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Hydrogen is a promising energy carrier for transportation, domestic and industrial applications. Nowadays hydrogen is consumed basically by the chemical industry, but in long term its demand is expected to grow significantly due to... more
Hydrogen is a promising energy carrier for transportation, domestic and industrial applications. Nowadays hydrogen is consumed basically by the chemical industry, but in long term its demand is expected to grow significantly due to emerging markets. Hence production of hydrogen with sustainable methods is a relevant issue. This work presents a review of the different CSP- aided thermochemical processes for hydrogen and syngas production. For each process, some relevant solar-tested reactor prototypes are described. In a second part, the developed solar furnaces for investigation of thermochemical process are also discussed. In addition, relevant research on hydrogen or syngas production in solar tower installations is presented. Finally the current challenges of the technology and the process for its future commercialization are also analyzed.
Research Interests: Engineering and Pergamon
ABSTRACT An analysis of the solar radiation database from the network of meteorological stations of the Mexican National Weather Service was carried out. The database includes global irradiance measurements from the oldest 136 stations... more
ABSTRACT An analysis of the solar radiation database from the network of meteorological stations of the Mexican National Weather Service was carried out. The database includes global irradiance measurements from the oldest 136 stations distributed in the Mexican territory. The consistency of data acquisition from the launch of the stations until 2010 was checked, and visual inspection of graphs of daily irradiance data was carried out, for the first three years operation, to ensure quality and reliability of the data. The results indicate that less than half of the stations have an adequate regularity for data records. With a limited number of selected stations that passed the applied quality criteria, evaluation of hourly and daily global irradiations was carried out. These results were compared to satellite derived data for Mexico, based on NREL's CSR model. The results of the comparison show a good agreement between measured and modeled daily global solar irradiation with an average RMSE of 6.6%. Based on the selected stations, a daily irradiation mean of 5.5 kWh/m²/day is estimated for the country.
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... 14341442. [4] CA Estrada, OA Jaramillo, R. Acosta, CA Arancibia-Bulnes, 2007. ... [5] Jaramillo OA, Pérez-Rábago CA, Arancibia-Bulnes CA, Estrada CA 2008, A Flat-Plate Calorimeter for Concentrated Solar Flux Evaluation, Renevable... more
... 14341442. [4] CA Estrada, OA Jaramillo, R. Acosta, CA Arancibia-Bulnes, 2007. ... [5] Jaramillo OA, Pérez-Rábago CA, Arancibia-Bulnes CA, Estrada CA 2008, A Flat-Plate Calorimeter for Concentrated Solar Flux Evaluation, Renevable Energy, vol. 33, pp. 2322-2328. ...
Both wet and dry deposition fluxes of sulfur, nitrogen, and phosphorus were estimated at three monitoring stations in Connecticut, one inland near the Connecticut-Massachusetts border and two along the Connecticut coastline of Long Island... more
Both wet and dry deposition fluxes of sulfur, nitrogen, and phosphorus were estimated at three monitoring stations in Connecticut, one inland near the Connecticut-Massachusetts border and two along the Connecticut coastline of Long Island Sound. Three years of data, from 1991 through 1993, were analyzed and are reported in this paper.The total annual deposition ranged from 1.27 to 1.58 gm−2
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Spatial and temporal variations of atmospheric aerosol optical thick-ness in northwestern Mexico
The Gompertz equation describes the evolution of an epidemic. Applied to the data from France, Spain, Germany, and the United Kingdom, it is adjusted with slight deviations since each country implemented different restriction or... more
The Gompertz equation describes the evolution of an epidemic. Applied to the data from France, Spain, Germany, and the United Kingdom, it is adjusted with slight deviations since each country implemented different restriction or distancing measures to prevent the spread. Some countries do not conform to Gompertz. With the data from Mexico, the graphs show that the measured and calculated data are overlapped. The deviations are not noticeable. We made adjustments with data up to recent dates. For the four countries, Gompertz predicts well the evolution of the epidemic. We tried to predict the growth of the epidemic using Gompertz. For Mexico, the maximum number of daily infections was predicted up to a month before it happened. RESUMEN La ecuación de Gompertz describe la evolución de una epidemia. Aplicada a los datos de Francia, España, Alemania y el Reino Unido, se ajusta con ligeras desviaciones, ya que cada país aplicó diferentes medidas de restricción o distanciamiento para evit...
