Sustainable development aspects of biodiesel production and application in Brazil

Concerns about climate change effects have prompted many countries to search for solutions to reduce fossil fuel consumption. In the last few years biodiesel production has gained world attention, as it is seen as a sustainable and renewable energy source. Biodiesel is a natural substitute for diesel oil, and can be obtained from different oleaginous plants. However, there are worries about devastation of forests and biodiversity-rich areas to produce biodiesel. Even considering biodiesel as a promising solution, the impacts of its production must be carefully evaluated. This work examines the Brazilian scenario for biodiesel production and use as an automotive fuel. Native and adapted oleaginous in many Brazilian regions and their potentiality for biodiesel production are presented. Experimental results of hydrocarbons (HC), carbon monoxide (CO), and carbon dioxide (CO2) emissions from a diesel power generator fuelled by blends of diesel oil and castor oil or soybean biodiesel are also presented

A Mathematical Model for the Exhaust Gas Temperature Profile of a Diesel Engine

This work presents a heat transfer model for the exhaust gas of a diesel power generator to determine the gas temperature profile in the exhaust pipe. The numerical methodology to solve the mathematical model was developed using a finite difference method approach for energy equation resolution and determination of temperature profiles considering turbulent fluid flow and variable fluid properties. The simulation was carried out for engine operation under loads from 0 kW to 40 kW. The model was compared with results obtained using the multidimensional Ansys CFX software, which was applied to solve the governor equations of turbulent fluid flow. The results for the temperature profiles in the exhaust pipe show a good proximity between the mathematical model developed and the multidimensional software

Further developments on biodiesel production and applications in brazil

Environmental concerns have motivated many countries to search for solutions to reduce fossil fuel consumption. In the last few years, biodiesel has attracted attention as a possible sustainable and renewable energy source to substitute diesel oil. Biodiesel can be produced from different oleaginous plants, but there are worries about food competition and forests and biodiversity-rich areas devastation to produce biodiesel. Even considering biodiesel as a promising solution, its production impacts must be carefully evaluated. This work examines the Brazilian prospects for biodiesel production and use as an engine fuel for automotive propulsion and power generation. The potential for biodiesel production of many native and adapted oleaginous plants in Brazilian territory is discussed. Experimental results of hydrocarbons, carbon monoxide, and carbon dioxide emis-sions from a diesel power generator fuelled by blends of diesel oil and castor oil or soybean biodiesel are also presented

Numerical analysis of heat transfer in the exhaust gas flow in a diesel power generator

This work presents a numerical study of heat transfer in the exhaust duct of a diesel power generator. The analysis was performed using two different approaches: the Finite Difference Method (FDM) and the Finite Volume Method (FVM), this last one by means of a commercial computer software, ANSYS CFX®. In FDM, the energy conservation equation was solved taking into account the estimated velocity profile for fully developed turbulent flow inside a tube and literature correlations for heat transfer. In FVM, the mass conservation, momentum, energy and transport equations were solved for turbulent quantities by the K-ω SST model. In both methods, variable properties were considered for the exhaust gas composed by six species: CO2, H2O, H2, O2, CO and N2. The entry conditions for the numerical simulations were given by experimental data available. The results were evaluated for the engine operating under loads of 0, 10, 20, and 37.5 kW. Test mesh and convergence were performed to determine the numerical error and uncertainty of the simulations. The results showed a trend of increasing temperature gradient with load increase. The general behaviour of the velocity and temperature profiles obtained by the numerical models were similar, with some divergence arising due to the assumptions made for the resolution of the models

ALDEHYDE EMISSIONS FROM A STATIONARY DIESEL ENGINE OPERATING WITH CASTOR OIL BIODIESEL – DIESEL OIL BLENDS

The presence of aldehyde in the exhaust gas of a stationary, direct injection, compression ignition engine operating with castor oil biodiesel/diesel oil blends (B5, B10, B20 and B35) is analyzed. The diesel engine was operated with constant speed of 1800 rev/min and load of 37.5 kW. The gas sample was collected directly from the exhaust. Aldehydes were identified and quantified using gas chromatography (GC) with flame ionization detector analyzer (FID). Acetaldehyde presented higher exhaust concentration than formaldehyde for all fuel blends tested. In general, the exhaust aldehyde levels were very low and did not present significant differences between the fuel blends tested

Comparison of engine power correction factors for varying atmospheric conditions

This work evaluates proposed methods to correct engine power output as a function of atmospheric conditions. The analysis was made through experiments carried out in a vehicle on the road, under different temperature, pressure and air humidity conditions. The vehicle had a four-cylinder gasoline-fuelled engine, with multi-point fuel injection system, variable intake pipe length and variable intake valve camshaft position. The vehicle was tested at sea level and at 827 m above sea level, corresponding to atmospheric pressures between 1027 and 926 mbar. Air temperature varied from 22.8 to 33.8°C at the test locations. The measured performance parameter in the tests was the vehicle acceleration time. The acceleration times from 0 to 400 m, 0 to 1000 m, 40 to 100 km/h and 80 to 120 km/h were all recorded, leaving from an initial vehicle speed of 40 km/h. The engine power curve obtained in laboratory under a standard ambient condition was corrected to the conditions of the road tests by the correction factors proposed by the methods under evaluation, and the corresponding acceleration times were calculated and compared with the measurements from the road tests. The evaluated methods for power correction were the following: DIN 70020, SAE J 1349, JIS D 1001 and ISO 1585. The SAE J 1349 method provided the best approach between the experimental and calculated acceleration times

