Effects of acetic acid addition methods on butyl acetate enzymatic synthesis

• Published in: Chemical engineering communications Vol. 207; no. 2; pp. 177 - 184
• Main Authors: Duarte, Nathália G., de Queiroz, Danielle Simas, Veloso, Cláudia de Oliveira, de Castro, Aline Machado, Langone, Marta Antunes Pereira
• Format: Journal Article
• Language: English
• Published: Philadelphia Taylor & Francis 01-02-2020; Taylor & Francis Ltd
• Subjects: Acetic acid; Acids; Butanol; Butyl acetate; Chemical industry; Chemical synthesis; Continuous acid addition; Conversion; Enzymes; Esterification; Inhibition; Lipase; Organic chemistry; Reagents
• ISSN: 0098-6445; 1563-5201
• DOI: 10.1080/00986445.2019.1575822

Butyl acetate is a versatile chemical due to its excellent solvency for polymers, resins, and oils. In this work, the butyl acetate synthesis was studied by the esterification of n-butanol with acetic acid using the commercial immobilized lipase Novozym
®
435. The acetic acid and n-butanol concentrations have to be limited in the enzymatic synthesis of this ester due to the deleterious effects caused by these reagents on the enzyme. Three methods of acetic acid addition (single, stepwise and continuous addition) were investigated to minimize the acid concentration. A significant drop on acid conversion was observed in the presence of a higher concentration of the reagents when single or stepwise acid addition was used. However, a solvent-free system using a continuous addition of acetic acid favored butyl acetate synthesis, reaching a conversion of 84% at 60 °C, employing 5 wt% of enzyme and n-butanol/acetic acid final molar ratio equal to 1/1.