Kinetics of lycopene degradation in sunflower and grape seed oils

The stability of lycopene in two vegetable oils, sunflower seed oil (SSO) and grape seed oil (GSO), was investigated by analyzing the carotenoid degradation kinetics in the temperature range of 10–40°C. A tomato oleoresin containing 6% (w/w) of lycopene was used to prepare lycopene-enriched oil samples. Analysis of kinetic data showed that lycopene degradation follows first-order kinetics, with an apparent activation energy of 70.7 kJ mol–1 in SSO and 69 kJ mol–1 in GSO. The estimated half-life of lycopene was found to depend on oil type and storage temperature. At 20°C, it varied between 59 and 122 days, while at 4°C it was comprised between 302 and 650 days. At all temperatures, lycopene was more stable in SSO than in GSO, which is likely due to the higher content of antioxidant compounds in SSO

FLEXIBLE LABORATORY SYSTEM FOR INVESTIGATION OF CATALYTIC PROCESSES

A new method for determining of reaction mechanism and kinetics, catalyst pellet model and adsorption kinetics was developed on the basis of a computer analysis of parametric sensitivity of models for various types of experimental equipments. For solving these problems the following elements of investigation are to variate: 1. the combination and number of laboratory reactors, 2. the character of the input signals supplied into each reactor, 3. the methods of parameter estimation and algorithm of numerical integration of the model equations. Using this method it is possible to decrease the parameter errors connected with the selection of the 'best' model

Econometric Modeling for Evaluation of Relation Between Access to Electricity and Quality of Life in Colombia

This paper analyzes the effect of energization on income, education, health and agricultural productivity in the dispersed rural areas of Colombia. For this, the results of the 3rd National Agriculture Census 2014 conducted by the National Administrative Department of Statistics (DANE, for its acronym in Spanish) were used. The sample size of the cross section of the CNA is 1122 municipalities, which includes the Archipelago of San Andrés and Providencia and 20 non-municipalized areas

VOLUME VARIATIONS OF ARTERIAL AND VENOUS VESSELS OF CORTICAL AND MEDULLARY KIDNEY SUBSTANCES IN THE PROCESS OF AGEING

Research objective is the study of volume variations of arterial and venous vessels of cortical and medullary kidney substances of male and female sexes. Morphological changes in kidneys in the process of ageing have been revealed and have been characterized as a progressive nephrosclerosis

Efecto de la composición del gas de refinería sobre las características del proceso de combustión

En este artículo de investigación científica se analiza el efecto del cambio de la composición del gas combustible (Gas de Refinería (GR) por Gas Natural (GN)) sobre las características del proceso combustión en hornos de la industria de refinación del petróleo; se evaluó el poder calorífico, el índice de Wobbe (IW) y exceso de oxígeno, para mezclas combustibles de composición variable. Mediante simulación computacional del proceso de combustión se calculó la temperatura adiabática de lama, eficiencia y la composición de los productos de combustión. Se evaluaron mezclas de gases combustibles con poderes caloríficos entre 800-2500 Btu/pie3 y se compararon con la combustión de gas natural. Se registró variabilidad en la temperatura adiabática y la eficiencia en función de la composición del gas y el exceso de oxígeno, lo que genera inestabilidad en el horno y mayor impacto ambiental

Two-Dimensional Cfd Simulation Approach of Combustion in a Furnace Using Refinery-Off Gases With Different Composition

This work analyses the effect of the variability of the chemical composition and calorific power of refinery gases in the combustion process of furnaces using Computational Fluid Dynamics (CFD), which is a technique that has been proven useful to obtain detailed information about the operation of furnaces

Simultaneous sulfidation/oxidation of a ferritic steel under a simulated mixture of flue gas from an oil refinery

Ferritic steels are exposed to simultaneous oxidizing/sulfiding environments during their service in industrial furnaces, which intensify their degradation and reduce their expected lifetime. This research supplies different corrosion details from those highly reported for the studied alloy under single oxidation or sulfidation atmospheres, as well as from those works developed on oxyfuel gas mixtures. The experimental data obtained by us were compared with an oxidation paper previously published by the same authors but without the additional effect of sulfur oxides. The simulated conditions used included temperatures from 450 to 750 °C, exposure times up to 200 h, and a flue gas molar composition without the carbon dioxide influence. As a result, the oxidation mechanism was markedly affected by bulk and surface sulfur compounds, due to their strong adsorption, pathways blocking, and induced layer spallation. This study aimed to identify sulfur compounds onto the oxide layers by means of X-ray photoelectron spectroscopy, which were later validated through a ferritic-steel sample extracted from a refinery furnace. Finally, the present work contributes to the field of physics-physical chemistry-by providing the thermodynamic equilibrium of sulfur oxides at tested conditions and the kinetic behavior of the scale

Desenvolvimento preliminar de uma metodologia para o abastecimento de CO2 a culturas de Botryococcus braunii para a produção de biocombustíveis

