Programa de Pós-Graduação em Engenharia Química - PPGEQ/ITEC

URI Permanente desta comunidadehttps://repositorio.ufpa.br/handle/2011/2308

O Programa de Pós-Graduação em Engenharia Química (PPGEQ) do Insituto de Tecnologia (ITEC) da Universidade Federal do Pará (UFPA). Sendo aprovado pela CAPES / MEC em 1991, foi oficialmente iniciado em março de 1992.

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Acesso aberto (Open Access)
Adsorção de ácido 2,4-diclorofenoxiacético em carvão ativado granular de resíduos de buriti (mauritia flexuosa l.): estudo em batelada e leito fixo. Orientador: Lênio José Guerreiro de Faria. 2024. 135 f.
(Universidade Federal do Pará, 2024-12-27) ARAÚJO, Raíssa Cristine Santos de; FARIA, Lênio José Guerreiro de; http://lattes.cnpq.br/7428609361678173
Pesticides, when applied responsibly, are essential for agricultural productivity, however, depending on their dosage or frequency of exposure, they can cause numerous problems for human health, in addition to the contamination of soil and surface or underground water. Following this problem, this manuscript aimed to evaluate the adsorption of the herbicide 2,4- dichlorophenoxyacetic acid (2,4-D) using physically activated granular carbon (CAT) and chemically activated granular carbon with ZnCl2 (CAQ) produced from the endocarp and endosperm of buriti (Mauritia flexuosa L.), typical fruit from the Amazon region. The adsorbents were characterized in terms their textural and physicochemical properties through the percentage of ash, moisture, specific surface area (SBET), pore volume (Vtotal), by SEM/EDS, XRD, FTIR spectroscopy, TGA/DTA, the surface functional groups, point of zero charge (pHPCZ) and the surface pH of the carbon. Batch adsorption tests were carried out to elucidate the influence of activated carbon dosage and the effect of solution pH. The adsorption mechanisms and the nature of the process were investigated by studying the kinetics, equilibrium and thermodynamics for the coal with the highest performance. The best results for adsorbate removal percentage were CAT (96.93%) and CAQ (92.46%) and the adsorption capacity CAT (29.00 mg.g-1 ) and CAQ (137.70 mg.g -1 ) within 24 hours, pH 2.0 and dosage of 0.25 g of CAT and 0.05 g of CAQ. The CAQ adsorbent showed superior results in removal and adsorption capacity, with its kinetics fitting the pseudo-second order model, with external diffusion being the determining stage of the adsorption process. The isotherms were satisfactorily fitted to the Sips model. The thermodynamic data revealed the endothermic, physical and spontaneous nature of the adsorption process. The adsorption on fixed bed confirmed that the adsorvent mass, concentration of solution and the inlet flow were influent in the adsorption process, highlighting the efficiency of simultaneous optimization tecnic, within the experimental region explored in this work. Both interactions showed that the charcoals produced present high yield, with the development of pores and surface groups, and excellent performance in removing the 2,4-D herbicide, promising substitutes for commercial carbons.
Acesso aberto (Open Access)
Adsorção monocomponente e binária de antiinflamatórios não esteroidais (Ibuprofeno e Diclofenaco) do meio aquoso por carvão ativado de resíduos da castanha-do-Brasil (Bertholletia excelsa H.B.K.)
(Universidade Federal do Pará, 2024-09-12) SILVA, João Paulo Sousa da; VIEIRA, Melissa Gurgel Adeodato; http://lattes.cnpq.br/6611289393148830; CARVALHO, Samira Maria Leão de; http://lattes.cnpq.br/6192858937057152
Emerging contaminants (ECs) present in low concentrations have caused damage to water bodies. This study investigated the single-component and binary adsorption of sodium ibuprofen (IBU) and diclofenac (DIC) using activated carbon (AC) produced from Brazil nut shells. The single-component adsorption process of IBU and DIC by AC was denoted as (AC_IBU and AC_DIC), and the binary adsorption process was denoted as (AC_IBU+DIC). The AC was synthesized by chemical activation using phosphoric acid (H3PO4) as the activating agent. The AC was characterized through physical, chemical, and textural analyses, including moisture content, ash content, yield, Thermogravimetric Analysis/Differential Thermal Analysis (TGA/DTA), X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy/Energy Dispersive X-ray Spectroscopy (SEM/EDS), surface pH, point of zero charge (pHPZC), Boehm titration, and nitrogen (N2) adsorption/desorption at 77 K. The AC presented moisture and ash contents of 8.62% and 4.2%, respectively. The XRD analysis confirmed the amorphous nature of the AC, while FT-IR, surface pH, and pHPZC analyses indicated its acidic nature. The specific surface area (SBET) of the AC was 1,383.624 m².g-1 , with a predominance of micropores (VMIC=77.88%). From the analysis of the Central Composite Rotational Design (CCRD), the experimental conditions for the kinetic and equilibrium adsorption tests were defined for single-component adsorption: (i) IBU (pH = 6.1; initial adsorbate concentration, C0 = 50 mg.L-1 ; adsorbent dosage, DA = 0.5 g.L-1 ) and (ii) DIC (pH = 5.5; C0 = 50 mg.L-1 ; DA = 0.5 g.L-1 ). In the single-component adsorption kinetics study, the pseudofirst-order (PFO) and pseudo-second-order (PSO) models resulted in the best fits to the experimental data for the AC_IBU and AC_DIC adsorption processes, respectively, and external mass transfer was the rate-controlling step of the processes. In the singlecomponent adsorption equilibrium study, the Langmuir, Freundlich, Sips, DubininRadushkevich, and Redlich-Peterson isotherms were investigated. The Sips and Freundlich models showed the best correlations for AC_IBU and AC_DIC, respectively. The thermodynamic parameters calculated from the adsorption isotherms showed that the AC_IBU and AC_DIC processes are spontaneous, favorable, and exothermic. The CCRD, the experimental conditions for the binary adsorption kinetics and equilibrium tests were defined: (i) AC_IBU+DIC (C0IBU = 50 mg.L -1 ; C0DIC = 50 mg.L-1 ; DA= 0.5 g.L-1 ). Binary adsorption indicated, through the calculation of the separation factor parameter, that the adsorption preference order by the adsorbent is IBU > DIC, and the interaction between the adsorbates was antagonistic. In the binary adsorption process, the PSO model was well fitted to the experimental kinetics data of IBU and DIC; the intraparticle diffusion (IPD) kinetic models and the Boyd equation were correlated with the experimental data, and external mass transfer was the rate-controlling step of the adsorption processes. The isotherms of binary adsorption (AC_IBU+DIC) at different temperatures (26 ºC, 45 ºC, and 55 ºC) showed inflection points, and after these inflection points, there was an increase in the adsorption capacity values of AC (qe). The qe values of binary adsorption (AC_IBU+DIC) were lower than the qe values of the singlecomponent adsorption processes of the adsorbates IBU and DIC. The reduction percentages of the qe values were approximately 35% to 48% for IBU and about 52% to 53% for DIC.
