Literatura académica sobre el tema "Valorisation en cascade"

The production of glucuronic acid (GA) directly from actual biomass via chemocatalysis is of great significance to the effective valorisation of biomass for a sustainable future. Herein, we have developed a one-step strategy for the conversion of cellulose in corncob residue into GA with the cooperation of Au/CeO2 and maleic acid, achieving a 60.3% yield. Experimental and density functional theory (DFT) results show that maleic acid is effective in the fractionation of cellulose from corncob residue and the depolymerisation of cellulose fragments to glucose, on account of the good capacity for proton migration. Au/CeO2 is responsible for the selective oxidation of glucose to GA, in which the formation of glucaric acid is restrained, due to the weak capacity of Au/CeO2 on the proton transfer without the occurrence of the ring-opening reaction of glucose. Therefore, the relay catalysis of Au/CeO2 and maleic acid enables the production of GA via the complex cascade reactions. This work may provide insight regarding the conversion of actual biomass to targeted products.

The use of renewable resources as feedstocks to ensure the production of goods and commodities for society has been explored in the last decades to switch off the overexploited and pollutant fossil-based economy. Today there is a strong movement to set bioeconomy as priority, but there are still challenges and technical limitations that must be overcome in the first place, particularly on biomass fractionation. For biomass to be an appellative raw material, an efficient and sustainable separation of its major components must be achieved. On the other hand, the technology development for biomass valorisation must follow green chemistry practices towards eco-friendly processes, otherwise no environmental leverage over traditional petrochemical technologies will be acquired. In this context, the application of green solvents, such as ionic liquids (ILs) and deep eutectic solvents (DES), in biomass fractionation is envisaged as promising technology that encompasses not only efficiency and environmental benefits, but also selectivity, which is a crucial demand to undertake cascade processes at biorefinery level. In particular, this article briefly discusses the disruptive achievements upon the application of ILs and DES in biomass delignification step towards an effective and selective separation of lignin from polysaccharides. The different physicochemical properties of these solvents, their interactions with lignin and their delignification capacity will be scrutinized, while some highlights will be given to the important characteristics of isolated lignin fractions for further valorisation. The advantages and disadvantages between ILs and DES in biomass delignification will be contrasted as well along the article.

The current paper describes the work carried out in the Horizon 2020 AFTERLIFE project – "Advanced Filtration TEchnologies for the Recovery and Later conversIon of relevant Fractions from wastEwater" – (Grant Agreement no. 745737) which focuses on bioprocess modelling and optimisation using computational tools. The project addresses the development of a flexible, cost- and resource-efficient process framed in the zero-waste and circular economy approach for the recovery and valorisation of the relevant fractions from wastewater. The first step of such a process is an initial step consisting of a cascade of membrane filtration units to separate the total solids in sewage. Then, the concentrates recovered in each unit will be treated to obtain high-pure extracts and metabolites or to be converted into value-added biopolymers (polyhydroxyalkanoates). Moreover, the outflow of the process is an ultra-pure water stream that can be directly reused. Following a holistic approach, the design and optimisation of the AFTERLIFE process will improve performance and reduce the costs associated with wastewater treatment by maximising the value recovery. The paper focuses on the work done developing and implementing computational tools to model and optimise the design of the process. A framework for modelling-based optimisation has been developed. The applied optimisation approach is not computationally demanding and can be systematically applied to different processes. Finally, a use case establishing a scenario for testing the developed framework is described. The defined process model and optimisation methodology were applied to simulate the treatment of wastewater from the fish processing industry. The performance of the optimisation tool is analysed considering the simulation results.

The River Mreznica (64 km) is a watercourse in the region of Central Croatia. In the valley of the Mreznica, the forms of the relief created by erosion and deposits present an important basis for tourism development. This paper explores their appeal (attractiveness). In terms of tourism, about 10 per cent of the direct resources have already been valorised, while the remaining resources represent potential tourist attractions. The real tourist attractions are located in the lower valley, whereas the potential attractions are found in the middle and upper river valley. Access to potential attractions and their valorisation in tourism is impeded by the spreading of the underbrush, which has advanced considerably over the past twenty years, and by the fact that the upper valley is located in the zone of the “Eugen Kvaternik” Military Polygon. Travertine barriers, which have created a specific type of waterfalls and cascades, together with mills, bridges and ferries, characterise the tourist attractions in the valley of the River Mreznica.

