Browsing by Issue Date, starting with "2023-03"
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- Application of Green Technology to Extract Clean and Safe Bioactive Compounds from Tetradesmus obliquus Biomass Grown in Poultry WastewaterPublication . Vladic, Jelena; Jazic, Jelena Molnar; Ferreira, Alice; Maletic, Snezana; Cvetkovic, Dragoljub; Agbaba, Jasmina; Vidovic, Senka; Gouveia, LuisaABSTRACT: Microalgae are capable of assimilating nutrients from wastewater (WW), producing clean water and biomass rich in bioactive compounds that need to be recovered from inside the microalgal cell. This work investigated subcritical water (SW) extraction to collect high-value compounds from the microalga Tetradesmus obliquus after treating poultry WW. The treatment efficiency was evaluated in terms of total Kjeldahl nitrogen (TKN), phosphate, chemical oxygen demand (COD) and metals. T. obliquus was able to remove 77% TKN, 50% phosphate, 84% COD, and metals (48-89%) within legislation values. SW extraction was performed at 170 degrees C and 30 bar for 10 min. SW allowed the extraction of total phenols (1.073 mg GAE/mL extract) and total flavonoids (0.111 mg CAT/mL extract) with high antioxidant activity (IC50 value, 7.18 mu g/mL). The microalga was shown to be a source of organic compounds of commercial value (e.g., squalene). Finally, the SW conditions allowed the removal of pathogens and metals in the extracts and residues to values in accordance with legislation, assuring their safety for feed or agriculture applications.
- Partitioning and sourcing of evapotranspiration using coupled MARMITES-MODFLOW model, La Mata catchment (Spain)Publication . Francés, Alain Pascal; Lubczynski, Maciek W.ABSTRACT: The new, two-way coupled, distributed and transient MARMITES-MODFLOW (MM-MF) model, coupling land surface and soil zone domains with groundwater, is presented. It implements model-based partitioning and sourcing of subsurface evapotranspiration (ETss) as part of spatio-temporal water balance (WB). The partitioning of ETss involves its separation into evaporation (E) and transpiration (T), while the sourcing of E and T involves separation of each of the two into soil zone (E-soil and T-soil) and groundwater (E-g and T-g) components. The objective of that development was to understand the system dynamics of a catchment with shallow water table, through spatio-temporal quantification of water fluxes and evaluation of their importance in water balances, focusing on the E-g and T-g components of ETss. While the E-g is computed using formulation from published study, the T-g is obtained through a novel phenomenological function, based on soil moisture availability and transpiration demand driven by climatic conditions. The MM-MF model was applied in the small La Mata catchment (similar to 4.8 km(2), Salamanca Province, Spain), characterized by semi-arid climate, granitic bedrock, shallow water table and sparse oak woodland. The main catchment characteristics were obtained using remote sensing, non-invasive hydrogeophysics and classical field data acquisition. The MM-MF model was calibrated in transient, using daily data of five hydrological years, between 1(st) October 2008 and 30(th) September 2013. The WB confirmed dependence of groundwater exfiltration on gross recharge. These two water fluxes, together with infiltration and E-soil, constituted the largest subsurface water fluxes. The E-g was higher than the T-g, which is explained by low tree coverage (similar to 7%). Considering seasonal variability, E-g and T-g were larger in dry seasons than in wet season, when solar radiation was the largest and soil moisture the most depleted. A relevant observation with respect to tree transpiration was that during dry seasons, the decline of T-soil, associated with the decline of soil moisture, was compensated by increase of T-g, despite continuously declining water table. However, in dry seasons, T was far below the atmospheric evaporative demand, indicating that the groundwater uptake by the tree species of this study constituted a survival strategy and not a mechanism for continued plant growth. The presented MM-MF model allowed to analyze catchment water dynamics and water balance in detail, accounting separately for impacts of evaporation and transpiration processes on groundwater resources. With its unique capability of partitioning and sourcing of ETss, the MM-MF model is particularly suitable for mapping groundwater dependent ecosystems, but also for analyzing impacts of climate and land cover changes on groundwater resources.
