminés, mais surtout des sels minéraux (chlorures et sulfates) et des colorants, rendant sa purification complexe. Afin d’améliorer les performances du procédé d’échange d’ions, au coeur de cette purification, la résine anionique faible Lewatit S4528 a été caractérisée. Le dosage de la résine et des mesures d’isothermes d’échange d’ions ont permis de définir : la capacité totale du support, l’ordre d’affinité des principaux anions de la vinasse et les coefficients d’échange d’ions associés, de même que la capacité pour l’acide d’intérêt dans cette matrice complexe. L’effet du pH, de la forme du support (sulfate, chlorure et base libre) et de l’éluant ont été étudiés en colonne pour différentes solutions (acide seul, vinasse « modèle », vinasse réelle), permettant de préciser les mécanismes de la purification.Les meilleures conditions (vinasse à pH 4,5, résine sous forme chlorure et élution par HCl 0,5 N) ont abouti à un éluat d’une pureté de 28 %MS avec un rendement global de 61 %. Pour éliminer les principales impuretés qui persistent dans l’éluat (ions chlorure et sulfate et des colorants), l’électrodialyse s’est avérée un procédé très performant en ce qui concerne l’élimination des ions chlorure (proche de 100 %) tandis qu’une étape d’adsorption sur résine polystyrénique XAD16 permet l’élimination de 80 % de la charge colorante de l’éluat acide. Le couplage le plus intéressant associe microfiltration, échange d’ions, électrodialyse et adsorption. Il permet d’obtenir une pureté estimée à 37 % MS, avec un facteur de purification de 3,6 par rapport à la vinasse initiale. Ces travaux ont permis d’améliorer d’un facteur 2,6 la pureté de l’acide par rapport à des études antérieures et de mieux comprendre les mécanismes de sa purification sur résine anionique faible. / Cane stillage or vinasse, a byproduct of cane industry, contains from 5 to 7 g/L of aconitic acid, a valuable trivalent carboxylic acid belonging to the second class of building block chemicals. Vinasse also contains a variety of organic compounds (organic acids, amino-acids, colouring matters) and minerals (chlorides, sulphates), which makes purification not straightforward. The objective of this work is to develop the extraction of aconitic acid from stillage, with anion exchange as the heart of the process. In order to improve performances, the main characteristics of the selected anion-exchange resin (Lewatit S4528) are studied. Acid-base dosage and ion-exchange equilibrium experiments allow the total capacity of this support and the ion-exchange coefficients for the major competing anions (aconitate, chloride and sulfate) to be obtained. Separation performances in column are studied for different pH, different solutions (aconitic acid alone, synthetic and industrial stillage) and different resin forms (sulfate, chloride and free- base) in order to elucidate the separation mechanisms.Elution step is also investigated. Best conditions are for stillage at its natural pH (pH 4.5) on the resin under chloride form and HCl 0,5N as the eluant. A 28% DM purity and a 61% global recovery are achieved for aconitic acid in the eluate. Main impurities still remaining are chlorides or sulfates and coloring matter. Homopolar electrodialysis proves successful for removing nearly 100% chlorides from aconitic acid with a limited loss of the acid (< 15%). Adsorption step on a polystyrenic resin (XAD16) of an acidic eluate leads to the retention of 80% of the colorants, with only 12% of the acid lost. At last, the most interesting process combination associates microfiltration, anion-exchange, electrodialysis and adsorption. Purity is 37% MS, namely 3.6 higher than the original vinasse. This work enables aconitic acid purity to be improved by a factor of 2.6 compared with prior studies and to have a better comprehension of the mechanisms involved in its purification on weak anionic resin.
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Spruce bark biorefinery / Bioraffenaderi för granbark

Ahlström, Leon, Mattsson, Rebecca, Eurén, Hampus, Lidén, Alicia January 2021 (has links)
Spruce Bark contains several fundamental main substances; lignin, non-cellulose polysaccharides, cellulose and extractives. This undergraduate study focuses on developing a process to extract each of these components from spruce bark using a biorefinery concept, with a main focus on extracting lignin without degradation. The purpose of the Bark biorefinery concept is to contribute to a circular bioeconomy, by making use of natural resources. With extended research on the area, it will be possible to produce polymers, green chemicals and biofuel from the components in bark.  This report covers the extraction of the bark components with soxhlet extraction, Hot-water extraction, organosolv extraction and peracetic acid delignification. The extraction was made on two samples, matchstick-sized bark (MS) and 20 mesh-sized bark with a diameter of 0.8 mm (20M). The purpose was to be able to compare the efficiency of the extraction between the two samples. Afterwards, the characterisation of extracts and residue was executed with carbohydrate analysis, 2D HSQC-NMR and FTIR-analysis.  The results showed that a smaller particle size led to more efficient extractions of all components as well as more pure extract solutions. Lignin concentration determinations of samples at each step showed that a significant amount of lignin was lost prior to the organosolv extraction. Future research should look into ways to reduce this loss in order to increase the lignin yield. The findings in the FTIR and NMR analyses correlates with what could be seen in other reports, discussing similar subjects. For upscaling of this process, future research should go toward optimization of all extraction methods in order to make an upscaling of the process economically viable.