AbstractHeterogeneous tin-based sulfonated graphite (Sn-GP) catalyst was prepared with graphite as carrier. The physicochemical properties of Sn-GP were captured by FT-IR, XRD, SEM and BET. Organic acids with different pKa values were used to assist Sn-GP for transforming corncob (CC), and a linear equation (Furfural yield = − 7.563 × pKa + 64.383) (R2 = 0.9348) was fitted in acidic condition. Using sugarcane bagasse, reed leaf, chestnut shell, sunflower stalk and CC as feedstocks, co-catalysis of CC (75.0 g/L) with maleic acid (pKa = 1.92) (0.5 wt%) and Sn-GP (3.6 wt%) yielded the highest furfural yield (47.3%) for 0.5 h at 170 °C. An effective furfural synthesis was conducted via co-catalysis with Sn-GP and maleic acid. Subsequently, E. coli CG-19 and TS completely catalyzed the conversion of corncob-derived FAL to furfurylalcohol and furoic acid, respectively. Valorisation of available renewable biomass to furans was successfully developed in tandem chemoenzymatic reaction. Graphical Abstract

AbstractThe catalytic valorisation of biomass to afford synthetically useful small molecules is essential for sustainable biorefinery processes. Herein, we present a mild cascaded electrochemical protocol for converting furoic acid, a common biomass-derived feedstock, into a versatile platform chemical, gamma-butyrolactone. In the platinum(+)|nickel(−) electrode paired undivided cell, furoic acid is electrochemically oxidised with 84.2% selectivity to 2(5H)-furanone, the olefin of which is then hydrogenated to yield gamma-butyrolactone with 98.5% selectivity. The final gamma-butyrolactone yield is 69.1% with 38.3% Faradaic efficiency and 80.1% carbon balance when the reaction is performed with 100 mM furoic acid at 80 °C at +2.0 VAg/AgCl. Mechanistic investigation revealed the critical temperature and electrolyte pH conditions that maximise the production and protection of the key intermediate, furan radical, promoting its transition to 2(5H)-furanone rather than self-polymerising. The reaction is scalable, as 2.1 g of 98.1% pure gamma-butyrolactone is isolated through a simple solvent extraction.

Ce mémoire est relatif à une nouvelle approche d'analyse globale des revalorisations (incluant réemplois, recyclages et autres valorisations) appliquée à tous les types d'entités physiques (matière, énergie, espace). Cette méthode est conçue pour prendre en compte la multiplicité des cycles de vie des ressources et est appelée « l’Analyse des Revalorisations par les Systèmes Cascade » (ARSC). Après une présentation des concepts de base, les différentes méthodes d'analyse des revalorisations sont décrites (notamment les nombreuses versions des Analyses de Cycle de Vie) et sont comparées à la méthode ARSC. La méthode ARSC est ensuite décrite parties par parties puis appliquée à un cas théorique
This PhD develops a new method for the global analysis of recoveries (including reuse, recycling and other waste recove1ies) applied to all types of physical entities (materials, energy, space). This method is designed to take into account the multiple cycles of resources and is called « Analysis of Recoveries with Cascade Systems » (ARCS). After a presentation of basic concepts, the existing methods for environmental analysis of recoveries are described (with a focus on the numerous LCA versions) and are compared with the ARCS method. The ARCS method is precisely described step by step and applied to a theoretical case study