Several studies about the cultivation of microalgae in laboratory and pilot scale have recorded the potential of these microorganisms for the production of raw material in the fabrication of biofuels. The provision of a carbon source for the mass cultivation of microalgae is one of the main constraints in the production process; these photosynthetically fixed inorganic carbon (CO2) and synthesized metabolites for biofuel production. In the present study the influence of various parameters of CO2 supply over Botryococcus braunii crops in laboratory scale photobioreactors was evaluated. Central composite experimental designs were proposed to correlate the parameters and determine their effect on the dilution of CO2 and production of metabolites (biomass, lipids and hydrocarbons). Regarding design parameters of the photobioreactor, heights > 36cm, diameter < 7cm and small bubble sizes help increase CO2 dilution up to 180%. It was found that high concentrations of CO2 (> 0.06v/vm) continuously supplied are ideal for cell growth. Moreover, medium concentrations of CO2 (0.04 – 0.06v/vm) are ideal for the production of lipids and low concentrations of CO2 (< 0.02v/vm) is ideal for the production of hydrocarbons. The potential of the Colombian B. braunii strain for biodiesel production was validated thanks to its high lipid synthesis.Diversos estudios sobre el cultivo de microalgas a escala laboratorio y piloto han registrado el potencial de estos microorganismos para la producción de materia prima en la elaboración de biocombustibles. El suministro de una fuente de carbono para el cultivo masivo de microalgas representa una de las principales limitantes en el proceso productivo; estas fijan fotosintéticamente carbono inorgánico (CO2) y sintetizan metabolitos para la producción de biocombustibles. En el presente estudio se evaluó la influencia de diversos parámetros de suministro de CO2 sobre cultivos de la especie Botryococcus braunii en fotobiorreactores a escala laboratorio. Se plantearon diseños experimentales centrales compuestos para correlacionar los parámetros a evaluar y determinar su efecto en la dilución de CO2 y producción de metabolitos (biomasa, lípidos e hidrocarburos). Respecto a los parámetros de diseño del fotobiorreactor, alturas > 36cm, diámetros < 7cm y pequeños tamaños de burbuja ayudan a incrementar la dilución del CO2 hasta en 180%. Se encontró que altas concentraciones de CO2 (> 0,06v/vm) suministrado de manera continua son ideales para el crecimiento celular. Por otra parte, concentraciones medias (0,04 – 0,06v/vm) de CO2 son ideales para la producción de lípidos y concentraciones bajas de CO2 (≤ 0,02v/vm) favorecen la producción de hidrocarburos. Se validó el potencial de la cepa de B. braunii colombiana para la producción de biodiésel gracias a sus altas tasas de síntesis de lípidos.Estudos sobre o cultivo de microalgas em escala laboratorial e piloto tem sido o potencial para o cultivo desses microorganismos para a produção de matéria-prima na produção de biocombustíveis. Fornecer uma fonte de carbono para o cultivo em massa de microalgas representa um dos principais constrangimentos no processo de produção; estas fotossinteticamente fixar carbono inorgânico (CO2 ) e sintetizam metabólitos para a produção de biocombustíveis. O presente estudo avaliou a influência de diferentes parâmetros de fornecimento de CO2 nas culturas da espécie Botryococcus braunii em fotobiorreatores à escala laboratorial. Composto Central projetos experimentais foram propostos para correlacionar os parâmetros para avaliar e determinar o seu efeito sobre a diluição de CO2 e produção de metabólitos (biomassa, lipídios e hidrocarbonetos). Em relação aos parâmetros de projeto da fotobiorreator, alturas > 36cm, diâmetro < 7cm e tamanhos pequenos da bolha ajudam a aumentar a diluição de CO2 até 180%. Verificou que altas concentrações de CO2 (> 0,06v/vm) fornecido continuamente são ideais para o crescimento de células. Por outro lado, média de concentrações (0,04 - 0,06v/vm) de CO2 são ideais para a produção de lipídios e baixas concentrações de CO2 (≤ 0,02v/vm) favorecem a produção de hidrocarbonetos. Validada a tensão potencial de B. braunii colombiano para a produção de biodiesel, devido a suas altas taxas de síntese de lipídios

Desenvolvimento preliminar de uma metodologia para o abastecimento de CO2 a culturas de Botryococcus braunii para a produção de biocombustíveis

