Banca de QUALIFICAÇÃO: MATEUS COSTA MEDEIROS

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : MATEUS COSTA MEDEIROS
DATE: 20/12/2019
TIME: 09:00
LOCAL: auditório do Química III
TITLE:

ELECTROCHEMICAL CONVERSION OF CASHEW NUTS IN AGGREGATE COMPOUND

KEY WORDS:

Anodic oxidation; Carboxylic Acids; Green Chemistry; Electrosynthesis

PAGES: 60
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Físico-Química
SPECIALTY: Eletroquímica
SUMMARY:

The development of new technologies in the conversion of renewable materials into value-added products is inevitable due to the scarcity of fossil resources, global warming and society's increasing demand for sustainability. The electrochemical oxidation mechanism of organic compounds depends on the nature of the electrode material used, ie the oxidizing species formed depends on the anode or cathode used. Boron-doped diamond (BDD) electrodes belong to the class of inactive anodes that lead to combustion of organic matter, producing few intermediates and low reaction selectivity. However, dimensionally stable anodes (DSA) belong to the class of active anodes that are characterized in producing various intermediates and having selective reactions. Therefore, in this work, the performance of BDD and DSA (Ti / RuO₂IrO₂TiO₂) in the cashew nut shell liquid (CNSL) electro-oxidation was evaluated in 0.05 mol L^-1 Na2SO4 medium. For both electrodes, initially a study was performed at different current densities (20, 40 and 60 mA cm^-2), however the results showed that anodic surface polymerization occurred, defining the best condition in terms of COD removal. that was 40 mA cm^-2. Using the selected condition, the influence of electrochemical oxidation on different NaOH concentrations (0.125; 1,000; 2,000 mol L^-1) at 0.01% CNSL concentration, different LCC concentrations (0.01; 0, 05 and 0.10%) at the concentration of 1,000 mol L^-1 NaOH for both electrodes. At the end of the process was evaluated the production of carboxylic acids (malic, fumaric, formic, acetic and oxalic) in BDD and DSA at concentrations of 0.10% and 0.01% of CNSL, respectively, using 1 mol L^-1 of NaOH. The results showed that oxidation is possible when working on 1,000 mol L^-1 NaOH medium for any CNSL concentration (0.01-0.10%) when using BDD and DSA only at 0.01 concentration. % of LCC. The j study provided 55, 70 and 80% removal in BDD and 41, 46 and 52% when DSA was used in the respective js (40, 70 and 100 mA cm^-2). The evaluation of carboxylic acid production when working with BDD showed yields of 2.00 and 3.90% when working at j = 70 mA cm^-2 for acetic and oxalic acids respectively. This work showed that the electrochemical oxidation of the CNSL is possible in 1.00 mol L^-1 NaOH medium using the anodes of BDD and DSA, however when working with the DSA the concentration range of CNSL should be lower due to the process. of polymerization on the electrochemical surface.

BANKING MEMBERS:
Presidente - 1645110 - CARLOS ALBERTO MARTINEZ HUITLE
Interno - 348475 - DJALMA RIBEIRO DA SILVA
Externa à Instituição - DANYELLE MEDEIROS DE ARAUJO - UERN