Banca de QUALIFICAÇÃO: THAIZA DOS SANTOS QUEIROZ

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
DISCENTE : THAIZA DOS SANTOS QUEIROZ
DATA : 19/04/2023
HORA: 14:00
LOCAL: https://meet.google.com/zfw-nifj-kqg
TÍTULO:

Use of Niobiosilicates as Catalysts Aiming at the Production of Biodiesel and Bioadditives

PALAVRAS-CHAVES:

Biodiesel; Glycerol; heterogeneous catalysis;

PÁGINAS: 36
GRANDE ÁREA: Outra
ÁREA: Ciências Ambientais
RESUMO:

Biodiesel is a biodegradable fuel derived from renewable sources and the most promising substitute for fossil fuels. It can be obtained through several routes, with emphasis on esterification and transesterification reactions. For both reactions, the need to use heterogeneous catalysts has been seen, so that benefits are added and good catalytic performance is obtained. The production of biodiesel from the transesterification reaction has glycerol as a co-product, with the high volume generated, the industries have become unable to absorb its high generated volume, so there are high amounts of glycerol without proper disposal, so that it has been alternatives for its valorization have been studied, one of them being its use as a bioadditive, for which the production of triacetin by the glycerol acetylation reaction has been highlighted. Thus, this work aims at obtaining biodiesel from sunflower oil via esterification reaction and obtaining triacetin from glycerol via acetylation reaction, both using niobium-based catalysts supported on SBA-15. The catalysts were obtained from the material bank of the Laboratory of Catalysis Environment and Materials - LACAM and the proper characterizations can be found in the reference literature. To obtain biodiesel, the hydrolysis of sunflower oil was initially performed in a reflux system, with a molar ratio of 1:3 oil/methanol and 1% sodium hydroxide, and then esterification with a molar ratio of oil/methanol. methanol of 1:12 using 3%, of the Nb30SBA-15 catalyst in relation to the mass of oil used, then the Nuclear Magnetic Resonance Spectra - NMR, Thermogravimetric curves (TGA) were obtained and the yields were evaluated. To obtain triacetin, a glycerol acetylation reaction was carried out in a reflux system, with a molar ratio of 1:6 glycerol/acetic acid and 5% of the catalysts Nb15SBA-15 and Nb30SBA-15 separately. Then, with the product obtained and the same catalysts as in the previous reaction, a new acetylation reaction was carried out, with a molar ratio of 1:3 of the products obtained/acetic anhydride. At the end of this reaction, the yields obtained were evaluated and the characterization technique called gas chromatography was applied. From the characterizations carried out, the transesterification reaction of sunflower oil using the Nb30SBA-15 catalyst presented a yield of 80.94% and conversion of 70% approaching reactions that used homogeneous catalysts and the glycerol acetylation reactions showed high selectivity for triacetin, Nb30SBA-15 showed selectivity of 100%, being superior to the standard reaction, of homogeneous catalysis. Thus, niobiosilicates are a promising alternative both for obtaining biodiesel and bioadditives, from the processing of a co-product of its production. In both processes, the use of catalysts, in addition to high efficiency, facilitate the separation of the reaction medium, provide low cost and allow reuse, thus bringing numerous environmental and economic benefits.

MEMBROS DA BANCA:
Presidente - 7961 - ANNE GABRIELLA DIAS SANTOS CALDEIRA
Interno - 13136 - LEANDRO BEZERRA DE LIMA
Externa à Instituição - ARUZZA MABEL DE MORAIS ARAUJO - UFRN