Navegando por Assunto "Transesterificação"

Agora exibindo 1 - 7 de 7

Acesso aberto (Open Access)
Preparação e avaliação de catalisador heterogêneo ácido baseado em óxido de grafeno funcionalizado para síntese de biodiesel
(Universidade Federal do Pará, 2021-09-24) SILVA, Paula Maria Melo da; CONCEIÇÃO, Leyvison Rafael Vieira da; http://lattes.cnpq.br/7467898936995220
The present study aims at the synthesis of a heterogeneous acid catalyst derived from graphene oxide, applied in the transesterification reaction of soybean oil to obtain biodiesel. The graphene oxide catalytic support was synthesized from graphite oxidation and the catalyst was functionalized by impregnation of molybdenum trioxide (MoO3) as the active phase. The synthesis of the support and the catalyst was confirmed through the characterization techniques of Fourier Transform Infrared Spectroscopy (FT-IR), Thermogravimetric Analysis (TG/DTG), Scanning Electron Microscopy (SEM), Energy Dispersion X-Ray Spectroscopy (EDS) and XRay Diffraction (DRX). The catalytic tests optimization of the transesterification reactions had as parameters evaluated the temperature in the range of 120–160 °C, the time between 1–5 h, the catalyst concentration comprised in 10% (m/m) and molar ratio oil/ alcohol in the range of 25:1–45:1. The reaction studies evidenced as an optimum point the temperature of 140 °C, time of 5 h, catalyst concentration 6% (m/m) and molar ratio of 35:1, leading to the obtainment of a biodiesel with an ester content above 90%. The catalyst also maintained its catalytic activity even in the seventh reaction cycle. Therefore, the results obtained demonstrate that the graphene oxide catalyst supported by MoO3 is a new and promising heterogeneous acid catalyst with high catalytic efficiency in the transesterification reaction for the biodiesel synthesis.
Acesso aberto (Open Access)
Produção de biodiesel a partir do processamento das oleaginosas amazônicas compadre-do-azeite (Plukenethia polyadenia) e comadre-do-azeite (Onphalea diandra)
(Universidade Federal do Pará, 2014-06) FURTADO, Matheus Braga; MACÊDO, Emanuel Negrão; http://lattes.cnpq.br/8718370108324505; FARIA, Lênio José Guerreiro de; http://lattes.cnpq.br/7428609361678173
Analyse experimentally the production of biodiesel from oilseeds processing compadre of Amazonian oil (plukenethia polyadenia) and Ruth-of-oil (Aubrey onphalea), as a potentially viable alternative to compose the energy matrix. Since the Industrial Revolution in the 19th century, the world energy matrix has always been based on fossil fuels. With the scarcity of such fuels, the rise of prices caused with the constant conflicts in major producing regions, has become the research into renewable sources increasingly attractive. The study of new sources of vegetable oils as alternative energy is important for the Country, particularly for the Amazon; enabling structure of oilseeds production chains in the region, generating employment in the field, distributional effects on regional economy and a vector of sustainable development in the Amazon, no aggression to the environment. The purpose of this work is to study two species of the family euphorbiaceae, lianas and polyadenia Onphalea Plukenethia diandra, better known as compadre of the olive oil and the olive oil Cummer respectively, oil-producing; extract and characterize them, suggesting possible applications and using them for the production of biodiesel through Transesterification using methyl potassium hydroxide as a catalyst, in the case the process based on statistical tests planned. The influence of input variables: oil/alcohol concentration, temperature and concentration of catalyst on biodiesel yield response by response surface methodology (RSM) employing the Box-Behenken planning. The aim is thus to add value to a tailing kaolin processing industry, using zeolites produced this material as a catalyst to KOH, comparing the efficiencies of the two treatments. The Box-planning Benhken proved efficient to optimize the homogeneous catalysis of the biodieseis, concluding that the concentration of the catalyst was the variable controlling the production process of biodieseis, and the increase of its concentration cause negative and undesirable influence the yield of the product.
