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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Acesso aberto (Open Access)
Inserção da temperatura no modelo de Langmuir aplicado na adsorção de íons cobre por zeólita 5A : experimental e estatística Bayesiana
(Universidade Federal do Pará, 2025-02-05) SOUSA, Ana Paula Souza de; RODRIGUES, Emerson Cardoso; http://lattes.cnpq.br/7459428211048580; HTTPS://ORCID.ORG/0000-0002-0303-4578; ESTUMANO, Diego Cardoso; http://lattes.cnpq.br/5521162828533153; https://orcid.org/0000-0003-4318-4455
The treatment of wastewater contaminated by heavy metals represents a significant environmental challenge, with adsorption being one of the main approaches for removing these contaminants, as it exhibits high efficiency in molecular separation. Understanding the interaction between adsorbent and adsorbate is essential for predicting dynamics under different operational conditions. Thus, the use of modeling techniques in isotherm prediction allows for estimating adsorption performance, reducing the need for intensive experimentation, while promoting process optimization. Considering these factors, this work aimed to develop a predictive model capable of estimating adsorption isotherms of copper ions by zeolite 5A at different temperatures. The methodology involved the production and characterization of kaolin waste, metakaolin, and the zeolitic product, utilizing characterization techniques such as X-ray Fluorescence Spectrometry (XRF), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and thermal analyses, including Thermogravimetry (TG), Differential Thermogravimetry (DTG), and Differential Scanning Calorimetry (DSC), to determine the chemical and mineralogical composition, morphology, and thermal stability of the material. Adsorption isotherms of copper ions were performed at temperatures of 25 ºC, 35 ºC, 45 ºC, 55 ºC, 65 ºC, 75 ºC, 85 ºC, and 95 ºC. To study the adsorption mechanisms and the adsorbent/adsorbate interaction, the Markov Chain Monte Carlo (MCMC) method with the Metropolis-Hastings algorithm was used to estimate model parameters and subsequently fit them to the experimental data. Based on these data, the Langmuir model was adapted to incorporate temperature, in the range of 25 ºC to 150 ºC, followed by the calibration, validation, and prediction of adsorption dynamics. The characterization results confirmed the potential use of kaolinitic waste for zeolite synthesis, as well as the successful formation of zeolite 5A through its chemical composition, mineralogy, and morphology. The isotherms revealed that copper removal capacity increased proportionally with temperature, obtaining a maximum adsorption capacity of 754.85 mg/g at 95 ºC. The parameter estimation validated the adaptation of the Langmuir model for different thermal conditions, which proved effective in predicting the isotherms, optimizing the adsorption process at different temperatures, and providing a good model estimate, thus enabling the reduction of extensive experimental activities.
Acesso aberto (Open Access)
Produção de material zeolítico em escala semi piloto com o calor proveniente da dissolução de hidróxido de sódio
(Universidade Federal do Pará, 2025-02-05) LIMA, Haianny Beatriz Saraiva; COSTA, Deibson Silva da; http://lattes.cnpq.br/1521124351431087; HTTPS://ORCID.ORG/0000-0002-2165-2628; ESTUMANO, Diego Cardoso; http://lattes.cnpq.br/5521162828533153; https://orcid.org/0000-0003-4318-4455
The increasing demand for zeolitic materials, due to their high adsorption capacity, selectivity, and ion exchange, highlights the need for more efficient and sustainable production methods. Thus, the study aimed to produce zeolites on a semi pilot scale from kaolin waste, utilizing reactive heat for hydrothermal synthesis and applying these zeolites for copper ion adsorption. The methodology involved drying, disaggregation, and calcination of the kaolinitic waste, followed by the synthesis of the zeolitic material. Characterization of the materials was performed using X-ray Diffraction (XRD), X-ray Fluorescence (XRF), Scanning Electron Microscopy (SEM), and Thermogravimetric Analysis (TGA), Differential Thermogravimetric Analysis (DTG), and Differential Scanning Calorimetry (DSC). Subsequently, equilibrium isotherms were conducted at temperatures of 25 ºC, 35 ºC, 45 ºC, 55 ºC, 65 ºC, 75 ºC, 85 ºC, and 95 ºC, along with parameter estimation to study the adsorption mechanisms and the adsorbate/adsorbent interface. Additionally, modeling of the adsorption process for hydrogen sulfide (H2S) and carbon dioxide (CO2) gases was carried out, using experimental data from the literature and employing analytical breakthrough curve models to describe the adsorption phenomenon in continuous flow. The results confirmed the predominant presence of kaolinite in the waste, the efficiency of the calcination process, and the formation of zeolitic material, evidenced by the mineralogical and chemical composition, as well as the cubic morphology characteristic of zeolite 4A and the spherical shapes of sodalite. Thermal analyses elucidated changes associated with water loss and phase transitions. Adsorption tests demonstrated that the produced material was effective in removing copper ions, with a maximum amount adsorbed of 782,76 mg/g at 95 ºC, indicating a good interaction between the adsorbent and the adsorbate. Furthermore, the use of Bayesian techniques for parameter estimation in isotherm and breakthrough curve models enabled a better understanding of the process dynamics. Finally, this study demonstrated the feasibility of producing zeolites from kaolin residue on a semi-pilot scale using reactional heat, offering an approach that is less harmful to the environment and reduces costs through the reuse of industrial waste and energy optimization of the process.
