Murumuru (Astrocaryum murumuru Mart.) butter and oils of buriti (Mauritia flexuosa Mart.) and pracaxi (Pentaclethra macroloba (Willd.) Kuntze) can be used for biodiesel production: Physico-chemical properties and thermal and kinetic studies

The research for new alternative energy sources has encouraged the study of different raw materials for the production of biodiesel. This work evaluated the use of murumuru (Astrocaryum murumuru Mart.) butter, and oils of buriti (Mauritia flexuosa Mart.) and pracaxi (Pentaclethra macroloba (Willd.) Kuntze) for biodiesel production by homogeneous alkaline transesterification. It was also studied their thermal stability by thermal gravimetric analysis (TG/DTG) and performed a kinetic study of the thermal decomposition of biodiesels using the Ozawa method. Classical physical and chemical analyses were used to characterize the oils and synthesized biodiesels. The results regarding the physico-chemical properties of the biodiesels were consistent with the values specified by Brazilian, American and European standards. Pracaxi biodiesel was thermally more stable than buriti and murumuru biodiesels. Due to their low decomposition temperatures, buriti and murumuru biodiesels showed high volatility, a very important feature associated with improved combustion properties, allowing their application in diesel engines. The values obtained for the activation energy of the thermal decomposition process of biodiesels confirmed that pracaxi biodiesel possesses greater thermal stability among the species studied.