Browsing by Author "Zalamea Piedra, Teresa Silvana"

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Ambiente en los hornos cerámicos y su influencia en el producto a nivel del Azuay
(2002-11-11) Avilés Tapia, Luisa Alejandrina; Granda Aucapiña, Víctor Marcelo; Zalamea Piedra, Teresa Silvana
Caracterización química de la biomasa procedente de las hojas, pseudotallo, raquis y pseudopeciolo de la planta de banano y su relación con el poder calorífico
(2016) Palacios Bau, Mayra Gabriela; Zalamea Piedra, Teresa Silvana
This research takes is part of the Project "Hydrogen production from biomass from the waste banana plant by catalytic gasification in supercritical temperature water", Objective is the chemical characterization and energy characterization of the biomass waste from the banana plant after its harvest,for subsequent comparison of results, these studies provide data on the structure of the raw material required for the development ofHydrogen Production Project. Initially the theoretical bases related to the lignocellulosic biomass, the banana plant and the calorific value. The experimental development mainly was carried out the engineering reactor and catalysis laboratory of the Faculty of Chemistry at the University of Cuenca, quantizing the structural components: lignin, cellulose and hemicellulose, of the leaves, rachis, pseudostem and pseudo-nippleof the banana plant that grown in Ecuador;the biomass waste consisted of leaves, rachis, pseudostem and pseudopetiole, that chemical level are qualitatively similar but quantitatively different, their pretreatment and treatment had been made strictly separate using traditional methods of chemical determination based on ASTMstandards and TAPPIstandardsfor the chemical characterization, and a calorimetric equipment for energy characterization. The results of chemical analysis presented percentages included between36-42 % for cellulose, 29-34 % for hemicellulose and 10-20 % for lignin,while for the calorific was obtained values between 12200-17400 kJ/kg. The highest percentage of cellulose was found in the rachis, of hemicellulose was in the external pseudostem and lignin was in the leaves,while the highest value of calorific was found in the leaves,reaching a direct relationship of calorific values with lignin percentage in all samples.
Diseño y desarrollo de reactor lecho fijo catalítico para gasificación de biomasa de banano en la producción de hidrógeno
(Universidad de Cuenca, 2021-05-05) Tacuri Sarmiento, Diego Mauricio; Zalamea Piedra, Teresa Silvana
Hydrogen and its production are currently an important research topic, since it is considered a clean energy vector that can be used in thermal machines or as a fuel without greenhouse gas emissions, which would contribute to the protection of the environment. There are several methods that are currently being investigated for the hydrogen production, among these the biomass gasification stands out. In general, this latter is carried out in two stages: hydrolysis of the biomass to produce water-soluble compounds and the reaction stage of gasification of these compounds. The use of catalysts in the gasification of biomass favors the formation of hydrogen, as well as reduces the formation of tar, which translates into a higher conversion of the biomass. One of the most abundant biomass in our country is the residue from banana plantations, whose energy potential to produce hydrogen has not yet been evaluated. Due to the aforementioned, the objective of this work was to design a bed catalytic reactor to carry out the banana gasification. For the design of the reactor, the length and diameter were estimated considering fluidization conditions and a ratio height/diameter of 3/1. After the design and construction of the reactor, the catalyzed and uncatalyzed gasification reaction was carried out at conditions of temperature of 640 °C, atmospheric pressure, mass of banana residue of 11.75 g, particle diameter of 1.84 mm biomass, and superheated water vapor as a gasifying agent. The catalyst used in the fixed bed was Ni/Al2O3, which was synthesized by coprecipitation of Ni(NO3)2.6H2O and Al(NO3)3.9H2O. The banana biomass was loaded into the reactor between two # 80 Tyler grids, in order to support and prevent carryover. Similarly, in the catalyzed reaction, the catalyst was placed between 2 grids of #200 Tyler, on the biomass bed. The gaseous mixture resulting from the reaction (superheated steam and synthesis gas) was condensed with excess