Acesso aberto (Open Access)
Recobrimento de pimenta-do-reino (piper nigrum l.), em leito de jorro, com suspensão polimérica de amido de mandioca, plasticizada com etanol
(Universidade Federal do Pará, 2024-12-13) QUEIROZ, Nian Iury Ferrão; REGO, José de Arimatéia Rodrigues do; http://lattes.cnpq.br/4163468898377462; HTTPS://ORCID.ORG/0000-0003-0891-6438; BRASIL, Davi do Socorro Barros; http://lattes.cnpq.br/0931007460545219; https://orcid.org/0000-0002-1461-7306
This study aimed to evaluate the black pepper coating technique using a fluidized bed, focusing on its applicability in the food industry. The research explored the optimization of operational parameters, such as suspension flow rate, temperature, and blower flow rate, using the response surface methodology within a Box-Behnken design. The goal was to improve the efficiency of the coating process, ensuring uniform distribution of the coating over the black pepper grains. This study investigated the fluid dynamic and physicochemical behavior of black pepper seeds coated with a cassava starch-based biofilm, applying the spouted bed process. The seeds were classified in group D of the Geldart classification, indicating good fluidization potential and excellent flowability, facilitating the coating process. The sphericity of the seeds (0,98) and their density (1,45 g/cm³) directly influenced their behavior in the bed, allowing minimal fluidization at a velocity of 38,32 cm/s and a pressure drop of 7,13 cmH2O. The molecular interaction between the starch and ethanol generated biofilms with flexibility and mechanical strength. However, ethanol's volatility requires control during the drying process to maintain the biofilm's quality. The spouted bed process proved efficient for coating application, and the desirability function analysis indicated that the established criteria were satisfactorily met. The results confirm the technical feasibility of applying biopolymer coatings to black pepper seeds, contributing to the development of biodegradable alternatives aligned with environmental demands
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)
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)
Simulação numérica da acidificação de carbonatos utilizando malhas obtidas a partir de imagens de MICRO-CT
(Universidade Federal do Pará, 2024-05-21) SANTANA, Beatriz dos Santos; VICENTE, Bruno José; http://lattes.cnpq.br/4190693236960837; AUM, Pedro Tupã Pandava; http://lattes.cnpq.br/7515419219571335
Matrix acidizing is one of the well stimulation techniques that consists of pumping an acid solution at a pressure lower than the fracture pressure of the rock. In carbonate formations, as a result of the acid-calcite reaction, part of the rock is dissolved and high conductivity channels, called wormholes, are created. One of the major challenges associated with simulating this type of process is to incorporate the heterogeneities inherent in carbonate rocks into the numerical meshes. The main objective of this work is to simulate acidification in carbonate rock plugs using the initial porosity field obtained from a microCT image. Two-scale modeling was used, with the balance of the amount of movement carried out using the Navier-Stokes-Brinkman approach. The simulations were carried out in a code developed in openFOAM, varying the speed of the acid on the face and obtaining the PVbt (Pore Volume to Breakthrough) for each condition. Mesh convergence analyses and the impact of varying the inlet interstitial velocity were carried out. Simulation results were compared with initial porosity fields generated using the uniform, normal and lognormal distributions. The initial porosity and permeability distributions obtained were consistent with the microCT image. Variations in the number of cells had no significant impact on the PVbt. By varying the injection speed on the face, it was possible to obtain the uniform, conical, branched, dominant wormhole, dissolution on the face and compact dissolution patterns, obtaining the PVbt curve to determine the optimum point (lowest PVbt). For the model developed from the image, the lowest PVbt obtained was 0.262 with an input speed of 4 2,12 10 m/s −  . For the models with uniform, normal and lognormal porosity distributions, the lowest PVbt values obtained were 0.276, 0.261 and 0.309 at an input speed of 5 8,3 10 m/s −  . The results presented showed that the methodology used to obtain porosity fields from microCT images can be used to obtain results that are more representative in terms of accounting for rock heterogeneities.
