Green synthesis of bio‐ethyl acetate over Egyptian natural red clay as a highly active, selective, and eco‐friendly catalyst

• Published in: Journal of the Chinese Chemical Society (Taipei) 2020-04, Vol.67 (4), p.567-575
• Main Authors: Said, Abd El‐Aziz A., Goda, Mohamed N.
• Format: Article
• Language: English
• Subjects: Acetic acid; acidity; Catalysts; Chemical synthesis; Chemisorption; Clay; Dehydration; Differential thermal analysis; Differential thermogravimetric analysis; Ester; Ethanol; Ethyl acetate; Fixed bed reactors; Fixed beds; Flow velocity; Fluorescence; Fourier transforms; Infrared analysis; stability; Thermogravimetry; Vapor phases; XRF
• ISSN: 0009-4536; 2192-6549
• DOI: 10.1002/jccs.201900160

The present work focused on the utilization of Egyptian red clay (ERC) without any treatment as a highly efficient, selective, and eco‐friendly catalyst for synthesis of bio‐ethyl acetate in the gas phase. The best conditions used in conventional fixed bed reactor were 130 cm3/min total flow rate of air with 1.6 and 2.1 vol% bio‐ethanol and bio‐acetic acid, respectively, 1 g clay catalyst calcined at 300 and 225°C reaction temperature. Under these conditions, the conversions to ester achieved were about 80 and 98% after 5 and 30 min, respectively, from the initial admission of the reactants into the reactor. The amount and type of surface acidity were identified by isopropanol reaction and chemisorption of basic probes. The results demonstrated that the majority of intermediate strength of BrØnsted acid sites are the key role for the dehydration reaction toward ester formation. The virgin and annealed clay solids were characterized using X‐ray fluorescence (XRF), thermogravimetry (TG) and differential thermal analysis (DTA), Fourier transform infrared (FTIR), X‐ray diffraction (XRD), and N2 sorption. The present work focused on the utilization of Egyptian red clay (ERC) without any acidic treatment as a highly efficient, selective, and eco‐friendly catalyst for synthesis of bio‐ethyl acetate in the gas phase. The conversions to ester achieved were about 80 and 98% after 5 and 30 min, respectively, from the initial admission of the reactants into the reactor at a reaction temperature of 225°C. The amount and type of surface acidity were identified by isopropanol reaction and chemisorption of basic probes.