UB - Comunicações em actas de encontros científicos internacionais
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- Agro-food industry residues for biodiesel production: BIOFFA projectPublication . Costa, Paula; Lukasik, Rafal M.; Passarinho, Paula; Oliveira, Ana CristinaThe aim of the project BIOFFA is to develop processes for the production of biofuels from residual raw-materials with high free fatty acid (FFA). In technological terms, two distinct approaches, leading to different final products, are being assessed: production of fatty acid methyl esters (FAME) – biodiesel, and hydrogenated oil – H-oil. Different residues available in Portugal, including poultry fat, cattle fat, olive pomace oil and used frying oils, were collected and characterised, and the objectives of the project will be considered to be met if it will be possible to produce mixtures of both biofuels (biodiesel + H-oil) similar to the nowadays commercially available formulas (biodiesel + petro-diesel) with the superior advantages of valorising residues and producing the overall mixture from biological materials.
- An expedite methodology for identification of inorganic contaminants in biomass origin feedstock: wavelength dispersive x-ray fluorescence (WD-XRF) spectrometryPublication . Crujeira, Teresa; Trancoso, Maria Ascensão; Oliveira, Ana CristinaABSTRACT: The use of biomass feedstock for bioenergy production has increased in recent years. In the context of a circular economy, wastes such as municipal solid wastes and industrial wastes (namely by-products from agrofood wastes, agro-livestock wastes and sewage sludge) have been tested as new feedstocks of biomass origin. However, the presence of some inorganic contaminants in these new feedstocks might be problematic for thermochemical and biochemical conversion processes. Wavelength Dispersive X-Ray Fluorescence (WD-XRF) spectrometry is an easy and fast technique that uses only a small amount of sample, presenting a low contamination risk and is a non-destructive methodology. Thus, if potential contaminants are identified, then samples remain available for subsequent analysis.
- Anaerobic digestion experiment using Cynara Cardunculus L. StalksPublication . Oliveira, I. D. B.; Di Berardino, Santino; Gominho, Jorge; Duarte, E.
- Anaerobic digestion of a fish processing industry sludgePublication . Carvalho, L.; Di Berardino, Santino; Duarte, E.Due to the fact that all fish processing plants operating in Portugal send their sludge from the wastewater treatment process to landfill, and because it is a costly management policy, the aim of this work was to assess the potential use of this substrate for the production of biogas through the anaerobic process technology. Anaerobic digestion has long proven to be an efficient way for the production of a renewable fuel – Biogas - that can be used as a source of energy to produce electricity and heat. This renewable energy resource can be used to reduce the plant processing costs, reducing also the industry carbon footprint. So, the produced sludge becomes a valuable sub-product of the wastewater treatment process instead of being considered a waste, with disposal costs associated. In this study we performed mesophilic (35 ± 1°C) batch assays during 51 days. The inoculum used was from an anaerobic digester operating in a municipal WWTP, also at mesophilic conditions. The anaerobic digestion of the fish sludge produced 700 m3 of CH4/ton SV, which is a really promising result.
- Anaerobic digestion process for biogas and biomolecules production: microflora identification and characterizationPublication . Eusebio, Ana; Chaves, S.; Tenreiro, R.; Almeida-Vara, Elsa; Morana, A.; Ionata, E.; La Cara, F.; Marques, Isabel PaulaThe anaerobic process was efficient in organic matter removal. During the process, an interesting compound as quercetin was produced inside of reactor. Phylogenetic analysis showed the presence of phylotypes affiliated with gamma-Proteobacteria, Choroflexi, and Bacteroidetes. Archaea were represented by phylotypes belonging to the genus Methanosarcina and Methanosaeta.
- Application of ionic liquids for bacterial carotenoid extractionPublication . Salgado, Francisco; Silva, Tiago; Alves, Luís; Roseiro, J. Carlos; Lukasik, Rafal M.; Paixão, Susana M.ABSTRACT: One of the ways to make microbial bioprocesses more economically viable is to enhance valorization of high added value products resulting from the biomass, like carotenoids, which have a high market value. To recover these pigments from microbial biomass a good extraction method is required. Solvent extraction is one of the methods commonly used to extract carotenoids, however, solvent extractions are both material and time-consuming, and moreover also present some health and safety concerns. Ionic liquids (ILs) are a promising step forward to tackle some of these problems, even with their high price, and has been tested for the extraction of microorganism’s components. These “molten salts” are a group of compounds that have been known for a long time, but only in the last decades they have been attracting more attention from both researchers and industry. ILs are solvents that have a high solvation power for a wide range of molecules. ILs are salts with a melting point below 100ºC, which possess unique properties that depend on both the cation and anion present, high thermal and chemical stability, a large electrochemical window, great solvent power, non-flammability, and a negligible vapor pressure. Their versatility is one of their most attractive features, making them adaptable to many technologies. Therefore, ILs can be used to facilitate chemical reactions, extraction and separation, biotransformation, and can be used in biorefineries and other processes. As shown in previous works, Gordonia alkanivorans strain 1B has the capacity to produce carotenoids, however, since it was originally isolated form hydrocarbon rich environments, it is highly resistant to different organic solvents commonly used in extraction protocols. This makes the process slow and laborious, lowering yields and increasing solvent spending. As such, new extraction protocols must be developed and tested to obtain higher pigments yield. So, herein, the potential of ILs for carotenoids extraction was evaluated, since these compounds have been described as a good option to extract pigments produced by microorganisms.
