Roberto Guimarães Pereira

Low temperature conversion (LTC)--an alternative method to treat sludge generated in an industrial wastewater treatment station--batch and continuous process comparison.

In this work low temperature conversion (LTC) process was applied in a dried sludge from a petrochemical industry wastewater treatment station located in Rio de Janeiro, Brazil. The process was performed in two modes: continuous and batch-scale. This process produced a pyrolysis oil (continuous 14%; batch-scale 40% yield); pyrolytic char (continuous 46%; batch-scale 56% yield); gas and water. Pyrolysis oil fraction was analyzed by gas chromatographic mass spectrometry (GCMS) and the main components identified were toluene, ethylbenzene, styrene, isopropyl benzene, alpha-methylstyrene, butanenitrile and 1,3- biphenyl propane. Metals content, sulfur content and calorific value have been determined for the pyrolysis oil fraction. The results showed that the pyrolysis oil obtained could be used for industrial purposes and/or as energetic matrix.

A study of the relationships among three variables

Purpose – The purpose of this paper is to investigate, for some countries, the nature of relationships among three variables: the character of governance, the potential for sustainable growth and the quality of energy management.Design/methodology/approach – This study was based on a sample of data drawn from a database available from the World Bank. This database provides CO2 emissions and other environmental measures for 54 countries for the period 2000 to 2008. The character of governance was measured by using an indicator of character of governance constructed by Transparency International. Data were analyzed by applying the method of linear regression with panel data after the method of structural equations had been applied in a test of robustness.Findings – The results of the analysis showed the existence of statistically significant relationships among character of governance, potential for sustainable growth and quality of energy management.Originality/value – The results of this investigation all...

The influence of the addition of oils in the diesel fuel density.

The world is looking for changes in its energetic matrix through the use of biofuels to reduce the dependence on oil derivatives. Currently, the number of studies concerning mixtures of triglycerides from animals or plants with diesel fuel has risen due to efforts to reduce the consumption of diesel oil. This paper studies the behavior of the density of plant oils mixed with diesel fuel in relation to temperature, which is essential to guarantee engine efficiency. The density is related to the mass and to the volume being a critical property to the assessment of the subministered energy to the engine by the injection system, which behaves like a pump of positive displacement. Samples of the diesel fuel mixture were made with plant triglycerides in proportion and range of ∼5–20%. The densities of the samples were measured in a density meter with temperature varying between 18 and 25°C, as well as at 15°C, according to ASTM standard. Afterwards, the uncertainties of measurement were calculated, and the density change with respect to temperature is presented and shown in density variation curves. An analysis of the density variation curves shows that.

Additional effects on internal flow of non-Newtonian fluids in the presence of a particle

Abstract The present work describes a numerical and experimental investigation concerning the relative motion between purely viscous non-Newtonian fluids and spherical and cylindrical particles inside a tube. The influence of the rheological behavior of the fluid and the geometry of the particle on the parameters ΔP+A/D (ratio between the additional force and the drag force acting over the particle) and Fw+/D (ratio between the additional force on the duct wall and the drag force acting over the particle) were investigated. Results are shown for the Reynolds number range between 0.008 and 2200, and for the power-law exponent of the fluid in the range from 0.1 to 2, and for the aspect ratio between the characteristic dimension of the particle and the duct in the range from 0.05 to 0.98. For all cases, and far beyond the Oseen’s regime, the ratios ΔP+A/D and Fw+/D can be directly evaluated by means of parameters of the undisturbed flow, which according to an existing theory, should only be expected for low Reynolds number. Suddenly, a strong transition occurs on the values of the ratios ΔP+A/D and Fw+/D.

Energy generation using coconut biodiesel and coconut oil in a stationary engine

This paper deals with the possibility of using coconut oil and coconut biodiesel in energy generation. The environmental, energetic and socio-economic aspects are discussed. The steps for obtaining biodiesel from coconut oil are presented as well as the characterisation of coconut oil and coconut biodiesel. Results for performance and emissions of using coconut oil and coconut biodiesel in a stationary engine are also shown. Coconut oil can be successfully applied in compression ignition engine blending with diesel up to 20% of coconut oil. Coconut oil can also be converted in biodiesel and applied in compression ignition engines neat or blended with diesel in any proportion. The possibility of using coconut oil in power generation leads to the concepts of sustainability and cleaner production, by the use of a raw material that contributes to CO2 absorption. [Received: August 16, 2012; Accepted: May 1, 2013]

