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Search Results: 1 - 10 of 191597 matches for " Gisel Chenard Díaz "
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Hydrolysis - Hydrogenation of soybean oil and tallow  [PDF]
Gisel Chenard Díaz, Rodolfo Salazar Perez, Neyda de la C. Om Tapanes, Donato Alexandre Gomes Aranda, Angel Almarales Arceo
Natural Science (NS) , 2011, DOI: 10.4236/ns.2011.37074
Abstract: Hydrolysis reactions are of major importance to the oleochemical industry in the production of fatty acid and their derivates. Hydrolysis of triglyceride from vegetable oil has been studied under various parameters such as: heterogeneous catalyst, temperature, reaction time and agitation speed. During the hydrolysis of soybean oil and tallow using nickel catalysts on alumina support was verified that the glycerol produced worked as hydrogen donor, allowing the hydrogenation of unsaturated fatty acids produced. Maximum conversion was achieved in 3 hours, catalysts 25% NiO/Al2O3, temperature of 250oC and 270oC and 250 rpm.
Biodiesel Production Based in Microalgae: A Biorefinery Approach  [PDF]
Lauren Espinosa González, Gisel Chenard Díaz, Donato Alexandre Gomes Aranda, Yordanka Reyes Cruz, Mariana Monteiro Fortes
Natural Science (NS) , 2015, DOI: 10.4236/ns.2015.77039
Abstract: It is of great knowledge nowadays that the use of fossil fuels is responsible for the emission of gases that intensify the greenhouse effect, which threatens the survival of the humankind. The gravity of this fact could be mitigated through the indirect use of solar energy for fuels derived from vegetable that can be planted and cultivated by the world of renewable and non-polisher. Microalgae play an important role in this regard, as they have promising characteristics as potential raw material for the production of biofuels, able to absorb large amounts of CO2. Chlorophyll organisms convert these simple substances in the atmosphere, absorbing sunlight into chemical energy stored, that is, compounds with high energy, biomass can also be used to obtain biocompounds human nutritional supplement and food animal, however, have been found an important number of difficulties to economically viable production like high cost of production of dry biomass and oil extraction. Here, we review the main approaches of biorefinery concept appearing as an alternative to achieve economic viability of the production of bio-diesel based on microalgae. The major points are the following: 1) use of re-residual water, 2) marketing of Carbon Credits, and 3) development of co-products resulting from high value added.
Primary Separation of Antioxidants (Unsaponifiables) the Wet Biomass Microalgae Chlamydomonas sp. and Production of the Biodiesel  [PDF]
Gisel Chenard Díaz, Yordanka Reyes Cruz, Mariana Monteiro Fortes, Carolina Vieira Viegas, René González Carliz, Nelson C. Furtado, Donato A. Gomes Aranda
Natural Science (NS) , 2014, DOI: 10.4236/ns.2014.615108
Abstract: This work studies the saponification which directs the wet biomass of algae Chlamydomonas sp. like a previous stage to production of biodiesel. This stage allows the obtainment of fatty acids to produce biodiesel, instead of the gross lipid fraction. In addition of the fatty acids, utilizing the same process one can also obtain the fraction unsaponifiable, these are soluble in apolar solvents and contain mainly carotenoids that can take action as antioxidants and photoprotectors, as they reduce the oxidation of unsaturated fatty acids. The saponification direct and extraction of fatty acids from biomass is faster and reduces the time and cost of operation. The separation of unsaponifiable matter from the biomass humid of microalgae Chlamydomonas sp., was held according to the method AOCS (Ca 6a-40), using extraction Liquid-liquid with hexane as solvent. Subsequently, phase hydroalcoholic or from soap, containing fatty acids, was acidified by addition of H2SO4 and the fatty acids were recovered by the addition of hexane. After acidulation of the soap, necessary for obtaining of the fatty acids was performed the stage of esterification for obtaining of biodiesel. The operating conditions were: molar ratio fatty acid:methanol (1:10), as catalyst 8% H2SO4 calculated in relation to the mass of fatty acid, 200 and reaction time of 90 minutes. The content of methyl esters was 96.8% determined by gas chromatography according to standard EN14103. The quality of biodiesel produced from wet biomass of Chlamydomonas sp. is according to the specification established by standard EN 14214 and RANP No. 14. For the identification of the composition the unsaponifiable fraction was used the method of High Performance Liquid Chromatography (HPLC). The composition of the material unsaponifiable found was of: Carotenoids total (0.76%); Lutein (0.45%); Zeaxanthin (0.07%); α-carotene (0.05%); β-carotene (0.11%); 13 cisβ-carotene (0.05%) and 9-cisβ-carotene (0.03%).