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.
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)
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)
Modelagem, simulação e estimação dos parâmetros por MCMC de um modelo que descreve a dinâmica de adsorção em uma coluna de leito fixo
(Universidade Federal do Pará, 2023-01-18) SOEIRO, Wilhamis Fonseca; VIEGAS, Bruno Marques; http://lattes.cnpq.br/1196600058247902; HTTPS://ORCID.ORG/0000-0002-2768-652X; ESTUMANO, Diego Cardoso; http://lattes.cnpq.br/5521162828533153; https://orcid.org/0000-0003-4318-4455
The treatment of industrial effluents is extremely important for both the environment and human health. The purification of water from polluting components, such as metals and organic compounds, for reuse in the industrial process can be considered one of the main applications in this field. Therefore, there is interest in modeling one of the most used treatment processes, adsorption. Aiming to describe the dynamics of the process in an adsorption column, in this work the method of lines and the pdepe function (matlab) are used to solve the model formed by the mass balance in the liquid phase, linear driving force equation (LDF) and the Langmuir isotherm for equilibrium. An evaluation of the model varying some experiment conditions was carried out, from which results congruent with those found in the literature were observed. In addition, a sensitivity analysis of the phenomenon was carried out in relation to the parameters: Langmuir constant, intraparticle mass transfer coefficient and axial dispersion coefficient. Subsequently, these parameters were estimated using the Monte Carlo technique via Markov chain (MCMC) using experimental data found in the literature. Finally, in general, the estimates were good enough to represent the adsorption dynamics of the evaluated experiments.
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)
Uso do óleo de açaí (Euterpe oleracea) e amido de mandioca (Manihot esculenta) na obtenção de produtos bioativos
(Universidade Federal do Pará, 2023-10-30) OLIVEIRA, Sara Caroline Pacheco de; LAGO, Gleice Vasconcelos Pereira do; http://lattes.cnpq.br/7932392876332323; HTTPS://ORCID.ORG/0000-0002-9702-250X; BRASIL, Davi do Socorro Barros; http://lattes.cnpq.br/0931007460545219; https://orcid.org/0000-0002-1461-7306
Cassava is found in abundance in nature, especially in the State of Pará, from them it is possible to extract starch, rich in amylose and amylopectin, components that help in the production of bioplastics. Furthermore, Pará is the largest producer of açaí, a raw material that is also natural and has antioxidant, phenolic and healing compounds. The oil extracted from açaí has the same characteristics found in the pulp, which makes it an excellent agent for incorporation into products added on polymers. The present study reports the characterization of cassava starch and evaluation of the biological characteristics of açaí oil, for the production of an active bioplastic, with the aim of incorporating the benefits found in the oil. To this end, some tests were carried out using plasticizers such as glycerol, ethylene glycol and sorbitol in the composition, to structure the bioplastic, where glycerol proved to be the most viable option. Cassava starch was dried at three temperatures: 45, 60 and 75°C, for the drying curve, and it wasobserved that starch dried at 45°C had better performance, without significant losses in its structure. The analyzes carried out were relevant to detect the potential of açaí oil on incorporating bioplastic. It is known that the characterization of the oil is essential to ensure its quality. Açaí oil was evaluated for 1H NMR, which was essential for quantifying iodine (67.05 I2/g) and saponification (109.06 mg KOH/g) levels. Furthermore, the oil also presented satisfactory results, with emphasis on the following activities: antioxidant (532.56 µM of Trolox/g), anticancer (with reduced metabolic activity and cell viability for the AGP01, SK19 and VERO lines, with IC50 75 .30; 80.15; 73.05 µg/ml, respectively), in addition to the promising result in anti-inflammatory activity that tested target gene TNF-α (tumor necrosis factor alpha) and detected that the samples analyzed with the oil presented anti-inflammatory effect even after 24 hours of exposure, which confirms its bioactivity. This highlights the gigantic potential of using açaí oil for improvement and application in new products, as it has proven to be a strong ally against infectious and cancerous diseases, with cell recovery capacity. Therefore, the oil was incorporated into a polymeric matrix based on cassava starch, which resulted in bioplastic with a thickness (0.157 mm), PVA (19.39 g.mm.KPa-1.d-1.m- 2), transparency (2.60), and one of the highlights was the colorimetric analysis that was able to detect shades of green in the sample, represented by values of -5.75 (a*) and 10.90 (b*), identifying the presence of chlorophyll from açaí oil. In this way, it was possible to note the relevance of using this oil for inclusion in products that bring benefits to the end consumer, in order to take advantage of the chemical and biological properties that this oil has in its composition, as is the case of bioplastic, which contributes to the pharmaceutical sector for presenting bioactivity, in addition to its possible use in the packaging sector and helping to reduce the use of plastics from petroleum, as it is a 100% biodegradable plastic.
Acesso aberto (Open Access)
Simulação do processo de extração supercrítica do óleo de tucumã-do-Pará (Astrocaryum vulgare) usando aspenHYSYS
(Universidade Federal do Pará, 2023-09-25) MORAIS, Rayelle Mendonça; CARVALHO JÚNIOR, Raul Nunes de; http://lattes.cnpq.br/5544305606838748; https://orcid.org/0000-0002-4433-6580
The adaptation of industrialization in the form of a sustainable economy, technological advances and computational benefits have motivated the use of process simulators to evaluate the potential of oleaginous species native to the Amazon region through fast and automated simulations. Therefore, the objective of this work was to apply the AspenHYSYS simulator to describe the tucumã-do-Pará oil extraction process using supercritical carbon dioxide as solvent. The feasibility of simulations of the tucumã oil extraction process using the mathematical models of Menezes et al. (2023) and Tan and Liou (1989) were comparatively evaluated with experimental data previously selected from the literature. Simulations of the supercritical extraction of tucumã-do Pará oil found that the model by Menezes et al. (2023) was adequate to describe the experimental kinetic data for all evaluated systems, which presented an RSD with a lower value of 0.57. The energy and material cost were calculated, and the value obtained (2.82 R$/g of oil) together with the high concentration of bioactives in the product demonstrate that the studied process presents a positive cost-benefit ratio. An increase in scale was carried out for beds 1, 5, 10 and 50L. For beds of up to 10L, an adequate projection of the process was obtained, considering that the deviations obtained were less than 1, however, for 50L, the adjustment presented a deviation of 58, which may infer that the model used has a scalability limit. Simulations of the supercritical extraction of tucumã-do-Pará oil, using AspenHYSYS, led to values consistent with the experimental data, thus confirming that the studied plant proved to be an effective tool for the study of the process.