Structure and dynamics of the Shapley Supercluster

We present results of our wide-field redshift survey of galaxies in a 285 square degree region of the Shapley Supercluster (SSC), based on a set of 10529 velocity measurements (including 1201 new ones) on 8632 galaxies obtained from various telescopes and from the literature. Our data reveal that the main plane of the SSC (v~ 14500 km/s) extends further than previous estimates, filling the whole extent of our survey region of 12~degrees by 30~degrees on the sky (30 x 75~h-1 Mpc). There is also a connecting structure associated with the slightly nearer Abell~3571 cluster complex (v~ 12000km/s. These galaxies seem to link two previously identified sheets of galaxies and establish a connection with a third one at V= 15000 km/s near R.A.= 13h. They also tend to fill the gap of galaxies between the foreground Hydra-Centaurus region and the more distant SSC. In the velocity range of the Shapley Supercluster (9000 km/s < cz < 18000 km/s), we found redshift-space overdensities with b\_j < 17.5 of ~5.4 over the 225 square degree central region and ~3.8 in a 192 square degree region excluding rich clusters. Over the large region of our survey, we find that the intercluster galaxies make up 48 per cent of the observed galaxies in the SSC region and, accounting for the different completeness, may contribute nearly twice as much mass as the cluster galaxies. In this paper, we discuss the completeness of the velocity catalogue, the morphology of the supercluster, the global overdensity, and some properties of the individual galaxy clusters in the Supercluster.Comment: Accepted for publication in Astronomy and Astrophysic

EXPERIMENTAL ANALYSIS OF A HEAT PUMP ASSISTED RECUPERATIVE AIR DEHUMIDIFIER

This paper describes the experimental analysis of a heat pump assisted recuperative air dehumidifier. The system consisted of an air-to-air vapor compression heat pump, coupled to the air ducting. Dehumidification was generated by reduction of the air temperature through the evaporator below the dew point, and thus promoting the condensation of the water vapor. Moist air was then warmed up in the condenser, resulting in a lowtemperature low-humidity air stream. Low energy consumption values are achieved in such systems as the latent heat of the water vapor acts as the heat pump own heat source. Occasionally, the compressor heat is also recoverable. The innovative feature of the present analysis was the introduction of an air-to-air plate recuperator, to further promote dehumidification, yet at the expense of greater compressor energy consumption. An experimental apparatus was constructed to perform comparative tests of the dehumidifier operating with and without the recuperator. A closed air circuit was employed, with the air mass flow rate as the controlling parameter of the experiment. Tests were also carried out with an open circuit

Application of an EGR system in a direct injection diesel engine to reduce NOx emissions

This work presents the application of an exhaust gas recirculation (EGR) system in a direct injection diesel engine operating with diesel oil containing 7% biodiesel (B7). EGR rates of up to 10% were applied with the primary aim to reduce oxides of nitrogen (NOx) emissions. The experiments were conducted in a 44 kW diesel power generator to evaluate engine performance and emissions for different load settings. The use of EGR caused a peak pressure reduction during the combustion process and a decrease in thermal efficiency, mainly at high engine loads. A reduction of NOx emissions of up to 26% was achieved, though penalizing carbon monoxide (CO) and total hydrocarbons (THC) emissions

J-PLUS: analysis of the intracluster light in the Coma cluster

The intracluster light (ICL) is a luminous component of galaxy clusters composed of stars that are gravitationally bound to the cluster potential but do not belong to the individual galaxies. Previous studies of the ICL have shown that its formation and evolution are intimately linked to the evolutionary stage of the cluster. Thus, the analysis of the ICL in the Coma cluster will give insights into the main processes driving the dynamics in this highly complex system. Using a recently developed technique, we measure the ICL fraction in Coma at several wavelengths, using the J-PLUS unique filter system. The combination of narrow- and broadband filters provides valuable information on the dynamical state of the cluster, the ICL stellar types, and the morphology of the diffuse light. We use the Chebyshev-Fourier Intracluster Light Estimator (CICLE) to disentangle the ICL from the light of the galaxies, and to robustly measure the ICL fraction in seven J-PLUS filters. We obtain the ICL fraction distribution of the Coma cluster at different optical wavelengths, which varies from $\sim 7\%-21\%$, showing the highest values in the narrowband filters J0395, J0410, and J0430. This ICL fraction excess is distinctive pattern recently observed in dynamically active clusters (mergers), indicating a higher amount of bluer stars in the ICL compared to the cluster galaxies. Both the high ICL fractions and the excess in the bluer filters are indicative of a merging state. The presence of younger/lower-metallicity stars the ICL suggests that the main mechanism of ICL formation for the Coma cluster is the stripping of the stars in the outskirts of infalling galaxies and, possibly, the disruption of dwarf galaxies during past/ongoing mergers.Comment: 10 pages, 3 figures, 1 table. Accepted for publication in A&