Cultivation of Microalgae Monoraphidium sp., in the Plant Pilot the Grand Valle Bio Energy, for Biodiesel Production  [PDF]
Gisel Chenard Díaz, Yordanka Reyes Cruz, René González Carliz, Rosa C. Vitorino de Paula, Donato A. Gomes Aranda, Marcellus A. G. Dario, Gustavo Saraiva Marass, Nelson C. Furtado
Natural Science (NS) , 2015, DOI: 10.4236/ns.2015.77040
Abstract: At present, Brazil imports approximately 11 billion liters/year of diesel. With the interruption of the works in the new Petrobras refineries, the projection is that by 2025 this volume will increase to 24.2 billion liters of diesel/year. In this sense, the biodiesel factory Grand Valle Bio Energy Ltda., located in the state of Rio de Janeiro, in conjunction with the FAPERJ makes some investments in technology development for the cultivation and use of microalgae as an alternative raw material in the production of biodiesel. Based on arguments previously said, this work presents the results of the microalgae cultivation Monoraphidium sp. in photobioreactors the pilot plant of the company. The installation with an area of 120 m2 is included with 2 open photobioreactors of type falling film (20 m × 1 m), with a cascade of 18mm and capacity of 4000 L. The lineage cultivated is selected from previous ecophysiological studies that are identified as promising for biodiesel production by having a high potential for the production of lipids. This lineage is maintained at collection of the stock of cultures Laboratory of Green Technologies of the School of Chemistry/ UFRJ. The cultivation was performed in means ASM-1 (Gorham et al., 1964), initial pH 8.0, with aeration and circulation average of 8 hours a day during 19 days. The culture was started with an inoculum of 1 × 107 cel/ml. The lipid production was determined in two phases of growth: on day 4 (exponential phase) and 15 day (stationary phase). For the determination and quantification of lipid content, two different methods were assessed for a sample of biomass, submitted to the same processes the separation and drying. The results showed the methodology of Bligh & Dyer with modifications as the most efficient in extracting lipids. The total lipid content of the biomass Monoraphidium sp. was 30.58%. The growth rate varied between 0.74 ± 0.01 and 0.68 ± 0.02.
Photobioreactor of Microalgas for CO2 Biofixation  [PDF]
Yordanka Reyes Cruz, Gisel Chenard Díaz, Andreina Z. Figuera Leonett, René Gonzalez Carliz, Vinicius Rossa, Luciano Basto Oliveira, Maurílio Novais da Paix?o, Donato Alexandre Gomes Aranda
Journal of Power and Energy Engineering (JPEE) , 2019, DOI: 10.4236/jpee.2019.71006
Abstract: Microalgae are unicellular organisms capable of photosynthesis, turning sunlight and carbon dioxide (CO2) into rich biomass. Precisely because of this definition, in recent years various sectors have been targeting their ability to reduce CO2 emissions and the capacity of simultaneously synthesize biomass which can be later used to produce bio-fuels. Besides being considered fast-growth microorganisms, microalgae have a diverse biochemical composition with similar characteristics to traditional biomass. In this context, the present work aimed to evaluate the biofixation of CO2 by the microalgae Monoraphidium sp., cultivated in a closed-window type photobioreactor, as well as characterization of microalgal biomass produced in relation to the total lipid content (TL), lipids converted into biodiesel (LCB), carbohydrates and proteins. The results achieved showed that the best result was obtained after 24 h of cultivation, where for each gram of biomass produced approximately 1.2 g of CO2 were consumed. In the growth phase the average biomass productivity in the Janela photobioreactor was 58 mg·L-1·day-1 concluding that microalgae culture systems could be coupled to the chimneys of large industries emitters CO2 using this gas, resulting from combustion processes, in the process of photosynthesis. The biomass Monoraphidium sp. produced had a content of lipids converted into biodiesel of approximately 8.36% ± 2.69%, carbohydrates 32% ± 3.37% and proteins 34.26% ± 0.41%.
Hydroesterification of Nannochloropsis oculata microalga’s biomass to biodiesel on Al2O3 supported Nb2O5 catalyst  [PDF]
Angel Almarales, Gisel Chenard, Roberto Abdala, Donato A. Gomes, Yordanka Reyes, Neyda Om Tapanes
Natural Science (NS) , 2012, DOI: 10.4236/ns.2012.44031
Abstract: Hydroesterification process has been presented biodiesel production from oil the green microalga Nannochloropsis oculata raw materials. Biodiesel studied in this work is the main product got from the hydroesterification of biomass the Nannochloropsis oculata and was obtained from esterification of fatty acid (product of a hydrolysis reaction) with methanol. It was used as catalyst the niobic acid pure and supported on δ-aluminum. The product was evaluated by gas chromatography and other analyses. The optimum conditions found in the conversion (%) for the hydrolysis reactions of the biomass (92.3%). Better results were observed in the algae concentration 20%, lead at 300?C with 20% of catalyst. For esterification of fatty acids of Nannochloropsis oculata (92.24%), were observed the molar ratio methanol: fat acid 3, lead at 200°C with 20% of catalyst supported.
