Banca de QUALIFICAÇÃO: LEONETE CRISTINA DE ARAUJO FERREIRA MEDEIROS SILVA

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : LEONETE CRISTINA DE ARAUJO FERREIRA MEDEIROS SILVA
DATE: 08/07/2022
TIME: 07:00
LOCAL: Link da videochamada: https://meet.google.com/riz-noig-nxn
TITLE:

Methyl Levulinate synthesis: renewable biomass conversion, kinetic study, and optimization of production

KEY WORDS:

biomass valorization, levulinic acid, levulinic esters, esterification, biofuels

PAGES: 93
BIG AREA: Engenharias
AREA: Engenharia Química
SUBÁREA: Tecnologia Química
SPECIALTY: Tratamentos e Aproveitamento de Rejeitos
SUMMARY:

Lignocellulosic biomass utilization is a sustainable alternative to the oil industry in producing sustainable chemicals. Levulinic acid (LA) is considered a versatile chemical building block generating several products with industrial applications. Methyl levulinate (ML) is one of the levulinic esters considered a promising chemical in the biofuels industry. The development of the present study was divided into three stages: scoping literature review, kinetic study, and optimization of methyl levulinate synthesis from the esterification of levulinic acid in methanol using Al2(SO4)3 as a catalyst. In the first phase, the focus of the scientific production analysis was directed to the possible synthesis routes, reaction parameters, and catalysts employed. The literature points out that Methyl levulinate can be produced from the utilization of lignocellulosic biomass residues, as and without pretreatment, C5 and C6 sugar, monosaccharides (glucose and fructose), derivatives from the decomposition of sugars, and intermediates of the reactions (hydroxymethylfurfural, furfural, furfuryl alcohol, furans, among others) and esterification of AL. The investigated parameters that can affect the feedstock conversions and the ML yield detected were pretreatments of the biomass; type of reactor; temperature and time of the reaction; the ratio between solvents and substrates and the catalyst used (performance, reusability, and effects on the installations). Research is at the laboratory level. However, few large-scale studies and simulations point to the possibility of levulinic ester production in the context of integrated biorefinery. The metallic salts present positive results in face of the problems faced in homogeneous catalysis, thus aluminum sulfate was chosen as a catalyst. The kinetic study performed reactions at temperatures of 120ºC, 140ºC, and 160ºC. From the fit of the experimental data, the pseudo-first-order kinetic model was used to calculate the activation energy, whose value was 11.37 kcal.mol-1. Applying a Box-Behnken type experimental planning of three factors, having as a response the conversion of Levulinic Acid, a significant and predictive regression model was obtained with R² equal to 0.86.  The reactions took place at a temperature of 140 ºC in a 300 mL capacity Parr Instruments stainless steel reactor. The samples were analyzed using high-performance liquid chromatography (HPLC). The results indicated that the interaction of the molar ratio and catalyst concentration significantly influences the conversion of AL. The levels chosen for analysis provided conversions ranging from 86.83% to 99.27%, demonstrating the efficiency of a low-cost catalyst at low concentrations.

 

COMMITTEE MEMBERS:
Presidente - 1308273 - EDUARDO LINS DE BARROS NETO
Externo ao Programa - 1566922 - LINDEMBERG DE JESUS NOGUEIRA DUARTE - UFRNExterno à Instituição - FRANCISCO WENDELL BEZERRA LOPES - UnP
Externa à Instituição - PAULA FABIANE PINHEIRO DO NASCIMENTO
Externo à Instituição - RICARDO PAULO FONSECA MELO - UFERSA