Banca de QUALIFICAÇÃO: LETICIA MILENA GOMES DA SILVA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : LETICIA MILENA GOMES DA SILVA
DATE: 09/08/2024
TIME: 09:00
LOCAL: Auditório do NUPPRAR
TITLE:

ELECTROCONVERSION OF GLYCEROL INTO VALUE-ADDED PRODUCTS BY ELECTROCHEMICAL OXIDATION.

KEY WORDS:

Electrochemical Oxidation; Glycerol; Carboxylic Acids; DSA; BDD

PAGES: 113
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Físico-Química
SPECIALTY: Eletroquímica
SUMMARY:

The environmental impacts generated by the use of fossil fuels, and the energy insecurity associated with this, have led to an increase in the production of biofuels. Therefore, an increase in the amount of glycerol that is generated as a by-product of transesterification reactions is also expected, which can generate an accumulation of residues containing this polyalcohol. Several techniques have been used to convert glycerol into products with high added value, including electrochemical oxidation, which stands out for the diversity of products that can be formed. Therefore, this work proposes the application of electrochemical oxidation to convert glycerol in order to obtain products with greater added value such as carboxylic acids and green hydrogen. To this end, oxidation was investigated under different conditions in order to obtain greater production of these products. The conversion of glycerol was monitored by ionic chromatography and chemical oxygen demand.  The results obtained are divided into two chapters. The first chapter presents the optimization to obtain a more favorable condition for glycerol oxidation. In this study, the effects of current density, electrolyte concentration and oxidation time were evaluated using DSA as anode for oxidation of 0.1 mol L^-1 of glycerol, so it was possible to observe that the current density of 90 mA cm^-2, with a supporting electrolyte concentration of 0.1 mol ^L-1 in the oxidation time of 480 min was the best condition for converting glycerol, generating 256.21 and 211.17 mg L^-1 of formic acid used, respectively, undivided and divided cells. 6.77 L of dry hydrogen was also produced in the divided cell. The second chapter presents the oxidation of glycerol using different anode materials (DSA and BDD) and the influence of different electrolytes. In this study, the production of carboxylic acids and green hydrogen was evaluated using divided and undivided configurations for the electrochemical cell, with a current density of 90 mA cm^-2, 0.1 mol L^-1 of supporting electrolyte for 360 min. The production of carboxylic acids was more efficient using NaOH as supporting electrolyte for both electrodes, generating 958.62 and 928.37 mg L^-1 of formic acid and 1358.75 and 1096.91 mg L^-1 of oxalic acid for cells undivided and divided, respectively when the BDD is used as the anode. Hydrogen production was independent of the anode material and the type of electrolyte used. Finally, it is concluded that the electrochemical oxidation process is an effective and viable alternative for the production of carboxylic acids, which are products of economic interest for the chemical and pharmaceutical industry.

COMMITTEE MEMBERS:
Presidente - 1645110 - CARLOS ALBERTO MARTINEZ HUITLE
Interno - 1803692 - FABRICIO GAVA MENEZES
Externo à Instituição - DANYELLE MEDEIROS DE ARAUJO - IFRN
Externo à Instituição - JOSÉ EUDES LIMA SANTOS - UFRN