Teses em Engenharia de Recursos Naturais da Amazônia (Doutorado) - PRODERNA/ITEC

URI Permanente para esta coleçãohttps://repositorio.ufpa.br/handle/2011/4045

O Doutorado Acadêmico inicou-se em 2006 e pertence ao Programa de Pós-Graduação em Engenharia de Recursos Naturais da Amazônia (PRODERNA) do Instituto de Tecnologia da UFPA (ITEC) da Universidade Federal do Pará (UFPA).

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Acesso aberto (Open Access)
Adsorção e dessorção supercrítica de carotenos e antioxidantes do óleo de buriti (Mauritia flexuosa, Mart) em leito de γ- Alumina
(Universidade Federal do Pará, 2012-03) CUNHA, Marcos Augusto Eger da; FRANÇA, Luiz Ferreira de; http://lattes.cnpq.br/6545345391702172; MACHADO, Nélio Teixeira; http://lattes.cnpq.br/5698208558551065
In this work we investigated the enrichment of antioxidants buriti oil (Mauritiaflexuosa Mart) adsorption process by supercritical. The adsorption was carried out experimentally by the method of frontal analysis in columns packed with y-alumina and 15, 20 e 25 MPa, 333 K, and flow of solvent QCO2 = 10,6 L/min, using an assembly of double columns of 81 cm3, tested and approved for use as a cell adsorption. The oil was buriti physic-chemically characterized according to the AOCS official methods and found to comply with the data reported in the literature. The composition of methyl esters was determined by gas chromatography (CG) and antioxidant activity by the method of capture of free radicals (DPPH). The adsorbent was characterized by fluorescence and x-ray diffraction, determining the particle size distribution, porosity and surface area by BET in each experiment, a material balance was performed in the adsorption column to calculate the mass of the adsorbed species in y-alumina in the process of supercritical adsorption. The influence of pressure on supercritical adsorption was investigated by examining the behavior of the isotherms. The Langmuir isotherm was used to model the experimental data of adsorption. The experimental results show an increased capacity adsorbent with higher pressures, showing a maximum of 90,9 ± 8,6 mg oil/g y-alumina, at 25 MPa. The adsorption supercritical buriti oil on γ-alumina using carbon dioxide as solvent appears to be an alternative method for extracting antioxidants from the includ carotenes.
Acesso aberto (Open Access)
Análise do processo de despolimerização de resíduos de resinas dentárias à base de pmma em diferentes escalas de produção
(Universidade Federal do Pará, 2024-06-26) RIBEIRO, Haroldo Jorge da Silva; MACHADO, Nélio Teixeira; http://lattes.cnpq.br/5698208558551065; BORGES, Luiz Eduardo Pizarro; http://lattes.cnpq.br/8756886156388456; https://orcid.org/0000-0002-2337-4238
In recent years, the increasing use of plastics has brought economic and industrial benefits but has also led to a significant rise in waste, representing a global environmental challenge. In this context, pyrolysis emerges as a promising technology, offering potential solutions to address the growing problem of plastic waste and promote a more sustainable circular economy. This study investigated the thermal decomposition of dental waste based on poly(methyl methacrylate) (PMMA), focusing on the thermodynamic characterization and optimization of pyrolysis processes at different production scales. Thermogravimetric analysis (TG) showed that PMMA waste remains stable up to 200 ºC, with degradation starting as mass loss occurs beyond this temperature. Thermal decomposition was observed to occur in a single stage, with a decomposition peak at 366 ºC, within the range of 327 ºC to 405 ºC, primarily due to radical depolymerization under inert nitrogen and argon atmospheres. Differential Scanning Calorimetry (DSC) analysis revealed an endothermic peak between 370 ºC and 433 ºC, highlighting the complexity of the pyrolysis processes. The energy characterization showed specific values of 423 J/g for total heat, 1748 J/g for gasification heat, and approximately 820 J/g for decomposition heat, indicating discrepancies that require further investigation for a more complete understanding. In studies using semi-batch fixed-bed reactors, a temperature gradient along the bed was observed to have an adverse impact on the liquid yield and MMA concentration, especially in technical and pilot scales, where the gradient was more pronounced due to the thicker bed. Two critical variables were identified: reactor load and power load, both of which decreased as the process scale increased, leading to lower pyrolysis temperatures and negatively affecting MMA production. Additionally, higher temperatures were found at the edges of the fixed bed, which increased gas production and reduced liquid yield. The liquid fraction analysis revealed a predominance of MMA at the beginning of the reaction, with a gradual transition to aromatic hydrocarbons in the final stages, associated with the pyrolysis of residual char, which increased with the scale of production. The results highlight the effectiveness of temperatures below 450 ºC in producing MMA-rich liquid fractions, even under temperature gradient conditions, emphasizing the importance of moderate heating rates for efficient PMMA depolymerization in semi-batch systems. These findings provide valuable insights for reactor design and are essential for the economic evaluation and optimization of PMMA recycling processes through pyrolysis at various production scales.
