The Use of Atmospheric Reanalysis Data for the Estimation of Solar Irradiation Considering the Effect of Atmospheric Aerosols over Brazil Bruno Ribeiro Herdies, Eder Paulo Vendrasco, Dirceu Luís Herdies, Celso Eduardo Lins de Oliveira, Mario Francisco Leal de Quadro Atmosphere, 2025 In recent years, several studies have evaluated the potential of renewable energy sources in response to climate change and high energy demand. Due to its equatorial location and significant solar and wind potential, Brazil has incorporated alternative sources into its energy matrix, driven by more efficient and economical technologies for solar energy. However, the availability of observed data is still limited, and many studies rely on satellite estimates or extrapolations of in situ observations from other regions, compromising the efficiency of new technologies. This study uses NASA MERRA-2 reanalysis data to evaluate the influence of aerosols and cloudiness on the estimate of solar irradiance in Brazil. INMET stations were chosen in regions representative of the Brazilian climate and geography, with more than 12 years of observational data. MERRA-2 includes aerosol fields that interact with the model’s radiation fields, with a spatial resolution of 0.5° and hourly temporal resolution. Variables used include shortwave radiation fluxes and aerosol optical depth. Statistical indices used in performance analysis include mean bias, mean squared error, and Pearson correlation coefficient. The stations’ diurnal solar irradiance cycles were compared with MERRA-2 reanalysis data, considering different scenarios of aerosol and cloudiness effects. The reanalysis data represented the Bauru and Santa Maria stations well, while others, such as Barreiras and Goiânia, showed underestimation. Monthly cycling was also analyzed, highlighting seasonality, with greater amplitude in Santa Maria and lower in Caicó. In some locations, such as Campo Grande, the influence of aerosols is more significant, especially during the dry months, when forest fires, mainly in the Amazon region, increase the aerosol optical depth. The results show that reanalysis estimates can be used to evaluate the temporal variability of solar irradiation in regions without observational data. In conclusion, the study was able to evaluate the temporal variability of solar irradiation in Brazil using MERRA-2 atmospheric reanalysis data, demonstrating that, although there are differences with observational data, reanalysis estimates are useful in areas without observed data, with values correlation values above 0.8 and reaching values close to 0.95. However, although small, the differences observed between measured and estimated solar irradiation are generally caused by the inability of models to adequately represent the fraction of clouds and aerosols in the atmosphere.
Biomass gasification under external heating and using steam as a gasifying agent: Numerical analysis Yuhan Arley Lenis-Rodas, Gilles Maag, Celso Eduardo Lins de Oliveira, Lesme Antonio Corredor, Marco Enrique Sanjuan Revista Facultad De Ingenieria, 2020 Gasification using an external heat source is considered as a high potential alternative to take high moisture content biomass into a fuel gas. This gas could reach energy densities close to 12 MJ/Nm3, which allows its use as a fuel in conventional thermal machines or as a precursor for higher fuel gases. Given this, in the present work allothermal gasification for a 50 %w.t. moisture content biomass was analyzed computationally aiming to yield a high hydrogen content syngas.
 Using a power supply of 8 kW, the dry tar-free gas yield was around 51.9 mol/kg of biomass with an average concentration of 45.7% CO, 44.8% H2, 4.8% CH4 and 4.6% CO2. A peak temperature of 1070 K and 33% for chemical efficiency were achieved. In spite of using homogeneous heating along the reactor wall, the process temperature decreases near the gas outlet. This is due to solid material depletion decreasing the process thermal inertia. During the final stages, H2 and CO concentration also record an increase due to the endothermic carbon gasification as well as water-gas shift and methanation reactions.
Effect of heat flux distribution profile on hydrogen concentration in an allothermal downdraft biomass gasification process: Modeling study Yuhan A. Lenis, Gilles Maag, Celso Eduardo Lins de Oliveira, Lesme Corredor, Marco Sanjuan Journal of Energy Resources Technology Transactions of the ASME, 2019 Considering the potential of using concentrating solar power systems to supply the heat required for the allothermal gasification process, this study analyzes hydrogen production in such a system by assuming typical radiative heat flux profiles for a receiver of a central tower concentrated solar power (CSP) plant. A detailed model for allothermal gasification in a downdraft fixed bed tubular reactor is proposed. This considers solid and gas phases traveling in parallel flow along the reactor. Results for temperature and gas profile show a reasonable quantitative agreement with experimental works carried out under similar conditions. Aiming to maximize H2 yield, eight Gaussian flux distributions, similar to those typical of CSP systems, each with a total power of 8 kW (average heat flux 20 kW/m2), but with varying peak locations, were analyzed. The results show a maximum producer gas yield and a chemical efficiency of 134.1 kmol/h and 45.9% respectively, with a molar concentration of 47.2% CO, 46.9% H2, 3.3% CH4, and 2.6% CO2 for a distribution peak at z = 1.4 m, thus relatively close to the flue gas outlet. Hydrogen production and gas yield using this configuration were 4% and 2.9% higher than the achieved using the same power but homogeneously distributed. Solar to chemical efficiencies ranged from 38.9% to 45.9%, with a minimum when distribution peak was at the reactor center. These results are due to high temperatures during the latter stage of the process favoring char gasification reactions.