Several studies about the cultivation of microalgae in laboratory and pilot scale have recorded the potential of these microorganisms for the production of raw material in the fabrication of biofuels. The provision of a carbon source for the mass cultivation of microalgae is one of the main constraints in the production process; these photosynthetically fixed inorganic carbon (CO2) and synthesized metabolites for biofuel production. In the present study the influence of various parameters of CO2 supply over Botryococcus braunii crops in laboratory scale photobioreactors was evaluated. Central composite experimental designs were proposed to correlate the parameters and determine their effect on the dilution of CO2 and production of metabolites (biomass, lipids and hydrocarbons). Regarding design parameters of the photobioreactor, heights > 36cm, diameter < 7cm and small bubble sizes help increase CO2 dilution up to 180%. It was found that high concentrations of CO2 (> 0.06v/vm) continuously supplied are ideal for cell growth. Moreover, medium concentrations of CO2 (0.04 – 0.06v/vm) are ideal for the production of lipids and low concentrations of CO2 (< 0.02v/vm) is ideal for the production of hydrocarbons. The potential of the Colombian B. braunii strain for biodiesel production was validated thanks to its high lipid synthesis.Diversos estudios sobre el cultivo de microalgas a escala laboratorio y piloto han registrado el potencial de estos microorganismos para la producción de materia prima en la elaboración de biocombustibles. El suministro de una fuente de carbono para el cultivo masivo de microalgas representa una de las principales limitantes en el proceso productivo; estas fijan fotosintéticamente carbono inorgánico (CO2) y sintetizan metabolitos para la producción de biocombustibles. En el presente estudio se evaluó la influencia de diversos parámetros de suministro de CO2 sobre cultivos de la especie Botryococcus braunii en fotobiorreactores a escala laboratorio. Se plantearon diseños experimentales centrales compuestos para correlacionar los parámetros a evaluar y determinar su efecto en la dilución de CO2 y producción de metabolitos (biomasa, lípidos e hidrocarburos). Respecto a los parámetros de diseño del fotobiorreactor, alturas > 36cm, diámetros < 7cm y pequeños tamaños de burbuja ayudan a incrementar la dilución del CO2 hasta en 180%. Se encontró que altas concentraciones de CO2 (> 0,06v/vm) suministrado de manera continua son ideales para el crecimiento celular. Por otra parte, concentraciones medias (0,04 – 0,06v/vm) de CO2 son ideales para la producción de lípidos y concentraciones bajas de CO2 (≤ 0,02v/vm) favorecen la producción de hidrocarburos. Se validó el potencial de la cepa de B. braunii colombiana para la producción de biodiésel gracias a sus altas tasas de síntesis de lípidos.Estudos sobre o cultivo de microalgas em escala laboratorial e piloto tem sido o potencial para o cultivo desses microorganismos para a produção de matéria-prima na produção de biocombustíveis. Fornecer uma fonte de carbono para o cultivo em massa de microalgas representa um dos principais constrangimentos no processo de produção; estas fotossinteticamente fixar carbono inorgânico (CO2 ) e sintetizam metabólitos para a produção de biocombustíveis. O presente estudo avaliou a influência de diferentes parâmetros de fornecimento de CO2 nas culturas da espécie Botryococcus braunii em fotobiorreatores à escala laboratorial. Composto Central projetos experimentais foram propostos para correlacionar os parâmetros para avaliar e determinar o seu efeito sobre a diluição de CO2 e produção de metabólitos (biomassa, lipídios e hidrocarbonetos). Em relação aos parâmetros de projeto da fotobiorreator, alturas > 36cm, diâmetro < 7cm e tamanhos pequenos da bolha ajudam a aumentar a diluição de CO2 até 180%. Verificou que altas concentrações de CO2 (> 0,06v/vm) fornecido continuamente são ideais para o crescimento de células. Por outro lado, média de concentrações (0,04 - 0,06v/vm) de CO2 são ideais para a produção de lipídios e baixas concentrações de CO2 (≤ 0,02v/vm) favorecem a produção de hidrocarbonetos. Validada a tensão potencial de B. braunii colombiano para a produção de biodiesel, devido a suas altas taxas de síntese de lipídios

Development of a methodology of transesterification of oil in the production line of Biodiesel from Microalgae

Existe actualmente a nivel mundial una fuerte tendencia hacia el desarrollo de un tipo de biocombustibles denominados de tercera generación, los cuales se obtienen mediante métodos de producción similares a los empleados en el desarrollo de biocombustibles de primera y segunda generación, pero aplicados a cultivos bioenergéticos específicamente diseñados o adaptados para mejorar la conversión de biomasa a biocombustible. Dentro de éstos, se destaca el cultivo de diferentes especies de microalgas, cuyo aceite puede ser utilizado como materia prima en la producción de biodiesel. Este artículo presenta una metodología de transesterificación de una mezcla de aceites vegetales cuya composición de ácidos grasos se aproxima a la del aceite de Chlorella Vulgaris, propuesta por los autores en el marco de proyectos apoyados por el Ministerio de Agricultura y Desarrollo Rural, conjuntamente con la Corporación Instituto de Morrosquillo, el Instituto Colombiano del Petróleo ICP-ECOPETROL, la Universidad Industrial de Santander UIS y el Programa Iberoamericano de Ciencia y Tecnología para el Desarrollo CYTED.Abstract. Exists now a strong worldwide trend towards the development of a type of so-called third generation biofuels, which are obtained by similar production methods to those used in the development of first and second generation biofuels, but applied to bioenergy crops specifically designed or adapted to enhance the conversion of biomass to biofuel. Among these, stands out the growing of different species of microalgae, whose oil can be used as feedstock in biodiesel production. This article presents a methodology for the transesterification of a mixture of vegetable oils whose fatty acid composition is close to the Chlorella Vulgaris oil, proposed by the authors in the framework of projects supported by the Ministry of Agriculture and Rural Development, in conjunction with the Institute of Morrosquillo Corporation, the Colombian Institute of Petroleum ICP-ECOPETROL, the Industrial University of Santander and the Iberoamerican Program of Science and Technology for Development CYTED