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- Acute toxicity evaluation of several compounds involved in fossil fuels biodesulphurisation studiesPublication . Alves, Luís; Paixão, Susana M.; Gírio, FranciscoThe increasing use of fossil fuels has led to increased emissions of sulphur oxides into the air, which is a major cause of acid rain. Legislation already adopted in 2009 stipulates that the maximum level of sulphur allowed in fuels is only 10 ppm. The process of hydrodesulphurization (HDS) used in refineries is based on very expensive physico-chemical techniques, and has limitations in the removal of organic sulphur. As for stricter legislation on the maximum levels of sulphur in fossil fuels, the most HDS recalcitrant compounds needs to be removed. This implies an increase in the intensity of the physical-chemical treatment and inherently its associated costs. As a result, the recalcitrant compounds to HDS represent a significant barrier to the achievement of very low levels of sulphur in some petroleum fractions. The alternative to the physical-chemical treatment could be the use of biological processes (biodesulphurisation) which is more effective for the desulphurization of fossil fuels, especially as the removal of sulphur covalently bound to organic matrices. The biodesulphurisation (BDS) occurs in more mild conditions of operation under conditions of atmospheric pressure and temperature, giving greater specificity of reaction due to the nature of the biocatalysts, not requiring molecular hydrogen. Thus, in the last 15 years there has been an increase of studies involving the use of microorganisms with the ability to specifically remove the HDS recalcitrant sulphur compounds. Several model compounds such as dibenzothiophene (DBT), DBT sulphone or benzothiophene (BT) are used in BDS studies to characterise organic sulphur in coal, coal tars and crude oils. The desulphurising microorganisms are able to remove the sulphur atom from these compounds and use it in their metabolism. However, such compounds are very toxic to the cells. The aim of this work was to evaluate the toxicity of several compounds used in BDS studies, such as DBT and its derivatives and organic solvents used to dissolve these hydrocarbons, to two typical desulphurising strains, namely: Gordonia alkanivorans strain 1B and Rhodococcus eritropolis strain D1. The toxicity bioassays evaluated the inhibitory effect of the studied compounds to the described bacteria by measuring the respiration rate (mg O2/l) under defined conditions in the presence of different concentrations of those compounds. The inhibitory or toxic effect of each chemical at a specific concentration is expressed as a percent of the baseline respiration rate. From these results the several IC50s were estimated and are described in Table 1. These toxicity values showed that strain 1B was less sensitive for almost all of the hydrocarbons, which is an important advantage considering the desulphurisation of fossil fuels process. On the other hand, strain 1B was more sensitive to dimethylformamide (DMF), a typical solvent used in BDS studies. However, a good correlation can be observed between IC50-1B versus IC50-D1 (IC50-D1 = 0.504 x IC50-1B + 2.84; r2 = 0.908, p < 0.05).
- Analytical protocol for the characterization of solid organic fractions: contribution for the biochemical and thermochemical potential assessment of biomass [Poster]Publication . Trancoso, Maria Ascensão; Crujeira, Teresa; Sousa, R.; Calisto, Sandra C.; Branco, J.; Oliveira, Ana Cristina; Passarinho, Paula; Abreu, Mariana; Moura, Patrícia; Gírio, FranciscoABSTRACT: In the scope of the CONVERTE project an optimised and uniformed methodology was developed in order to better evaluate the use of endogenous biomasses for energy production by biochemical or thermochemical processes. A protocol for preparation and characterization was designed and validated by the use of biomass certified reference materials and quality control actions. Extensive analytical work was performed and the results were summarized in accordance with their relevance for either biochemical or thermochemical processes.
- Aplicação da digestão anaeróbia em pequena escala: PortoSantoPublication . Di Berardino, Santino
- Biodiesel from heterotrophic and autotrophic microalgae: a sustainable production [Poster]Publication . Santos, Carla A.; Semião, Filipe; Barata, Carlos; Reis, Alberto
- 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.