Detection of heat produced during roughage digestion in ruminants by using infrared thermography Márcia Saladini Vieira Salles, Suelen Correa Silva, Luiz Carlos Roma, Lenira El Faro, Carla Maris Machado Bittar, Celso Eduardo Lins Oliveira, Fernando André Salles Animal Production Science, 2018 The present study aimed to establish the relationship of infrared thermography (IRT) with fermentation dynamics in ruminants, and to initiate the development of a method that allows associating these images with the heat produced during feed digestion. The experiment was conducted at APTA, Brazil. Twenty-four Jersey heifers (mean liveweight of 221.25 ± 59.41 kg) were subjected to the following treatments: 30R (30% corn silage and 70% concentrate), 50R (50% corn silage and 50% concentrate) and 70R (70% corn silage and 30% concentrate) in a Latin square design. The diet (corn silage + concentrate) was offered at 3% of liveweight from 0800 hours to 1400 hours. Infrared images were collected from the whole body on the left and right sides, from the eyes, from the left foreleg on the cranial and caudal side, and from the forehead. IRT images were taken at 2-h intervals for 12 h (from 0600 hours to 1800 hours) and 24 h (0600 hours of the following day) after the beginning of feeding and so on. Physiological parameters were obtained at the same time as the IRT were taken. Ruminal parameters were collected after 4 h of feeding. The thermograms of the right (P < 0.001) and left flank (P < 0.001) differed among sampling times, with an increase in temperature until 1400 hours and a reduction thereafter. The temperatures on the right (P = 0.037) and left (P = 0.017) flank were higher in animals consuming the 50R diet and lower in those consuming the 70R diet. When the 50R diet was offered, the heifers exhibited higher dry-matter intake (P < 0.001), neutral detergent fibre (P < 0.001), non-fibrous carbohydrates (P < 0.001) and total digestible nutrients (P < 0.001). A decrease in the concentrations of butyric acid (P = 0.042), isobutyric acid (P = 0.001), isovaleric acid (P = 0.019) and ammonia nitrogen (P = 0.001) in the rumen fluid of heifers was observed with an increasing dietary roughage level. Infrared thermography was able to detect differences in the body temperature of animals associated with different fibre proportions in the diets. However, the magnitude of these differences was small and further research is needed to investigate the application of IRT to the detection of possible differences in the body temperature of ruminants as part of the digestive process.
Mapping the body surface temperature of cattle by infrared thermography Marcia Saladini Vieira Salles, Suelen Corrêa da Silva, Fernando André Salles, Luiz Carlos Roma, Lenira El Faro, Priscilla Ayleen Bustos Mac Lean, Celso Eduardo Lins de Oliveira, Luciane Silva Martello Journal of Thermal Biology, 2016
Heliostat tailored to Brazil P. Bezerra, Andreas Pfahl, Erwin Hölle, Phillip Liedke, Érico Tadao Teramoto, Johannes Hertel, Marcelo Lampkowski, Celso Eduardo Lins de Oliveira Ises Solar World Congress 2015 Conference Proceedings, 2015 For Brazil it is important to realize a high local production share because of high import tax rates. The rim drive concept offers an alternative for expensive heliostat drive solutions with slew and linear drives from abroad. By (locally produced) rims the demands on the drives regarding strength and precision are reduced to a very low value and low cost drives can be used. Sandwich facets (which are usually foreseen for rim drive heliostats) are not available from Brazilian manufacturers and are replaced by a frame work steel structure with 4mm glass mirrors. The mirrors are bended only about one axis to avoid too high stress of the mirrors when low focal lengths (e.g. 30m) have to be realized. For an 8.1m² heliostat the mirror panel was divided into six stripes of 2.5m x 0.54m. The stripes have to be canted to reach a sufficiently small focal spot. An accordant heliostat was designed and built. High stiffness was reached and sufficient durability of the mirror facets against wind loads. For 8m² heliostats the framework design should be simplified but for 16m² heliostats (or bigger) it seems to be appropriate.
Human thermal comfort: An irreversibility-based approach emulating empirical clothed-body correlations and the conceptual energy balance equation José A. Rabi, Robson L. Silva, Celso E. L. Oliveira Journal of the Brazilian Society of Mechanical Sciences and Engineering, 2012 Exergetic analysis can provide useful information as it enables the identification of irreversible phenomena bringing about entropy generation and, therefore, exergy losses (also referred to as irreversibilities). As far as human thermal comfort is concerned, irreversibilities can be evaluated based on parameters related to both the occupant and his surroundings. As an attempt to suggest more insights for the exergetic analysis of thermal comfort, this paper calculates irreversibility rates for a sitting person wearing fairly light clothes and subjected to combinations of ambient air and mean radiant temperatures. The thermodynamic model framework relies on the so-called conceptual energy balance equation together with empirical correlations for invoked thermoregulatory heat transfer rates adapted for a clothed body. Results suggested that a minimum irreversibility rate may exist for particular combinations of the aforesaid surrounding temperatures. By separately considering the contribution of each thermoregulatory mechanism, the total irreversibility rate rendered itself more responsive to either convective or radiative clothing-influenced heat transfers, with exergy losses becoming lower if the body is able to transfer more heat (to the ambient) via convection.
Potential assessment of prospective application of clean development mechanisms concerning brazilian food and beverage industries 6th International Cigr Technical Symposium Towards A Sustainable Food Chain Food Process Bioprocessing and Food Quality Management, 2011
Energetic evaluation of cogeneration systems in sugar cane plants in Brazil - Case studies ECOS 2009 22nd International Conference on Efficiency Cost Optimization Simulation and Environmental Impact of Energy Systems, 2009
