Maria Aparecida Ferreira César-Oliveira
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Research Subjects
Maria Aparecida Ferreira César-Oliveira has a total of 12 co-authors. Here are the top co-authors by number of shared publications:
- Angelo Roberto dos Santos Oliveira
Chemistry Department, Federal University of Paraná (UFPR), Rua Coronel Francisco Heráclito dos Santos 100, Jardim das Américas, Curitiba 81531-980, PR, Brazil
2 shared publications - Danays Kunka
Karlsruhe Institute of Technology
2 shared publications - Maria Aparecida F. César‐Oliveira
Chemistry Department, Federal University of Paraná (UFPR), Rua Coronel Francisco Heráclito dos Santos 100, Jardim das Américas, Curitiba 81531-980, PR, Brazil
2 shared publications - Vitor Vlnieska
Karlsruhe Institute of Technology (KIT), Institute of Microstructure Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
2 shared publications Aline S. Muniz
Laboratory of Polymer Chemistry and Organic Synthesis (LEQUIPE) − Department of Chemistry Federal University of Paraná UFPR, P.O. Box 19032 81531‐980 Curitiba Paraná Brazil
1 shared publicationAline Silva Muniz
Laboratório de Química de Polímeros e Síntese Orgânica, Departamento de Química Universidade Federal do Paraná—UFPR, CP 19031, CEP 81531‐980 Curitiba Paraná Brazil
1 shared publication
Latest Publications
- Open Access
Oligocat: Oligoesters as Pseudo-Homogenous Catalysts for Biodiesel Synthesis
Biodiesel production from first-generation feedstock has shown a strong correlation with the increase in deforestation and the necessity of larger areas for land farming. Recent estimation from the European Federation for Transport and Environment evidenced that since the 2000s decade, an area equal to the Netherlands was deforested to supply global biodiesel demand, mainly originating from first-generation feedstock. Nevertheless, biodiesel is renewable, and it can be a greener source of energy than petroleum. A promising approach to make biodiesel independent from large areas of farming is to shift as much as possible the biodiesel production chain to second and third generations of feedstock. The second generation presents three main advantages, where it does not compete with the food industry, its commercial value is negligible, or none, and its usage as feedstock for biodiesel production reduces the overall waste disposal. In this manuscript, we present an oligomeric catalyst designed to be multi-functional for second-generation feedstock transesterification reactions, mainly focusing our efforts to optimize the conversion of tallow fat and sauteing oil to FAME and FAEE, applying our innovative catalyst. Named as Oligocat, our catalyst acts as a Brønsted-Lowry acid catalyst, providing protons to the reaction medium, and at the same time, with the course of the reaction, it sequesters glycerol molecules from the medium and changes its physical phase during the transesterification reaction. With this set of properties, Oligocat presents a pseudo-homogenous behavior, reducing the purification and separation steps of the biodiesel process production. Reaction conditions were optimized applying a 42 factorial planning. The output parameter evaluated was the conversion rate of triacylglycerol to mono alkyl esters, measured through gel permeation chromatography (GPC). After the optimization studies, a conversion yield of 96.7 (±1.9) wt% was achieved, which allows classifying the obtained mono alkyl esters as biodiesel by ASTM D6751 or EN 14214:2003. After applying the catalyst in three reaction cycles, Oligocat still presented a conversion rate above 96.5 wt% and as well an excellent recovery rate.
Open AccessOligocat: Oligoesters as Pseudo-Homogenous Catalysts for Biodiesel Synthesis
Biodiesel production from first-generation feedstock has shown a strong correlation with the increase in deforestation and the necessity of larger areas for land farming. Recent estimation from the European Federation for Transport and Environment evidenced that since the 2000s decade, an area equal to the Netherlands was deforested to supply global biodiesel demand, mainly originating from first-generation feedstock. Nevertheless, biodiesel is renewable, and it can be a greener source of energy than petroleum. A promising approach to make biodiesel independent from large areas of farming is to shift as much as possible the biodiesel production chain to second and third generations of feedstock. The second generation presents three main advantages, where it does not compete with the food industry, its commercial value is negligible, or none, and its usage as feedstock for biodiesel production reduces the overall waste disposal. In this manuscript, we present an oligomeric catalyst designed to be multi-functional for second-generation feedstock transesterification reactions, mainly focusing our efforts to optimize the conversion of tallow fat and sauteing oil to FAME and FAEE, applying our innovative catalyst. Named as Oligocat, our catalyst acts as a Brønsted-Lowry acid catalyst, providing protons to the reaction medium, and at the same time, with the course of the reaction, it sequesters glycerol molecules from the medium and changes its physical phase during the transesterification reaction. With this set of properties, Oligocat presents a pseudo-homogenous behavior, reducing the purification and separation steps of the biodiesel process production. Reaction conditions were optimized applying a 42 factorial planning. The output parameter evaluated was the conversion rate of triacylglycerol to mono alkyl esters, measured through gel permeation chromatography (GPC). After the optimization studies, a conversion yield of 96.7 (±1.9) wt% was achieved, which allows classifying the obtained mono alkyl esters as biodiesel by ASTM D6751 or EN 14214:2003. After applying the catalyst in three reaction cycles, Oligocat still presented a conversion rate above 96.5 wt% and as well an excellent recovery rate.
