Banca de QUALIFICAÇÃO: RAYANE MARIA DO NASCIMENTO

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : RAYANE MARIA DO NASCIMENTO
DATE: 29/07/2024
TIME: 14:00
LOCAL: Em ambiente virtual (Google meet)
TITLE:

ADVANCED CHEMICAL CHARACTERIZATION OF BIO-OILS PRODUCED BY HYDROTHERMAL LIQUEFACTION (HTL) FROM THE PROCESSING OF RESIDUAL BIOMASSES

KEY WORDS:

Bio-oil, biomass, characterization, gas chromatography/ mass spectrometry, GC-MS, Design of experiments, DOE.

PAGES: 60
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Química Analítica
SUMMARY:

Growing energy demand has encouraged studies dedicated to the development of
sustainable fuels and products based on the use of renewable sources. One example is the
use of residual biomass to produce bio-oils through thermal processes. The chemical
characterization of bio-oils at the molecular level using chromatographic and mass
spectrometry techniques aids in the chemical understanding of the products generated and
can be used to evaluate the conditions and efficiency of the bio-oil production process.
Among biomass conversion technologies, hydrothermal liquefaction (HTL) has stood out
in the production of sustainable liquids. Therefore, the aim of this study was to investigate
the operating parameters of the process for producing bio-oils from sugarcane bagasse
and straw using HTL and to carry out the chemical characterization of the bio-oils using
gas chromatography/mass spectrometry (GC-MS). The parameters of the operating
conditions for the production of bio-oils by HTL were investigated using experimental
planning, where the variables evaluated were: (T) temperature between 280 oC and 350
°C at high pressures using water or ethanol as a solvent, (t) residence time between 0 and
30 minutes, (C) potassium carbonate catalyst with 0.5 mol L-1

or no catalyst. The bio-oils
produced were analyzed by GC-MS and the retention times of the chromatographic peaks
and their respective mass spectra were used in data processing, where the chemical
components identified were grouped into chemical classes according to their organic

functions. In general, the chemical characterization of sugarcane bagasse and straw bio-
oils contains oxygenated compounds from the classes of alcohols, phenolic compounds,

aliphatic and branched hydrocarbons, esters, aldehydes, carboxylic acids, and oxygenated
derivatives, derived from the lignocellulosic composition of the biomass. The HTL
operating parameters had different influences on the distribution of the compounds in the
chemical classes identified. The factors temperature and the presence of a catalyst in the
experimental plans with water led to an increase in phenolic compounds and polar
compounds, such as alcohols, long-chain carboxylic acids and aldehydes. However, the
use of a catalyst hinders the formation of hydrocarbons when water is used in the HTL
process. In the experimental designs with ethanol as the solvent, the main classes
identified were: alcohols, acids, aldehydes, phenols and esters. The studies of the effects
of the operating parameters for HTL revealed that the most significant effects for the
classes of alcohols, phenols, hydrocarbons and esters studied were T, C and the
interactions between the three parameters for the designs with water as the solvent; and
T, t and the T x t interaction in the designs with ethanol. In this way, the application of
experimental planning to evaluate HTL conditions revealed bio-oils with a diverse
chemical composition and made it possible to infer the influence of experimental
parameters to obtain promising chemical classes with potential for renewable products.

COMMITTEE MEMBERS:
Presidente - JANDYSON MACHADO SANTOS
Interno - ***.826.764-** - FAUSTHON FRED DA SILVA - UFPB
Externo à Instituição - PAULO ROBERTO RIBEIRO DE MESQUITA
Externa à Instituição - NATTANY TAYANY GOMES DE PAULA - UFPE