Dissertações em Engenharia Química (Mestrado) - PPGEQ/ITEC

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

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

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Agora exibindo 1 - 6 de 6

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)
Extratos de sementes de gergelim preto (Sesamum indicum L) obtidos via CO2 supercrítico: isotermas de rendimento global, dados cinéticos e ajustes, ácidos graxos totais, fitosteróis e efeitos neuroprotetores
(Universidade Federal do Pará, 2013-12-17) BOTELHO, José Rafael Santos; ARAUJO, Marilena Emmi; http://lattes.cnpq.br/8983914018546682; CARVALHO JÚNIOR, Raul Nunes de; http://lattes.cnpq.br/5544305606838748
In Brazilian folk medicine, black sesame (Sesamum indicum L) seeds is one of the most important ingredients present in the tea used to treat encephalic stroke victims. Nevertheless, isolation of black sesame extracts to medicinal finality using supercritical fluid technology has not been performed. The objective of this work was to investigate some process variables of supercritical fluid extraction in black sesame to generate extracts applicable in stroke research. Two isothermal (40 and 60 °C) were explored, combined with pressures that ranged from 200-400 bar, at a constant CO2 mass flow rate of 5,9 x 10-5 kg/s. The global yields ranged from 37-53% in dry basis. The highest mass yield was obtained at 60 °C and 400 bar. The fatty acid composition comprised a high unsaturated/saturated ratio. Chromatographic analysis of phytosterol content in the high global yield extract revealed higher amounts of β-sitosterol + sitostanol, cholesterol, campesterol + campestanol + 24-methylene cholesterol, Δ-5 avenasterol and stigmasterol, while lower levels of Δ-5,24 stigmastadienol, brassicasterol, clerosterol + Δ-5-23 stigmastadienol, Δ-7 avenasterol, eritrodiol and Δ-7 stigmastenol were present in the black sesame extract. Overall extraction curves from the supercritical fluid extraction in lower and higher global yields (200 e 400 bar at 60 °C) fitted the Tan and Liou (1989), Martinez et al. (2003), Esquível et al. (1999), Goto et al. (1993) e Sovová models (1994 and 2012). The models of Tan and Liou (1989), Goto et al. (1993) and Sovová (1994 and 2012) presented the best residual sum of squares values. Pilot experiments suggest that black sesame extract is neuroprotective following endothelin-1 induced focal ischemia into the motor cortex of male adult rat, observing indications that a prejudicial cell form for the stroke`s status was inhibited by the treatment.
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)
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)
Obtenção de gordura das sementes de Ucuúba (Virola surinamensis) por meio de extração com CO2 em estado supercrítico: rendimento global, dados cinéticos, ácidos graxos totais e atividade antimicrobiana
(Universidade Federal do Pará, 2015-09-28) CORDEIRO, Renato Macedo; CARVALHO JÚNIOR, Raul Nunes de; http://lattes.cnpq.br/5544305606838748
The Virola surinamensis, popularly known as ucuúba, is a typical tree found in floodplain habitats and along rivers in the Amazon region. The fat extracted from the seeds has a high melting point and is a product appreciated by the cosmetic industry. The objective of this work was to study the extraction of ucuúba seed fat using supercritical fluid and compare, in terms of process yield and composition of the extracts, with those obtained from the organic solvent extraction technique (via soxhlet). The extraction technique Supercritical Fluid Extraction (SFE) was used because it is regarded as a clean technology, economically attractive, and environmentally safe, avoiding the consumption of large amounts of organic solvents, which are often expensive and potentially harmful. The supercritical extracts of ucuúba seeds were obtained at temperatures of 40, 60 and 80 °C, combined with a pressure of 350 bar, the solvent density varied between 789.2 and 935.6 kg / m3, and a flow of 2.7 L / min. The highest yield obtained using supercritical CO2 was 64.39% for the extraction condition of 350 bar and 80 °C. The yield for the extraction via soxhlet was 61.38%. The mass transfer models of Goto et al. (1993), Esquivel et al. (1999), Tan and Lio (1989), Barton (1991) and Martinez et al. (2003) were employed to describe the extraction kinetics using supercritical fluid. The models that best described the extraction kinetics, with low average deviations, were the models of Martinez et al. (2003) and Goto et al. (1991). The fatty acid profile analysis showed that the ucuúba fat is composed predominantly of saturated fatty acids, mainly of myristic and lauric acids. The antimicrobial activity of the fats obtained was tested on the following organisms: Candida albicans, Staphylococcus aureus and Escherichia coli. Only the bacterium Staphylococcus aureus showed zone of inhibition, ranging from 10 to 11 mm.
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.

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