Le café est l'une des boissons les plus populaires à l'échelle mondiale. Entre 2017 et 2022, sa production a augmenté de 2,2% tandis que sa consommation a progressé de 7,7% d'après l'Organisation Internationale du Café. L'unique coproduit solide résultant de l'extraction aqueuse permettant d'obtenir la boisson chaude caféinée est le marc de café. Ce biodéchet représente environ 6 millions de tonnes chaque année.L'objectif principal de cette thèse est de définir et d'évaluer une approche de valorisation en cascade du marc de café, visant à l'épuiser de manière progressive et efficace pour générer différents produits d'intérêt industriel. Pour atteindre cet objectif, deux procédés ont été sélectionnés. Tout d'abord, l'éco-extraction solide-liquide, notamment assistée par ultrasons, a été utilisée pour la récupération des composés phénoliques antioxydants du marc. Puis, de manière séquentielle, la fermentation en milieu solide a été mise en œuvre sur le marc appauvri avec l'aide de Penicillium solitum pour la production d'un cocktail enzymatique hydrolytique.La cascade de valorisation a été appliquée sur un marc qui a été collecté et stocké par la société Gecco (SCG-1), provenant de bars et de restaurants de la région Hauts-de-France. Un marc frais provenant du laboratoire d'accueil de la thèse (SCG-2) a également été étudié, pour une meilleure compréhension des contraintes industrielles liées au stockage. La comparaison de deux méthodes d'extraction appliquées au SCG-1, une conventionnelle (CE) et une assistée par ultrasons (UAE), a permis de mettre en évidence l'influence positive des ultrasons sur la récupération des composés phénoliques antioxydants. L'UAE a permis d'extraire environ 30% de plus de polyphénols totaux (11,8 contre 9,1 mg GAE/g) et de réduire la consommation d'énergie d'au moins 3 fois (170 contre 630 Wh) dans les conditions optimales d'extraction (eau-éthanol 50-50 (v/v), 40 mL/g, puissance de 571 W/L pour l'UAE ou température de 70°C pour la CE). L'application de ces conditions optimisées sur le SCG-2 a permis d'obtenir 23% d'activité antioxydante supplémentaire (77,9 contre 63,5 µmol Trolox/g) dans l'extrait par rapport au SCG-1.L'extrait de composés phénoliques obtenu à partir de SCG-2 dans les conditions d'UAE optimisées montre la présence d'acides chlorogéniques fréquemment retrouvés dans un marc de café avec 4,3 mg/g, 5,9 mg/g et 0,4 mg/g de 3-CQA, 5-CQA et 3,5-diCQA respectivement. Ces trois composés sont absents de l'extrait obtenu dans les mêmes conditions à partir de SCG-1, qui montre la présence d'autres composés aux propriétés antioxydantes formés lors du stockage par divers micro-organismes colonisateurs.Suite à l'isolement et l'identification d'une quarantaine de champignons filamenteux présents sur SCG-1, Penicillium solitum a été retenu pour l'optimisation d'une fermentation en milieu solide (FMS) en vue de la production d'un cocktail enzymatique. Les conditions optimisées d'extraction (7 mL/g, 55 minutes) et de fermentation (74,1% d'humidité, 7 jours d'incubation et un inoculum de 10^7 spores/g) obtenues par modélisation, ont permis de produire un complexe enzymatique avec des activités lipase, mannanase et glucanase sur SCG-1. Au regard de la production de ces mêmes enzymes, les conditions optimales de fermentation sur SCG-2 ont été : (75% d'humidité, 7 jours d'incubation et un inoculum de 8,1x10^6 spores/g). Les activités calculées dans ces conditions par le modèle ont été de 65,3 et 49,5 U/g pour l'activité lipase, 948 et 939 mU/g pour l'activité mannanase, 295 et 206 mU/g pour l'activité glucanase respectivement pour les extraits obtenus à partir des fermentations sur SCG-1 et SCG-2. L'extrait produit sur SCG-1 dans les conditions optimisées par Penicillium solitum montre aussi d'autres activités mesurées avec 56,4 U/g, 626 mU/g et 856 mU/g respectivement d'activité protéase, xylanase et pectinase
Coffee is one of the most popular beverages. According to the International Coffee Organization, between 2017 and 2022, its production increased by 2.2%, while consumption grew by 7.7%. The sole solid co-product resulting from aqueous extraction to obtain the caffeinated hot beverage is spent coffee grounds. This bio-waste represents approximately 6 million tons annually.The primary objective of this thesis is to define and evaluate a cascade valorization approach for spent coffee grounds, aiming to progressively and efficiently exploit this resource to generate various industrially valuable products. To achieve this goal, two processes were selected. Firstly, solid-liquid eco-extraction, including ultrasound-assisted extraction, was used for the recovery of antioxidant phenolic compounds from spent coffee grounds. Subsequently, in a sequential manner, solid-state fermentation was implemented on the depleted grounds with the assistance of Penicillium solitum to produce a hydrolytic enzyme cocktail.The valorization cascade was applied to a type of spent coffee grounds collected and stored by the Gecco company (SCG-1), sourced from bars and restaurants in the Hauts-de-France region. Fresh marc from the thesis host laboratory (SCG-2) was also investigated to gain a better understanding of the industrial constraints related to storage. The comparison of two extraction methods applied to SCG-1, conventional extraction (CE) and ultrasound-assisted extraction (UAE), revealed the positive influence of ultrasound on the recovery of antioxidant phenolic compounds. UAE enabled the extraction of approximately 30% more total polyphenols (11.8 vs. 9.1 mg GAE/g) and consumed at least 3 times less energy (170 vs. 630 Wh) under optimal extraction conditions (50-50 (v/v) water-ethanol, 40 mL/g, power of 571 W/L for UAE, or temperature of 70°C for CE). The application of these optimized conditions to SCG-2 resulted in a 23% additional antioxidant activity (77.9 vs. 63.5 µmol Trolox/g) in the extract compared to SCG-1.The phenolic compound extract obtained from SCG-2 under optimized UAE conditions showed the presence of chlorogenic acids commonly found in spent coffee grounds, with concentrations of 4.3 mg/g, 5.9 mg/g, and 0.4 mg/g for 3-CQA, 5-CQA, and 3,5-diCQA, respectively. These three compounds were absent in the extract obtained under the same conditions from SCG-1, which exhibited the presence of other antioxidant compounds formed during storage by various colonizing micro-organisms.Following the isolation and identification of around forty filamentous fungi present on SCG-1, Penicillium solitum was selected for optimizing solid-state fermentation (SSF) to produce a hydrolytic enzyme cocktail. The optimized extraction conditions (7 mL/g, 55 minutes) and fermentation conditions (74.1% moisture, 7 days of incubation, and an inoculum of 10^7 spores/g) obtained through modeling allowed for the production of an enzymatic complex with lipase, mannanase, and glucanase activities on SCG-1. Regarding the production of these same enzymes on SCG-2, the optimal fermentation conditions were (75% humidity, 7 days of incubation, and an inoculum of 8.1x10^6 spores/g). The activities calculated under these conditions for both types of spent coffee grounds were 65.3 and 49.5 U/g for lipase activity, 948 and 939 mU/g for mannanase activity, and 295 and 206 mU/g for glucanase activity, respectively, for extracts obtained from fermentations on SCG-1 and SCG-2. Additionally, the optimized extract produced on SCG-1 by Penicillium solitum also exhibited other measured activities, with 56.4 U/g, 626 mU/g, and 856 mU/g, respectively, for protease, xylanase, and pectinase activities