Biodiesel production by hydroesterification of microalgal biomass using heterogeneous catalyst  [PDF]
Yordanaka Reyes, Gisel Chenard, Donato Aranda, Cristiane Mesquita, Mariana Fortes, Rafael Jo?o, Leonardo Bacellar
Natural Science (NS) , 2012, DOI: 10.4236/ns.2012.410102
Abstract: This paper assesses the hydroesterification process for the production of Biodiesel from Monoraphidium contortum (MORF-1) microalgae biomass, as it is a sustainable alternative not only economically, but also environmentally and ecologically to replace petroleum diesel fuel. The Biodiesel studied in this work was obtained from fatty acid esterification, a product of microalgae and methanol biomass hydrolysis reaction. CBMM’s (HY-340) niobium oxide powder was used as catalyst. The reactions were carried out in a properly closed autoclave reactor (batch), where the reagents were mixed under constant stirring at 500 rpm for hydrolysis and esterification. The products generated were submitted to gas chromatography and oxidative stability analysis. The hydroesterification process showed itself to be a promising alternative to the conventional biodiesel production process (transesterification) as it favors the use of feedstocks with any acidity and moisture content and may be performed with acid catalyst, which favors high conversions in a small range of time (30 minutes).
Production of Hydrogen from Aqueous Phase Reforming of Glycerol: Economic Evaluation  [PDF]
Rodolfo Salazar Pérez, Mariana M. V. M. Souza, Neyda C. Om Tapanes, Gisel Chenard Diaz, Donato A. G. Aranda
Engineering (ENG) , 2014, DOI: 10.4236/eng.2014.61003

Glycerol is the main byproduct from the production of biodiesel by transesterification of vegetable oils, and approximately 10% of total biodiesel production volume corresponds to glycerol. The profitability of various chemical processes depends, in part, on the sale of byproducts, which enables a reduction in the production costs and consequently, in the product’s final price. Thus, it is necessary to look for alternatives to solve the problem of glycerol buildup, in order to avoid future environmental impacts and make biodiesel competitive in the growing market of biofuels. In this context, this study’s objective is the development of a low cost and environmental clean technology that allows the conversion of glycerin into a greater value product. In this paper, an economic evaluation of production hydrogen using Aqueous Phase Reforming (APR) was conducted. Firstly, we detailed the technical assumptions in the study. Reactions were performed in batch reformer of 10 liters of capacity, at the temperature of 250℃ and pressure of 38 atm. Finally, a sensitivity analysis was performed. The results from economic evaluation show that APR of glycerol, using nickel catalysts supported on alumina or zirconium oxide, is a promising and competitive technology for hydrogen production.

Bases genéticas del síndrome de ovarios poliquísticos
Ovies Carballo,Gisel; Martínez de Sandelices,Alicia; Monteagudo Pe?a,Gilda; Sardi?as Díaz,Irelys;
Revista Cubana de Endocrinolog?-a , 2011,
Abstract: the syndrome of polycystic ovaries is the endocrine disorder involving more the reproductive sphere of the woman in fertile age, its causes are unknown with accuracy, but most of experts coincide in propose that it is a multifactor entity where the genetic factor more and more have a great significance. in past years, it has been possible to identify some genes involved in the pathogenic processes of this syndrome and among the more important are included those codifying for enzymes of the steroidogenesis, for the insulin receptor and other hormones related to the insulin action, as well as the gonadotropins and its receptors, features that are the aim of present review.
Bases genéticas del síndrome de ovarios poliquísticos Genetic bases of polycystic ovary syndrome
Gisel Ovies Carballo,Alicia Martínez de Sandelices,Gilda Monteagudo Pe?a,Irelys Sardi?as Díaz
Revista Cubana de Endocrinología , 2011,
Abstract: El síndrome de ovarios poliquísticos es el trastorno endocrino que más afecta la esfera reproductiva de la mujer en la edad fértil, sus causas se desconocen con exactitud, pero la mayoría de los expertos coinciden en plantear que es una entidad multifactorial, en la que los factores genéticos cada vez cobran mayor importancia. En los últimos a os se han identificado varios genes involucrados en los procesos patogénicos de este síndrome, y dentro de estos, los más importantes son aquellos que codifican para enzimas de la esteroidogénesis, para el receptor de insulina y otras hormonas relacionadas con la acción de la insulina, así como las gonadotropinas y sus receptores, aspectos sobre los cuales trata la siguiente revisión. The syndrome of polycystic ovaries is the endocrine disorder involving more the reproductive sphere of the woman in fertile age, its causes are unknown with accuracy, but most of experts coincide in propose that it is a multifactor entity where the genetic factor more and more have a great significance. In past years, it has been possible to identify some genes involved in the pathogenic processes of this syndrome and among the more important are included those codifying for enzymes of the steroidogenesis, for the insulin receptor and other hormones related to the insulin action, as well as the gonadotropins and its receptors, features that are the aim of present review.
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