- Interactions between marine microorganisms and metal: the start point of a new bioinspired solution for corrosion protectionPublication . Marques, Maria João; Jaume, Julien; Diderot, Anthony; Délia, Marie-Line; Basseguy, RegineABSTRACT: Among the strategies currently used to protect metallic materials from corrosion, and thus increase their durability, conversion treatments and coatings can be considered as the most efficient and cost-effective alternatives. However, these techniques must comply with increasingly stringent regulations such as REACH. On another note, in the field of interactions between microorganisms and conductive material, it has been shown that microorganisms can not only accelerate corrosion in some cases (biocorrosion or MIC) but also inhibit it in others, thus protecting the underlying material (MIC Inhibition). In this context, the MICOATEC ANR project is based on the observation that interactions between an aluminium alloy (AA5083) and microorganisms in the marine environment lead to the formation of a protective layer against corrosion. The MICOATEC project aims to develop, via a biomimetic strategy, a new type of process for producing anti-corrosion coatings. The main goal is therefore to translate the natural biotic process into an abiotic technological process for corrosion protection, without replicating the biofilm itself or incorporating active biocompounds into the coating matrix.
- Production of Oligosaccharides from Pine Nut Shells by AutohydrolysisPublication . Torrado, Ivone; Dionísio, Ana; Fernandes, M. C.; Roseiro, Luisa B.; Carvalheiro, Florbela; Pereira, Helena; Duarte, Luís C.ABSTRACT: Pinus pinea nuts are commercial relevant Mediterranean edible forest nuts, with an increasing production and market value, whose industrial processing yields a lignocellulosic by-product, the pine nut shells, currently only used for combustion. Little research has been done on pine nut shells that could support a value-added application for this residue. This work studies for the first time the production of oligosaccharides by autohydrosis, and aims at an integrated upgrade within the biorefinery framework. Autohydrolysis was explored in the temperature range between 150 and 230 degrees C (corresponding to severity factors 2.13-4.63). Oligosaccharides, mainly xylo-oligosaccharides (95% of the total), were the key soluble products, reaching 28.7 g/100 g of xylan of the feedstock at the optimal conditions (log R-0 4.01). Other products were monosaccharides and phenolic compounds that reached 7.8 and 4.7 g/L, respectively, under the most severe conditions. The stability of the oligosaccharides at different temperatures (room, 37 degrees C and 100 degrees C) and pH (between 1 and 11) grant them significant market potential in the food and pharma sectors. The pre-treated pine nut shells by autohydrolysis presented an improved, although low, enzymatic digestibility (14%), and an improved high-heating value, therefore advising their further valorization by thermochemical pathways.
- Corrosion and material protection in green and low carbon energy technologies [Comunicação oral]Publication . Cunha Diamantino, Teresa
- The Economic Sustainability of Variable Renewable Energy Considering the Negotiation of Different Support SchemesPublication . Algarvio, HugoABSTRACT: The increase in the prices of fossil fuels and environmental issues are leading to a high investment in wind power and solar photovoltaic all over Europe, reducing its dependence on imported fossil fuels. The European countries started incentive programs for investment in these renewable technologies, which consisted of fixed and market premium feed-in tariffs. These feed-in schemes involve long-term contracts with updated prices over inflation. These incentives highly increase the investment and installation of new renewable capacity in Europe. They lead to high renewable penetrations in power systems but originate a tariff deficit due to the difference between market prices and the tariffs paid to these technologies. End-use consumers pay the tariff deficit on retail tariffs. This work analyzes the market-based remuneration of variable renewable energy considering different support schemes and the role of risk-sharing contracts in mitigating the spot price volatility. It presents models able to negotiate bilateral contracts considering risk management, notably risk attitude and risk sharing, bid establishment, and clause (by-laws) negotiation. Furthermore, to evaluate the economic sustainability of renewable generation in Spain, it presents a study for different 12-year support schemes starting in 2010. The results confirmed that, in the case of using risk-sharing contracts during crisis periods, the incidence of low energy prices (price "cannibalization") decreases, such as the tariff deficit. Furthermore, in the case of high-inflation periods, these contracts hedge against the increase in retail prices, resulting in an economic surplus for consumers.
