Acetylation of Eugenol on Functionalized Mesoporous Aluminosilicates Synthesized from Amazonian Flint Kaolin

The present work was aimed to investigate the catalytic activity of a mesoporous catalyst synthesized from 3-mercaptopropyltrimethoxysilane (MPTS) functionalized Amazonian flint kaolin in the acetylation of eugenol with acetic anhydride. Materials were characterized by thermogravimetry (TGA), N2 adsorption (BET), X-ray dispersive energy spectroscopy (EDX), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and acid-base titration. The results presented proved the efficiency of flint kaolin as an alternative source in the preparation of mesoporous materials, since the material exhibited textural properties (specific surface area of 1071 m2 g−1, pore volume of 1.05 cm3 g−1 and pore diameter of 3.85 nm) and structural properties (d100 = 4.35 nm, a0 = 5.06 nm and Wt = 1.21 nm) within the required and characteristic material standards. The catalyst with the total amount of acidic sites of 4.89 mmol H+ g−1 was efficient in converting 99.9% of eugenol (eugenol to acetic anhydride molar ratio of 1:5, 2% catalyst, temperature and reaction time 80 °C and 40 min reaction). In addition, the reused catalyst could be successfully recycled with 92% conversion activity under identical reaction conditions

Acetylation of Eugenol over 12-Molybdophosphoric Acid Anchored in Mesoporous Silicate Support Synthesized from Flint Kaolin

A new prepared catalyst, 12-molybdophosphoric acid (HPMo) anchored to the mesoporous aluminosilicate AlSiM, synthesized from Amazon kaolin, was characterized and used as a heterogeneous acid catalyst for the production of eugenyl acetate by acetylation of eugenol with acetic anhydride. The effect of various reaction parameters, such as catalyst concentration, eugenol/acetic anhydride molar ratio, temperature and reaction time, was studied to optimize the conditions of maximum conversion of eugenol. The kinetics studies showed that in eugenol acetylation, the substrate concentration follows a first order kinetics. The results of activation energy was 19.96 kJ mol−1 for HPMo anchored to AlSiM. The reuse of the catalyst was also studied and there was no loss of catalytic activity after four cycles of use (from 99.9% in the first cycle to 90% in the fifth cycle was confirmed), and an excellent stability of the material was observed. Based on catalytic and kinetic studies, HPMo anchored to AlSiM is considered an excellent catalyst

Activated carbon obtained from amazonian biomass tailings (acai seed): Modification, characterization, and use for removal of metal ions from water

Federal University of Pará. Graduate Program of Chemistry. Laboratory of Amazon Oils. Laboratory of Catalysis and Oilchemistry. Belém, PA, Brazil.Federal University of Amazonas. Department of Chemistry. Manaus, AM, Brazil.Federal University of Pará. Graduate Program of Chemistry. Laboratory of Amazon Oils. Laboratory of Catalysis and Oilchemistry. Belém, PA, Brazil / Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Ananindeua, PA, Brasil.Federal University of Pará. Graduate Program of Chemistry. Laboratory of Amazon Oils. Laboratory of Catalysis and Oilchemistry. Belém, PA, Brazil.Federal University of Pará. Graduate Program of Chemistry. Laboratory of Amazon Oils. Laboratory of Catalysis and Oilchemistry. Belém, PA, BrazilFederal University of Pará. Graduate Program of Chemistry. Laboratory of Amazon Oils. Laboratory of Catalysis and Oilchemistry. Belém, PA, BrazilFederal University of Pará. Graduate Program of Chemistry. Laboratory of Amazon Oils. Laboratory of Catalysis and Oilchemistry. Belém, PA, BrazilMinistério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Ananindeua, PA, Brasil.Federal University of Pará. Graduate Program of Chemistry. Laboratory of Amazon Oils. Laboratory of Catalysis and Oilchemistry. Belém, PA, BrazilAcai seed was used herein as an Amazon biomass waste for the synthesis of activated and modified carbon in order to find a possible use for the large volume of residues generated during the processing of this fruit and to add value to this residue. Activated carbon materials were used to remove Pb2+, Fe2+, and Mg2+ metal ions from water. The efficiency of removal of these ions by the acai seed activated carbon was compared with that by commercial activated carbon. Activated carbon materials were prepared by carbonization and chemical activation using two KOH impregnation ratios, namely 1:1 (ACK1) and 5:1 (ACK5), by mass. These samples were modified by treatment with nitric acid under microwave heating (ACK1-M) and (ACK5-M), respectively. The result of the elemental analysis indicated that this biomass has carbon and sulfur contents of 43.29% and 0.10% wt, respectively. The textural parameters showed that the obtained activated carbon samples presented high surface areas between 1462 and 2774 m2 g−1. Raman analysis revealed the different degrees of graphitization of the activated carbon materials. Boehm titration identified the presence of phenolic, carboxylic, and lactonic groups in samples that were confirmed by Fourier transform infrared spectroscopy. In the metal adsorption tests, ACK5-M showed better removal efficiency, reaching 86% removal for Pb2+, 69% for Fe2+, and 8% for Mg2+in 1 h of contact time; these results were superior to those obtained for commercial carbon. The results indicated that acai seed can be used for the production of activated carbon and can also be used for metal removal