Acesso aberto (Open Access)
Análise experimental da secagem do corante hidrossolúvel de urucum (Bixa orellana L.) em leito de jorro
(Universidade Federal do Pará, 2016-02-15) SILVA, Adriano Gomes Paixão da; FARIA, Lênio José Guerreiro de; http://lattes.cnpq.br/7428609361678173; https://orcid.org/0000-0002-9534-9998; COSTA, Cristiane Maria Leal; http://lattes.cnpq.br/0581730621014796
The water-soluble dye annatto norbixin salt is mainly used in the pharmaceuticals industry, cosmetics and especially in industrial food sector in breads, sausages, yogurts, confectionery, pasta, cheese, sandwich cookies, juice concentrates and others. The low toxicity and its coloring ability make the annatto norbixin salt a very attractive and convenient dye, replacing many synthetic dyes. These characteristics encourage to seek ways to facilitate the use of natural dyes in the various segments of industry, as well as promoting research about obtaining in order to get a product with the desired characteristics and qualities. This work it is carried out experimental analysis of water soluble dye drying annatto (Bixa orellana L.) in spouted bed, using cassava starch as a carrier agent and particles of low-density poliestileno (LDPE) as an inert material. The extraction of the dye was carried out by immersion and agitation of annatto seeds in 5% potassium hydroxide solution. It is statistically evaluated the influence of the drying process input variables, temperature (70, 80 and 90 ° C), atomization pressure (10, 15 and 20 psi), and atomization of the suspension flow (10, 7 and 8.5 mL/min) one the response variables: efficiency (η), moisture content (U) and norbixin salt content of the dye powder (S), using Statistica®7.0 application. The estimate of the optimum condition of drying within the analyzed experimental area is determined based on the input variables applying the concept of global desirability. The conditions in this work, it was reached a optimum value of Desirability Function considered as very good and that matches the temperature of the drying air 82.6 °C, atomization pressure of 13.7 psi and flow of suspension dye 10 ml / min, generating satisfactory values for the response variables corresponding to 71.69 % yield, 0.06161 g H2O/g dry solids of moisture and 2.3605 % dye of norbixin salt powder.
Acesso aberto (Open Access)
Aproveitamento da torta de dendê (elaeis guineenses) para a produção do acetato de celulose
(Universidade Federal do Pará, 2022-06-17) MORAES JUNIOR, Elio Ferreira de; ALMEIDA, Ossalin de; http://lattes.cnpq.br/7040173036131516; HTTPS://ORCID.ORG/0000-0003-3895-0952; CHAVES NETO, Antônio Maia de Jesus; http://lattes.cnpq.br/3507474637884699; https://orcid.org/0000-0002-9730-3512
This work aimed to produce cellulose acetate (CA) from in natura palm kernel pie (TD) it was subjected to different chemical treatments: bleaching (TDB), alkaline (TDA) and alkaline followed by bleaching (TDAB). The CA was obtained from the different materials by homogeneous acetylation in the mass ratios: 1:5, 1:10 and 1:15 (acetic acid), 1:15 (acetic anhydride) and 1:0.1 (sulfuric acid). Reactions were carried out at room temperature under constant stirring (120 rpm, 24 h). The characterization was performed using scanning electron microscopy (SEM), infrared spectroscopy (FTIR) and nuclear magnetic resonance (1H and 13C-NMR) techniques. The degree of substitution (GS) was determined by titration with 0.25 mol.L-1 sodium hydroxide solution, being confirmed by FTIR and 1H and 13C NMR with different GS. The CA synthesized from the combination of pre-treatments presented DS of 2.81 (TDAB5), 3.02 (TDAB10) and 3.07 (TDAB15), being, therefore, it characterized as cellulose triacetate, corresponding to the yield values (m/m) of 50.45%, 65.5% and 97.21%. By analyzing the results, TDAB15 was the best condition for obtaining cellulose acetate from palm kernel cake.