Acesso aberto (Open Access)
Aplicação de destilados provenientes do bio- óleo de pirólise de resíduos de gordura animal no asfalto diluído de petróleo
(Universidade Federal do Pará, 2024-08-12) VALENTE, Alex Lopes; MACHADO, Nélio Teixeira; http://lattes.cnpq.bhttp://lattes.cnpq.br/1500327307736428r/5698208558551065; https://orcid.org/0009-0002-4461-7611; BERNAR, Lucas Pinto
Waste animal fats (WAF) can be converted into distillate fractions similar to petroleum solvents and used as biofuels or in other applications through pyrolysis and fractional distillation. The distillate fractions from the pyrolysis of triglycerides exhibit adequate viscosity and volatility compared to petroleum-derived fuels but show acid values between 60-140 mg KOH/g, preventing their direct use as biofuels without considerable purification of the distilled fractions. Diluted petroleum asphalt (DPA), used for priming soil in the construction of flexible pavement, requires adequate viscosity, volatility, and penetration, and the distillate fractions from WAF pyrolysis oil can be used as partial or full substitutes for the standard solvent (kerosene) in DPA production. The aim of this study was to test the compliance of DPAs prepared by substituting kerosene with bio-oil fractions from WAF according to DPA standards. First, WAF is obtained from meat waste through the rendering process. Then, WAF is subjected to pyrolysis in a semi-batch fixed-bed reactor (2L), and the resulting bio-oil is fractionally distilled into gasoline, kerosene, and diesel fractions. The pyrolysis process is analyzed concerning the type of reactor used, with a focus on the influence of temperature and reaction time, as well as the distillation profile. The distilled fractions are characterized by density, viscosity, and acid value before being used in the preparation of DPAs by partial and/or total (0-40% by weight) substitution of standard kerosene. The mixtures were tested for kinematic and Saybolt-Furol viscosity, flash point, and penetration, according to road pavement standards. The results showed that the kerosene and diesel fractions from WAF can be adequately used in the preparation of DPAs as a total substitute for the petroleum kerosene typically used.
Acesso aberto (Open Access)
Caracterização morfológica, cristalina e textural de bio-adsorventes produzidos via processamento hidrotérmico de resíduos de palha de milho com H2O sub-crítica: Aplicação na adsorção de ácido acético.
(Universidade Federal do Pará, 2021-12-06) COSTA, Maria Elizabeth Gemaque; MACHADO, Nélio Teixeira; http://lattes.cnpq.br/5698208558551065
This work aims to investigate the influence of temperature on the textural, morphological and crystalline characterization of bioabsorbents produced by hydrothermal processing of corn husk residues with hot compressed H2O. The experiments were carried out at 175, 200, 225 and 250 ºC, 240 minutes, heating rate of 2.0 ºC/min and biomass/H2O ratio of 1:10, using a pilot scale reactor of 18,927 L. The process is analyzed in terms of yields of reaction products as a function of temperature. The results showed yields of solids ranging from 62.92 to 35.82% (weight), gas yields ranging from 1.49 to 9.59% (weight) and liquid products ranging from 35.43 to 54.59% ( Weight). The yield of the solid phase decreases with temperature, presenting an inflection region between 200 and 225 °C, in which a drastic change occurs, while that of the liquid phase increases, presenting the same inflection region between 200 and 225 °C. The gas phase yield increases exponentially with temperature up to approximately 10% (weight) in the investigated temperature range. Elemental analysis of solid products shows that the carbon content increases, while the oxygen and hydrogen content decreases with temperature. The textural, morphological and crystalline characterization of solid phase products analyzed by TG/TDG, SEM/EDX, XRD and BET. The solid phase product (bio-adsorbent) obtained by hydrothermal processing of corn husk residues at 225 and 250 °C, 240 minutes, and biomass/H2O ratio of 1:10, were chemically activated with 2.0 NaOH solutions. M and 2.0 M HCl to investigate the adsorption of acetic acid solutions (1.0; 2.0; 3.0; and 4.0 mg/mL). The adsorption kinetics investigated at 30, 60, 120, 240, 480 and 960 seconds. The adsorption isotherm showed that chemically activated carbons were able to remove acetic acid from aqueous solutions.
Acesso aberto (Open Access)
Carbonização hidrotérmica dos caroços de açaí (Euterpe oleracea, mart) com H20 quente comprimida
(Universidade Federal do Pará, 2021-08-13) SILVA, Conceição de Maria Sales da; MACHADO, Nélio Teixeira; http://lattes.cnpq.br/5698208558551065
This work aims to investigate systematically the influence of process temperature, biomass-to-water ratio, and production scales (laboratory and pilot) on the chemical composition of aqueous and gaseous phases and mass production of chemical by hydrothermal processing of Açaí (Euterpe Oleraceae, Mart.) seeds. The hydrothermal carbonization carried out at 175, 200, 225, and 250 °C, 2 °C/min, biomass-to-water ratio of 1:10, and at 250 °C, 2 °C/min, and biomass-to-water ratios of 1:10, 1:15, and 1:20, in technical scale, as well as at 200, 225, and 250 °C, 2 °C/min, biomass-to-water ratio of 1:10, in laboratory scale. The elemental composition (C, H, N, S) of solid phase determined to compute the HHV. The chemical composition of aqueous phase determined by GC and HPLC and the volumetric composition of gaseous phase by using an infrared gas analyzer. For the experiments in pilot scale with constant biomass-to-water ratio of 1:10, the yields of solid, liquid, and gaseous phases varied between 53.39 and 37.01% (wt.), 46.61 and 59.19% (wt.), and 0.00 and 3.80% (wt.), respectively. The yield of solids shows a smooth exponential decay with temperature, while that of liquid and gaseous phases a smooth growth. By varying the biomass-to-water ratios, the yields of solid, liquid, and gaseous reaction products varied between 53.39 and 32.09% (wt.), 46.61 and 67.28% (wt.), and 0.00 and 0.634% (wt.), respectively. The yield of solids decreases exponentially with increasing waterto-biomass ratio and that of liquid phase increases in a sigmoid fashion. For constant biomass-to-water ratio, the concentrations of Furfural and HMF decrease drastically with increasing temperature, reaching a minimum at 250 °C, while that of phenols increases. In addition, the concentrations of CH3COOH and total carboxylic acids increase, reaching a maximum at 250 °C. For constant process temperature, the concentrations of aromatics vary smoothly with the temperature. The concentrations of furfural, HMF, and cathecol decrease with temperature, while that of phenols increases. The concentrations of CH3COOH and total carboxylic acids decrease exponentially with temperature. Finally, for the experiments with varying water-tobiomass ratios, the productions of chemicals (furfural, HMF, phenols, cathecol, and acetic acid) in the aqueous phase is highly dependent on the biomass-to-water ratio. For the experiments in laboratory scale with constant biomass-to-water ratio of 1:10, the yields of solid ranged between 55.9 and 51.1% (wt.), showing not only a linear decay with temperature, but also a lower degradation grade. The chemical composition of main organic compounds (furfural, HMF, phenols, cathecol, and acetic acid) dissolved in the aqueous phase in laboratory scale shows the same behavior of those in obtained in pilot scale.