Acesso aberto (Open Access)
Avaliação da formação zeolítica em sínteses com diferentes proporções de Si/Al via processo hidrotermal a partir de caulim durp (flint)
(Universidade Federal do Pará, 2023-02-23) FERREIRA, Aline Lopes; PINHEIRO, Alice dos Prazeres; http://lattes.cnpq.br/6671972168040423; MACÊDO, Emanuel Negrão; http://lattes.cnpq.br/8718370108324505
The zeolite synthesis is composed of several reactional factors, in which changing a condition can significantly modify the intensity trend of the zeolite crystals or even the type of zeolite formed. In this context, this work aims to explore the change in the Si/Al ratio in different time periods and analyze the formed product. Initially, the characterization of hard kaolin was carried out through FRX, DRX, MEV, TG, DTG and DSC analyses. Subsequently, the hard kaolin was calcined at 650 °C for 2 hours, with the aim of transforming the starting material into metakaolinite, facilitating the restructuring into zeolite in the reaction medium of the dynamic hydrothermal process. Altogether, 7 hydrothermal syntheses with different Si/Al ratios were carried out, each lasting 6 hours. In each synthesis, aliquots were removed every half hour and filtered, the liquid of which was used to carry out the titration, while the particulate material from the period of 1, 2, 4 and 6 hours was applied for verification in the X-Ray Diffractogram (DRX) and MEV. In all products, the crystalline phases referring to zeolite A, sodalite and in some points of faujasite and cancrinite were observed. In view of the data obtained, it was verified that all the compositions used had satisfactory results with zeolite formation from 1 hour of synthesis, that is, a short period of time. Furthermore, it was possible to verify in a visible way, through the intensity of the peaks and appearance or disappearance of zeolite types, the interference of time and the proportion of Si/Al in the medium. In addition to the XRD, the dendrogram analysis was used in order to identify clusters, that is, which products had similar characteristics, being able to analyze intervals of better formation. The MEV was carried out with the 1-hour material, verifying the characteristic morphology of zeolite A and sodalite, mainly in the proportions of Si/Al=1 and 1,5. The concentration of NaOH in the medium, verified by titration, showed little consumption of this reagent throughout the synthesis. However, it was concluded that the reaction conditions applied to the hard kaolin showed the capacity to form zeolites, allowing the verification of the formation.
Acesso aberto (Open Access)
Simulação do escoamento EMHD de um fluido micropolar em um duto quadrado utilizando a técnica da transformada integral generalizada
(Universidade Federal do Pará, 2023-04-28) SOUZA, Andreo Carlos Magalhães; MIYAGAWA, Helder Kiyoshi; http://lattes.cnpq.br/5848592858919971; HTTPS://ORCID.ORG/0000-0001-9346-4696; QUARESMA, João Nazareno Nonato; http://lattes.cnpq.br/7826389991864785; https://orcid.org/0000-0001-9365-7498
This paper aims to perform the kinetic, microrotational and thermal analyses of an electromagnetohydrodynamic (EMHD) flow of a micropolar fluid within a quadratic section duct subjected to an external magnetic field, where the mathematical formulation takes into account a pulsatile pressure difference. The flow is transient, two-dimensional in laminar regime and has constant physical properties. The resulting nonlinear differential equations (Navier-Stokes Equation, Microrotation Equation and Energy Equation) were solved using the hybrid (analytic-numerical) GITT (Generalized Integral Transform Technique) technique and a computer code was synthesized in Wolfram Mathematica v. 11.3 software with the objective of numerically solving the proposed model. Aiming to analyze the consistency of the technique, the convergence analysis of the variables central velocity, central microrotation, central temperature, average velocity, average temperature, wall stress and Nusselt number was initially performed. Next, the numerical verification of the method is presented by comparing the results of GITT with that of the NDSolve routine of the software used. The analysis of the parameters involved in the flow (Strouhal number, Hartmann number, Prandtl number, Eckert number, electrical parameter, micropolarity parameter, mean pressure gradient, microrotation viscosity and pressure pulse frequency) and the physical interpretation of the variation of each of them is also performed.
