Study of Biodiesel Preparation Using Different Niobium Compounds as Catalysts in the Transesterification of Vegetable Oils and Short Chain Alcohols
Name: BRUNO HENRIQUE ARPINI
Type: MSc dissertation
Publication date: 30/03/2016
Advisor:
Name |
Role |
|---|---|
| VALDEMAR LACERDA JUNIOR | Advisor * |
Examining board:
| Name |
Role |
|---|---|
| ÁLVARO CUNHA NETO | Internal Examiner * |
| ANDRÉ ROMERO DA SILVA | External Examiner * |
| VALDEMAR LACERDA JUNIOR | Advisor * |
Summary: The attainment of new methodologies for biodiesel production is very important both from an environmental point of view, since it is not a fossil fuel, such as from an economic point of view, being derived from abundant raw materials in Brazil. The main biodiesel preparation method involves the transesterification of vegetable oils thus have similar physic-chemical properties of the fossil analog diesel.
This study aims to obtain new methods of obtaining ethyl and methyl biodiesel from three different compounds of niobium acting as catalysts in transesterification reactions, they are niobium pentoxide, pentachloride and niobium ammonium oxalate niobium. Various parameters such as temperature, reaction time, mass ratio of the catalyst, the reaction system (refluxing and ultrasound bath) were varied to obtain the best conditions for obtaining biodiesel.
The NbCl5 did not obtain satisfactory yields due to its difficult handling and the presence of water as a byproduct in parallel reaction to transesterification, the esterification of free fatty acids. NH4[NbO(C2O4)2(H2O)].nH2O showed good yields mainly at reflux for 48 hours, using ethanol and in particular in a proportion of 100% by weight towards oils. Nb2O5 may act as both Bronsted acid as Lewis acid, but in calcination temperature of 300 ° C it leads to higher yields, related to a rise of Lewis sites and a larger organization of their crystalline structure.
The reactions using ultrasound bath has not shown satisfactory results compared to reflux reactions, due to the much lower reaction time and consequently lower energy addition to the reaction system