Acesso aberto (Open Access)
Concentração e bioensaios alelopáticos e antifúngicos de princípios ativos da raiz de timbó via extração com CO2 supercrítico, extração com solventes e adsorção de soluções diluídas em leito fixo.
(Universidade Federal do Pará, 2014-12-18) ALMEIDA, Ossalin; ARAÚJO, Marilena Emmi; MACHADO, Nélio Teixeira
Acesso aberto (Open Access)
Estudo de processo de upgrading catalítico de vapores da pirólise de resíduos plásticos de equipamentos de informática em reator catalítico com carvão ativado impregnado com NaOH
(Universidade Federal do Pará, 2023-04-03) COSTA, Augusto Fernando de Freitas; MACHADO, Nélio Teixeira; http://lattes.cnpq.br/5698208558551065
This study investigated thermal cracking and catalytic upgrading of plastic waste from computer equipment on a semi-batch reactor coupled to a heated catalyst fixed bed (2-stage vapor cracking). The catalyst used was a Si–Al ash obtained from commercial activated carbon pellets treated with concentrated NaOH solution and calcination. The purpose of the study was to characterize the waste stream through its thermogravimetry (TG) analysis and pyrolysis products, study the effect of temperature (350 - 500 °C) and catalyst quantity (0.0 - 7.5 wt%) on yields of reaction products, physical chemical properties, and chemical composition of organic liquid product in order to understand and evaluate production of fuels and chemical feedstock by recycling of plastic waste from computer equipment through catalytic upgrading. Time fractioned samples were taken in determined reaction times (15 min, 30 min, 45 min, and 60 min) to study the evolution of cracking reactions during experiment runs through changes to chemical composition (GC-MS). A comparison with other previous work was also presented to show similarities between different feedstocks using the same thermal unit. The results indicate composition of brominated acrylonitrile-butadiene-styrene (Br-ABS), polycarbonate (PC), and high impact polystyrene (HIPS) for the plastic waste from computer equipment. The temperature of 350 °C produced better results when considering acid value but presented lower liquid phase yields (38 %) and high gas phase yields (42 %). Catalytic upgrading experiments revealed the increased presence of polycyclic aromatic hydrocarbons (PAH) with an increase in kinematic viscosity of organic liquid product, increase in char yield (from 11 % to 24 %), and decrease in gas yields (15 % to 5 %). Chemical composition showed presence of aromatic hydrocarbons such as styrene, methyl-styrene, and diphenyl-propane and nitrogenated compounds such as benzene butane-nitrile, phenolic compounds, polycyclic aromatic hydrocarbons, and brominated compounds. Plastic waste from computer equipment pyrolysis is a challenging subject due to contaminant presence and varying composition, and chemical composition evaluation according to reaction time provides interesting insights into the evolution of semi-batch pyrolysis/catalytic upgrading experiments. Standardization and reproducibility of the tool should be conducted to continue the evaluation of pyrolysis and catalytic upgrading of a wide range of feedstocks.