Acesso aberto (Open Access)
Simulação da separação e purificação do biodiesel de óleo de palma com CO2 supercrítico
(Universidade Federal do Pará, 2016-07-11) GONÇALVES, Aline Lobato; ARAÚJO, Marilena Emmi; http://lattes.cnpq.br/8983914018546682
Biodiesel has attracted growing attention worldwide in recent years. The production of biodiesel from biomass involves separation and purification steps. The method generally used, the aqueous washing, has major disadvantages such as the generation of wastewater and forming emulsions. The objective of present work is to investigate the biodiesel purification using carbon dioxide, which in supercritical conditions has properties capable of separating glycerol phase of esterified phase (biodiesel), providing higher quality products and less waste. In this study, two simulations were used for analysis and investigation of purification of crude palm oil biodiesel. Both configurations conventionally designed the project process via ethylic route by basic catalysis to the reaction step. The "case 1" used a fractional distillation column for separating excess ethanol and a liquid-liquid column extraction using water as solvent for the separation of glycerol. The "case 2" applied a fractionating column in countercurrent, used for the glycerol separation step, carbon dioxide as supercritical solvent and for separating excess of ethanol, a flash vessel in the final purification of biodiesel. The simulator employed was Aspen HYSYS V8.4 that used binary parameters, adjusted with the equations of state of Soave-Redlich-Kwong (SRK) and Redlich-Kwong-Aspen (RK-ASPEN) to study systems, performed the simulations appropriately. The supercritical CO2 proved to be efficient in the separation of glycerol, given that biodiesel produced with this purification technology met the ANP main standards rules.
Acesso aberto (Open Access)
Síntese de biodiesel utilizando catalisador bifuncional baseado em ferrita com óxido metálico suportado
(Universidade Federal do Pará, 2021-07-23) GONÇALVES, Matheus Arrais; CONCEIÇÃO, Leyvison Rafael Vieira da; http://lattes.cnpq.br/7467898936995220
In this study, a solid magnetic acid catalyst MoO3/SrFe2O4, composed of molybdenum oxide (MoO3) supported on strontium ferrite (SrFe2O4), was synthesized and applied in the transesterification of waste cooking oil (WCO). The catalyst was characterized by acid-base titration method in order to determine Surface acidity, Thermogravimetric analysis (TG/DTG), X-ray diffraction (XRD), Fourier transformed infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), Energy dispersion X-ray spectroscopy (EDS) and Vibrating sample magnetometry (VSM) techniques. A central composite design of centered face 24 (FCCD) and a mathematical model was developed in order to describe the behavior of the ester content as a function of the independent variables temperature, alcohol:oil molar ratio, catalyst dosage and time reaction. The mathematical model (R2=0.9900) was validated and showed a relative error below 5% between the experimental and predicted values. Using linear regression methods and response surface methodology (RSM) the conditions of biodiesel synthesis reaction were optimized and 95.4% conversion into esters was obtained from the use of the reaction temperature of 164 °C, alcohol:oil molar ratio of 40:1, catalyst dosage of 10% and reaction time of 4 h . The catalyst showed high reusability, since it was possible to use it in 8 reaction cycles which it is an indication of its good prospectus for development and application as bifunctional catalyst.
Acesso aberto (Open Access)
Síntese de catalisador heterogêneo magnético básico aplicado no processo de produção de biodiesel
(Universidade Federal do Pará, 2023-08-30) SANTOS, Hiarla Cristina Lima dos; CONCEIÇÃO, Leyvison Rafael Vieira da; http://lattes.cnpq.br/7467898936995220
This research focus on the development of a basic magnetic heterogeneous catalyst, using, for the first time, NaAlO2 as an active species supported in a magnetic material, CuFe2O4, being highly stable and effective to produce value-added products, such as biodiesel. With this purpose, a series of catalysts (x-NaAlO2/CuFe2O4) have been successfully synthesized by means of conventional and low-cost methods, such as coprecipitation and impregnation, each one being assessed in the soybean oil transesterification reaction. The features of the 25-NaAlO2/CuFe2O4 catalyst with the higher performance have been elucidated through techniques such as basicity by acid-base titration method, XRD, FTIR, SEM, EDS, TG/DTG and VSM. To optimize the biodiesel’s ester content, the face-centered central composite design (FCCD), integrated with the response surface methodology (RSM), was employed to assess the effect of the following aspects on the process: reaction temperature, MeOH:oil molar ratio, catalyst dosage and reaction time. The regression model presented R2 = 0.9394 and experimentally reached a maximum ester content of 95.9% (relative error < 5%) attributed to the biodiesel attained under the following optimal reaction conditions: temperature of 95 °C, MeOH:oil molar ratio of 13:1, catalyst dosage of 8% and time of 60 min. The NaAlO2/CuFe2O4 catalyst presented a stable catalytic performance during four transesterification cycles (>90.0%) and an efficient magnetic property for the catalyst separation and recovery process (Ms = 23.62 emu g-1). The results showed that the biodiesel’s physicochemical properties were in compliance with ASTM D6751 standard. Finally, this extensive study reveals the basic magnetic heterogeneous catalyst NaAlO2/CuFe2O4 as a practical and promising alternative to produce a sustainable biofuel.