Acesso aberto (Open Access)
Aproveitamento de resíduos sólidos da mandiocaba (Manihot esculenta Crantz) para o desenvolvimento de bioadsorventes
(Universidade Federal do Pará, 2023-07-10) DIAS, Rafael Silva; MARTELLI, Marlice Cruz; http://lattes.cnpq.br/1213009262936026; BRASIL, Davi do Socorro Barros; http://lattes.cnpq.br/0931007460545219; https://orcid.org/0000-0002-1461-7306
The chemical contamination of water by dyes resulting from the disposal of industrial effluents triggered the need to develop technologies to remove such pollutants. Occurring naturally in the Amazon region, cassava differs from other cassava varieties in that it has high humidity and low starch yield. As part of a project on cassava technologies, this study analyzed the best conditions for the production of activated carbon from cassava solid waste for the adsorption of methylene blue dye. The Box-Behnken experimental design was used to determine the optimal production conditions. First, a physical-chemical analysis of the precursors was carried out, then 30 coal samples were produced according to the experimental plan. The maximum adsorbed amount and percentage of removal were determined under finite bath conditions, at a concentration of 120 mg/L and with 0.01 g of coal sample. The best conditions of temperature, acid concentration and heat contact time were observed at 600 ºC, 25 % and 3 h for peel and 600 ºC, 10.2 % and 3 h for pulp. These samples were subjected to physical-chemical and morphological characterization analyzes using scanning electron microscopy and Fourier transform infrared. For the adsorption kinetics tests, the models that best fitted the experimental data were intraparticle diffusion for shell and pulp coals, and for the adsorption equilibrium tests, the Freundlich and Langmuir models best fitted the experimental data for shell and pulp, respectively. Analysis of the adsorbents reveals a lower concentration of functional groups, however, in the pulp adsorbent, the loss of functional groups related to groups containing oxygen can be observed, which may help explain the lower adsorption capacity observed for pulp adsorbents. The activated carbons produced from the solid residues of cassava roots (pulp and peel) showed that, under the conditions used in this work, they can be applied as effective bioadsorbents in the removal of methylene blue in aqueous solution.
Acesso aberto (Open Access)
Decomposição catalítica do glicerol em fase vapor usando a perovskita cecuxni1-xo3 (x=0;0.25) como precursor catalítico
(Universidade Federal do Pará, 2017-03-09) ESTRADA, Marcial Antonio Fuentes; FRANÇA, Luiz Ferreira de; http://lattes.cnpq.br/6545345391702172; RIBEIRO, Nielson Fernando da Paixão; http://lattes.cnpq.br/0755443458423442
The utilization of the fuels fossils like main source of energy has carried to the generation of countless environmental and economic problems, creating the need of diversification of the energetic matrix. In Brazil, country with vast territorial extension and agroindustry very established stands out the production of biofuels, such as: ethanol and biodiesel. Particularly, the production of biodiesel with the increasing governmental incentives exponentially has its production increased to each year placing Brazil in prominence in the worldwide scene of biofuels. In the process of transesterification of vegetal oils with a primary alcohol, beyond biodiesel, the rude glycerin in a ratio of 10% is generated 11% in volume. The bio refining of the deriving glycerin of the manufacture of biodiesel, becomes the production of biodiesel economically more viable, leading to the formation of products with raised aggregate values. For this reason, the present work has as main objective the valuation of the chain of production of biodiesel for the transformation of glycerol to the products of bigger value added through reaction catalytic decomposition of glycerol using perovskitas of the CeNi1-xCuxO3 type (x=0 and 0,25) as you will catalyze. The gotten results had shown that the use of high temperature (500 °C) favors the gas production of synthesis with approach relation H2/CO of 1, this occur for the strong craqueamento of the molecule of glycerol, At 410 ° C and inert reaction atmosphere, hydroxyacetone (acetol) was the major product exhibiting selectivity in the range of 22-28% depending on the catalyst used. The effect of the addition of hydrogen on the reaction load was investigated and its insertion promoted the hydrogenation of the hydroxyacetone, leading to an increase in selectivity for 1,2-propanediol whose selectivity varied in the range of 4-9% depending on the catalyst.
Acesso aberto (Open Access)
Determinação de propriedades termofísicas e estudo do equilíbrio líquido-líquido de sistemas envolvendo líquidos iônicos próticos
(Universidade Federal do Pará, 2017-03-24) GOMES, Rossimar dos Santos; SILVA, Silvana Mattedi e; http://lattes.cnpq.br/8741124364246075; SANTOS, Geormenny Rocha dos; http://lattes.cnpq.br/0844662601945669
This work consisted of the synthesis of protic ionic liquids (Ethyl 2-hydroxyethylammonium propionate [E2HEAP][PR], Diethylammonium propionate, [DEA][PR] and Butylammonium propionate, [BA][PR] and determination of density and viscosity of protic ionic liquids [DEA] [PR] and [BA] [PR] pure and the binary systems formed by these ionic liquids + water at different temperatures and atmospheric pressure. The density data were determined using a digital densimeter and viscosity by the viscometer, both of Anton Paar, the experimental results were used to obtain excess molar volume (𝑉𝑚𝐸), apparent molar volume (𝑉∅,1), viscosity deviation (Δη) and excess Gibbs free energy (ΔGE), being the results correlated with the Redlich-Kister or Redlich-Meyer equation. The results were compared and discussed based on the molecular interactions between the studied componentes. It was also made the study of liquid-liquid equilibrium data (LLE) for systems, involving 1-butanol + water + protic ionic liquids: [E2HEA][PR] or [DEA][PR] or [BA][PR] K and atmospheric pressure, being the systems quantified by the gravimetric method. The quality of the equilibrium data was verified by the semi-empirical methods of Othmer-Tobias and Hand. From the obtained equilibrium data, the values of the distribution coefficient found indicated the hydrophilic behavior of the LIs studied. Data liquid–liquid equilibrium was correlated by the NRTL and UNIQUAC thermodynamic models, which was observed that the NRTL model correlated in a more satisfactory way the results presenting global deviation of 1,56% for NRTL and 1,78% for UNIQUAC.