Acesso aberto (Open Access)
Estudo de viabiliade econômica do processo de pirólise e craqueamento termo-catalítico em escala piloto utilizando-se material ligno-celulósico, lipídico, de óleo de palma (elaeis guineensis, jacq) e resíduo da neutralização do óleo de palma
(Universidade Federal do Pará, 2022-12) AMARAL, Anderson Rocha; SANTOS, Marcelo Costa; http://lattes.cnpq.br/5640587707776287; MACHADO, Nélio Teixeira; http://lattes.cnpq.br/5698208558551065
In this work, it is accomplished a tecno-economic assessment of the production of bio-oil, coke and gas, via thermos-catalytic pyrolysis followed by distillation. The raw materials were: lipid-base material (residual fat/scum from fat retention box of the University Restaurant at the Federal University of Pará - UFPA), lignin-cellulosic material Açaí seed (Euterpe oleracea. Mart), palm oil and neutrilzing sludge palm oil. From the literature is made a review of the physic-chemical analysis of the raw materials, of the bio-oil and of chemical composition of the biofuels produced (biogasoline, bioquerosene, light-diesel and heavy-diesel). Are also presented the bio-oil yields for each experiment of pyrolysis and distillation and compared with the literature. The economic indicators demonstrated feasibility of the all projects, with exception with the use of açaí seeds. The indicators used to analysis the projects were: a) simple payback criterion, b) discounted payback, c) net present value (NPV), d) internal rate of return (IRR), and e) index of profitability (IP). The minimum fuel selling price (MFSP) obtained is this work for the biofuels was of 1.34 US$/L for all projects, with exception to the palm oil, which was 1,59 US$/L. The sensibility analysis demonstrated that the pyrolysis and distillation yields are the most important variables to affect the minimum fuel selling price (MFSP).
Acesso aberto (Open Access)
Estudo do processo de craqueamento térmico catalítico do sebo bovino para produção de biocombustível
(Universidade Federal do Pará, 2017-12-01) PEREIRA, Anderson Mathias; SANTOS, Marcelo Costa; http://lattes.cnpq.br/8380189608965320; MACHADO, Nélio Teixeira; http://lattes.cnpq.br/5698208558551065
This work aims to study the use of beef tallow as raw material for the production of bio fuel through the process of catalytic thermal cracking reaction. Three catalytic thermal cracking experiments were carried out in a 143 liters reactor, operating in discontinuous mode at 450 °C at atmospheric pressure, using sodium carbonate (Na2CO3) as the catalyst. Two experiments were carried out with crude beef tallow (5 and 10 % Na2CO3 - mass/mass) and one with bovine tallow soap (5 % Na2CO3 - mass/mass). The organic liquid products obtained from the reactions were analyzed through physicochemical analysis and chemical composition. Fractional distillation was also realized in order to obtain fractions of petrol, kerosene and light diesel similar to petroleum. In order to follow the reactions over time, aliquots were withdrawn every 10 minutes up to a total of 10 samples with the first point collected within 30 minutes of reaction. For the collected samples physicochemical analysis and identification of the chemical compounds were realized. The results showed a tendency to obtain higher yields in organic liquid product (OLP) using the catalyst in larger quantities with the crude sample. The chemical identification showed the amount of hydrocarbons present (paraffins and olefins) ranging from 89.28 to 92.23 % and oxygenates (ketones) from 7.77 to 10.72 %. After the distillations, a predominance was observed in the diesel fraction (235-305 °C) while the petrol and kerosene fractions were lower, this behavior was repeated in all experiments. Regarding the samples collected over the time of the reactions it is possible to verify an increase in the acidity index and formation of oxygenates up to 60/70 minutes indicating the occurrence of the primary cracking and then, until the end of the reaction, a decrease in these values evidencing the secondary cracking.
Acesso aberto (Open Access)
Estudo do processo de craqueamento termocatalítico da borra de neutralização do óleo de palma para produção de biocombustível
(Universidade Federal do Pará, 2015-04-17) SANTOS, Marcelo Costa; BORGES, Luiz Eduardo Pizarro; http://lattes.cnpq.br/8756886156388456; MACHADO, Nélio Teixeira; http://lattes.cnpq.br/5698208558551065
The Soap phase residue derived from refining vegetable oils are agro-industrial residues obtained after the neutralization stage of vegetable oils, which are aggregate low-value material, in addition to being an environmental liability for agribusiness thus is becoming increasingly attractive the use of these residues as raw material for generation bio-fuels. This work studies the neutralization sludge of palm oil as an alternative raw material, from the point of view, economic and environmental to the process of catalytic and Thermic-catalytic cracking. Initially were carried experiments of Thermic and catalytic cracking of the neutralization sludge and palm oil (in one reactor) and catalytic tests (the second reactor coupled in the first decarboxylation) both in bench scale; experiments were perfomed of the thermic-catalytic and catalytic (only in semi-pilot scale) of the neutralization sludge in the semi-pilot and pilot scale using different types of catalysts (Na2CO3, CaCO3, activated alumina, zeolite HY, HZSM-5, and FCC). The organic liquid product (OLP) obtained and the fractions obtained from the distillation in bench and pilot scale were characterized and compared with the current standard. The results obtained in laboratory scale have shown that the activated alumina catalyst provided the highest yield in wet basis (83.70%), with palm oil as raw material, however, the bio-fuel obtained Na2CO3 had a better quality how much the physicochemical characteristics. . In the semi-pilot scale, the highest yield was the thermal experiment of the sludge (78.36%), followed by the experiment with 5% activated alumina (71.47%), but the use of Na2CO3 showed better quality in the how much the physicochemical characteristics.The experiments in the pilot scale showed the highest yield (71%) obtained with 15% Na2CO3 at a temperature of 440 ° C. The results of the chromatographic analysis of this OLP obtained in the pilot scale confirmed that the percentage increase in the catalyst enabled the formation of a OLP rich in hydrocarbonate (91.22%) containing aliphatic, olefinic, naphthenic, aromatic and low amounts of oxygenates (8 , 78%). While in the distillation of PLO of the Experiment 5 makes possible to get fractions rich in hydrocarbons and without oxygenates compounds.
