Browsing by Author "Queiroz, Ana"
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- 14th International Chemical and Biological Engineering Conference (CHEMPOR-2023): Book of AbstractsPublication . Queiroz, Ana; Peres, António M.; Ribeiro, António E.; Barreiro, Filomena; Ferreira, Olga; Brito, Paulo; Pinho, Simão; Simão Pedro de Almeida PinhoWelcome to the 14th edition of the International Chemical and Biological Engineering Conference (ChemPor-2023) held at Bragança Polytechnic University (Instituto Politécnico de Bragança, IPB), Portugal, from 12 to 15 of September, 2023. This triennial conference, organized by a Portuguese Higher Education Institution and the Portuguese Engineers Association (Ordem dos Engenheiros), gathers experts from the chemical and biological engineering areas and related subjects to exchange knowledge and technological experiences within the academic, industrial, scientific, and technological communities. ChemPor-2023 addresses these research fields in different topics, from green chemistry to engineering education, always envisaging a sustainable development. The etymology of the word “conference”, from the Medieval Latin, means literally “bring together”. This 14th edition comes with a two-year delay following the global sanitary crisis since only a full inperson meeting could fulfill this purpose. ChemPor-2023 encompasses a gathering in a vivid, enlightening, and convivial way, and this hiatus did not limit this spirit or its objectives. The conference aims to celebrate creativity, diversity, and friendship among participants, promoting ideas exchange and fruitful interactions. We have circa 300 delegates from 4 continents, and your active participation is highly acknowledged. The general relevance of ChemPor-2023 is addressed in a variety of settings, including biorefinery, biotechnology, energy and environment, innovative materials, creation and design of novel reaction and separation processes, always foreseeing industrial applications for a sustainable shaping of the future. This edition includes an opening lecture by Jorge Calado in the immense but much less explored area of ArtScience, and an Honor Session dedicated to Alírio Rodrigues for his academic and scientific contributions, particularly regarding IPB. Besides, the conference includes 11 invited lectures from internationally recognized scientists and experts from the industry, 107 oral presentations distributed in 27 sessions, and 135 posters in two dedicated sessions. A session exclusively dedicated to companies and another for Ph.D. studies in industrial environments are to be highlighted. The “Professor Almiro e Castro” award, established in 2014 by PARALAB – Equipamentos Industrial and Laboratory SA, to recognize the scientific merit of a Portuguese professor or researcher in the last three years in the fields of Chemical and Biological Engineering, and related areas, will be announced at the closing of the conference. In that ceremony, the two best posters and the best oral communication awards by young scientists will also be granted. We want to reinforce our deepest appreciation to all the participants, but also to the members of the Honor, Scientific, and Local Organizing Committees for their invaluable contribution to the conference and acknowledge the institutional support of Instituto Politécnico de Bragança, Ordem dos Engenheiros, Centro de Investigação de Montanha, Sociedade Portuguesa de Química, and Câmara Municipal de Bragança. Expressing enormous gratitude is mandatory to all our Sponsors and associated scientific journals and publishers. Nothing could have been possible without all of you! Finally, our best wishes for success for the next ChemPor organization.
- Acid leaching of alloys within the quaternary system Fe-Si-Ca-AlPublication . Margarido, Fernanda; Figueiredo, Maria Ondina; Queiroz, Ana; Martins, João Pedro de AlmeidaSilicon with high purity and fine particle size can be produced by acid leaching of Fe-Si industrial alloys under the condition that they have adequate chemical composition and structural constitution. Such alloys contain phases that fall within the system Fe-Si-Ca-Al, where the quaternary phase Caalsifer, with aproximate formula (Fe0.8Al0.1 0.1) (Si0.8Ca0.2)2, is found along with several binary and ternary phases (Fe-Si, Ca-Si, Al-Fe-Si, Ca-Al-Si). With the purpose of optimizing the phase, constitution alloys were synthesized within the system Fe-Si-Ca-Al. The results of leaching experiments performed using HCl (150 and 220g/L) at constant temperature (T=102 1 C) and ordinary atmosphere indicate that the Caalsifer plus Al-Fe-Si phases should be maximized whereas the FeSi2 phases should be minimized, by controlling Al/Ca and Fe/Si concentration ratios in the synthesis process.