- Flexibility chart 2.0: An accessible visual tool to evaluate flexibility resources in power systemsPublication . Yasuda, Yoh; Carlini, Enrico Maria; Estanqueiro, Ana; Eriksen, Peter Børre; Flynn, Damian; Herre, Lars Finn; Hodge, Bri-Mathias; Holttinen, Hannele; Koivisto, Matti; Gómez-Lázaro, E.; Martínez, Sergio Martín; Menemenlis, Nickie; Morales-España, Germán; Pellinger, Christoph; Ramos, Andrés; Smith, Charlie; Vrana, Til KristianABSTRACT: Various aspects of power system flexibility are evaluated within the multi-country study framework of IEA Wind Task 25. Grid components and actions which have been adopted for enhancing flexibility in different areas, countries, regions are addressed, as well as how Transmission System Operators, Independent System Operators, Utilities intend to manage variable generation in their operating strategies. A visual assessment to evaluate the diversity of flexibility sources, called a “flexibility chart”, is further developed to illustrate several flexibility parameters (e.g., hydropower, pumped hydro, gas turbine, combined heat and power, interconnection and battery) in a polygonal radar (fan-shaped) chart. This enhanced version of the Flexibility Chart is an “at-a-glance” and “easy-to-understand” tool to show how to estimate the potential of flexibility resources in a given country or area, and is accessible for non-technical experts. The Flexibility Chart 2.0 is also a useful tool to compare the past and future flexibility of a system. Comparing the historical change of flexibility resources may not only be helpful to discuss energy policy in regions with high installed variable renewable generation, but also to contribute to the discussion in other regions where renewables have not been widely adopted yet.
- Quality of urban climate adaptation plans over timePublication . Reckien, Diana; Buzási, Attila; Olazabal, Marta; Spyridaki, Niki-Artemis; Eckersley, Peter; Simoes, Sofia; Salvia, Monica; Pietrapertosa, Filomena; Fokaides, Paris; Goonesekera, Sascha M.; Tardieu, Léa; Balzan, Mario V.; de Boer, Cheryl L.; Hurtado, Sonia De Gregorio; Feliu, Efren; Flamos, Alexandros; Foley, Aoife; Geneletti, Davide; Grafakos, Stelios; Heidrich, Oliver; Ioannou, Byron I.; Krook-Riekkola, Anna; Matosović, Marko; Orru, Hans; Orru, Kati; Paspaldzhiev, Ivan; Rižnar, Klavdija; Smigaj, Magdalena; Csete, Mária; Viguie, Vincent; Wejs, AnjaABSTRACT: Defining and measuring progress in adaptation are important questions for climate adaptation science, policy, and practice. Here, we assess the progress of urban adaptation planning in 327 European cities between 2005 and 2020 using three 'ADAptation plan Quality Assessment' indices, called ADAQA-1/ 2/ 3, that combine six plan quality principles. Half of the cities have an adaptation plan and its quality significantly increased over time. However, generally, plan quality is still low in many cities. Participation and monitoring and evaluation are particularly weak aspects in urban adaptation policy, together with plan 'consistency'. Consistency connects impacts and vulnerabilities with adaptation goals, planned measures, actions, monitoring and evaluation, and participation processes. Consistency is a key factor in the overall quality of plans. To help evaluate the quality of plans and policies and promote learning, we suggest incorporating our ADAptation plan Quality Assessment indices into the portfolio of adaptation progress assessments and tracking methodologies.