Acesso aberto (Open Access)
Estudo do processo de depolimerização de resíduos de resinas dentárias de polimetilmetacrilato (PMMA) via pirólise
(Universidade Federal do Pará, 2022-01-05) SANTOS JUNIOR, Paulo Bisi dos; MACHADO, Nélio Teixeira; http://lattes.cnpq.br/5698208558551065
Polymer materials, due to the diversity of their properties, ease of processing and ability to replace traditional materials, have become indispensable in modern society, although the growing accumulation of plastic waste has become a relevant problem that is difficult to manage. Given this situation, sustainability research has invested in new strategies focused on the processing and transformation of plastic waste where the pyrolysis process presents itself as a promising technology. In this work, the cross-linked PMMA-based dental resins scraps submitted to pyrolysis to recover MMA (Methylmethacrylate). The thermal degradation of cross-linked PMMA-based dental resins scraps analyzed by TG/DTG to guide the operating conditions. The pyrolysis carried out in a reactor of 143L, at 345, 405, and 420 °C, 1.0 atm. The reaction liquid products obtained at 345 °C, 30, 40, 50, 60, 70, 80, and 110 minutes, physicochemical characterized for density, kinematic viscosity, and refractive index. The chemical composition of reaction liquid products obtained at 354 °C, 30, 40, 50, 60, 70, 80, and 110 minutes, at 405 °C, 50, 70, and 130 minutes, and at 420°C, 40, 60, 80, 100, 110, and 130 minutes determined by GC-MS. The experiments show that liquid phase yields were 55.50%, 48.73%, and 48.20% (wt.), at 345, 405, and 420 °C, respectively, showing a smooth sigmoid behavior, decreasing with increasing process temperature, while that of gas phase were 31.69%, 36.60%, and 40.13% (wt.), respectively, increasing with temperature. The reaction liquid products density, kinematic viscosity, and refractive index obtained at 30, 40, 50, 60, 70, 80, and 110 minutes, varied between 0.9227 and 0.9380 g/mL, 0.566 and 0.588 mm2/s, and 1.401 and 1.414, respectively, showing percentage errors between 0.74 and 2.36%, 7.40 and 10.86%, and 0.00 and 0.92%, respectively, compared to standard values for density, kinematic viscosity, and refractive index of pure MMA (Methylmetaclylate) at 20 °C. The GC-MS identified in the reaction liquid products during pyrolysis at 345, 405, and 420 °C, 1.0 atm, esters of carboxylic acids, alcohols, ketones, and aromatics, showing concentrations of MMA (Methylmetaclylate) between 83.454 and 98.975% (area.). For all the depolymerization kinetic experiments at 345, 405, and 420 °C, 1.0 atm, the concentrations of MMA (Methylmetaclylate) in the liquid phase, between 30 and 80 minutes, reach purities above 98% (area.), decreasing drastically with increasing reaction time after 100 minutes, thus making it possible to depolymerize the cross-linked PMMA-based dental resins scraps by pyrolysis to recover MMA (Methylmethaclylate).
Acesso aberto (Open Access)
Estudo do processo de produção de bio-combustíveis via pirólise de resíduos de pneus
(Universidade Federal do Pará, 2019-10-24) SANTOS, Wenderson Gomes dos; DUVOISIN JÚNIOR, Sérgio; http://lattes.cnpq.br/1737235899259374; MACHADO, Nélio Teixeira; http://lattes.cnpq.br/5698208558551065
In this study, the pyrolysis process of waste tires was analyzed in the laboratory and pilot scales. In the lower scale, the temperature variation, the type of catalyst commercially obtained (CaCO3, Na2CO3 and Ca(OH)2), the type of catalyst synthesized / treated from industrial waste (LV 1M HCl, LV 2M HCl and zeolite of kaolin) and the concentration of the NaOH solution impregnated into the tire (0.5, 1 and 2M) in the yields and compositions of the tire pyrolysis oil (TPO). In the larger scale, the evolution of the physicochemical and compositional properties of the TPO’s during the thermal cracking process (T = 400 °C, T = 450 °C and T = 500 °C) was evaluated in order to obtain a liquid product with characteristics of fossil fuels and / or compounds of high commercial value. The results showed that the yield of the TPO's are influenced by the increase in process temperature, by the type of catalyst and by the chemical treatment in the raw material. Being the process at 500 °C and with kaolin zeolite as the catalyst which most optimized the process for the yield and production of aliphatic compounds in the TPO. The use of catalysts led to the reduction of aromatic compounds and sulfur compounds in the liquid fraction. On the smaller scale, the behavior of the aliphatic compounds in thermocatalytic processes and chemical impregnation of the raw material was strongly influenced by the composition of d-limonene in the oils of pyrolysis of tires. The results of the pilot scale allowed us to conclude that there were variations in the physicochemical and rheological properties during the cracking process, but tend to stabilize in 65 minutes of process, presenting low acidity and low viscosity. The main substances identified throughout the process were d-limonene, BTX (benzene, toluene and xylenes) and cymenes. In the fractionation of TPO’s, the fraction of gasoline (C8 to C10) and kerosene (C8 to C17) are essentially hydrocarbons, while light diesel (C15 to C21) and heavy diesel (C17 to C23) by heteroaromatics. It is also concluded that sulfur and halogen compounds tend to be separated from the light diesel range.
