Desidrogenação parcial de butanol por fluxo contínuo catalisada por óxidos metálicos mistos modificados com cu+2
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Data
2021-10-08
Autores
Rocha, Luís Fernando Batista da
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Universidade Estadual Paulista (Unesp)
Resumo
Nos últimos anos tem aumentado o interesse pela obtenção de energia e produtos químicos de maior valor agregado a partir de matérias-primas renováveis, que substituam os produtos derivados de petróleo devido seus problemas ambientais. Entre os processos existentes como por exemplo a biorrefinaria de substratos renováveis, a reação de Guerbet também tem sido muito utilizada na síntese de produtos orgânicos a partir de álcoois de cadeia curta. Para essas reações são utilizados catalisadores com propriedades ácido/básicas e grande capacidade de desidrogenação/hidrogenação, como podemos citar principalmente os óxidos metálicos mistos (OMM) derivados de Hidróxidos Duplos Lamelares (HDL). Neste trabalho foi realizado a desidrogenação parcial de 1-butanol empregando OMM substituindo 10% dos íons Mg+2 por íons Cu+2, utilizando um reator de fluxo contínuo ajustado a 500°C durante 3 horas de reação. Os HDL foram sintetizados pelo método de co-precipitação mediante variação do pH (8 ,10 e 13) e proporções entre M+2/M+3 (3:1 e 5:1), visando modificar a morfologia e as propriedades físico-químicas dos OMM finais. A caracterização físico-química dos HDL e seus respectivos OMM foram realizadas através de diferentes técnicas analíticas: Difração de Raios X (DRX), Análise Termogravimétrica (TGA), Área Superficial Específica (MÉTODO BET) e Espectroscopia Vibracional no Infravermelho (FTIR-ATR). Os ensaios catalíticos foram realizados mediante fluxo contínuo de 1-butanol de 0,2 mL/min com aquecimento a 500°C em colunas reacionais devidamente empacotadas, obtendo como resultados reacionais um consumo de 1-butanol de até 92,3%. Foram também coletados e quantificados os gases gerados nas reações catalíticas, obtendo volumes que chegaram até 6,7 litros desses gases, considerando que as quantidades de gases coletados são correspondentes a matéria perdida nas reações. Através da Cromatografia Gasosa Acoplada com Espectrometria de Massas (GC–MS), foram identificados e quantificados os produtos orgânicos obtidos nas reações e suas respectivas classes orgânicas. Os produtos com maior seletividade obtidos nas reações catalíticas foram: butiraldeído, n-butil éter e o 2- buteno, produtos estes com maior valor agregado que o 1-butanol, fato que demonstra sucesso reacional e qualidade dos catalisadores derivados de HDL sintetizados em diferentes pH e proporções molares.
In recent years, interest has increased in obtaining energy and chemical products with greater added value from renewable raw materials, which replace petroleum- derived products due to their environmental problems. Among existing processes such as the biorefinery of renewable substrates, the Guerbet reaction has also been widely used in the synthesis of organic products from short-chain alcohols. For these reactions, catalysts with acid/basic properties and great dehydrogenation/hydrogenation capacity are used, as we can mention mainly the mixed metallic oxides (MMO) derived from Double Lamellar Hydroxide (HDL). In this work the partial dehydrogenation of 1-butanol was carried out using OMM replacing 10% of the Mg+2 ions by Cu+2 ions, using a continuous flow reactor set at 500°C for 3 hours of reaction. HDL were synthesized by the co-precipitation method by varying the pH (8,10 and 13) and proportions between M+2/M+3 (3:1 and 5:1), aiming to modify the morphology and physicochemical properties of the Final OMM. The physicochemical characterization of HDL and its respective OMM were performed using different analytical techniques: X-Ray Diffraction (DRX), Thermogravimetric Analysis (TGA), Specific Surface Area (BET METHOD) and Infrared Vibrational Spectroscopy (FTIR-ATR). The catalytic tests were carried out by means of a continuous flow of 1-butanol at 0.2 mL/min with heating at 500°C in properly packed reaction columns, obtaining as reaction results a consumption of up to 92.3% of 1- butanol. The gases generated in the catalytic reactions were also collected and quantified, obtaining volumes that reached up to 6.7 liters of these gases, considering that the quantities of collected gases correspond to the matter lost in the reactions. Through Gas Chromatography Coupled with Mass Spectrometry (GC-MS), the organic products obtained in the reactions and their respective organic classes were identified and quantified. The products with greater selectivity obtained in the catalytic reactions were: butyraldehyde, n-butyl ether and 2-butene, these products with greater added value than 1-butanol, a fact that demonstrates the reaction success and quality of the HDL-derived catalysts synthesized in different pH and molar ratios.
In recent years, interest has increased in obtaining energy and chemical products with greater added value from renewable raw materials, which replace petroleum- derived products due to their environmental problems. Among existing processes such as the biorefinery of renewable substrates, the Guerbet reaction has also been widely used in the synthesis of organic products from short-chain alcohols. For these reactions, catalysts with acid/basic properties and great dehydrogenation/hydrogenation capacity are used, as we can mention mainly the mixed metallic oxides (MMO) derived from Double Lamellar Hydroxide (HDL). In this work the partial dehydrogenation of 1-butanol was carried out using OMM replacing 10% of the Mg+2 ions by Cu+2 ions, using a continuous flow reactor set at 500°C for 3 hours of reaction. HDL were synthesized by the co-precipitation method by varying the pH (8,10 and 13) and proportions between M+2/M+3 (3:1 and 5:1), aiming to modify the morphology and physicochemical properties of the Final OMM. The physicochemical characterization of HDL and its respective OMM were performed using different analytical techniques: X-Ray Diffraction (DRX), Thermogravimetric Analysis (TGA), Specific Surface Area (BET METHOD) and Infrared Vibrational Spectroscopy (FTIR-ATR). The catalytic tests were carried out by means of a continuous flow of 1-butanol at 0.2 mL/min with heating at 500°C in properly packed reaction columns, obtaining as reaction results a consumption of up to 92.3% of 1- butanol. The gases generated in the catalytic reactions were also collected and quantified, obtaining volumes that reached up to 6.7 liters of these gases, considering that the quantities of collected gases correspond to the matter lost in the reactions. Through Gas Chromatography Coupled with Mass Spectrometry (GC-MS), the organic products obtained in the reactions and their respective organic classes were identified and quantified. The products with greater selectivity obtained in the catalytic reactions were: butyraldehyde, n-butyl ether and 2-butene, these products with greater added value than 1-butanol, a fact that demonstrates the reaction success and quality of the HDL-derived catalysts synthesized in different pH and molar ratios.
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Palavras-chave
1-butanol, Hidroxidos duplos lamelares, Óxidos metálicos mistos, Reação de guerbet, Double lamellar hydroxides, Mixed metallic oxides, Guerbet reaction