Acesso aberto (Open Access)
Síntese de éster de cadeia longa via catálise básica heterogênea
(2009) MORAES, Dorsan dos Santos; ROCHA FILHO, Geraldo Narciso da; ZAMIAN, José Roberto
A long chain ester was prepared by transesterification of methyl palmitate with long chain alcohol using magnesium oxide as catalyst prepared by thermal decomposition of different precursors with the intention of establish relations among structural properties and activities. Temperature and catalyst amounts were modified in order to evaluate the yield of the ester in function the precursors used in preparation of the oxide.
Acesso aberto (Open Access)
Síntese e caracterização do material hidrotalcita-hidroxiapatita e sua aplicação na reação de transesterificação do óleo de soja
(Universidade Federal do Pará, 2016-11-28) PEREIRA, Patricia Magalhães; CORRÊA, José Augusto Martins; http://lattes.cnpq.br/6527800269860568
The development of new materials with different properties (acid-base, composites, hybrids, among others) allied in a single product can present a relevant performance regarding the application in catalysis processes. The hydrotalcite characterized by high surface area and basic character, and hydroxyapatite because of its ion exchange capacity and amphoteric character, can be synthesized as the only material with catalytic potential for the transesterification reaction of soybean oil. This coexistence of phases in a Single material represents a new form of synthesis with the advantage of using an efficient route, low cost and with a decrease in the energy process. In this context, the general objective of this work is the synthesis of the HT-HAp material using the co-precipitation and homogenization method in ultrasonic bath (2h / 40 ° C), pH = 10, aging (24h), filtration and drying (24h/80 ° C). These materials were synthesized varying the molar ratio Mg / Al = 3, 1 and 0.33 and maintaining the Ca / P = 1.67 ratio. For comparison purposes the HT and HAp materials were synthesized and the material with a Mg / Al = 3 ratio was calcined at temperatures of 500 ° C and 900 ° C. The catalytic tests were performed under the following reaction conditions: Time (4h), Temperature (180 ° C), oil: alcohol ratio (1:12) and 2.5 % w/w material. The chemical physical characterization was performed by different analytical techniques: X-ray diffraction (XRD), Infrared Region Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), EDS chemical analysis, Thermal Analysis (TGA / DTA) and Superficial Analyses (BEHT / BHJ). The catalytic activity was analyzed by the Hammett (Qualitative and Quantitative) and Hydrogen Nuclear Magnetic Resonance (1H NMR) tests. The XRD spectrum showed the typical basal planes of the HT phase (003), (009), (110) and (113) of the phase HAp (002) (211) (300), (202), (213), (222), in the Mg / Al = 1 ratio and 0.33, there was the appearance of the manasseite, a hydrotalcite politype. The cell parameters and unit cell volume calculated were characteristic of the identified phases. The HT and HAp presented lamellar and granular morphology, and in the HTHAp materials, there is presence of both forms. The HT and HAp phases present in HTHAp materials presented cationic ratios of Mg / Al = 2 and Ca / P ~ 1.5, respectively. The FTIR spectrum recorded the characteristic bands of HT and HAp (OH-, CO3 2-, PO4 3- and H2O). The materials presented events of loss of endothermic mass, with appearance of peaks exotherm in the 0.33HTHAp material, dehydration, dehydroxylation and decarbonation events attributed. The materials presented a basic character in the pKBH range between 6.8 and 9.8. All materials showed the conversion of soybean oil into monoesters (biodiesel) and in the 1HTHAp material the best conversion rate (70%) was recorded.