Banca de QUALIFICAÇÃO: GUILHERME QUINTELA CALIXTO

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : GUILHERME QUINTELA CALIXTO
DATE: 20/09/2024
TIME: 10:00
LOCAL: auditório do NUPPRAR
TITLE:

Biofixation of CO2 through Microalgae Cultivation as a strategy for capturing and converting carbon into biofuels and bioproducts

KEY WORDS:

microalgae, CO₂ bio fixation, greenhouse gases, biomass.

PAGES: 110
BIG AREA: Engenharias
AREA: Engenharia Química
SUMMARY:

The increasing concentrations of CO₂ in the atmosphere due to human activities have led to the search for alternative methods of CO₂ capture, including microorganisms such as microalgae. Several authors study the effect of carbon dioxide concentration on the growth of microalgae, even using residual CO₂ from industries such as cement, which is responsible for more than 6% of global CO₂ emissions. This work studies the effect of various CO2 concentrations (0.04%, 5%, 10%, and 15%) on the cultivation of two strains of microalgae: Chlorella vulgaris and Spirulina platensis, to evaluate their CO₂ biofixation capacities, possible bioproducts, and system scaling. The microalgae were characterized by proximate analysis (ash content, moisture, volatiles, and fixed carbon), elemental analysis (CHNO), thermogravimetric analysis (TGA), FRX of the ashes, lipid content, protein content, and conventional and catalytic analytical pyrolysis. Additionally, during cultivation, dry mass and pH data were collected daily. The results show that both microalgae achieved a higher yield at a concentration of 10% CO₂ (v/v), with 1.41g L^-1 for Chlorella and 3.17g L^-1 for Spirulina. Despite a large amount of ash due to the flocculation method, Chlorella showed greater potential for biofuel production due to its high lipid content (21.7%) compared to Spirulina (11.2%). Conventional pyrolysis indicated a high amount of oxygenated (>25%) and nitrogenated (>20%) compounds for both microalgae, which were mostly converted (more than 90%) into aromatic compounds and hydrocarbons after using the HZSM-5 catalyst in the thermochemical process. The analysis of the system scaling for photobioreactors (80L) proved economically viable with the use of an external CO₂ source, making it possible to obtain a self-sufficient system considering only the sale price of raw microalgae.

COMMITTEE MEMBERS:
Presidente - 1979301 - RENATA MARTINS BRAGA
Interna - ***.948.834-** - KARINE FONSECA SOARES DE OLIVEIRA - UFRN
Interno - 6347420 - MARCUS ANTONIO DE FREITAS MELO
Externo ao Programa - 3304576 - RODOLFO LUIZ BEZERRA DE ARAÚJO MEDEIROS - UFRN