- Open Access
Synthesis and Chemical Functionalization of Pseudo-Homogeneous Catalysts for Biodiesel Production—Oligocat
With the increase in global demand for biodiesel, first generation feedstock has drawn the attention of governmental institutions due to the correlation with large land farming areas. The second and third feedstock generations are greener feedstock sources, nevertheless, they require different catalytic conditions if compared with first generation feedstock. In this work, we present the synthesis and characterization of oligoesters matrices and their functionalization to act as a pseudo-homogeneous acid catalyst for biodiesel production, named Oligocat. The main advantage of Oligocat is given due to its reactional medium interaction. Initially, oligocat is a solid catalyst soluble in the alcoholic phase, acting as a homogeneous catalyst, providing better mass transfer of the catalytic groups to the reaction medium, and as the course of the reaction happens, Oligocat migrates to the glycerol phase, also providing the advantage of easy separation of the biodiesel. Oligocat was synthesized through polymerization of aromatic hydroxy acids, followed by a chemical functionalization applying the sulfonation technique. Characterization of the catalysts was carried out by infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (NMR), gel permeation chromatography (GPC), and thermogravimetric analysis (TGA). The synthesized oligomers presented 5357 g·mol−1 (Mw) and 3909 g·mol−1 (Mn), with a moderate thermal resistance of approximately 175 °C. By sulfonation reaction, it was possible to obtain a high content of sulphonic groups of nearly 70 mol%, which provided the catalytic activity to the oligomeric matrix. With the mentioned physical–chemical properties, Oligocat is chemically designed to convert second generation feedstock to biodiesel efficiently. Preliminary investigation using Oligocat for biodiesel production resulted in conversion rates higher than 96.5 wt.%.
Open AccessSynthesis and Chemical Functionalization of Pseudo-Homogeneous Catalysts for Biodiesel Production—Oligocat
With the increase in global demand for biodiesel, first generation feedstock has drawn the attention of governmental institutions due to the correlation with large land farming areas. The second and third feedstock generations are greener feedstock sources, nevertheless, they require different catalytic conditions if compared with first generation feedstock. In this work, we present the synthesis and characterization of oligoesters matrices and their functionalization to act as a pseudo-homogeneous acid catalyst for biodiesel production, named Oligocat. The main advantage of Oligocat is given due to its reactional medium interaction. Initially, oligocat is a solid catalyst soluble in the alcoholic phase, acting as a homogeneous catalyst, providing better mass transfer of the catalytic groups to the reaction medium, and as the course of the reaction happens, Oligocat migrates to the glycerol phase, also providing the advantage of easy separation of the biodiesel. Oligocat was synthesized through polymerization of aromatic hydroxy acids, followed by a chemical functionalization applying the sulfonation technique. Characterization of the catalysts was carried out by infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (NMR), gel permeation chromatography (GPC), and thermogravimetric analysis (TGA). The synthesized oligomers presented 5357 g·mol−1 (Mw) and 3909 g·mol−1 (Mn), with a moderate thermal resistance of approximately 175 °C. By sulfonation reaction, it was possible to obtain a high content of sulphonic groups of nearly 70 mol%, which provided the catalytic activity to the oligomeric matrix. With the mentioned physical–chemical properties, Oligocat is chemically designed to convert second generation feedstock to biodiesel efficiently. Preliminary investigation using Oligocat for biodiesel production resulted in conversion rates higher than 96.5 wt.%.