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)
Estudo da influência do óxido de cálcio nas reações de estado sólido na produção de agregado cerâmico a base de aluminossilicatos e resíduo do processo Bayer
(Universidade Federal do Pará, 2023-02-10) BRITO, Carlos Eduardo Costa; SOUSA, Jose Antonio da Silva; http://lattes.cnpq.br/6157348947425968; MACÊDO, Emanuel Negrão; http://lattes.cnpq.br/8718370108324505
The most important worry involving the generation of industrial waste is associated with the effects those materials can have on the environment and human health, considering that the dangerous waste produced by the industry requires particular care and attention, because if managed improperly, it can become a serious environmental threat. Therefore, this paper demonstrates the studies conducted to recycle the residue from the Bayer process, as a raw material in the production of synthetic aggregate, intended for civil construction. Furthermore, this paper has analyzed the influence of calcium oxide in the solid state reactions during sintering in the production of ceramic aggregates based on residue from bauxite processing because this oxide, besides being a melting material, also influences the formation of glass with lower viscosity, and may positively influence the mechanical strength of the material. For the conformation of the aggregates a composition based on bauxite residue and silica was adopted with and without the addition of calcium oxide. The pellets were produced in a rotating cylinder and sintered at temperatures of 1180, 1200 and 1250 °C with a burn time of 3 hours. For the characterization of the raw materials the techniques of X-ray Fluorescence (XRF), X-ray Diffraction (XRD), Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TG) were employed. For the characterization of the aggregate, scanning electron microscopy (SEM), XRD and DSC tests were performed on the formulations composed of bauxite residue and clay with and without the addition of calcium oxide. The physical and technological properties determined were: Water absorption, apparent porosity and apparent specific mass. The results of this paper indicate that bauxite residue can be used as a source of alternative raw material for the production of synthetic ceramic aggregate. The results obtained also prove that the use of calcium oxide directly influenced the solid state reactions, especially in the mullite formation reaction. Therefore, the production of synthetic aggregate with the addition of calcium oxide proved to be a promising destination for the Bayer process residue.
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)
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)
Fotocatalisadores de dióxido de titânio dopados com metais de transição: síntese, caracterização e aplicação na fotodegradação de fármacos
(Universidade Federal do Pará, 2024-12-27) AZEVEDO, Carla Arnaud de; FARIA, Lênio José Guerreiro de; http://lattes.cnpq.br/7428609361678173
Heterogeneous photocatalysis has shown promise in ecological remediation and in the adequate treatment of pharmaceuticals as emerging contaminants. This study evaluated the photocatalytic activity of materials synthesized from the modification of the TiO₂ surface with transition metals (copper and cobalt) at concentrations of 0.5% and 1.5%, analyzing the physical, chemical and textural properties of the materials by N2 physisorption (BET) analysis, X-ray diffractometry (XRD), scanning electron microscopy–energy-dispersive X-ray spectrometry (SEM-EDS) and Fourier transform infrared (FT-IR). The experimental tests were carried out in an annular photoreactor with UV mercury lamp, following the Box-Behnken design, to evaluate the influence of catalyst mass (50 – 150 mg.L-1 ), drug concentration (2 – 8 mg.L-1 ) and irradiation time (60 – 120 min) on the photodegradation of acetaminophen (ACT) and diclofenac sodium (DCF). The BET results indicated that the materials have a mesoporous structure with an average pore diameter of 14.52 nm. XRD characterization confirmed the mixed structure of anatase and rutile and the absence of metal oxide peaks. The SEM-EDS analysis revealed irregular surfaces formed by misshapen grains and small particles attributed to metal oxides. The FT-IR showed O-H and Ti-O stretching bands, characteristic of photocatalytic materials. The FTCu1.5 photocatalyst was chosen for use in the photodegradation tests of the drugs due to its surface area, porosity and good anatase and copper content. The photocatalysis tests, in comparison with the photolysis tests, showed superior results, evidencing the functionality of the photocatalyst used. The degradation percentages reached 100% for both drugs and the concentration of the pollutant solution had a negative effect on the response variables, indicating that degradation increases with the reduction of the initial concentration of this solution. The proposed polynomial models presented a coefficient of determination (R²) > 0.9 and good predictive capacity. The Response Surface Methodology (RSM) and Desirability Function analyses indicated that it is possible to obtain a substantial reduction in the amount of photocatalyst used, when combined with an adequate adjustment in the irradiation time. The optimal conditions within the experimental domain for ACT are mcat = 100 mg.L-1 , CFA = 2 mg.L-1 and tIRR = 75 minutes, resulting in EffACT(%) = 99.05% and for DCF, the optimal conditions were mcat = 72 mg.L-1 , CFA = 2 mg.L-1 and tIRR = 65 minutes, resulting in EffDCF(%) = 90.39%. The developed photocatalyst significantly degraded the drugs and demonstrated promise for photocatalysis applications.