- Acid refining of synthesised alloys within the quaternary system Fe-Si-Ca-Al: effect of ferric ionsPublication . Queiroz, Ana; Margarido, Fernanda; Martins, J.P.A systematic study of synthesis of different chemical composition of alloys within the quaternary Fe-Si-Ca-Al system, versus acid leaching refining using HCl with or without FeCl3 has been undertaken. Such study has the aim of achieving an adequate structural composition of Fe-Si alloys, in order to obtain high purity and fine particle size silicon by acid leaching, at more reduced costs. The experimental results show that an adequate control of Fe/Al and Si/Ca concentration ratios can hinder the formation of tetragonal and orthorhombic FeSi2 phases, and consequently promotes a successful refining of ferro-silicon alloys. The presence of ferric ion influences on a distinct way the rate of removal of Al-Fe-Si and Fe-Al-Si-Ca phases, increasing the first and decreasing the second one. The suitable starting composition which could give the expected results must be the following: 92-94% Si; 3-3.5% Fe; 3.5-4% Al and Ca ≤ 0.5%.
- Acidic waste cooking oil valorization by biodiesel synthesis catalyzed by hydrogen sulfate 1-butyl-3-methylimidazoliumPublication . Baú, Ana; Lenzi, Giane G.; Ribeiro, António E.; Queiroz, Ana; Brito, PauloBiodiesel is a fuel that shows growing demand as a promising alternative to petroleum-derived fuels. It is produced by esterification or transesterification reactions from renewable raw materials such as animal fats and vegetable oils , where the presence of catalysts is used for an effective conversion. The basic catalysts are very sensitive to the presence of water and FFAs, promoting saponification reactions. On the other hand, the use of acid catalysts means reaction times up to 4000 times higher, higher alcohol/oil molar ratios and higher reaction temperatures. In this context, Ionic Liquids (ILs) used as catalysts, come as a viable alternative to overcome these problems in biodiesel production processes. Imidazolium-based ILs, have been extensively studied, mainly due to their specific characteristics such as, low pressure and ability for self-organization in different states. Hydrogen sulfate 1-butyl-3-methylimidazolium [BMIM]HSO4 has been showing promising results in this type of applications. Therefore, the objective of this work is to study the application of the [BMIM]HSO4 IL in the catalysis of esterification/transesterification reactions of triglycerides mixtures with high free fatty acid contents coming from waste cooking oils samples, with further characterization of the quality of the biodiesel produced. The present work includes also the assessment of the catalyst potential for recovery and recycling.
- Acidic waste cooking oil valorization by biodiesel synthesis catalyzed by hydrogen sulfate 1-butyl-3-methylimidazoliumPublication . Baú, Ana; Lenzi, Giane G.; Ribeiro, António E.; Queiroz, Ana; Brito, PauloBiodiesel is a fuel that shows growing demand as a promising alternative to petroleum-derived fuels. It is produced by esterification or transesterification reactions from renewable raw materials such as animal fats and vegetable oils , where the presence of catalysts is used for an effective conversion. The basic catalysts are very sensitive to the presence of water and FFAs, promoting saponification reactions. On the other hand, the use of acid catalysts means reaction times up to 4000 times higher, higher alcohol/oil molar ratios and higher reaction temperatures. In this context, Ionic Liquids (ILs) used as catalysts, come as a viable alternative to overcome these problems in biodiesel production processes. Imidazolium-based ILs, have been extensively studied, mainly due to their specific characteristics such as, low pressure and ability for self-organization in different states.
- Avaliação da atividade antimicrobiana de óleos essenciais de eucalipto (Eucalyptus globulus)Publication . Cidres, Eliana Soraia Santos Alves; Queiroz, Ana; Amaral, Joana S.A espécie E. globulus é considerada a principal fonte mundial de óleo de eucalipto, sendo este constituído por uma ampla gama de compostos, sendo o mais importante o monoterpeno 1,8-cineol. O óleo de eucalipto é amplamente utilizado para fins medicinais, tais como alívio da tosse, dor de garganta e outras infeções, como antissético e utilizado como ingrediente em produtos farmacêuticos e cosméticos. O objetivo deste trabalho foi avaliar a atividade antimicrobiana de óleos essenciais do fruto e folhas do eucalipto obtidos por hidrodestilação em aparelho de Clevenger e também de dois óleos comerciais. No estudo usaram-se bactérias Gram-positivas (Staphylococcus aureus, Bacillus cereus, Bacillus subtilis, Enterococcus faecalis), Gram-negativas (Escherichia coli, Klebsiella pneumoniae, Enterobacter sp., Proteus mirabilis, Pseudomonas aeruginosa) e o fungo Candida albicans. A atividade antimicrobiana dos óleos essenciais do fruto e folhas do eucalipto foi avaliada pelo método da macrodiluição em caldo, tendo sido testadas diferentes concentrações (2,5% a 0,04%, v/v) para determinação da concentração mínima inibitória (CMI). O estudo realizado mostrou que os óleos essenciais comerciais (n=2) e extraídos das folhas (n=3), apresentaram atividade inibitória no crescimento de todos os microrganismos estudados à exceção de P. aeruginosa, cujo crescimento não foi suscetível à presença dos óleos essenciais, mesmo na concentração mais elevada (2,5% v/v). De uma forma geral, o óleo essencial do fruto apresentou uma eficácia inferior comparativamente às amostras comerciais e das folhas, à exceção da bactéria S. aureus, para a qual a amostra do óleo de fruto apresentou o mais baixo valor de CMI (0,16%, v/v).
