CIMO - Posters em Encontros Científicos Internacionais
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Percorrer CIMO - Posters em Encontros Científicos Internacionais por Domínios Científicos e Tecnológicos (FOS) "Engenharia e Tecnologia::Biotecnologia Industrial"
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- Biodiesel production by transesterification using choline hydroxide as catalystPublication . Lima, Renata; Queiroz, Ana; Ribeiro, António E.; Brito, PauloBiodiesel is a mixture of alkyl esters derived from vegetable oils or animal fat. Itis a biodegradable and renewable fuel and does not contribute to the emission of polluting gases into the atmosphere. Still, its major disadvantage is its relatively high cost, usually regarding production and raw materials costs (Langet al., 2001). Crude oils and fats extracted from plants and animals are alternatives to highly polluting fossil fuels. They are composed of triglycerides, which can be converted into biofuels through transesterification processes. The alcoholysis of vegetable oils or animal fats may be carried out using different catalysts: acids, bases, and enzymes. Basic catalysts, sodium or potassium hydroxide, are about 4,000 times faster than acid catalysts and do not require large amounts of alcohol. On the other hand, ionic liquids (ILs) use in catalytic processes has been studied mainly in the ecological field, as it allows a high recycling efficiency. ILs based on the choline cation (2-hydroxyethyl trimethylammonium) have received much attention, mainly due to its biocompatibility characteristics and potential for various industrial applications. Choline hydroxide (ChOH – see Fig. 1) in particular represents a promising option due to its good catalytic performance in methanol solution and its successful reuse (Fan et al., 2013). This work's main objective was to optimize the methyl transesterification reaction conditions using commercial and waste sunflower oil as raw material and ChOH as catalyst. The possibility of recovering the ChOH catalyst between reaction cycles was also assessed.
- Biodiesel production from residual cooking oils and its purification through adsorption processes using activated carbon prepared from cork wastePublication . Garção, Maria Isabella Lima; Queiroz, Ana; Brito, Paulo; Ribeiro, António E.; Gomes, Maria Carolina SérgiBiodiesel is a renewable fuel that can be produced from waste cooking oil mainly through transesterification . However, from its production results a contaminant called glycerol, which must be removed. Wet washing is the most common method for biodiesel purification, but it has several drawbacks,including high costs and the generation of large amounts of aqueous effluent. This study proposes using activated carbon obtained from industrial cork waste in adsorption as an alternative method for glycerol removal. This approach could potentially reduce the environmental impact and cost ofproducing biodiesel, while also providing an alternative for the valorization of industrial cork waste.
- Estrogen removal through adsorption on carbon materials prepared from biomass wastes: A reviewPublication . Exposto, Bruno Marques; Ribeiro, António E.; Brito, Paulo; Queiroz, AnaCompounds with an ever-growing presence in the biosphere and water. Related to inadequate waste disposal. Emerging pollutant that causes harmful effects in concentrations in the order of μg/L and ng/L. Examples: hormones pharmaceuticals, heavy metals, etc… Class of micropollutants that deregulate the endocrine system in humans and animals . Not easily removed by wastewater and sewage treatment facilities. To solve the issue of estrogen contamination, several separation methods have been proposed. Adsorption has been studied as a viable and practical alternative with a variety of highly efficient adsorbents, such as resins, silica, clays, zeolites, graphene oxides, chitosan, multi-walled carbon nanotubes and activated carbons.
- Remoção de estrogénios por adsorção: Produção de adsorventes a partir de resíduos de cortiça e estudo cinéticoPublication . Exposto, Bruno Marques; Ribeiro, António E.; Brito, Paulo; Queiroz, AnaEstrogénios são hormonas sexuais responsáveis pelo desenvolvimento das características sexuais secundárias femininas. Estes podem ser naturalmente produzidos pelo organismo através das glândulas suprarrenais e gónadas, ou sintetizadas e utilizadas em contracetivos. O principal estrogénio natural é o 17β-estradiol (E2), responsável pela manutenção do ciclo menstrual, sendo a estrona (E1) o seu principal produto metabólico. Já o 17α-etinilestradiol é o principal estrogénio sintético.
