Dissertações em Engenharia Química (Mestrado) - PPGEQ/ITEC

URI Permanente para esta coleçãohttps://repositorio.ufpa.br/handle/2011/2309

O Mestrado Acadêmico iniciou-se em 1992 e pertence ao Programa de Pós-Graduação em Engenharia Química (PPGEQ) do Instituto de Tecnologia (ITEC) da Universidade Federal do Pará (UFPA).

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Agora exibindo 1 - 4 de 4

Acesso aberto (Open Access)
Ativação alcalina para a produção de geopolímeros a partir de resíduo industrial
(Universidade Federal do Pará, 2018-02-02) BRITO, Woshington da Silva; SOUZA, José Antônio da Silva; http://lattes.cnpq.br/6157348947425968
The sustainable construction of the future, and has low energy consumption and greenhouse gas emissions must also adopt the principle of reuse of wastes impacting the environment generated by the productive chain. The aluminum production chain has as one of the leading waste impact on the environment the gray generation. The present study focused on the research and development of a cement-based material. Refers to an inorganic polymer, formed by the activation of amorphous aluminosilicates (Al2O3. SiO2), which react in a strongly alkaline medium, called geopolymer. As a raw material furnace fly ash, mineral residue from the combustion of the boilers of the company of the municipality of Barcarena-PA; As a source of aluminosilicate, and the kaolin that underwent the process of burning at 800 ºC that became metakaolin; And the alkaline medium of sodium silicate (Na2SiO3) and sodium hydroxide (NaOH), used as activators. As fly ash partially crystallizes during burning and loses some of its amorphous state, so are its reactive properties to chemically combine during the geopolymerization reaction are reduced. To increase reactive properties of fly ash and added metakaolin. As the main analyzes, no X-ray diffraction (XRD), X-ray fluorescence (FRX), scanning electron microscopy (SEM) and EDS. Tests of resistance to compression of the traces in the hardened state were also carried out and the rheological test of the geopolymer was carried out at the start of the reaction in the fresh state. For Davidovits ratios in the range of 2.5 to 3.23, the best geopolymers with compressive strength were obtained reaching 25 MPa in 24 hours of cure. For 60 days of cure at room temperature the geopolymers reached a resistance of 45, 36 MPa. The research carried out through the characterization analysis of the samples and the mechanical and rheological tests were presented in a satisfactory way and demonstrated that the residues of fly ash and metakaolin, when activated with sodium silicate and sodium hydroxide, are an alternative for the possible application of Geopolymer materials in construction.
Acesso aberto (Open Access)
Estudo de métodos de extração, quantificação dos polifenóis totais, avaliação das atividades antioxidantes e antimicrobianas da casca do caule de Croton palanostigma Klotzsch
(Universidade Federal do Pará, 2017-02-22) RODRIGUES, Cintya Cordovil; BRASIL, Davi do Socorro Barros; http://lattes.cnpq.br/0931007460545219; https://orcid.org/0000-0002-1461-7306; FARIA, Lênio José Guerreiro de; http://lattes.cnpq.br/7428609361678173; https://orcid.org/0000-0002-9534-9998
The Croton palanostigma is popularly known as "dragon blood" and used in folk medicine for the treatment of inflammatory diseases and wound healing. This paper proposes a study between the methodologies of conventional mining and extraction in supercritical carbon dioxide of stem bark of C. palanostigma, aiming to evaluate the extracts obtained income, the amount of total polyphenols, activities, antioxidant and anti-microbial. For the extraction process was conventional used jacketed extractor glass, in addition to a factorial design experiment of three factors and three levels of type Box-Behnken, with the objective of determining which variables (temperature, the extraction time and the relationship between mass/solvent) could influence the process, extraction for quantification of total polyphenols was used the method of Folin-Ciocalteau, with some changes and using the chart acid as a standard of reference, to analyze the antioxidant activity, we used the method of IC50, which measures the concentration needed to reach 50%of decrease in absorbance of DPPH radical and to the analysis antibiological was used the method of microdilution, whose goal was the determination of the minimum inhibitory concentration (CIM) Of all the tests ahead of the bacterial and fungal studied. The extraction methods used were efficient to obtain the extracts, with some qualitative differences, such as for example: color, viscosity and flavor. Quantitatively, the technique of conventional extraction presented a higher yield in their tests, however the same demanded much more time to process and greater amount of material used, both as botanist of solvent, in addition to all the variables assessed in this study were considered significant for the process, while the extraction supercritical the time used was significantly lower, as well as a lesser amount of botanical material and the co-solvent used (ethyl alcohol). For the quantification of total polyphenols found that the conventional extraction test 9 (T=45ºC; t=30 