- Biodiesel production from residual cooking oils and its purification by adsorption processes based on adsorbents of natural originPublication . Garção, Maria Isabella Lima; Gomes, Maria Carolina Sérgi; Queiroz, Ana; Ribeiro, António E.; Brito, PauloTotal global energy consumption has increased significantly in recent decades, and nowadays the main sources of world energy are oil, coal and natural gas. In addition to environmental concerns, the limited availability of fossil fuels has increased the interest in exploring alternative energy sources. In this quest, biofuel is a promising renewable energy source with low carbon emissions, also, it can be produced from a variety of resources, including waste cooking oil (WCO). Biodiesel is renewable, biodegradable, non-toxic, sulfur-free and free of aromatic carcinogens
- 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 of producing biodiesel, while also providing an alternative for the valorization of industrial cork waste. The highest value of removal of 89% of glycerol occurred with a cork chemically activated carbon with KOH at a load of 2%wt at 25°C for 6 hours of contact. After the biodiesel washing using adsorption process, the remaining glycerol content was 0.016%wt, below the maximum value of 0.02%wt specified by the EN14214:2012 standard.
- Biodiesel production from residual cooking oils and purification by adsorption processes based on adsorbents of natural originPublication . Garção, Maria Isabella Lima; Gomes, Maria Carolina Sérgi; Queiroz, Ana; Ribeiro, António E.; Brito, PauloTotal global energy consumption has increased significantly in recent decades. International Energy Agency predicts that from 2012 to 2040, and also the International Energy Agency (IEA), by 2030, the world's demand for energy will increase by 50%. Nowadays, the main sources of energy supply in the world are oil, coal and natural gas. In addition to the environmental problems, the supply of fossil fuels is limited, which makes many researchers increasingly interested in exploring alternative energy sources [1]. In this pursuit, biofuels are promising renewable energy sources with lower carbon emissions, besides the possibility of being made from a variety of resources, including residues such as waste cooking oil (WCO), oily sludge from factories, and discarded animal fats [2]. In contrast to petroleum-derived diesel, biodiesel is renewable, biodegradable, non-toxic, sulphur-free and aromatic carcinogen-free [3]. The cost of biodiesel is now 10% to 50% higher than petroleum diesel. A more possible way to increase biodiesel production is to use WCO as a feedstock, which is 25% to 40% of the price of edible oil. This way, WCO gets a better destination than its discard [3]. Biodiesel is produced through transesterification/esterification which are reactions that convert oils or free fatty acids into alkyl esters. Through transesterification, the triglycerides react with small chain alcohol in order to obtain methyl or ethyl esters of fatty acids and glycerol. The process occurs in three reversible and consecutive reactions, which produce molecules of diglycerides and monoglycerides as intermediates [4]. The properties of biodiesel will depend on the feedstock used in its production, and it should be similar to petroleum diesel in order to be functional in motors without any changes. All parameters, such as cetane number, fatty acid methyl esters content, density, and acid value, are defined by standards and vary depending on the location. For example, in Europe, they are defined by the European Biodiesel Standard EN 14214, whose last version was published in 2008. It is set to specify characteristics that define the behaviour of biodiesel combustion in an engine and also the methods that have to be used to determine those parameters
- Biodiesel production from residual edible oils catalyzed by ionic liquid hydrogen sulfate 1-butyl-3-methylimidazolium, [BMIM][HSO4]Publication . Almeida, Fretson Micaela; Queiroz, Ana; Ribeiro, António E.; Brito, PauloDue to the countless environmental and energy problems related to the burning of fuels from fossil resources, that is, non.renewable fuels such as oil, naturl gas, or coal, leading to a significant decrease in reserves and to an increase in concern about the global warming problem, has led the scientific community to look for sustainable and renewable alternatives