- Removal of estrogens from water using activated carbon adsorbent materials prepared from olive stonesPublication . Milani, Eduardo C.; Menezes, Maraísa L.; Diáz de Tuesta, Jose Luis; Ribeiro, António E.; Brito, Paulo; Queiroz, AnaEstrogens belong to the class of water micropollutants named as endocrine disrupting chemicals and are considered persistent substances in the environment. Estrogens are a type of hormones that are continuously released to environment presenting several undesirable effects on aquatic species and human health even when present at very low concentrations (trace levels) . Additionally, it is known that traditional sewage and drinking water treatment plants are not able to remove or degrade these compounds and additional treatments are required. Activated carbons (ACs) are low-cost carbonaceous materials with a high surface area. ACs undergo an activation process in order to increase its adsorption performance. Activation can be performed by physical treatment, in which the organic material is thermal treated with an atmosphere of air, CO2, and water vapor, or also by applying some chemical treatments using generally, strong acids, chloride salts or strong bases. With this work, we present an extensive set of experimental results that shows the valorization of olive stones residues to prepare activated carbons to be used as adsorbent for the removal of estrone (E1), 17β-estradiol (E2) and 17α-ethinylestradiol (EE2) by adsorption from water.
- Study of biodiesel production from waste cooking oil by ethyl transesterification and its purification with the use of activated carbons derived from olive pitsPublication . Camilo, Gabriel L.; Queiroz, Ana; Ribeiro, António E.; Gomes, Maria Carolina Sérgi; Brito, PauloIn recent years, a collective effort is made in search of alternative forms of energy through renewable and more friendly to the environment sources, currently, about 80% of the world consumption of energy comes from fossil fuels. The environmentalm problems associated with the use of these non-renewable fuels include air pollution and global warming. In this scenario, biodiesel presents itself as a renewable fuel, environmentally friendly and with similar characteristics to common diesel. The cost of conventional biodiesel production is higher than the production of diesel from petroleum, since it is produced mainly from high quality virgin oils, it is estimated that 70 to 80% of the total cost of biodiesel production is associated with the cost of their raw materials. Hence, biodiesel production from waste cooking oil (WCO) has become an economic opportunity and an environmental strategy to help address global renewable energy challenges and contribute to a sustainable society.
- Study of biodiesel production from waste cooking oil by ethyl transesterification and its purification with the use of natural adsorbentsPublication . Camilo, Gabriel L.; Gomes, Maria Carolina Sérgi; Queiroz, Ana; Ribeiro, António E.; Brito, PauloIn recent years, a collective effort is being done in search of alternative forms of energy through renewable and more friendly to the environment sources. Thus, currently, about 80% of the world consumption of energy comes from fossil fuels. Some of the most severe environmental problems associated with the use of non-renewable fuels include air pollution and global warming. In this scenario, biodiesel presents itself as a renewable fuel, environmentally friendly and with similar physicochemical characteristics to common diesel. The cost of conventional biodiesel production is higher than the production of diesel from petroleum, since it is produced mainly from high quality virgin oils, moreover it is estimated that 70 to 80% of the total cost of biodiesel production is associated with the cost of their raw materials. Hence, biodiesel production from waste cooking oil (WCO) has become an economic opportunity and an environmental strategy to help address global renewable energy challenges and contribute to a sustainable society.
- Valorization of waste cooking oils through [HMIM][HSO4] ionic liquid-catalyzed biodiesel conversionPublication . Diniz, Heloísa Oliveira Resende; Queiroz, Ana; Ribeiro, António E.; Brito, PauloA recent trend is the search for alternative technologies to fossil fuel-based energy sources. One possible solution is to use biodiesel as a diesel substitute, reducing environmental impacts such as pollutant emissions. Biodiesel consists of a mixture of long-chain fatty acid alkyl esters and is produced by converting vegetable oils or animal fats by transesterification reactions (Ullah et al., 2015). Due to the relatively high raw material cost, there is a need to reduce the final price of biodiesel. Thus, oil sources not competing with the food market, such as waste cooking oils (WCOs), are used. However, these oils show high levels of free fatty acids (FFA), which can cause problems in alkaline transesterification in the classic biodiesel production process. To minimize these problems, ionic liquids (ILs) can be used as catalysts, since they also promote esterificationreactions of FFA to biodiesel. ILs present a few advantages related to their recoverability and reusability, as well as environmental and safety perspectives(Ullah, 2015). Thus, the objective of this work is to study the production of biodiesel by applying 1-methylimidazolium hydrogen sulphate IL([HMIM][HSO4]) as a catalyst in esterification/transesterification reactions with methanol, for oleic acid (OA) and samples of simulated high acidic oils, prepared by a mixture of 40%(w/w) OA and 60%(w/w) WCO. The IL recovery procedure was studied to evaluate the maximum number of recovery cycles that can be performed without significant loss of reaction yield.