min; g/mL=1:2) was less efficient than those obtained by extracting supercritical (Test 1; T=40ºC; P=100 bar and Test 3; T=60ºC; P=300 bar) and having significant variables for the analysis time and relationship between mass and solvent. For antioxidant activity the best result was to extract conventional (IC50=30.71%) in relation to the test 3 (T=60ºC; P=300 bar) to extract supercritical (IC50=52.36) and having the variables, time and temperature its favorable conditions for the process. To analyze microbial all extracts obtained with the conventional extraction showed, in at least one of their concentrations, inhibitory activity against at least one of the pathogenic strains used in the test. For the samples obtained from the extraction in supercritical carbon dioxide to test 2 (T:60 ºC; P:200bar) showed no inhibitory activity against any bacterial strain used in the test, strain, bacterial Enterobacter did not suffer disqualification for none of the samples of supercritical carbon dioxide at a temperature of 60°C and E. coli also did not inhibit forward samples of extraction supercritical except test 1(T=40ºC; P=100 bar).
Acesso aberto (Open Access)
Simulação da separação e purificação do biodiesel de óleo de palma com CO2 supercrítico
(Universidade Federal do Pará, 2016-07-11) GONÇALVES, Aline Lobato; ARAÚJO, Marilena Emmi; http://lattes.cnpq.br/8983914018546682
Biodiesel has attracted growing attention worldwide in recent years. The production of biodiesel from biomass involves separation and purification steps. The method generally used, the aqueous washing, has major disadvantages such as the generation of wastewater and forming emulsions. The objective of present work is to investigate the biodiesel purification using carbon dioxide, which in supercritical conditions has properties capable of separating glycerol phase of esterified phase (biodiesel), providing higher quality products and less waste. In this study, two simulations were used for analysis and investigation of purification of crude palm oil biodiesel. Both configurations conventionally designed the project process via ethylic route by basic catalysis to the reaction step. The "case 1" used a fractional distillation column for separating excess ethanol and a liquid-liquid column extraction using water as solvent for the separation of glycerol. The "case 2" applied a fractionating column in countercurrent, used for the glycerol separation step, carbon dioxide as supercritical solvent and for separating excess of ethanol, a flash vessel in the final purification of biodiesel. The simulator employed was Aspen HYSYS V8.4 that used binary parameters, adjusted with the equations of state of Soave-Redlich-Kwong (SRK) and Redlich-Kwong-Aspen (RK-ASPEN) to study systems, performed the simulations appropriately. The supercritical CO2 proved to be efficient in the separation of glycerol, given that biodiesel produced with this purification technology met the ANP main standards rules.
Acesso aberto (Open Access)
Síntese de sodalita para adsorção utilizando como fonte de calor a variação de entalpia de dissolução dos reagentes
(Universidade Federal do Pará, 2016-12-29) COELHO, Danilo dos Santos; ROCHA JUNIOR, Carlos Augusto Ferreira da; http://lattes.cnpq.br/9333542718006007; SOUZA, José Antônio da Silva; http://lattes.cnpq.br/6157348947425968
Zeolites are ceramic materials formed by four oxygen atoms enclosing a cation, rearranged in interconnected tetrahedra and presenting channels and "cages" as a framework of open cavities, normally occupied by water molecules and extra-structural cations capable of ion exchange. The objective of this work was to synthesize sodalite zeolite from filler kaolin (CE) with the use of heating mantle and / or heat dissolution of sodium hydroxide and sodium silicate, as well as to evaluate the energy cost of zeolite synthesis Only with heat of dissolution and thus to elaborate through the material synthesized pellets of varied composition of sodalite, and other materials like treated clay, charcoal and hair in order to study the effect on the efficiency in the adsorption of water vapor and copper ion . The zeolite used for the conformation of the pellets was synthesized using calcined filler kaolin at 600 ° C, sodium hydroxide and silicate and distilled water. The zeolitic products as well as the starting materials were characterized by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Thermal Analysis (DSC, DTG, TG). From the reaction conditions studied it was possible to obtain zeolitic material in the short time 3, 6, 9, 12, 15 min using dissolution heat and 30 and 60 min using dissolution heat and heating mantle. Through the zeolitic material obtained, as well as its pellets, water vapor adsorption tests were carried out in systems with and without moisture control, as well as copper ion adsorption in which the final concentration was measured in Uv-1800 model spectrophotometer. The results showed that the adsorption of water vapor with and without moisture control applying pulverized sodalite and pellets had statistically similar values. The adsorption of the copper ion had a good efficiency when compared to other studies available in the literature.

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