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In the present work, the analysis of the first images obtained from de Solar Furnace of High Radiative Flux in Mexico is presented. The solar furnace has five different focal distance groups. The images were acquired using the first two... more
In the present work, the analysis of the first images obtained from de Solar Furnace of High Radiative Flux in Mexico is presented. The solar furnace has five different focal distance groups. The images were acquired using the first two groups of mirrors from complete optics of main concentrator. We used a Heliostat with a reflective surface of 36 m2. The Images was captured with a CCD camera and the irradiance profile was modeled with a ray-tracing program in order to estimate the global optical error for the concentrator-heliostat optical system. The results shows that the optical error is less to 3 mrad and the calculations indicates that the flux peak for the complete groups of mirrors could be higher than 12 000 suns and the average flux could be higher than 5,000 suns.
The design and location of solar energy technologies are based chiefly on the availability of solar resource. Specialized measurement equipment and solar resource assessment techniques are mandatory in order to identify appropriate... more
The design and location of solar energy technologies are based chiefly on the availability of solar resource. Specialized measurement equipment and solar resource assessment techniques are mandatory in order to identify appropriate locations for deploying solar systems while minimizing risk and increasing the return rate of the site. These needs have given the scientific community a motivation to design highly reliable and cost-competitive sensors. This work presents a novel methodology to estimate solar irradiance components using a low-cost sky-imager system. Captured images are processed to correct the spherical aberration of the dome and to achieve a pixel-radiance model, allowing each pixel of the image to be considered as an individual source of irradiation. The performance of the proposed model is analyzed and compared in four different weather scenarios against a secondary standard solarimetric station, obtaining a normalized mean bias error for direct normal irradiance, glo...
More than 7 thousand wildfires were recorded over Mexico in 2019, affecting almost 640 thousand hectares. Most of these fires occurred during the spring season generating dense smoke plumes, impacting urban areas in the central part of... more
More than 7 thousand wildfires were recorded over Mexico in 2019, affecting almost 640 thousand hectares. Most of these fires occurred during the spring season generating dense smoke plumes, impacting urban areas in the central part of the Mexican plateau. From May 10 to 17, 2019, biomass burning (BB) plumes affected Mexico City (MC) and diffused across the basin, producing PM2.5 levels ~ 2 times higher than the nation's air quality standards. Average PM2.5 concentrations increased sharply from 29.4 ± 7.2 µg m−3 to 65.1 ± 13.6 µg m−3 when the dense smoke plumes were detected. The higher particle concentration impacted the aerosol optical depth (AOD) as values ~ 3 times greater than the annual mean (0.32 ± 0.12) were measured, which resulted in a 17% loss of global horizontal irradiation (GHI). Under these severe pollution conditions, the visibility (Va) was reduced by ~ 80%. The high incidence of strong absorbent particles, such as soot and tarballs was revealed through electron...
The radiation flux distributions produced by the concentrating solar systems used to produce thermal/electrical power are usually non-homogeneous. This results in non-uniform temperature distributions on the solar receivers, causing... more
The radiation flux distributions produced by the concentrating solar systems used to produce thermal/electrical power are usually non-homogeneous. This results in non-uniform temperature distributions on the solar receivers, causing adverse effects on the system’s overall performance. An approach to better understand the problem is to study the surfaces around the focal zone where the radiation density is homogeneous (isosurfaces), generating them from experimental data. For this, it is necessary to superimpose built volumes of the different irradiance levels using parallel planes in different directions from the focal point of a concentrator. These volumes are known as effective volumes. This study presents the model used to generate effective volume produced by a point focus concentrator, comparing it with experimental results in a direction perpendicular to the focal axis. The effective volumes were developed considering a global optical error of the system of 2.8 mrad. The set o...