- Anaerobic Digestion of Microalga Chlorella protothecoides and Metagenomic Analysis of Reddish-Colored DigestatePublication . Eusebio, Ana; Santos, Carla A.; Marques, Isabel PaulaABSTRACT: Microalga Chlorella protothecoides materials were assessed as substrates for anaerobic digestion (AD) aiming at the simultaneous production of biogas/methane and pigments: whole autotrophic (AA) and heterotrophic algae (H); extracted heterotrophic microalgae from lipid production (HExt); and pretreated heterotrophic microalgae through enzymatic (HPEnz), autoclave (HPA), and ultrasound (HPU) processes. AA was more suitable for AD than H, as it was more efficiently converted into methane (279 vs. 180 L CH4/kg VSin). In comparison, the pretreatment of heterotrophic microalgae had a positive effect on AD, with registered methane yield increases from 263 to 290 L CH4/kg VSin (HPU, HPA, HExt). Reddish pigmentation developed in H and HPU units due to the presence of purple non-sulfur bacteria (PNSB). This phenomenon and the changes in microbiota structure during AD were confirmed by metagenomic analysis. At the end of the process, the relative abundance of Clostridiales and Bacillales increased, enhancing the hydrolysis of compounds in acetate. Consistently, Methanosaeta became the comparatively dominant methanogen, meaning that methane was produced through the acetoclastic methanogenesis pathway. The obtained results indicate for AD biorefinery feasibility-regarding the simultaneous production of biogas/methane-a digestate flow and pigments (bacteriochlorophyll a and carotenoids).
- BIOFLEXPOR Technology towards 2G Bioethanol Biorefineries [Poster]Publication . Marques, Susana; Lopes, Tiago; Paixão, Susana M.; Alves, Luís; Carvalheiro, Florbela; Coelho, Lucas; Diebold, Eduardo; Gírio, FranciscoABSTRACT: By 2030, decarbonizing the transport sector will become mandatory requiring the introduction of advanced biofuels into the market, with minimum targets of 1% in 2025 and 3.5% in 2030 in accordance with the RED II Directive. To avoid future biofuels imports, it is essential that an industrial cluster emerges in Portugal with the capacity to produce advanced biofuels, such as 2G Bioethanol. In this context, the team from Bioenergy and Biorefineries Unit (UBB) of LNEG (Laboratório Nacional de Energia e Geologia) has been actively working on the development of an innovative and fully integrated technological strategy to produce advanced bioethanol using agricultural and forestry residual biomass as sustainable feedstock. The target is the demonstration, at relevant environment, all stages of the production technology, enabling the direct obtention of a biofuel that complies with EN standards, allowing its immediate blending with other fuels, such as gasoline. The prototype is based on a proprietary non-catalyzed steam explosion technology, i.e., without the addition of acids and using only high-pressure steam, called FLEXBIO™, initially developed by the company Stex and since 2019 in partnership with LNEG. The LNEG team has also been conducting R&D aiming at the development of new yeasts and enzymes that enhance the conversion of both cellulosic and hemicellulosic fractions of biomass. All technology will be environmentally sustainable, in terms of GHG emissions and waste production, promoting the circular bioeconomy. This innovative technology for a 2G bioethanol biorefinery, enabling to obtain a biofuel with high energy quality and sustainable origin from different types of biomasses, has been demonstrated in a relevant environment (TRL 5) in a prototype simulating (at scale 1:15) the commercial installation, under the BIOFLEXPOR project. The consortium is led by the company Prio Bio, S.A., the largest producer of biofuels in Portugal, and includes, in addition to LNEG, I.P., teams from CBE (Centro de Biomassa para a Energia) and Florecha – Forest Solutions, S.A. (Forest Solutions). The technology - under optimization but already demonstrated for the conversion of corn stover, olive tree pruning and eucalyptus-based forest residual biomass, yielding close to 150 L Ethanol /ton biomass (oven-dried weight) - will respond to a lack of economically viable technical solutions for small-scale biorefineries that process 200-700 tons/day of biomass, corresponding to a nominal bioethanol production capacity of 10,000-30,000 ton/year. It may therefore be close to a commercial application, which will be of strategic importance for the BIOFLEXPOR consortium, and for the LNEG team.