Acesso aberto (Open Access)
Estudo do processo de upgrading catalítico de vapores da pirólise de gordura residual em reator de leito fixo com catalisador carvão ativado impregnado com NAOH
(Universidade Federal do Pará, 2022-08-17) BERNAR, Lucas Pinto; MACHADO, Nélio Teixeira; http://lattes.cnpq.br/5698208558551065; BORGES, Luiz Eduardo Pizarro; http://lattes.cnpq.br/8756886156388456
This work investigated influence of reaction time and catalyst-to-residual fat ratio by catalytic upgrading from pyrolysis vapors of residual fat at 400 °C and 1.0 atmosphere, on the yields of reaction products, physicochemical properties (density, kinematic viscosity, and acid value) and chemical composition of bio-oils, over a catalyst fixed bed reactor of activated carbon pellets impregnated with 10.0 M NaOH, in semi pilot scale. The experiments were carried out at 400 °C and 1.0 atmosphere, using a process schema consisting of a thermal cracking reactor of 2.0 L coupled to a catalyst fixed bed reactor of 53 mL, without catalyst and using 5.0, 7.5, and 10.0% (wt.) activated carbon pellets impregnated with 10.0 M NaOH, in batch mode. Results show yields of bio-oil decreasing with increasing catalyst-to-feed ratio. The GC-MS of liquid reaction products identified the presence of hydrocarbons (alkanes, alkenes, ring-containing alkanes, ring-containing alkenes, and aromatics) and oxygenates (carboxylic acids, ketones, esters, alcohols, and aldehydes). Physico-chemical and compositional analysis show that cracking occurred along the carbon chain present in triglycerides and fatty acids initially present, producing gaseous hydrocarbons. Tha activated carbon catalyst was not selective for the liquid biooil deoxygenation, but the obtained results are of great value for understanding the catalytic cracking reaction mechanism.
Acesso aberto (Open Access)
Evolução estrutural do hidro-carvão e cinética da decomposição da palha de milho no processamento hidrotérmico com H2O quente comprimida
(Universidade Federal do Pará, 2023-04-24) TERIBELE, Tiago; SANTOS, Marcelo Costa; http://lattes.cnpq.br/8380189608965320; MACHADO, Nélio Teixeira; http://lattes.cnpq.br/5698208558551065
In this work, the effect of reaction time and biomass-to-H2O ratio on the structural evolution of hydrochar and kinetic of by hydrothermal processing of corn Stover with hot compressed H2O, have been systematically investigated. The experiments were carried out at 250 °C, heating rate of 2.0 °C/min, biomass-to-H2O ratio of 1:10, and reaction times of 60, 120, and 240 minutes, and at 250 °C, 240 minutes, heating rate of 2.0 °C/min, and biomass-to-H2O water ratio of 1:10, 1:15, and 1:20, using a pilot scale stirred tank reactor of 5 gallon. The characterization of solid phase products performed by thermo-gravimetric analysis, scanning electron microscope, energy dispersive X-ray spectroscopy, X-ray diffraction, and elemental analysis (C, N, H, S). The physical-chemistry properties of solid phase analyzed in terms of dry matter (DM), total organic content (TOC), and ash. The yields of solid and gas phases decrease linearly with decreasing biomass-to-H2O ratio, while that of liquid phases increases linearly. For constant biomass-to-H2O ratio, the yields of solid, liquid, and gaseous reaction products varied between 52.97 and 35.82% (wt.), 44.84 and 54.59% (wt.), and 2.19 and 9.58% (wt.), respectively. The yield of solids decreases exponentially by decreasing the reaction time, while the yields of liquid and gas phases increase exponentially. For constant biomass-to-H2O ratio, TG/DTG curves shows that reaction time of 60 minutes was not enough to carbonize corn Stover. For constant reaction time, TG/DTG curves shows that increasing the H2O-to-biomass ratio worse the carbonization of corn Stover. For constant biomass-to-H2O ratio, the SEM images show the main morphological structure of the corn Stover remains practically unchanged, while for constant reaction time, SEM images show that plant microstructure retains part of its original morphology, demonstrating that a decrease on biomass-to-H2O ratio worse the carbonization of corn Stover. For constant biomass-to-H2O ratio, the EDX analysis shows that the carbon content in hydrochar increases with reaction time, while for constant reaction time, the carbon content decreases with increasing biomass-to-H2O ratio. The kinetic of corn Stover degradation was correlated with a pseudo-first order exponential model, exhibiting a root-mean-square error (r2) of 0,996, demonstrating that degradation kinetics of corn Stover with hot compressed H2O, expressed as hydrochar formation, is well described by an exponential decay kinetics.