Acesso aberto (Open Access)
Espectroscopias RAMAN, IR, DOS, UV-Vis e dicroismo circular das toxinas (anatoxina-a, anatoxina-as, cilindrospermopsina, homoanatoxina-a e saxitoxina) das algas.
(Universidade Federal do Pará, 2024-02-02) LOBATO, Marinaldo Carvalho; COSTA, José Francisco da Silva; http://lattes.cnpq.br/9492719731740641; CHAVES NETO, Antônio Maia de Jesus; http://lattes.cnpq.br/3507474637884699
This thesis aims to understand Raman, IR, DOS, UV-Vis and Circular Dichroism spectroscopy of algal toxin molecules Anatoxin-a, Anatoxin-a(s), Cylindrospermopsin, Homoanatoxin-a and saxitoxin. The Gaussian 09W software was used for the theoretical calculations of energy minimization corresponding to the molecular mechanics method MM+ as well as the functional level B3lyp/6-311++G (d,p), used both in the optimization of the geometry and in the calculations of UV-Vis spectrometry, State Density and Circular Dichroism of non-solvent water molecules. The research results show relevant UV-Vis spectra, State Density, Circular Dichroism, Raman and Infrared in the elaboration of Tables that identify the modes of molecular vibrations of the aforementioned toxins, which lead to identifying the types of vibrations in each region contained in us specific wave compression intervals. Verify that each algal toxin presents a specific gap or that makes it possible to identify the one that presents the greatest reativity in relation to others (smallest gap) or greatest stability (largest gap). For the MEP (electrostatic potential map) it is possible to observe the region that presents the highest concentration of negative charges or that can be useful to identify regions of reaction between a toxin and a protein. The research was concluded considering an experimental comparison between the cylindrospermopsin toxin with graphical analyzes of two UV-Vis spectra that with a percentage of 0.5% of error, showing that based on B3lyp/6-311++G(d, p) selected was very significant for comparison between theoretical data in relation to experimental data.
Acesso aberto (Open Access)
O estudo da docagem e dinâmica molecular de potenciais fármacos: rodatina, scedapina C e cequinadolina A, utilizados no tratamento da SARS-COV-2
(Universidade Federal do Pará, 2022-05-06) LIMA, Antonio Sanderlei dos Santos; ALMEIDA, Ossalin de; http://lattes.cnpq.br/7040173036131516; HTTPS://ORCID.ORG/0000-0003-3895-0952; CHAVES NETO, Antônio Maia de Jesus; http://lattes.cnpq.br/3507474637884699; https://orcid.org/0000-0002-9730-3512
Due to the study of new drugs to combat the SARS-COV-2 virus, which is causing the COVID-19 pandemic. In this work, we address the use of three drugs (Rhodatin, Scedapin C and Scequinadoline A) as possible inhibitors of SARS-CoV-2, as they have several interactive properties, showing potential to be used in the treatment of COVID19 disease. Molecular docking provided information about the affinity energy which was -8.186, -9.617, -7.866, -7.601, -7.527 kcal/mol, for the best conformations with Scequinadoline A. Molecular couplings and affinity energy showed the residues of the site macrostructures, and analyzed the electrostatic potential map to predict some promising candidates for virus antagonists. Molecular dynamics techniques were used, where the targets were the external structures of the virus, but specifically the envelope protein, main protease, Spike glycoprotein. Using the GROMACS 2021.2 modules, the results showed that the ligands have characteristics of interaction over time. Molecular dynamics provided values between 1.5 and 4.5Å for the mean square deviation of atomic positions. Among the results obtained through molecular dynamics, it was noted that the hydrogen bonds, when compared to the calculation of the square root of the mean square deviation, underwent a change in the amount of hydrogen bonds in the bonding process, according to the proximity of the ligand used to filter out unrealistic poses in the snap, and also improved the accuracy of binding energy calculation. Analysis of molecular couplings showed that the S-gly active site residues strongly interacted with the three drugs. The reuse of these drugs in the fight against SARSCoV-2 may be candidates via virus antagonists, which if confirmed through experimental approaches, can contribute to the resolution of the global crisis of the COVID-19 pandemic.
