Banca de QUALIFICAÇÃO: BEATRIZ MENEGHETTI COSTA DE ARAÚJO

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : BEATRIZ MENEGHETTI COSTA DE ARAÚJO
DATE: 10/03/2023
TIME: 14:00
LOCAL: Via Google Meet
TITLE:

VALUE OF GREEN COCONUT FIBER FOR THE PRODUCTION OF SECOND-GENERATION LIGNOSULFONATE AND ETHANOL

KEY WORDS:

lignocellulosics, lignosulphonate, green coconut husk, lignin, ethanol

PAGES: 62
BIG AREA: Engenharias
AREA: Engenharia Química
SUBÁREA: Processos Industriais de Engenharia Química
SPECIALTY: Processos Bioquímicos
SUMMARY:

Environmental damage caused by the use of petroleum derivatives and other fossil fuels has increased the world's demand for renewable energy sources. Since the production of first-generation ethanol raises concerns about the global food crisis, associated with the high rate of agro-industrial waste generated in Brazil, the second-generation ethanol industry has gained significance. The cultivation of green coconut is present in several states of Brazil. However, despite the variety of products derived from coconut, approximately 80-85% becomes waste, but it has great potential for use as lignocellulosic biomass, mainly composed of cellulose, hemicellulose, and lignin. By being pre-treated to remove lignin (delignification) from the cellulosic matrix, the biomass has its recalcitrance reduced, thus allowing cellulolytic enzymes to access the polysaccharides of interest that will be converted into fermentable sugars, in the case of cellulose, so that Saccharomyces cerevisiae produces ethanol of industrial interest. It is noteworthy that the removal of lignin is not total, this residual lignin can cause the non-productive adsorption of the enzymes used in the hydrolysis, reducing their access to the polysaccharides, and decreasing the cellulosic conversion into sugars. Thus, the use of surfactants, including lignosulfonate, a precursor of lignin, could reduce this unproductive adsorption, increase enzymatic activity, promote conformational stability, and stabilize the electrostatic forces of repulsion between the enzyme and lignin, by occupying the Biomass lignin interaction sites. In this context, the present study proposes the production of lignosulphonate, reusing the lignin extracted after pretreatment with 1% sulfuric acid (v/v), through the sulfomethylation process. This surfactant will be added in the enzymatic hydrolysis of biomass from the pretreatment by steam explosion, alkaline (NaOH 2% (w/v)), and combined (steam explosion + alkaline), followed by alcoholic fermentations to evaluate the ethanol yield at the end of the process. The biomass will be characterized, before and after the pretreatments, by Fourier Transform Infrared Spectroscopy - FTIR, Scanning Electron Microscopy - SEM and thermogravimetric analysis, in addition to quantifying the levels of extractable, ashes, insoluble lignin, polysaccharides (cellulose and hemicellulose) and moisture. The lignosulfonate produced will be analyzed by DLS (Dynamic Light Scattering) and its adsorption and desorption capacity will be evaluated.

COMMITTEE MEMBERS:
Presidente - 1346198 - EVERALDO SILVINO DOS SANTOS
Interno - 3304882 - CARLOS EDUARDO DE ARAÚJO PADILHA
Interna - 3214434 - NATHALIA SARAIVA RIOS