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Development of Processes for the Extraction of Industrial Grade Rubber and Co-Products from the Roots of Taraxacum kok-saghyz (TK)

Ramirez Cadavid, David A. January 2017 (has links)
No description available.
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Flexibilité métabolomique du saule : De la tolérance au stress salin à la bioraffinerie intégrée avec le traitement des eaux usées

Sas, Eszter 04 1900 (has links)
La transition des activités humaines vers des modèles de développement durable pourrait contribuer à mieux s’adapter aux enjeux mondiaux interconnectés comme les changements climatiques, l’insécurité alimentaire, la santé globale, et l’épuisement des ressources. Cette thèse représente l’un des premiers travaux de recherche visant à combiner l’utilisation des saules à croissance rapide (Salix sp.) pour la phytoremédiation avec leur potentiel pour les bioraffineries. La métabolomique non-ciblée utilisée avec des saules dans deux études complémentaires a permis d’acquérir à la fois des connaissances appliquées sur la valorisation des composés extractibles et une compréhension fondamentale des mécanismes de tolérance au sel. Des saules matures, utilisés pour traiter des eaux usées, ont été évalués à travers un processus de transformation allant de la biomasse brute aux rendements finaux (bioéthanol, lignines, composés bioactifs). L’irrigation avec des eaux usées a triplé les rendements en biomasse, avec une augmentation significative du glucane au détriment d’une réduction des extractibles. Ces variations suggèrent l’allocation des ressources pour soutenir la croissance plutôt que les molécules de défense. Un prétraitement par liquide ionique a fractionné la biomasse, une méthode compatible avec des biomasses contaminées et permettant d’obtenir des composantes séparées de grande qualité. La saccharification enzymatique a livré les rendements en bioéthanol tandis qu’un contre-solvant a précipité la lignine brute, avec une efficacité similaire aux saules témoins. Malgré une teneur réduite en extractibles, l’irrigation par les eaux usées a enrichi le profil phytochimique en flavonoïdes et lignans, potentiellement associés aux perturbations causées par l’inondation et la salinité, et ayant de possibles propriétés antimicrobiennes et antioxydantes. En intégrant deux approches vertes, cette étude démontre une augmentation significative des rendements annuels de bioproduits par unité de surface cultivée, renforçant la viabilité économique et la durabilité environnementale de chacune des deux approches prises individuellement. Une seconde étude s’intéresse plus profondément aux mécanismes de tolérance d’un saule face à deux sels abondants, le NaCl et le Na2SO4, la salinisation étant généralement associée à l’utilisation d’eaux usées et fréquente sur de nombreuses terres marginales. Malgré une conductance stomatique réduite, Salix miyabeana a maintenu sa capacité photosynthétique et sa production de biomasse, même à des niveaux élevés de sel. Les cations et anions salins sont gérés différemment par la plante, qui restreint largement l’absorption du Na+ aux racines, alors que le Cl- et le SO42- sont transportés jusque dans les feuilles. Les analyses révèlent une tolérance résultant à la fois de la plasticité des métabolites constitutifs et des métabolites spécialisés associés aux organes. Les réponses nuancées en fonction des organes et des ions indiquent des adaptations spécifiques dans l’allocation du carbone, la production d’antioxydants ou le métabolisme du soufre par exemple. Seulement 3% des métabolites constituaient une réponse généralisée aux deux types de sels, incluant une réduction de saccharides et un enrichissement de composés phénoliques simples, comparativement aux 28% impliqués au total. Le NaCl induit une réduction du métabolisme énergétique à l’échelle de toute la plante, potentiellement combinée au renforcement racinaire par l’augmentation de précurseurs de la lignine et d’antioxydants. À niveaux équivalents d’électroconductivité et de sodium, Na2SO4 induit une perturbation métabolique plus limitée. Même à concentration double de Na2SO4, l’activité métabolique se caractérise par un enrichissement préférentiel, probablement facilité par l’assimilation de l’excès de SO42- en composés organiques plutôt que leur séquestration. Notre étude des ajustements métaboliques complexes des saules, une espèce non-modèle mais d’importance biologique, environnementale et économique, a contribué à