Acesso aberto (Open Access)
Estudo das alterações petrofísicas e mineralógicas em amostras de calcita e dolomita decorrentes da interação com água carbonatada e CO2 supercrítico
(Universidade Federal do Pará, 2023-05-29) SOUZA, Felipe Pereira de; LUCAS, Cláudio Regis dos Santos; http://lattes.cnpq.br/1695226159975283; HTTPS://ORCID.ORG/0000-0001-5443-462X; AUM, Pedro Tupã Pandava; http://lattes.cnpq.br/7515419219571335; https://orcid.org/0000-0002-2339-9865
CO2 capture, utilization, and storage techniques, known by the acronym CCUS (Carbon capture, utilization, and storage), have been studied as primary tools for achieving the decarbonization targets, stipulated to slow down the rise in temperature earth average. In this context, geological storage consists of injecting CO2 into the rock formation, so that it is trapped in saline aquifers, coal deposits or oil reservoirs. CO2 injection is already carried out, for example, in the Brazilian pre-salt fields, where the oil produced has a high concentration of CO2 in its composition. It is expected that other geological structures can be used for geological carbon storage. However, the geological sites must be carefully selected, one of the key points being the geochemical stability due to the contact of CO2 with the rock formation. Thus, this project aimed to study the process of interaction of CO2 with formations of carbonate rocks, to increase the fundamental knowledge regarding the processes of rock-fluid interaction in the geological storage of CO2. The methodology included the analysis of the petrophysical properties of commercial carbonate rocks (Indiana Limestone and Silurian Dolomite) and of the dolomitic carbonate sample from the Itaituba Formation, before and after exposure to CO2 in the form of carbonated water and in the supercritical form. We also used X-ray microtomography to study the porous structure of samples at different scales. The results showed that the Indiana rock samples present distributed porosity, being essentially formed by structures predominantly composed of pallets, skeletal grains, ooids and shell fragments. The samples of Silurian Dolomite presented a structure formed by less pores, however larger and more concentrated. The rock samples from the Itaituba formation showed very low porosity and permeability. The petrophysical properties evolved after contact with CO2. Rock-fluid interaction studies will show changes in rock matrices resulting from the dissolution/or expansion process. The microtomography technique of x-ray was used in the imaging of the samples to visualize the change in the morphology of the rocks, the technique allowed the comparison of before and after CO2 attack. The DRX and FRX analyzes showed positive results regarding the mineral composition of the samples used. The results of this work will contribute to the reduction of uncertainties related to the processes and mechanisms of the geological storage of CO2.
Acesso aberto (Open Access)
Estudo de quantificação de compostos fenólicos, avaliação de atividades antioxidantes e modelagem molecular da croton pullei var. Glabrior lanj
(Universidade Federal do Pará, 2021-04-16) SOUZA, Alexandre Augusto Moraes de; COSTA, Renato Araújo da; http://lattes.cnpq.br/6578338979054891; BRASIL, Davi do Socorro Barros; http://lattes.cnpq.br/0931007460545219
The study aimed to evaluate, from extracts, the yield (on a dry basis), quantify the total polyphenols, evaluate the antioxidant activity, perform a theoretical NMR research of the julocrotine, crotonimide A and crotonimide B structures, from Croton pullei VAR. glabrior LANJ. and evaluate these molecules in molecular docking against the enzymes Candida albicans (PDB ID: 1AI9), Staphylococcus aureus (PDB ID: 1DIM) and Salmonella thyphimurium (PDB ID: 4URM). A conventional extraction was performed using a stainless-steel extractor and three-factor planning (temperature, particle size and solid/liquid ratio) and three Box-Behnken levels, to determine which variables were influential in the responses. The quantification of total polyphenols was performed according to the Folin-Ciocalteu methodology. For the antioxidant analysis, the IC50 method was applied. And the theoretical NMR study was carried out via DFT, where the computational methods DFT/B3LYP/cc-pvDZ and DFT/B3LYP/6-31 G* were applied to obtain the chemical displacements (δH and δC), to compare to the experimental ones and thus provide which computational method is the most efficient. Yields vary between 5.57 and 10.61. In the quantification of total polyphenols, there was a variation between 101.33 and 308.84 mg EAG/g. The minimum and maximum antioxidant values were 94.74% and 98.97%. In general, the DFT/B3LYP/cc-pvDZ methodology was more efficient compared to the analyzed structures. The molecules showed hydrogen bonds with residues Lys 57 (A), Arg 56 (A), Cys37, Gly38, Asp62, Gly193, Tyr342, Gly56, Arg37, Tyr128, Arg56, Thr58 (A), Gly114 (A) and Thr 127.
Acesso aberto (Open Access)
Estudo do efeito da saturação de óleo na acidificação de carbonatos
(Universidade Federal do Pará, 2023-02-27) NEYRA, Jair Rodrigues; LUCAS, Cláudio Regis dos Santos; http://lattes.cnpq.br/1695226159975283; HTTPS://ORCID.ORG/0000-0001-5443-462X; AUM, Pedro Tupã Pandava; http://lattes.cnpq.br/7515419219571335; https://orcid.org/0000-0002-2339-9865
Carbonate acidizing is a well stimulation technique used to increase oil production. This technique aims to inject acid into the formation below the fracture pressure, creating paths of high conductivity resulting from the dissolution of the rock by the acid. In the laboratory, most experiments are performed on rock samples saturated with water, due to the assumption that there is only water in the formation, after preflush and previous drilling and completion operations. However, different saturation conditions can occur in the formation due to its petrophysical characteristics and history of operations. One scenario is oil saturation in the porous medium. This work proposes to carry out physical experiments and evaluate the influence of oil saturation on the acidizing of carbonates. Reactive flow experiments were carried out using acid systems, with HCl 0.5M and HCl 15%, in rocks saturated with ultra pure water and liquid paraffin. The carbonate rock samples are from the Indiana Limestone outcrop with 3 in length and 1.5 in diameter. For oil saturation, a high flow rate of 20 mL/min was used for the two acid systems at room temperature (25°C); and with HCl 15%, the study was deepened with a temperature of 45°C at flow rates of 1 and 20 mL/min. The x-ray microtomography technique was used to image the samples to visualize the wormhole morphology. Through it, the influence of oil on the structure of the wormhole and the value of PVBt was compared, highlighting the impact of oil for each acid concentration. The PVBt curve of HCl 0.5M has values above those presented using HCl 15%, in samples saturated with water. This effect is due to the lower concentration promoting a lower dissolution power of carbonates. The analysis of the wormhole area and the porosity distribution after acidizing show that the oil influenced an efficient propagation of the wormhole and lower consumption of acid. PVBt values are lower when the sample is saturated with oil in all scenarios. The use of HCl 15% in the sample saturated with oil and at a temperature of 45°C. In this scenario, the value reduces by about 54% when using HCl 15% at 20 mL/min.
