Síntese e caracterização do material hidrotalcita-hidroxiapatita dopado com nanotubos de carbono e sua aplicação na catálise da reação de transesterificação

Rodrigues, Elizabeth; Brasil, Henrique; Barros, Thiago Henrique Bragato; Pereira, C.; Reis, Michel Silva; Almeida, Oriana

doi:10.1590/0366-69132018643702230

Cited by 8 publications

(4 citation statements)

References 29 publications

(35 reference statements)

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“…The NMR spectra were recorded on a Bruker Avance DRX-500 spectrometer in deuterated chloroform (CDCl 3 ). The data were processed using Bruker Top Spin software and used for the calculus of biodiesel conversion via Equation (3) [30,31]. The integral areas at 3.7 ppm from the methyl esters (-CH 3 ) and 2.2-2.3 ppm from the α-carbonyl methylene in the fatty ester derivatives (-COOCH 2 -) were used for calculation.…”

Section: H Nmr-biodiesel Conversion and Uv-vis-oxidative Stabilitymentioning

confidence: 99%

“…However, despite its accuracy and reproducibility for compound quantification and quality control [29], NMR remains underutilized in analytical investigations. In our work, 1 H NMR was employed to determine the conversion of the safflower and babassu biodiesel samples using the integrated areas of specific signals (methyl esters (-CH 3 ) and α-carbonyl methylene (-COOCH 2 -)) [30][31][32].…”

Section: Introductionmentioning

confidence: 99%

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1H NMR and UV-Vis as Analytical Techniques to Evaluate Biodiesel Conversion and Oxidative Stability

Braga,

Damasceno,

Barros de Sousa Silva

et al. 2024

Fuels

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The present study evaluated the applicability of 1H NMR and UV-Vis spectroscopies as analytical techniques for the characterization and determination of biodiesel conversion and for monitoring the oxidative stability of biodiesel samples with antioxidants. For this study, safflower and babassu biodiesels were obtained through transesterification, and physicochemical properties confirmed the success of both reactions. A bench-top accelerated oxidation system was used as an alternative to the Rancimat® method, with samples of 6.0 g heated at 110 ± 5 °C and collected every 2 h for 12 h. The agreement for biodiesel conversions was good, with divergences between 2% and 0.4% for safflower biodiesel and 1.9% for babassu biodiesel. As for UV-Vis spectroscopy, the technique showed the same trend as the Rancimat® method, showing efficiency in evaluating the oxidative stability of safflower biodiesel and in the performance of antioxidants BHT and DMP-30. The accuracy of NMR signals integration for mixtures of safflower oil and safflower biodiesel and the use of UV-Vis spectroscopy associated with a bench-top accelerated oxidation system to investigate the performance of phenolic and amine antioxidants in safflower and babassu biodiesel were explored for the first time, showing results close to the standard methods. Therefore, 1H NMR and UV-Vis spectroscopies could be applied as alternatives to the GC and Rancimat® methods to determine conversion and monitor the oxidative stability of biodiesel rapidly and practically.

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Section: H Nmr-biodiesel Conversion and Uv-vis-oxidative Stabilitymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

1H NMR and UV-Vis as Analytical Techniques to Evaluate Biodiesel Conversion and Oxidative Stability

Braga,

Damasceno,

Barros de Sousa Silva

et al. 2024

Fuels

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“…Recently, the synthesis of a material composed of the hydrotalcite and hydroxyapatite phases [HT-HAp: (Mg6Al2(OH)16CO3.4H2O) (Ca10 (PO4)6(OH)2)] has been proposed, and its performance evaluated in the transesterification of soybean and water treatment (Rodrigues et al, 2018). Several studies have investigated the conditions of synthesis and composition of hydrotalcite and hydroxyapatites in the catalytic performance in biodiesel production (Vilas Bôas et al, 2020;Coral et al, 2019;Navajas et al, 2018;Brasil et al, 2017;Essamlali et al, 2017).…”