- 15 February 2019
- Published by Wiley in Macromolecular Symposia
- Vol. 383 (1)
Polymer Additives as Cold Flow Improvers for Palm Oil Methyl Esters
Biodiesel is a fuel that can be originated from different raw materials. However, even a good quality biodiesel has its properties strongly dependent upon its fatty acid profile. For instance, samples with a high content of saturated fatty acids may present poor cold flow properties, meaning that they tend to solidify under low temperatures. In this work, we propose to synthesize polymer additives and apply them as cold flow improvers for palm methyl esters (biodiesel) and their blends with petrodiesel. The synthetic additives were evaluated at different concentrations to assess their effect on the pour point (PP) of the resulting neat or blended biofuel. By using 1000 ppm of poly(dodecyl acrylate‐co‐tetradecyl methacrylate), it was possible to decrease the PP of B5 (5 vol.% biodiesel + 95 vol.% diesel) and B20 (20 vol.% biodiesel + 80 vol.% diesel) to −35 °C and −14 °C, respectively, which allowed the use of these blends in regions where their flow properties would eventually be prohibitive. However, the performance of the additive on the neat fuel (B100) was negligible.
- 15 February 2019
- Published by Wiley in Macromolecular Symposia
- Vol. 383 (1)
Polymer Additives as Cold Flow Improvers for Palm Oil Methyl Esters
Biodiesel is a fuel that can be originated from different raw materials. However, even a good quality biodiesel has its properties strongly dependent upon its fatty acid profile. For instance, samples with a high content of saturated fatty acids may present poor cold flow properties, meaning that they tend to solidify under low temperatures. In this work, we propose to synthesize polymer additives and apply them as cold flow improvers for palm methyl esters (biodiesel) and their blends with petrodiesel. The synthetic additives were evaluated at different concentrations to assess their effect on the pour point (PP) of the resulting neat or blended biofuel. By using 1000 ppm of poly(dodecyl acrylate‐co‐tetradecyl methacrylate), it was possible to decrease the PP of B5 (5 vol.% biodiesel + 95 vol.% diesel) and B20 (20 vol.% biodiesel + 80 vol.% diesel) to −35 °C and −14 °C, respectively, which allowed the use of these blends in regions where their flow properties would eventually be prohibitive. However, the performance of the additive on the neat fuel (B100) was negligible.
- 15 February 2018
- Published by Wiley in Journal of Polymer Science Part A: Polymer Chemistry
- Vol. 56 (10) , 1039-1045
Bio‐based comb‐like copolymers derived from alkyl 10‐undecenoates and maleic anhydride
In this article, 10‐undecenoic acid, based on castor oil, was used a raw material for the synthesis of alternating copolymers. ω‐Unsaturated fatty esters as alkyl 10‐undecenoates were prepared by the esterification reaction of 10‐undecenoic acid with alkyl alcohol. A series of comb‐like copolymers were synthesized by free radical polymerization from maleic anhydride and alkyl 10‐undecenoates copolymers with different length of alkyl side chains in a toluene solution. These copolymers were investigated by 1H and 13C nuclear magnetic resonance, Fourier transform infrared spectroscopy, gel permeation chromatography, thermogravimetric analysis, differential scanning calorimetry (DSC). The copolymers were obtained in a low molecular weight in a range 3370–12,240 g mol−1 and their structural characterization indicated the formation of alternating copolymers. DSC characterization revealed that these comb‐like copolymers showed amorphous to semicrystalline behavior by increasing the length of side chains. The bio‐based comb‐like copolymers allow for the development of new polymeric materials for several applications. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 1039–1045
- 15 February 2018
- Published by Wiley in Journal of Polymer Science Part A: Polymer Chemistry
- Vol. 56 (10) , 1039-1045
Bio‐based comb‐like copolymers derived from alkyl 10‐undecenoates and maleic anhydride
In this article, 10‐undecenoic acid, based on castor oil, was used a raw material for the synthesis of alternating copolymers. ω‐Unsaturated fatty esters as alkyl 10‐undecenoates were prepared by the esterification reaction of 10‐undecenoic acid with alkyl alcohol. A series of comb‐like copolymers were synthesized by free radical polymerization from maleic anhydride and alkyl 10‐undecenoates copolymers with different length of alkyl side chains in a toluene solution. These copolymers were investigated by 1H and 13C nuclear magnetic resonance, Fourier transform infrared spectroscopy, gel permeation chromatography, thermogravimetric analysis, differential scanning calorimetry (DSC). The copolymers were obtained in a low molecular weight in a range 3370–12,240 g mol−1 and their structural characterization indicated the formation of alternating copolymers. DSC characterization revealed that these comb‐like copolymers showed amorphous to semicrystalline behavior by increasing the length of side chains. The bio‐based comb‐like copolymers allow for the development of new polymeric materials for several applications. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 1039–1045