Acesso aberto (Open Access)
Estudo do processo de pirólise de caroços de açaí Í (Euterpe oleracea Mart.) em escala piloto para produção de biocombustíveis
(Universidade Federal do Pará, 2022-06-27) BAIA, Ana Cláudia Fonseca; SANTOS, Marcelo Costa; http://lattes.cnpq.br/8380189608965320; HTTPS://ORCID.ORG/0000-0002-2352-2050; CARVALHO JÚNIOR, Raul Nunes de; http://lattes.cnpq.br/5544305606838748; https://orcid.org/0000-0002-4433-6580
The objective of this work was to study the process of bio-oil production through the pyrolysis of raw acai kernel on a pilot scale, focusing on the yield of products obtained at temperatures of 350°C, 400°C and 450°C at 1 atm. In addition to studying the results obtained via gas chromatography coupled to mass spectrometry (GC-MS) of the bio-oils produced. For the experimental procedure, the raw material used was the açaí pits, a residue obtained after the process of pulping the fruit. This material went through stages of drying, comminution and sieving to remove unwanted residues for the process. This material was characterized by determining the moisture content, volatile content, ash content, fixed carbon content and higher calorific value. After the characterization process, the lumps were submitted to the pyrolysis process and, after the due separation processes, the bio-oil obtained was submitted to tests to determine its acidity index, absolute density, refractive index, and dynamic viscosity. After this step the bio-oil was subjected to analysis in a gas chromatograph coupled to a mass spectrometer. The moisture content found in the açaí seeds was approximately 40% and the yield of the pre-treatment step was 46.84%. In the physical characterization of the seeds the results found were within the existing literature showing interesting properties for use in the pyrolysis process. With the increase in temperature there was a favorable production of bio-oil and biogas, while for the biochar there was a decrease in its mass produced. The physicalchemical analyses applied to the Bio-Oil produced were within the values that are available in the literature for this same type of material, however, it is still outside the standards that the National Petroleum Agency establishes for green diesel. The increase in temperature reduced the acidity of the bio-oil and increased its viscosity and density. With this, there was a reduction 92.87 (Exp.1) to 70.26 (mg of NaOH/g of sample) (Exp.3) and the lowest kinematic viscosity obtained of 77.62 mm²/s for the pyrolysis process with the temperature set up to 350°C. The chromatographic analysis showed that the compound with the highest percentage of peak area was phenol, where the average retention time was 8,466 min-1 independent of the programmed temperature. Exp.2 had the highest yield in terms of aromatic hydrocarbons and the lowest yield for phenols, showing that there is no linear behavior with temperature change.
Acesso aberto (Open Access)
Estudo do processo de salga e secagem de camarão (Litopenaeus vannamei) cultivado no estado do Pará
(Universidade Federal do Pará, 2011-08-10) CORREA, Ana Cristina Leite; CORRÊA, Nádia Cristina Fernandes
We conducted the study of two forms of food preservation, salting and drying, the shrimp come from cultivation in the state of Pará. The salting process was conducted in brines with 36% concentrations m/m at 80°C and 38% m/m 100°C, using the shrimp in natura in shell and shelled, with and without agitation to evaluate the influence of these variables in the process. The drying process was carried out in the pre-cooked and salted shrimp at “Fazenda Nossa Senhora de Fátima”, in the municipality of Curuçá/Pará, at temperatures of 60°C, 80°C and 100°C. Regarding the treatment of salting, the factors that most influenced the process were the concentration and agitation; as the drying process, there was less drying time for the 100°C temperature. It proposed a mathematical model of the salting process from Fick's Law. The best fit for the process was carried out with the shrimp headless, shelled, with shaking (R2 = 0.99), effective diffusivity values ranged from 0,9x10-8 the 2,0x10-8. The kinetics of shrimp drying was set with models of Henderson and Pabis, Midilli et al., Newton, Page and Wang and Singh. The Midilli et al. model showed the best fit to the kinetic data drying shrimp at temperatures of 80ºC and 100ºC.