- Bio-Hydrogen production from glycerol by a strain of Enrerobacter aerogenesPublication . Marques, Paula; Bartolomeu, M. Lourdes; Tomé, M. Manuela; Neves, L. M.In this work, H2 production by a strain of Enterobacter aerogenes using as substrate pure glycerol and glycerol-containing biodiesel wastes was compared. The effect of physico-chemical parameters such as temperature, initial substrate and biomass concentrations on the bio-hydrogen production efficiency was investigated. The influence of the simultaneous removal of gases produced was also evaluated The results obtained showed that a decrease of the process temperature of 37 to 30 ºC leads to both, an increase of the bio-hydrogen production rate and a decrease of the equilibrium time of the process. Furthermore, it was also observed that using 10 g/dm3 of pure glycerol or biodiesel wastes containing the same concentration of glycerol as substrate lead to very similar bio-hydrogen production yields (2.5dm3 H2/dm3 fermentation medium). This proves that the performance of the strain of E. aerogenes used was not influenced by the presence of other components than glycerol in biodiesel residues, at least for the biodiesel wastes concentration studied. Simultaneous removal of gaseous phase (mainly H2 and CO2), with its production, shows to be very efficient leading to an increase of the value of the H2/CO2 volumetric ratio, in the headspace, from 2 to 8, which is very promising regarding costs involved in the technologies for purification of H2 produced.
- Bioactive compounds through anaerobic digestion of heterotrophic microalgae residuesPublication . Morana, A.; Squillaci, G.; Santos, Carla A.; La Cara, F.; Marques, Isabel PaulaSeveral important biomolecules are available into anaerobically digested effluents that were obtained from the biodiesel production process using heterotrophically grown microalga Chlorella protothecoides. Defatted microalgae residues and crude glycerol may undergo anaerobic digestion, separately and in admixture, providing methane/hydrogen and a digestate exploitable for agriculture applications. Furthermore, industrial interesting bioactive compounds such as polyphenols provided with antioxidant activity can be obtained. Anaerobic process offers a promising chance and can be advantageously combined with algae lipid-extraction techniques in order to make it more sustainable.
- Biodegradation ability of three bacterial strains isolated from a Jacto reactor used for the treatment of an agro-industrial effluentPublication . Eusebio, Ana; Mateus, Marta; Baeta-Hall, Lina; Sàágua, M. C.; Gadanho, M.; Tenreiro, R.; Almeida-Vara, Elsa; Duarte, José Cardoso
- Biodesulfurization biorefinery using Gordonia alkanivorans strain 1B: life cycle inventory of the integrated processPublication . Silva, Tiago; Silva, Carla; Paixão, Susana M.; Alves, LuísABSTRACT: High sulfur concentrations are a problem common to fossil fuels and derivatives (such as oil and coal), as well as many new generation fuels and biofuels (such as pyrolysis oils, syngas, biogas or even biodiesel). If the sulfur present in these fuels is released into the atmosphere it can result in SO2/SOx emissions, leading to environmental damage, and health issues. Transportation fuels have sulfur limits that go below 5000 ppm in ships, 3000 ppm in airplanes and 10 ppm in cars, and without treatment fuels can have several thousand ppm of sulfur. As such, they must be submitted to desulfurization, typically through a thermochemical process known as hydrodesulfurization, in which H2 is combined with the fuel at high temperatures and pressures, in the presence of metal catalysts. However, this process has significant environmental impacts. Usually, it depends on hydrogen and heat/steam produced from natural gas, totalizing 4.17 kg natural gas per 2.89 kg sulfur removed. It also involves high electricity and water consumption (approximately 2.9 kWh and 86.9 kg, respectively, per 2.89 kg sulfur removed). Furthermore, these impacts are greater for lower sulfur demands (Burgess & Brennan, 2001). Thus, there has been a search for alternative/complementary processes, one of which is biodesulfurization (BDS). It consists of the use of microorganism that consume the sulfur present in the fuels, at ambient temperature and pressure, without the need for metal catalysts. BDS still presents several bottlenecks, common to many microbial processes, such as low conversion rates and high production costs for the microbial biocatalyst. To surpass these limitations researchers have pursued different strategies: minimization/optimization of culture medium and culture conditions; employment of cheaper alternative nutrient sources; exploitation of added value products. Gordonia alkanivorans strain 1B is a bacterium known for its biodesulfurization properties. It has demonstrated several characteristics which make it interesting: it can perform BDS of different compounds, several of which extremely recalcitrant for the thermochemical process; it has very low nutritional needs; it can be cultivated on several alternative carbon sources; it has been shown to produce two different types of added value products: carotenoids and biosurfactants (Alves et al., 2015; Silva et al., 2020, 2022). Therefore, G. alkanivorans strain 1B is the ideal candidate for a biodesulfurization biorefinery, that simultaneously removes sulfur from fuels and produces carotenoids and biosurfactants.