water, and the synthesis gas was separated by a two-phase separator. Finally, the synthesis gas passed through a silica gel filter and was collected in a 1L Tedlar sleeve for analysis by gas chromatography. The design results established a reactor length of 9 cm and 3 cm in diameter. In the uncatalyzed reaction, the components obtained in the highest percentage were carbon dioxide> hydrogen> ethylene. On the contrary, in the catalyzed reaction, it was obtained: hydrogen> ethylene> carbon dioxide. The hydrogen content went from 25.8 %mol to 51.8 %mol when using a catalyst; while carbon dioxide reduced its molar content by 50%. Additionally, a mass and energy balance established a conversion of 0.295 based on water vapor, and a global heat transfer coefficient of 4.13 W/m2K. The results of this study show the good selectivity of the used catalyst towards the formation of hydrogen and reduction of carbon dioxide
Estudio del área superficial específica en la caracterización de los catalizadores a utilizarse en la gasificación catalítica para la producción de hidrógeno
(2017) Chungata Cabrera, Luis Andrés; Zalamea Piedra, Teresa Silvana
This research is developed as part of the characterization of the catalysts to be used in the Catalytic Gasification Reaction for the Hydrogen Production. Therefore, the study of the specific surface area of three supported catalysts: Al2O3 10%Ni, TiO2 10%Ni y ZrO2 10%Ni, synthesized by the incipient wet impregnation method. The process of activation by calcination of the catalysts was realized considering the time in heating ramp with variations of 1 and 2 hours and the residence time at temperatures of 500°C and 600°C with variations of 1 and 2 hours in each case. In the activated catalysts, the specific surface area is determined using the BET technique at 77K with liquid N2 in a NOVA Quantachrome 2200e Surface Area & Pore Size Analyzer physisorption equipment, obtaining the adsorption isotherms, with which the mesoporous nature of the sample. The influence of the calcination process on the specific surface area was analyzed. The catalyst with the highest specific surface area was TiO2 10% Ni, calcined for 2 hours in a heating ramp with a rate of 4.02°C / min and 1 hour of permanence at a constant temperature of 500°C.
Formulación de pastas cerámicas refractarias ricas en alúmina para materiales de laboratorio
(2002-11-11) Bustos Carrera, Hugo Enrique; Ordóñez Guillén, Julio César; Zalamea Piedra, Teresa Silvana
Influencia de la granulometría en el comportamiento de las fritas utilizadas en cerámica utilitaria y decorativa
(2002-11-11) Alvarado B., María Augusta; Robles A., María Eugenia; Zalamea Piedra, Teresa Silvana
Optimización de la reacción de hidrólisis ácida de los residuos de la planta de banano, para mayor rendimiento a glucosa
(2016) Abril González, Mónica Fernanda; Zalamea Piedra, Teresa Silvana
The depletion of the not renewable raw materials, as well as the increasing environmental conscience, has generated the need in the countries to increase his energetic counterfoil, stimulating the investigation towards the production of biocommbustibles of the second generation, that they allow the utilization of the lignocellulosic residual material, being this the intention of the Project Production of Hydrogen from the Biomass Proceeding from the Residues of the Plant of Banana by means of Catalytic Gasification in Supercritical Water, inside which the present work places. The reaction of hydrolysis that will drive us to reach the raised aim was effected by each of the parts of the plant, using dilutions of sulphuric acid in concentrations of 3, 6 and 10 % v/v, with times of reaction of 15, 30 and 60 min, temperatures of 60 and 93°C. The results obtained of this reaction, they were analyzed by means of the reading of the degrees Brix as measure of reference of the soluble sugars in the liquid. Analysis Dissolved Organic Carbon (DOC) to determine the quantity of carbon dissolvedand by means of High-performance Liquid Chromatography (HPLC) to identify and to quantify the present sugar. The best quantity of glucose was in the pseudo stem, when the sulfuric acid hydrolysis process was used diluted varying its concentration, temperature and reaction time.
Proceso de fabricación de té de cáscaras de cítricos
(2007) Arias Astudillo, Marcos; Zalamea Piedra, Teresa Silvana
Tratamientos térmicos en cerámica
(2001-11-11) Bacuilima Guamán, Víctor Orlando; Peralta Maldonado, Santiago Raúl; Zalamea Piedra, Teresa Silvana