Acesso aberto (Open Access)
Influência das características do fluido na corrosão e erosão em amostras de aço 5l x65
(Universidade Federal do Pará, 2024-09-30) NASCIMENTO, Nina Benchimol Xavier do; FARIA, Lênio José Guerreiro de; http://lattes.cnpq.br/7428609361678173
The objective of this research was to evaluate the corrosive and erosive behavior of API 5L X65 carbon steel samples with an external FBE coating used for transporting an aqueous suspension containing around 40% solids with a high content of aluminum hydrated silicates, mainly kaolinite and water, to identify the best operational method for intermittent pumping regimes, focusing on their influence on steel integrity. The samples were divided as follows: three samples of carbon steel pipes with an outer diameter (OD) of 14 inches, thickness (Th) of 8.74 mm (original), and 1 meter in length; a sample of process water and a sample of aqueous suspension with an average of 40% solids with a high content of aluminum hydrated silicates and acidic pH, each with approximately 60 liters (divided into two plastic containers of 30 liters). The results show that the KM-0 sample presented a yield limit below the specified minimum, and the KM-23 sample also showed a high standard deviation, suggesting a lack of homogeneity. The new pipe samples presented values within specifications. The significant difference in hardness between samples lies in the very low carbon percentage presented in the TR sample. This minimizes issues with potential weak points and increases material weldability; however, in some cases, pipes treated by controlled rolling achieve high mechanical strength and toughness with relatively low hardness, which can provide greater erosion resistance than tempered pipes. Samples KM-23 and KM-0, although having similar hardness and chemical composition, showed differences in absorbed energy and area reduction. This may be attributed to the higher sulfur content in sample KM-23, evidenced by detected sulfur-rich inclusions. Overall toughness was high for all samples, with no indication of brittleness under the tested conditions. The results of uniform and localized corrosion, disregarding the influence of oxygen, indicated that the acidic pH slurry is less corrosive than water. During water operation, the corrosion rate stabilizes over time; however, when production is intermittent, the film formed by water disappears, returning this rate to its initial condition, being even more detrimental to the pipe's integrity.
Acesso aberto (Open Access)
Influência do transporte advectivo no processo de dissolução de rochas carbonáticas em ácido clorídrico.
(Universidade Federal do Pará, 2024-04-30) COSTA, Brenda Matos da; SILVA, Daniel; AUM, Pedro Tupã Pandava; http://lattes.cnpq.br/7515419219571335
Carbonate rock stimulation is a technique used in the petroleum industry to increase the productivity index of wells by increasing the permeability of a region close to the well. In acidification, an acid is injected into the reservoir rock. In carbonate rocks, the acid interacts with the rock to promote dissolution. The acid-rock occurrence is characterized by being essentially heterogeneous due to the different phases of the reactants. The quantification of occurrence taxa in heterogeneous systems is complex, as it involves a combination of several variables that are relevant to the manifestation of transport. The way in which acid interacts with the porous medium can be analyzed using various techniques and equipment that can help with understanding. The most common equipment is the Rotating Disk Apparatus (RDA), which consists of a reactor, which can operate different pressure and temperature ranges and different rotations. However, due to the difficulty of acquiring this type of equipment, several experiments have been reported using alternative methodologies. Thus, this work aims to study how measuring the reaction rate using different methodologies can influence the result. A comparative experimental study was conducted using three different methodologies, namely, static dissolution, dynamic dissolution, and rotating disk, to measure the impact of mineralogy, porosity, rotation speed, and pressure applied to the reaction system. The focus is to evaluate to what extent the results of the static and dynamic dissolution experiments diverge from the experiments conducted with the rotating disk, which is considered the standard for this type of analysis. In general, it was observed that increasing rotation promotes an increase in the reaction rate of 10.36% from static to dynamic at 100 RPM and 63.07% from static to dynamic at 500 RPM for Indiana limestone, a similar behavior was observed for other mineralogies. Additionally, from obtaining the diffusion coefficient in the process of dynamic dissolution and rotating disk of 3.75x10^-5 and 9.13x10^-5, respectively, for coquina samples, it was evidenced that the absence of pressure in the system hinders the mass transfer process due to the presence of CO2 (g), thus underestimating the diffusion in the carbonate – HCl system.
Acesso aberto (Open Access)
Interações de Quantum Dot com estruturas externas de vírus Nipah utilizando docking e dinâmica molecular
(Universidade Federal do Pará, 2023-01-30) ALMEIDA, Aguinaldo Pantoja de; OLIVEIRA, Mozaniel Santana de; http://lattes.cnpq.br/0810227136654245; HTTPS://ORCID.ORG/0000-0002-4076-2443; CHAVES NETO, Antônio Maia de Jesus; http://lattes.cnpq.br/3507474637884699; https://orcid.org/0000-0002-9730-3512
Performing the interaction of the outermost protein of the Nipah virus with fourteen structures with possible potential for the emission of quantum dots, using anchoring and molecular dynamics, using molecular docking platforms: CB Docking, Swiss DOCK, AutoDock Vina 4.2.6 to perform a comparison of results explaining the best values, in addition to using Gromacs 2022 to make ligand trajectories in relation to time. The mostly hydrophobic complexes at the receptor binding site. The tolerance energy results tolerated the partial loads of the tips which showed better stability, the RMSD results also respected this premise. Thus, the set formed by combining proteins with a quantum dot has the potential to more efficiently adsorbing of the protein components of the virus. Molecular dynamics and docking studies and verification of binding energy revealed strong and stable binding between para QD K and QD-G and QD-F with the macrostructure of NIPAH virus. It was established in the docking studies, that the binders have emission energy scores of -13,658 kcal/mol, -13.6 kcal/mol, -13.9 kcal/mol, for K, G and F respectively. The same result was applied in the Gibbs free energy verification study with values for F of 239.00 kcal/mol, G of 246.65 kcal/mol and K of 259.52 kcal/mol.