approfondir notre compréhension de leur résilience face aux stress abiotiques, informant ainsi les approches de gestion de l'eau et des terres ainsi que les pratiques de production durables. / Transitioning towards sustainable models that harmoniously integrate human activities within natural cycles could address interconnected global challenges such as climate change, social and economic inequalities, food insecurity, global health, and resource depletion. Phytoremediation, leveraging plant-microorganism interactions to mitigate soil and water pollution, offers a potentially efficient and environment-friendly solution, while also being economically viable and socially acceptable. This thesis represents one of the initial efforts to integrate the application of fast-growing willows (Salix sp.) for phytoremediation, capitalizing on their stress tolerance, with its potential for widerange biorefineries, harnessing their high biomass productivity as a renewable resource for bioenergy and bio-based products. Two complementary studies employed untargeted metabolomics to acquire both applied knowledge on the extensive valorization potential of extractable phytochemicals, and fundamental understanding of their salt stress tolerance mechanisms. Mature field-grown willows used for phytofiltration of primary municipal wastewater effluent were comprehensively characterized to assess their biorefinery potential through a complete process, from raw biomass to final bioethanol, lignin, and extractives yields. Wastewater irrigation tripled biomass yield and structural biochemical compound quantification revealed a significant increase in constitutive glucan along with a significant decrease in extractives, suggesting resource investment into growth over specialized defensive compounds. Ionic liquid pretreatment enabled biomass fractionation, chosen for its versatility in recovering multiple highquality streams and its suitability for contaminated biomass. Subsequently, enzymatic saccharification determined the final bioethanol yields, while counter-solvent precipitation recovered crude lignins. Despite a generalized reduction of extractives, wastewater irrigation enriched the extractable phytochemical profile with flavonoids and lignans, potentially associated with flooding, salinity, antimicrobial and antioxidant activities. Wastewater irrigated willows maintained quality and conversion potential, enhancing the annual valorization yields per growing surface, and strengthening the economic viability and environmental sustainability. These results demonstrated mutual benefits of integrating wastewater treatment and biorefineries. A subsequent study investigated Salix miyabeana tolerance and metabolic response to two environmentally abundant salts, NaCl and Na2SO4, considering salinity as a potential consequence of wastewater irrigation. Despite reduced stomatal conductance, willows maintained photosynthetic capacity and biomass productivity even under high soil salinity levels, demonstrating their salt tolerance. Elemental analysis revealed differential fate of salt ions, restricted Na+ absorption in roots, while Cl- and SO4 2- accumulated in aerial parts. Untargeted metabolomics exposed willow’s efficient metabolic plasticity in response to salts, modulating both constitutive and organ-specialized metabolites. Differential organ- and anion-specific responses indicated nuanced adaptation mechanisms, involving adjustments in carbon allocation, antioxidant production, and sulfur metabolism. Only 3% of metabolites constituted a generalized salt stress response, including reduced saccharides alongside enriched simple phenolics, as compared to 28% involved in overall salt response. NaCl triggered plant-wide energy metabolism reduction, potentially coupled with reinforced root structure through increased lignin precursors and antioxidant compounds. At similar soil EC and sodium concentration, Na2SO4 caused lower metabolic disruption, and as Na2SO4 concentration increased, willow was able to support the metabolic enrichment instead of depletion, likely associated with the ability to integrate SO4 2- in sulfur metabolism instead of passive sequestration. Our investigation into the complex metabolic adjustments of willows, a non-model species but of biological, environmental and economic importance, contributed to deepen our understanding of its resilience towards abiotic stresses, further informing effective water and land management approaches as well as sustainable production practices.