- Biofuels and high value added products from the yeast Rhodosporidium toruloides NCYC 921: Strategies towards a true cost-effective and environmentally sustainable integrated multiproduct driven biorefinery [Poster]Publication . Reis, Alberto; Dias, Carla; Caldeira, João; Teles, Marta; Oliveira, Bruno; Passarinho, Paula; Silva, Teresa Lopes daSingle-cell oils (SCO) have been considered a promising source of 3rd generation biofuels mainly in the final form of biodiesel. However, its high production costs have been a barrier towards the commercialization of this commodity. The fast growing yeast Rhodosporidium toruloides NCYC 921 has been widely reported as a potential SCO producing yeast. In addition to its well-known high lipid content (that can be converted into biodiesel), is rich in high value added products such as carotenoids with commercial interest. The process design and integration may contribute to reduce the overall cost of biofuels and carotenoid production and is a mandatory step towards their commercialization. The present work addresses the biomass disruption, extraction, fractionation and recovery of products with special emphasis on high added valued carotenoids (beta-carotene, torulene, torularhodin) and fatty acids directed to biodiesel. The chemical structure of torularhodin with a terminal carboxylic group imposes an additional extra challenge in what concern its separation from fatty acids. The proposed feedstock is fresh biomass pellet obtained directly by centrifugation from a 5L fed-batch fermentation culture broth. The use of a wet instead of lyophilised biomass feedstock is a way to decrease processing energy costs and reduce downstream processing time. These results will contribute for a detailed process design. Gathered data will be of crucial importance for a further study on Life-Cycle Assessment (LCA).
- A biorefinery approach for the simultaneous production of biofuels and bioplastics [Poster]Publication . Ortigueira, Joana; Leite, T.; Pereira, J.; Serafim, L.S.; Silva, Carla; Moura, Patrícia; Lemos, Paulo Costa
- Chemical and bioassay fractionation of chars obtained in the co-pyrolysis of different wastesPublication . Bernardo, Maria; Lapa, Nuno; Gonçalves, Maria Margarida; Mendes, Benilde; Pinto, FilomenaThe present work is devoted to the study chars obtained in the co-pyrolisis of plastics, biomass and tyres wastes. The composition of these chars is not yet well studied and only recent an attempt was made by the aithors to provide some information about the composition and risk assessment of these materials. The objectives of this work were to perform solvent extractions, using differents, in chars obtained in the co-pyrolysis process to evaluate the extraction efficiency by characterising the different solvent extracts obtained as well as the extracted chars, to perform a chemical ans bioassay franctionation in the most toxic crude extraction in order to study the chemical composition of the fractions as well as their individual contribution to the global toxicity of the crude extarct. The results will allow to conclude which solvent should be used in the decontamination of the pyrolysis chars.
- Detoxification of olive mill wastewaters using a packed-bed batch reactorPublication . Paixão, Susana M.; Sàágua, M. C.; Baeta-Hall, Lina; Correia, Anabela; Ribeiro, Belina; Duarte, José CardosoOlive oil production is a traditional agricultural industry in Mediterranean countries and Portugal is one of the ten major producers. This industry generates an effluent, olive mill wastewater (OMW), which does not undergo any treatment and, usually, is stored in evaporation lagoons or spread on the land. Disposal of olive oil mill wastewaters is a serious environmental problem due to its high organic loading, presence of polyphenols and tannins, high content in suspended solids and acidity, which contributes to its ecotoxicity. In this work, a biological treatment system: a packed-bed batch reactor was applied to a Portuguese OMW using its autochthon microbial population as inoculum. Thus, the biodegradation potential of OMW’ microrganisms naturally present in these wastewaters was assessed monitoring several physico-chemical parameters along the process. Ecotoxicity tests (Pseudomonas putida growth inhibition test and Vibrio fisheri growth inhibition test) were carried out to follow the detoxification capacity of the system as well as its potential to be used in the treatment of this type of agroindustrial effluent. In this aerobic treatment, an active microbial community with high degradation ability for the OMW organic load was detected, accounting for 80%, 71% and 61% removal of COD, TSS and phenols, respectively. In addition, a significant decrease in the chronic toxicity of the treated OMW to both bacteria, V. fisheri (62.8%) and P. putida (64.3%), was also observed after 140 days of treatment, highlighting the detoxification potential of the system studied
- Effects of engineered nanoTi02 on aquatic speciesPublication . Picado, Ana; Moita, Liliana; Paixão, Susana M.; Silva, Luís; Diniz, M. S.; Mendonça, E.
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