Section: Introductionmentioning

confidence: 99%

Process simulation of biodiesel production from vegetable oil deodorization distillate using hydrotalcite-hydroxyapatite as catalyst

Almeida

Bôas

Mendes

2021

RSD

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In There are few simulation studies in the literature focusing on the production of biodiesel from vegetable oil deodorization distillate (VODD), a waste originating from the vegetable oil processing stage, using hydrotalcite-hydroxyapatite as a heterogeneous catalyst. In this study, the simulation process was performed using open interface software DWSIM® Version 6.3. The motivation relied on the positive performance of the catalyst during the experimental studies. So, in the simulator design, the lipid raw material, ethanol, and the catalyst were fed together in a CSTR-01 conversion reactor. The thermodynamic fluid package used for this process was the Non-Random Two-Liquid (NRTL) activity coefficient model. The process flowchart consisted of the reaction step (oil transesterification), and separation steps of the ethyl esters produced, excess ethanol and purification of biodiesel. As a result, different scenarios were simulated, using commercial soybean oil as a comparative form, different types of catalysts and different molar ratios of alcohol and VODD. Among the main differences between the simulated cases, it was demonstrated that the excess of alcohol (1:45) caused greater quantity of VODD consumption, and consequently the greater formation of ethyl esters (biodiesel), resulting higher conversions (> 95%). In addition, the results obtained confirmed the adequacy of VODD as a potential raw material to produce biodiesel, as it is relatively cheaper than edible oils and contributes to the use of waste. Thus, confirming that the chemical catalyst was able to form the main esters of fatty acids even using a residual raw material.

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“…Ressonância Magnética Nuclear de Próton (RMN 1 H)Para avaliação da conversão em ésteres metílicos utilizou-se a Ressonância Magnética Nuclear de Próton (RMN 1 H), espectrômetro Avance DRX 500 MHz (Bruker) e clorofórmio deuterado (CDCl3) como solvente, analisando-se os sinais correspondentes aos hidrogênios metoxílicos dos ésteres (-CO-O-CH3) identificados na região de 3,7 ppm e aos prótons metilênicos α-carbonílicos (-CH2-CO-O-) entre 2,2 -2,4 ppm. A taxa de conversão foi calculada por meio da Equação 9(Gelbard et al 1995, Rodrigues et al 2018, Morgenstern et al 2006 e Colzato et al 2008.…”

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Ressonância Magnética Nuclear de Próton como Ferramenta Analítica para Avaliação da Conversão em Ésteres Metílicos

Damasceno,

Nascimento,

Braga

et al. 2024

RCT

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O objetivo do trabalho foi produzir biodiesel a partir dos óleos de soja, babaçu e fritura, utilizando duas metodologias, e avaliar o uso da Ressonância Magnética Nuclear de próton como ferramenta para avaliação da conversão em ésteres metílicos. As amostras foram produzidas por transesterificação. De acordo com os resultados, a 2ª metodologia contribui para o aumento da conversão na ordem de 22,14% (BOS), 2,64% (BOB) e 10,16% (BOF). A RMN 1H foi eficaz na determinação das conversões em ésteres metílicos, obtendo-se a mesma tendência dos resultados da cromatografia a gás, bem como na análise dos perfis dos ácidos graxos das matérias-primas, indicando diferença de intensidade dos sinais em ~ 4,1 – 4,3 e ~ 5,3 ppm.

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Síntese e caracterização do material hidrotalcita-hidroxiapatita dopado com nanotubos de carbono e sua aplicação na catálise da reação de transesterificação

Cited by 8 publications

References 29 publications

1H NMR and UV-Vis as Analytical Techniques to Evaluate Biodiesel Conversion and Oxidative Stability

1H NMR and UV-Vis as Analytical Techniques to Evaluate Biodiesel Conversion and Oxidative Stability

Process simulation of biodiesel production from vegetable oil deodorization distillate using hydrotalcite-hydroxyapatite as catalyst

Ressonância Magnética Nuclear de Próton como Ferramenta Analítica para Avaliação da Conversão em Ésteres Metílicos

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