Production and Consumption of Biodiesel and Ethanol: A Comparison, from 2000 to 2010

The present work, an investigation concerning the biofuels production and consumption, from 2000 to 2010, of different regions: Asia and Oceania; Central and South America; European Union and North America. The Brazilian case is also studied. In all regions studied, the production and consumption grows significantly in this period. The production is local and adapts to agricultural inputs available for production, being an activity related to regional development. It is also observed that Europe has greater production and consumption of biodiesel, while Brazil and the U.S. have higher production and consumption of ethanol. It is also presented the top 5 countries in the world in biodiesel and ethanol production and consumption, from 2000 to 2010. Furthermore, biofuels increased their relevance in energy matrices around the world.

Experimental investigation of the enhanced oil recovery process using a polymeric solution

Enhanced oil recovery methods are becoming an important source of oil production of wells that have already been explored and, by these methods, of increase of the total volume of oil extracted. An important example is the injection of polymeric solutions after the injected water has reached the breakthrough point. In the present work an experimental apparatus was built in order to test the ability of enhanced oil recovery of polymeric solutions, composed by Xanthan Gum (XG) dissolved in distilled water. This apparatus consists of an idealized porous media made with small spheres inserted in a cylindrical cell and then filled with oil with the same viscosity as the petroleum found in Campos Basin (Rio de Janeiro, Brazil). As displacing fluid, we tested polymeric solutions of different concentrations of Xanthan Gum and these non-Newtonian fluids were characterized using a rotational rheometer. The resulting characterization has shown that increasing the concentration, not only the level of viscosity, but also the elasticity of the fluid increases. The shear-thinning behavior of the solution can be well captured by a power-law model. For higher concentrations the shear-thinning feature of the Xanthan Gum solution is more pronounced. We conducted an experimental procedure to mimic enhanced oil recovery process by first injecting water until the breakthrough point. Increasing the polymer concentration, the extra amount of oil recovered also increase. Theoretical and heuristic analyses show that in the shear dominated regions, the Xanthan Gum polymeric solutions do not increase pore efficiency, but increase sweep efficiency, while the extensional character of the polymeric solution seems to indicate that in extensional dominated regions the polymeric solutions play an important role on the oil recovery efficiency from both perspectives: pore and sweep efficiencies.

Governance and risk of Brazilian publicly traded companies

This study estimates the relations between the governance practiced by a significant sample of Brazilian publicly listed companies and the risk of them. Local beta, the beta obtained using the S&P 500, share price volatility, idiosyncratic risk and the weighted average cost of capital were used to express their risk. The study confirmed that better governance were associated with lower risk. The structural equations results confirmed the linear regressions results. The endogeneity observed did not invalidate the results. The evidence predominately showed that the direction of causality runs from governance to the risk variables and not vice-versa.

Energy generation and exhaust emissions analysis in a stationary engine using palm biodiesel, palm oil and diesel

This paper is related with the use of palm oil and palm biodiesel mixed with diesel in different percentages in a stationary engine. It presented the steps for obtaining biodiesel from palm oil and the characterisation of palm oil and palm biodiesel. It also shows the results for performance and emissions of using palm oil and palm biodiesel in a stationary engine. It was concluded that palm oil can be successfully applied in compression ignition engine blending with diesel up to 20% of palm oil. Palm oil can also be converted in biodiesel and used in compression ignition engines neat or blended with diesel in any proportion. The use of neat palm biodiesel is not recommended in cold weather conditions due to its low pour point. The use of palm oil and palm biodiesel in power generation lead to the concepts of sustainability, by the use of a raw material that contributes to CO2 absorption. [Received: September 23, 2015; Accepted: July 24, 2016]

CO 2 emissions, energy use and country governance

The purpose of this study is to investigate for selected countries, the possibility of relationships among CO2 emissions, the use of energy, and an aspect of the governance of countries. This investigation is based on a sample of data composed of variables from 54 countries, from 2000 to 2008, available at the World Bank website. The methods of analysis that were employed included linear regression with panel data and the method of structural equations for a robustness test. The results of the two models converged and showed the existence of statistically significant relationships: a) between CO2 emissions and that aspect of governance; b) between the use of energy and electricity and the same aspect of governance.