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In the present work, the optical design of a new high radiative flux solar furnace is described. Several optical configurations for the concentrator of the system have been considered. Ray tracing simulations were carried out in order to... more
In the present work, the optical design of a new high radiative flux solar furnace is described. Several optical configurations for the concentrator of the system have been considered. Ray tracing simulations were carried out in order to determine the concentrated radiative flux ...
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A directly irradiated cavity solar reactor devoted to the thermal reduction of SnO2 particle-cloud is studied numerically by using the Monte Carlo method. The steady-state model solves the radiation and convection heat transfers in the... more
A directly irradiated cavity solar reactor devoted to the thermal reduction of SnO2 particle-cloud is studied numerically by using the Monte Carlo method. The steady-state model solves the radiation and convection heat transfers in the semitransparent particle suspension and the chemical reaction. It was used to predict the temperature distribution and the reaction extent inside the cavity, as well as the theoretical thermochemical efficiency for different operational conditions. The simulations assume that the reactor contains a nonuniform size suspension of radiatively participating reacting SnO2 particles. The model takes into account the radiative characteristics of the particles, as well as the directional characteristics of the power distribution of the incoming concentrated solar energy. The particle concentration, the particle size, and the length of the reactor are varied. Results show that the particle temperature and the yield of the endothermic reaction are higher when the reactor is fed with a cloud of particles with average diameter of 20 μm. The maximal thermochemical efficiency reached is 10%, which corresponds to an optimal optical thickness of around 2.
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The design and optimization of novel type of receiver for a paraboloidal concentrator with 90 rim angle is carried out by means of detailed ray tracing simulations. Cylindrical, conical, and spherical geometries are compared and their... more
The design and optimization of novel type of receiver for a paraboloidal concentrator with 90 rim angle is carried out by means of detailed ray tracing simulations. Cylindrical, conical, and spherical geometries are compared and their dimensions ...
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The atmospheric conditions existing where concentrated solar power plants (CSP) are installed need to be carefully studied. A very important reason for this is because the presence of clouds causes drops in electricity generated from... more
The atmospheric conditions existing where concentrated solar power plants (CSP) are installed need to be carefully studied. A very important reason for this is because the presence of clouds causes drops in electricity generated from solar energy. Therefore, forecasting the cloud displacement trajectory in real time is one of the functions and tools that CSP operators must develop for plant optimization, and to anticipate drops in solar irradiance. For short forecast of cloud movement (10 min) is enough with describe the cloud advection while for longer forecast (over 15 min), it is necessary to predict both advection and cloud changes. In this paper, we present a model that predict only the cloud advection displacement trajectory for different sky conditions and cloud types at the pixel level, using images obtained from a sky camera, as well as mathematical methods and the Lucas-Kanade method to measure optical flow. In the short term, up to 10 min the future position of the cloud ...
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The measurement of solar B band Ultraviolet radiation (UVB) should be considered a priority in Mexico due to implications on public health throughout the country (total population, 108 million), but this is not carried out at present.... more
The measurement of solar B band Ultraviolet radiation (UVB) should be considered a priority in Mexico due to implications on public health throughout the country (total population, 108 million), but this is not carried out at present. Installed sensors cover only 0.12% of the country. However, there are alternative methods for estimating UVB radiation to overcome the lack of surface data. The most successful of these are based on the use of satellites for environmental monitoring. In the present work, UVB maps are constructed for the entire country using a single, daily satellite measurement of UVB at solar noon from 1978‒2003. Satellite-derived values are compared with the ground measurements by a surface station located in Mexico City in order to validate the former. Wavelet spectrum analysis is employed to this end. A close correlation is observed between the two sets of data. Moreover, there is qualitative correspondence between the spatial distribution of the satellite-derived ...