Name: KÁRITA FERNANDA FONTES LIMA
Type: MSc dissertation
Publication date: 23/02/2018
Advisor:
Name |
Role |
|---|---|
| PAULO SÉRGIO DA SILVA PORTO | Co-advisor * |
| RODRIGO RANDOW DE FREITAS | Advisor * |
Examining board:
| Name |
Role |
|---|---|
| EDUARDO PERINI MUNIZ | Internal Alternate * |
| PAULO SÉRGIO DA SILVA PORTO | Co advisor * |
| RENATO DO NASCIMENTO SIQUEIRA | External Alternate * |
| RODRIGO RANDOW DE FREITAS | Advisor * |
| TAISA SHIMOSAKAI DE LIRA | Internal Examiner * |
Summary: Current research has shown a great interest in microalgae due to its ability to capture CO2 from the atmosphere, a harmful gas to the environment, and to store a high added value oil. However, the extraction of oil from microalgae represents a stage of high energy demand, and it is necessary to develop a viable process in this aspect. In this context, the present work aims to extract the bio-oil from the microalgae of the species Nannochloropsis oculata via humid base, in order to remove the drying step of the extraction process. For this, an experimental planning of the factorial type (3²) with two central points was used, totalizing 11 experiments for each solvent (ethanol and hexane). The variables studied in the planning were the time of application of the ultrasound and the time of extraction by Soxhlet. Extraction with the ultrasonic application for 60 min followed by Soxhlet for 8 h with hexane showed a better yield (20.29%) of bio-oil. The production of bio-oil under the same conditions with ethanol was 16.83%. The lowest energy expenditure in relation to the production of 1 g of oil of di gave under the conditions of application of 60 min of ultrasound and 4h of solid-liquid extraction. It also compared the energy expenditure via dry and wet basis two solvents. In the dry base extraction, the yield was lower than the wet basis. By the analysis of GC-MS it was observed that drying influences the profile of fatty acids, reducing the percentage of monounsaturated and polyunsaturated fatty acids. It is concluded that the wet basis extraction is the best option, since drying deteriorates the bio-oil and does not influence significantly the yield of the bio-oil.
