Camila Martins Garcia

Transesterification of soybean oil catalyzed by sulfated zirconia

Two sulfated zirconias were synthesized and characterized by X-ray diffraction and infrared spectroscopy. They were used as catalysts in the alcoholysis of soybean oil and in the esterification of oleic acid. Using sulfated zirconia prepared by the solvent-free method (S-ZrO(2)) as catalyst, the alcoholysis conversions of soybean oil under optimized conditions (120 degrees C, 1h and 5wt% of catalyst) were 98.6% (methanolysis) and 92% (ethanolysis), respectively. The esterification of oleic acid with methanol was complete after 2h. Zirconia sulfated by standard methods (SZ) had low activity in the methanolysis of soybean oil (conversion of 8.5%) and conventional zirconia (NS) was inactive for methanolysis under the conditions optimized for S-ZrO(2).

Síntese de biodiesel: uma proposta contextualizada de experimento para laboratório de química geral

The contextualized understanding of concepts in Chemistry by students from other areas is a challenging task. In this experiment, the synthesis of biodiesel is done by base catalyzed transesterification of refined soy oil with methanol at room temperature and common glassware found in any chemistry laboratory. The proposal permits introducing several concepts, such as that of emulsion, viscosity and catalysis to illustrate an activity based on an actual problem. In this didactic approach, some common problems of biodiesel production, such as soap formation and phase separation, are introduced into the procedure in order to raise questions and motivate the students to participate in the experimental work and stimulate reflections about critical aspects of biodiesel production. This experiment was carried out in the first semester of 2006, in experimental general chemistry taken by physics and agricultural, civil and chemical engineering students of UNICAMP.

Evolving factor analysis-based method for correcting monitoring delay in different batch runs for use with PLS: On-line monitoring of a transesterification reaction by ATR-FTIR

In this work, the base-catalyzed transesterification of soybean oil with ethanol was monitored on-line using mid-infrared spectroscopy (MIRS) and the yield of fatty acid ethyl esters (biodiesel) was obtained by (1)H NMR spectroscopy. The MIRS monitoring carried out for 12min, was performed using a cylindrical internal reflectance cell of PbSe in the range of 3707-814cm(-1) with eight co-added scans. Two different data treatment strategies were used: in the first, the models were built using the raw data and in the other, evolving factor analysis (EFA) was used to overcome the sensor time delay due to the on-line analysis, producing significantly better results. In addition, models based on partial least squares (PLS) using three batches for calibration and another for validation were compared with models with just one batch for calibration and three for validation. The models were compared between each other using root mean square error of prediction (RMSEP) and root mean square prediction difference (RMSPD), obtaining relative errors under 3%.

Blends of soybean biodiesel with petrodiesel: direct quantitation via mass spectrometry

Quantitation and identification of blends of soybean biodiesel with petrodiesel were performed via mass spectrometry using two ionization techniques: electrospray ionization (ESI) and Venturi easy ambient sonic-spray ionization in its liquid mode (VL-EASI). Different soybean biodiesel/petrodiesel blends (from B0 to B100) were diluted and then directly infused and analyzed by both techniques. To investigate adulteration of Bn blends, different soybean oil/biodiesel and soybean oil/petrodiesel blends were analyzed. Analytical curves were obtained in three replicates. The two techniques were shown to provide reasonably accurate quantitation in the B1-B20 range. These techniques were also successfully used to detect contamination or adulteration of Bn blends with vegetable oils. ESI is a widely used and commercially available technique whereas a VL-EASI source can be easily mounted using common laboratory parts requiring no use of high voltages. Both techniques require no pre-separation or derivatization steps and offer, therefore, simple and fast methods for the quantitation of Bn blends. The comprehensive snapshots of the molecular composition also allow quality control and typification of the biodiesel and eventually of the vegetable oils in illegal admixtures.

Synthesis of biodiesel: a contextualized experiment proposal for the general chemistry laboratory

The contextualized understanding of concepts in Chemistry by students from other areas is a challenging task. In this experiment, the synthesis of biodiesel is done by base catalyzed transesterification of refined soy oil with methanol at room temperature and common glassware found in any chemistry laboratory. The proposal permits introducing several concepts, such as that of emulsion, viscosity and catalysis to illustrate an activity based on an actual problem. In this didactic approach, some common problems of biodiesel production, such as soap formation and phase separation, are introduced into the procedure in order to raise questions and motivate the students to participate in the experimental work and stimulate reflections about critical aspects of biodiesel production. This experiment was carried out in the first semester of 2006, in experimental general chemistry taken by physics and agricultural, civil and chemical engineering students of UNICAMP.

Bioenergy II: Acid Diphosphates as Catalysts for the Production of Methyl and Ethyl Esters from Vegetable Oils

Acidic lanthanum and aluminum diphosphates were prepared and characterized (surface area, XRD, FT-IR, 31P-NMR and 27Al-NMR). These materials were used as catalyst for the esterification of oleic acid and transesterification of soybean oil. Under optimized conditions the methyl and ethyl ester yields were above 95%. Although the catalysts are recyclable, they slowly lost their catalytic activities, due to leaching of the phosphate.

Synthesis of biodiesel: a contextualized experiment proposal for the general chemistry laboratory (Síntese de biodiesel: uma proposta contextualizada de experimento para laboratório de química geral )

The contextualized understanding of concepts in Chemistry by students from other areas is a challenging task. In this experiment, the synthesis of biodiesel is done by base catalyzed transesterification of refined soy oil with methanol at room temperature and common glassware found in any chemistry laboratory. The proposal permits introducing several concepts, such as that of emulsion, viscosity and catalysis to illustrate an activity based on an actual problem. In this didactic approach, some common problems of biodiesel production, such as soap formation and phase separation, are introduced into the procedure in order to raise questions and motivate the students to participate in the experimental work and stimulate reflections about critical aspects of biodiesel production. This experiment was carried out in the first semester of 2006, in experimental general chemistry taken by physics and agricultural, civil and chemical engineering students of UNICAMP.