Acesso aberto (Open Access)
Modelagem e simulação do fracionamento de óleos vegetais e do produto líquido orgânico do processo de craqueamento termocatalítico do óleo de palma em colunas multiestágios em contracorrente
(Universidade Federal do Pará, 2016-10-03) COSTA, Elinéia Castro; ARAÚJO, Marilena Emmi; http://lattes.cnpq.br/8983914018546682; MACHADO, Nélio Teixeira; http://lattes.cnpq.br/5698208558551065
In this work, a method was developed employing the commercial process simulator Aspen Hysys using a countercurrent multistage column to the fractioning/deacidification of vegetable oils applying processes such as liquid-liquid extraction, using ethanol as solvent, and supercritical fractioning, with CO2 as solvent. Palm and olive oil were used in the case study. Experimental equilibrium data of multicomponent systems published in the literature were correlated with both NRTL model and RK-Aspen models, the binary interaction parameters obtained from these correlations were used in the simulations. The same procedure was applied to the fractioning/deacidification process of the organic liquid products (OLP) from the thermal-catalytic cracking of palm oil, using supercritical CO2 as solvent. The correlation of liquid-liquid equilibrium data of the systems showed that the NRTL model was able to suitably fit the experimental data for all the studied systems with RMSD between 0.15 to 1.72%. For all the S/F ratios analyzed, simulation results demonstrated, on the 10 stage column, that only when a mixture water+ethanol (12.41%) was used as solvent, the maximum acceptable level of neutral oil loss for industrial physical refining (5%wt) was attained. Correlation of experimental equilibrium data at high pressures indicated that the RK-Aspen model was able to properly fit the equilibrium data for all studied systems, with RMSD from 3.0E-05% to 0.58% for the liquid phase and between 2.0E-06% to 0,02% for vapor phase, for each composition of free fatty acid in the feed. The absolute mean deviations between the supercritical fractioning process simulated with 10 stages using the olive oil model mixture and the experimental results of supercritical fractioning of olive oil in a pilot scale column at 313K, S/F=20, with varying pressure and different fatty acid composition in the feed, were 2.25% for the yield of raffinate stream and 0.15% for the fatty acid concentration in the raffinate stream. The simulations of supercritical fractioning of OLP, with 10-staged columns, showed that the CO2 was able to deacidificate the produced fractions. For both proposed process diagrams with the column 1 using S/F=17 or 19, column 2 for all the studied S/F ratios, presented top streams (extract) containing compositions characteristic of kerosene from petroleum, with lower olefin and oxygenated content compared to the experimental fraction distillated within the same temperature range of petroleum kerosene published in the literature.
Acesso aberto (Open Access)
Obtenção de extratos da polpa de açaí (Euterpe oleracea) por extração supercrítica: isotermas de rendimento global, atividade alelopática dos extratos, enriquecimento de antocianinas e compostos fenólicos
(Universidade Federal do Pará, 2016-10-04) BATISTA, Camila de Cássia Rodrigues; MACHADO, Nélio Teixeira; http://lattes.cnpq.br/5698208558551065; CARVALHO JUNIOR, Raul Nunes de; http://lattes.cnpq.br/5544305606838748
Açaí is one of the most popular functional foods of the Amazon, widely consumed in Brazil and became known in other countries, especially due to the many benefits it has for a wide use in the growing market for nutraceuticals. Açaí extracts derived have a number of components with antioxidant, vasodilatory, anti-inflammatory and energy. Among the appropriate technologies in the processes, supercritical technology has become advantageous to obtain extracts with higher quality, adding value to products and by-products of the process. This work presents as objective a study of the supercritical extraction process of acai pulp to obtain extracts rich in bioactive compounds. A evaluation of the variables of the supercritical extraction process with CO2 (temperature, pressure, and solvent density) of Açai pulp showed the conditions that maximize the amount extracts (lipid fraction) obtained, and enable the concentration anthocyanins in açai pulp defatted for subsequent extraction of these compounds. The extracts obtained from extraction with CO2 were evaluated for fatty acid composition and allelopathic activities. The overall yield isotherms showed that the maximum amount of extract obtained in the process was in the condition of 70°C/490 bar followed by the condition of 50°C/350 bar.
Acesso aberto (Open Access)
Produção de biocombustíveis um craqueamento termo-catalítico de gordura residual com lama vermelha ativada quimicamente como catalizador
(Universidade Federal do Pará, 2019-12-04) OLIVEIRA, Romero Moreira de; SOUZA, José Antônio da Silva; http://lattes.cnpq.br/6157348947425968; MACHADO, Nélio Teixeira; http://lattes.cnpq.br/4688021995450878
In this work, a biofuels study was carried out by the pilot scale thermo-catalytic cracking process, of the residual fat from the fat boxes of the university restaurant of the Federal University of Pará (RU-UFPA), using activated red mud as a catalyst. The residual fat used in the experiments was treated by sieving, decantation, dehydration and storage, to be introduced into the cracking reactor. The red mud was subjected to a pre-treatment of dehydration in an oven at 100°C for 24 hours, then subjected to a chemical treatment with 0,5M, 1M and 2M hydrochloric acid solution (HCl). Subsequently calcination of this material was carried out at 1000°C for 2 hours, to be applied as a catalyst in the proportions 5%, 10% and 15% m/m. The cracking process was performed at a fixed temperature of 550°C, and the generated PLO was collected by reaction time 10 at 20, 40, 60 and 80 minutes, these were then characterized and subjected to fractional distillation. Distillation was performed on a Vigreux column with 12 stages, and condensed fractions were collected according to the distillation ranges of gasoline (45°C-175°C), kerosene (175°C-235°C), light diesel (235°C-305°C) and heavy diesel (>305°C), to be characterized later. The highest yield (PLO + gas) was from experiment 5 with 90%, prepared with 15% m/m catalyst treated with 1M HCl. Also presenting biofuels with better physical-chemical characteristics such as the acid value of gasoline in point 4 (9,4 mg KOH/g) and composites with the highest of 92.91% of total hydrocarbons for kerosene.