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Fractionnement analytique de la graine de neem (Azadirachta indica A. Juss.) et de la graine de dattier du désert (Balanites aegyptiaca L.) - Valorisation des constituants de la graine de neem par bioraffinage / Analytical fractionation of neem seed (Azadirachta indica A. Juss) and desert date seed (Balanites aegyptiaca L.) - Valorization of neem seed constituents by biorefinery

Diedhiou, Djibril 05 December 2017 (has links)
Les graines de neem et de dattier du désert ont été caractérisées et leurs perspectives de fractionnement orientées. Un procédé de fractionnement des graines de neem en extrudeur bi-vis a été étudié en vue d’une production et d’une valorisation intégrée de ses fractions: huile, coextrait d’azadirachtine, protéines et lipides, et raffinat d’extrusion. La mise en oeuvre de l’eau et des mélanges hydroéthanoliques (jusqu’à 75% d’éthanol) comme solvants d’extraction avec une configuration de l’extrudeur bi-vis définissant quatre zones (une zone d’alimentation, une zone de broyage, une zone d’extraction solide-liquide et une zone de séparation solide/liquide), permet d’extraire au filtrat 83 à 86% de l’azadirachtine, 86 à 92% des lipides et 44 à 74% des protéines de la graine et de produire un raffinat essentiellement fibreux, contenant au plus 8% de lipides, 12% de protéines et 0,82 g/kg d’azadirachtine. Une des meilleures voies de traitement de la suspension que constitue le filtrat brut est la séparation solide-liquide par centrifugation. Ce procédé de séparation permet d’obtenir une émulsion diluée contenant 42 à 64% des lipides et jusqu’à 41% des protéines de la graine. La décantation centrifuge permet de le réaliser efficacement, mais elle peut présenter des inconvénients pour le traitement de grands volumes. Considérée comme sous-produit du traitement du filtrat brut, la phase insoluble peut contenir 24 à 48% des lipides, 32,9 à 47% des protéines et 10 à 13% de l’azadirachtine de la graine. L’eau s’est avérée être le meilleur solvant de ce procédé de fractionnement. Le pressage des graines de neem suivi de l’extraction aqueuse ou hydroalcoolique dans le même extrudeur bi-vis permettent d’exprimer jusqu’à 32% de l’huile de la graine et de récupérer 20% de l’huile de la graine sous forme claire, avec très peu d’azadirachtine, en assurant de meilleurs rendements en azadirachtine et en protéines au filtrat brut. Deux voies de traitement des filtrats ont été étudiées : celle conduisant à une émulsion d’azadirachtine et celle conduisant à l’obtention d’une poudre lyophilisée d’azadirachtine. La valorisation du raffinat d’extrusion, fibreux, a été orientée vers la production d’agromatériaux par thermopressage. Un schéma de bioraffinage de la graine de neem pour la valorisation de ses constituants a été ainsi mis en place. / Neem and desert date seeds were characterized and their fractionation perspectives oriented. A process of fractionation of neem seeds in twin-screw extruder has been studied for the purpose of production and integrated valorization of its fractions: oil, co-extract of azadirachtin, proteins and lipids, and extrusion raffinate. The use of water and water/ethanol mixtures (up to 75% ethanol) with a twin-screw extruder configuration defining four zones (a feed zone, a grinding zone, a solidliquid extraction zone and a solid / liquid separation zone), allows to extract from the filtrate 83 to 86% of the azadirachtin, 86 to 92% of the lipids and 44 to 74% of the proteins of the seed thereby producing a raffinate essentially fibrous containing at most 8% lipids, 12% proteins and 0.82 g/kg azadirachtin. One of the best ways of processing the suspension that is the crude filtrate, is a solid-liquid separation by centrifugation. This separation process makes it possible to obtain a diluted emulsion containing 42 to 64% of the lipids and up to 41% of the proteins of the seed. A centrifugation achieves it effectively, but this separation process can have disadvantages in the treatment of large volumes. Considered as a by-product of the treatment of crude filtrate, the insoluble phase can contain 42 to 64% of the lipids, 32.9 to 47% of the proteins and 10 to 13% of the azadirachtin of the seed. Water has proven to be the best solvent in this fractionation process. The pressing of the neem seeds followed by the aqueous or hydroalcoholic extraction in the same twin-screw extruder makes it possible to extract up to 32% of the oil of the seeds and to recover 20% of the seed oil in clear form, with very little azadirachtin, ensuring better extraction yields of azadirachtin and proteins to the crude filtrate. Two treatment pathways of the filtrates were studied: one leading to an emulsion of azadirachtin and another to a freeze-dried powder of azadirachtin. The valorization of the fibrous extrusion raffinate has been oriented towards the production of agromaterials by thermopressing. A biorefinery scheme of the neem seed for the valorization of its constituents has thus be implemented.

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