Melquizedeque B. Alves

Oils and fats based biofuels: technological chalendges

Periodically, during petroleum shortage, fatty acids and their derivatives have been used as alternative fuels to those derived from petroleum. Different approaches have been proposed, including the use of neat fats and oils or their derivatives. Indeed, the utilization of biodiesel produced by alcoholysis of triacilglycerides or esterification of fatty acids, or hydrocarbons obtained from cracking of fatty materials were studied and used in several countries. Increasing concerns about energy security and climate changes have lead several countries, including Brazil, to start up biofuels programs. Different technologies are currently being developed in order to produce biofuels with economical feasibility. In this work are discussed alternative fatty raw-materials and processing technologies that are currently being studied in order to produce fuels suitable to sustainable substitute diesel fuel.

New heterogeneous metal-oxides based catalyst for vegetable oil trans-esterification

The preparation of new materials obtained from the co-precipitation of aluminum, tin and zinc oxides and their use as catalytic system activities for vegetable oils alcoholysis are reported herein. It was observed that these metal-oxides of the type (Al2O3)X(SnO)Y(ZnO) Z are active for soybean oil alcoholysis, uzing several alcohols, including branched ones. Best result was achieved using methanol, with conversion yields up to 80% in 4 h. It was also possible to recycle the catalysts without apparent loss of activity.

Cadmium and Tin Magnetic Nanocatalysts Useful for Biodiesel Production

Nanoparticulas magneticas compostas por oxidos mistos de ferro/cadmio (ICdO) e ferro/ estanho (ISnO) foram usadas como catalisadores em reacoes relevantes para diferentes tecnologias de producao de biodiesel. Estes compostos foram ativos para hidrolise e transesterificacao de oleo de soja, bem como para a esterificacao de acidos graxos obtidos a partir do oleo de soja. Na esterificacao mediada por ISnO foram alcancados altos rendimentos, ca. 84%, apos 1 h de reacao a 200 oC. O oxido foi recuperado magneticamente e reutilizado quatro vezes sem perda da sua atividade catalitica, enquanto que uma perda significativa foi observada quando ICdO foi usado. ISnO demonstrou tambem atividade para a producao de biodiesel a partir de oleo de macauba, um substrato altamente acido.