Acesso aberto (Open Access)
Produção de biocombustíveis via craqueamento térmico-catalítico de resíduos sólidos de caixas de gordura com carbonato de sódio e lama vermelha ativada termicamente
(Universidade Federal do Pará, 2015-04) ALMEIDA, Hélio da Silva; MENDONÇA, Neyson Martins; http://lattes.cnpq.br/7534816053779593; MACHADO, Nélio Teixeira; http://lattes.cnpq.br/5698208558551065
This work has the main objective to study the production of biofuels from Thermal-Catalytic Cracking process pilot scale using residual fat removed from the grease traps of the university restaurant of Universidade Federal do Pará (RU-UFPA). The residual fat was collected and treated by sifting, dewatering and separating and introduced into the cracking pilot unit. Were used as catalysts soda ash and red mud thermally activated at 1000 ° C, reject material from the production of alumina Hydro-Alunorte company, which also is an environmental liability. After cracking the organic liquid product obtained was distilled and characterized in the laboratory and pilot scales, obtaining the biofuel Biokerosene band, biogasoline, light and heavy diesel. Additionally, it was investigated the consumption of drinking water of that restaurant and the generation of wastewater, determining the per-capita water consumption, the coefficient of sewage return, the pollution load and the population equivalent. The PLO higher yield of around 82% was obtained with 15% sodium carbonate catalyst. The acid value of the PLO (14.97 mg KOH / g) showed a figure considered low and very satisfactory when compared with the values obtained in the literature. The chromatographic results of the experiment with 10% sodium carbonate showed high content PLO hydrocarbons (78.98%), green kerosene (92.64% of oil) and light diesel (90.21% hydrocarbons). The results denote viability in the production of biofuels from the treated residual fat of the fat boxes.
Acesso aberto (Open Access)
Produção, fracionamento e desacidificação de biocombustíveis obtidos via craqueamento térmico catalítico de óleos vegetais
(Universidade Federal do Pará, 2015-04) MANCIO, Andréia de Andrade; BORGES, Luiz Eduardo Pizarro; http://lattes.cnpq.br/8756886156388456; MACHADO, Nélio Teixeira; http://lattes.cnpq.br/5698208558551065
In this work, we investigated the following steps: (1) production step of biofuels via catalytic thermal cracking; (2) fractionation step of the biofuels and (3) treating step of the biofuels by applying the liquid-liquid extraction and adsorption as alternatives deacidification of biofuels. The results of biofuel production step show that conversion varied from 86 to 97%. The yield in OLP increased from 41 to 76%, and the physicochemical properties such as TAN, decreased with increasing percentage of catalyst. The GC-MS results show that increasing the percentage catalyst promotes an increase in the content of hydrocarbons and reduction of oxygenates in the OLP. The olefins are the main classes of hydrocarbons present in the OLP. The OLP fractionation showed that the major distilled fraction is heavy diesel fraction followed by light diesel, reaching a maximum yield of 36.37 and 30.51%, respectively. In relation to the deacidification step by liquid-liquid extraction, the results show that increasing the concentration of water in the solvent causes a decrease in the partition ratio of acid. The methyl alcohol was the only solvent showed an increase in their FFA removal capacity with increasing temperature. Regarding the deacidification of distilled fractions by adsorption, the results indicate that the red mud chemically activated with 0.25, 1 and 2M HCl show a high potential for application in adsorptive processes of FFA, since qt these adsorbents was greater than 2000 mg/g.
Acesso aberto (Open Access)
Simulação do processo de desacidificação de misturas de hidrocarbonetos, em colunas de absorção em contracorrente, usando co2 supercrítico como solvente no simulador aspen hysys
(Universidade Federal do Pará, 2022-08-11) SANTOS JUNIOR, Manoel Raimundo dos; MACHADO, Nélio Teixeira; http://lattes.cnpq.br/5698208558551065; COSTA, Elineia Castro; http://lattes.cnpq.br/9685402675283869
In this work, the deacidification of organic liquid products (OLP) obtained by thermal catalytic cracking of palm oil at 450 C, 1.0 atmosphere, with 10% (wt.) Na2CO3 as catalyst, in multistage countercurrent absorber columns using supercritical carbon dioxide (SC-CO2) as solvent, with Aspen HYSYS® process simulator was systematically investigated. In a previous study, the thermodynamic database and the modeling of equations of state necessary to simulate the deacidification of OLP were presented [Molecules 2021, 26, 4382. https://doi.org/10.3390/molecules26144382 ]. This work addresses a new flowsheet, consisting of 03 absorber columns, 10 expansions valves, 10 flash drums, 08 heat exchanges, 01 high pressure pump, and 02 make-up of CO2, aiming to improve the deacidification of OLP. The simulation was performed at 333 K, 140 bar, and (S/F) = 17; 350 K, 140 bar, and (S/F) = 38; 333 K, 140 bar, and (S/F) = 25. The simulation shows that 81.49% of OLP could be recovered and the concentrations of hydrocarbons in the extracts of absorber-01 and absorber-02 were 96.95% and 92.78% (wt.) in solvent-free basis, while the bottom stream of absorber-03 was enriched in oxygenates compounds with concentrations up to 32.66% (wt.) in solvent-free basis, showing that SC-CO2 was able to deacidify liquid organic products, obtaining fractions with lower olefin content. The best deacidifying conditions was obtained at 333 K, 140 bar, and (S/F) = 17.