doctoralThesis
Estudo da obtenção e caracterização da quitina e quitosana a partir de resíduos de carcinicultura e suas aplicações energéticas sustentáveis
Fecha
2019-02-04Registro en:
GOMES, Mayara Feliciano. Estudo da obtenção e caracterização da quitina e quitosana a partir de resíduos de carcinicultura e suas aplicações energéticas sustentáveis. 2019. 80f. Tese (Doutorado em Engenharia Química) - Centro de Tecnologia, Universidade Federal do Rio Grande do Norte, Natal, 2019.
Autor
Gomes, Mayara Feliciano
Resumen
Currently one of humanity's biggest concerns today is the fate of industrial waste
and the study of alternatives to sustainable energy. In this context, the aim of this work was to
obtain chitosan from the discards of carniciculture, the biopolymer chitin results the
deacetylation by means of alkaline hydrolysis. The demineralization steps were performed
through deproteinization to obtain chitin, and deacetylation to obtain chitosan, were
characterized by X-ray diffraction (XRD), X-ray fluorescence (FRX), scanning electron
microscopy (SEM/EDS/TEM), thermogravimetry (TG), UV-visible and Fourier transformer
spectroscopy (FTIR) for confirmation of the obtain chitin and chitosan with an acetylation
degree of the DA of 70% and 75%, respectively. The biopolymers was possible to perform the
hydrothermal carbonization synthesis, which is a low cost process, of two renewable
precursors, which are materials derived from biomass (chitin and chitosan) and graphite as a
third material used to obtain two solid phase and liquid. The liquid phase was used for the
formation of carbon quantum dots (CQDs) with application in solar cells and photocatalysis,
and the solid phase for the formation of heterogeneous catalysts for reactions of
transesterification of biodiesel. The phases were characterized arrange for needed of their
applications obtaining for the liquid phase a CQDs with quantum yield of 17.1% with doping
in ZnO / CQDs for the apllicattions on the photocatalysis property. The solid phase a
heterogeneous graphite-chitosan catalyst obtained process efficiency by gas chromatography
with 36% conversion. Obtaining chitin and chitosan biopolymers is a great solution for the
tons of waste produced in the shrimp industry. The realization of hydrothermal carbonization
synthesis to obtain two products, the CQDs and graphite-chitosan catalysts demonstrated
great alternatives for the use of sustainable energy in photocatalysis and transesterification
reactions.