Acesso aberto (Open Access)
Investigação do processo de adsorção do carvão do caroço de açaí (euterpea olerácea mat.) obtido via craqueamento térmico
(Universidade Federal do Pará, 2022-07-04) GUERREIRO, Lauro Henrique Hamoy; SANTOS, Marcelo Costa; http://lattes.cnpq.br/8380189608965320; HTTPS://ORCID.ORG/0000-0002-2352-2050; CARVALHO JÚNIOR, Raul Nunes de; http://lattes.cnpq.br/5544305606838748; https://orcid.org/0000-0002-4433-6580
This work aims to investigate the influence of temperature and chemical impregnation on the textural and morphological composition of bioadsorbents produced via thermal cracking of açaí seeds. The experiments were carried out at 400°C and 450°C, using a pilot scale reactor. The efficiency of the process was analyzed in terms of liquid and solid products, it was verified that with the increase of the temperature of the process and with chemical impregnation with NaOH in the raw material there was a greater conversion of liquid organic product. Elementary analyzes of solid products showed how carbonization occurs with increasing process temperature and the presence of sodium due to impregnation and . The textural and morphological characterization occurred with the analysis of FT-IR, SEM/EDS, XRF and B.E.T. The solid phase product obtained by cracking the açaí seed in natura and impregnated with NaOH solution (2M), at temperatures of 400°C and 450°C. The adsorption kinetics of acetic acid investigated at 5, 10, 15, 20, 60, 120 and 180 seconds. The adsorption isotherms showed that the biochar produced at 450°C and with chemical impregnation of NaOH were able to remove acetic acid in greater amounts.
Acesso aberto (Open Access)
NFPR - Um Coletor automático de amostras de baixo custo
(Universidade Federal do Pará, 2021-07-23) MATOS JÚNIOR, Berilo Costa de; RIBEIRO, Nielson Fernando da Paixão (in memorian); http://lattes.cnpq.br/0755443458423442; MACÊDO, Emanuel Negrão; http://lattes.cnpq.br/8718370108324505
The evolution of automation in industrial processes has brought many benefits to humanity. The use of automatic systems has been growing and becoming more and more frequent in machines and projects. Aiming at greater production, reliability and cost reduction. Due to the high value of technological equipment, it is necessary to seek more financially viable alternatives to obtain efficient and accurate results. An issue commonly encountered in chemical engineering laboratories is the difficulty of collecting samples over a long period, eg experiments to determine adsorption breakthrough curve. Thus, this work proposes to develop a low-cost equipment, in which a liquid can be collected automatically. From a microcontroller, the Arduino Mega, it is possible to interconnect the programming technique with an open source language based on C++. Developing a command algorithm for the control and operation of stepper motors and solenoid valve. Several tests were performed for accuracy of positioning and volume collection for: 5, 10 and 15 ml. In which, the prototype presented good results defined by the mean and standard deviation of the collected samples. The implementation of this equipment tends to improve the working conditions of users, ensuring better accuracy, avoiding waste by manual collection and bringing convenience. It is observed that the prototype has a monetary value up to ten times lower than the equipment consolidated in the market. Demonstrating that it is a viable and promising proposal for laboratories that need automatic volume collection.
Acesso aberto (Open Access)
Obtenção de extratos de mururé (brosimum acutifolium) por extração sequencial em leito fixo via scCO2: isotermas de rendimento global, perfil químico e atividade antioxidante
(Universidade Federal do Pará, 2022-06-30) SOUSA, Kelly Roberta Pinheiro de; CARVALHO JÚNIOR, Raul Nunes de; http://lattes.cnpq.br/5544305606838748; https://orcid.org/0000-0002-4433-6580
The species Brosimum acutifolium Huber, popularly known as mururé da terra firme, exhibits therapeutic characteristics responsible for its use in folk medicine as antiinflammatory, bactericidal, ant syphilitic, antirheumatic and among others, due to the significant presence of phenolic compounds. This work, then, aims to perform an extraction via supercritical fluid (SFE) in a sequenced way with: CO2; CO2+ EtOAc; CO2+ EtOH, evaluating the parameters of the extraction process, to carry out an evaluation of the chemical composition and the antioxidant activity of the extracts. Therefore, a proximate characterization of the raw material (moisture, ash, lipids and proteins) was carried out, and the average particle diameter was determined. For the EFS tests, the dynamic extraction time (Td) with CO2 was 60 minutes and CO2 flow rate of 3 L/min, Td of 60 minutes for CO2+ EtOAc and flow rate of 1.18 ml/min and Td of 60 minutes for CO2+ EtOH and CO2 flow rate of 1.34 ml/min, and raw material mass of 10 g. The selection of the temperature and pressure variables was based on the difference in the density of CO2 + co-solvent, the isotherms of 40°C and 60°C combined with the pressure values of 250, 300 and 350 bar. The results of the proximate characterization were in agreement with the literature, nominal values of moisture (%) (13.63), 0% lipids, ash (%) (2.12±0.05) and proteins (g/100 mL) (4.41±0.10), with mean particle diameter of 0.456 mm. Regarding the process parameters, the SFE global yield values on a dry basis were better in the extraction conditions with CO2+ EtOAc at 40° C and 60° C at 350 bar and in the extraction with CO2+ EtOH at 40° C and 60 °C at 250 bar. The evaluation of the chemical composition by high performance thin layer chromatography (CCDAE) allows us to infer that the extract obtained in the CO2+ EtOH system in the condition (40° C at 250 bar) showed a better chemical profile in relation to phenolic compounds, flavonoids and fatty acids. , it is noteworthy, however, that the extracts obtained in the CO2+ EtOAc system, under conditions of 40° C and 60° C at 350 bar, exhibited a more evident profile of coumarins in relation to the other extracts evaluated. Regarding antioxidant activity, all extracts showed good activity. Thus, the results made it possible to characterize the matrix in the aforementioned aspects, revealing information that is not available in the researched literature, in addition to inferring the best operational conditions in terms of yield, for the EFS extraction of this raw material based on the operational parameters analyzed.