Estudio del proceso de obtención de vainillina a partir de lignina mediante un proceso asistido con microondas : Efecto de la concentración de hidróxido de sodio (NaOH) sobre la obtención de vainillina a partir de lignina en un proceso asistido con microondas.

Abstract

Vanillin is one of the most widely used flavorings and aromatizers in the food industry; however, its extraction from the vanilla plant is expensive and the yields are low. Therefore, several methods of extraction have been developed to obtain this compound synthetically. The objective of this project was to study the effect of the concentration of sodium hydroxide (NaOH) on the yield in the production of vanillin from lignin, by means of a microwave-assisted process. Three concentrations of NaOH were tested: 0,3, 0,5 and 0,7 M. Commercial lignin solutions were prepared and mixed with NaOH and Ca(OH)2, and introduced into a microwave-assisted reactor at 170 °C for 120 min. Then, an extraction of the compound of interest with chloroform was performed, and the extract was injected into an HPLC chromatograph for the detection of the compounds in the mixture. The concentration with the best results was used in a process to obtain vanillin from lignin recuperated from bamboo chips. Vanillin concentrations of 49,528 ± 1,529, 45,383 ± 2,743 and 46,058 ± 2,202 ppm were obtained for the concentrations of 0,3, 0,5 and 0,7 M of NaOH, respectively, while an average concentration of 44,489 ± 1,031 ppm was achieved in the process of obtaining vanillin from the black liquor of bamboo. The general and specific yields were 0,712 and 0,178 %, respectively.