In this work, ethylic biodiesel was produced through changes in TDSP methodology (Transesterification Double Step Process), settling the optimal transesterification conditions – time, temperature and alcohol:oil:catalyst molar ratio – for... more
In this work, ethylic biodiesel was produced through changes in TDSP methodology (Transesterification Double Step Process), settling the optimal transesterification conditions – time, temperature and alcohol:oil:catalyst molar ratio – for both reaction steps, aiming the obtaining of biodiesel from waste cooking oil (WCO) and ethanol. The ethylic biodiesel had its physicochemical properties evaluated according to standards established by the National Agency of Petroleum, Natural Gas and Biofuels (ANP), with a primary focus on cold flow properties and oxidation stability. These properties were also evaluated in mixtures with different types of biodiesel and blends with petrochemical diesel. Biodiesel was also used as feedstock in epoxidation reactions carried out in a solvent-free media. Hydrogen Nuclear Magnetic Resonance and Infrared Spectroscopy were used in order to characterize chemically and structurally the starting material (WCO), the ethylic biodiesel and the epoxidized ethyl esters. The spectroscopic analysis of the products indicated high conversion and yields of ethyl esters from WCO. The ethylic TDSP process presented easy and clear phase separation and high purity biodiesel. The physicochemical analyses according to the ANP specifications testified the effectiveness of the reaction as well as the post-synthesis purification process. The evaluation of oxidative stability and cold flow properties indicated that the use of partially hydrogenated esters may contribute to improve biodiesel resistance against oxidative processes and environments, without major losses occurring to the flow properties at low temperatures. Evaluation of blends of petrochemical diesel with biodiesel evidences the need for development of a methodology able to determine with effectiveness, accuracy and reliability the oxidation stability of all types of fuels applied in Diesel engines. The study of epoxidation of ethylic biodiesel indicates the possibility of applying the proposed method to replace the currently used, because the epoxidized ethyl esters meet the conditions of conversion and selectivity necessary. The proposed methodology eliminates the use of organic solvents, providing a time saving for the reaction and subsequent purification steps, being also less aggressive to the environment.
Since concentrated emulsions are the basis for many commercial products, conducting comprehensive studies on structureefunction relationships of emulsion systems is necessary for targeted product design. Hence, the objectives of this... more
Since concentrated emulsions are the basis for many commercial products, conducting comprehensive studies on structureefunction relationships of emulsion systems is necessary for targeted product design. Hence, the objectives of this study were to 1) characterize the effects of fish gelatin concentration and oil phase volume fraction on the rheological, tribological and microstructural properties of concentrated emulsions and 2) determine structureefunction relationships based on the measured parameters. Emulsions were prepared using different amounts of oil and fish gelatin, and characterized by rheometry and microscopy. Emulsions containing higher oil or fish gelatin concentrations had greater stability to creaming, larger critical strains, and lower friction profiles. However, they exhibited increased nonlinear behavior under large amplitude oscillatory shear. These results were ascribed to increased homogeneity, higher network extension, and smaller oil droplets in emulsions with higher protein or oil concentrations. These results can be used to incorporate concentrated emulsions in emulsion-based formulations.
Biodiesel, as an alternative fuel is steadily gaining attention to replace petroleum diesel partially or completely. The tribological performance of biodiesel is crucial for its application in automobiles. In the present study, effect of... more
Biodiesel, as an alternative fuel is steadily gaining attention to replace petroleum diesel partially or completely. The tribological performance of biodiesel is crucial for its application in automobiles. In the present study, effect of temperature on the tribological performance of palm biodiesel was investigated by using four ball wear machine. Tests were conducted at temperatures 30, 45, 60 and 75 °C, under a normal load of 40 kg for 1 h at speed 1200 rpm. For each temperature, the tribological properties of petroleum diesel (B0) and three biodiesel blends like B10, B20, B50 were investigated and compared. During the wear test, frictional torque was recorded on line. Wear scars in tested ball were investigated by optical microscopy. Results show that friction and wear increase with increasing temperature.
The four-ball tester was used in this analysis to demonstrate the lubricity of tire pyrolysis oil (TPO). The tribological performance of the tire pyrolysis oil was compared with diesel fuel (DF) and their blends, DT10 (TPO 10%, Diesel... more
The four-ball tester was used in this analysis to demonstrate the lubricity of tire pyrolysis oil (TPO). The tribological performance of the tire pyrolysis oil was compared with diesel fuel (DF) and their blends, DT10 (TPO 10%, Diesel 90%) and DT20 (TPO 20%, Diesel 80%). A scanning electron microscope (SEM) was used to investigate the wear scar. In contrast to diesel fuel, TPO demonstrated better antiwear behaviour in terms of higher load-carrying capacity. DT10, DT20, and TPO’s wear scar diameter (WSD) was 22.35%, 16.01%, and 31.99% smaller than that of diesel at 80 kg load, respectively. The scanning electron microscope micrographs showed that the TPO and DT10 had less wear than their counterparts.
In this study, seven mixtures of diisopropanolamides that were synthesized from various vegetable oils (sunflower oil, soybean oil, cotton seed oil, olive oil, tobacco seed oil, coconut oil, used frying oil) were used as lubricating... more
In this study, seven mixtures of diisopropanolamides that were synthesized from various vegetable oils (sunflower oil, soybean oil, cotton seed oil, olive oil, tobacco seed oil, coconut oil, used frying oil) were used as lubricating additives in a low-sulfur marine gas oil. All tribological measurements were carried out by using the high-frequency reciprocating ring (HFRR) test procedure, according to EN ISO 12156-1. The obtained wear results showed that all mixtures of diisopropanolamides used provide satisfactory a mean wear scar diameter (WS 1.4) of less than 520 µm, at concentration levels of 60–120 ppm. The concentrations below 60 ppm had no effect on the fuel lubricity. An increase in the concentration of the diisopropanolamide mixtures led to an insignificant increase of the lubrication effectiveness.
In this study, AISI 4140 steel surfaces were alloyed with preplaced SiC/C powders using a tungsten–inert gas (TIG) heat source. The effects of different production parameters on the microstructure, hardness, and wear resistance of the... more
In this study, AISI 4140 steel surfaces were alloyed with preplaced SiC/C powders using a tungsten–inert gas (TIG) heat source. The effects of different production parameters on the microstructure, hardness, and wear resistance of the alloyed surfaces were investigated. Following the surface alloying, conventional characterization techniques such as optical microscopy, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD) were used to study the microstructure of the alloyed surfaces. Hardness measurements were performed across the alloyed zones, and wear properties of the alloyed surfaces were evaluated using a block-on-disc wear test method. The collected data suggest that alloyed zones solidify into different microstructures depending on the production parameters. The alloyed surfaces exhibited an increase in hardness and wear resistance; this was attributed to the presence of harder phases and graphite. Lamellar or layered crystal structures of graphite have good lubricity and decrease coefficient of friction. Hardness values of the alloyed surfaces varied between 670 and 1165 HV. The minimum mass loss was observed in the sample that was alloyed with a 0.0581 cm/s process speed, 0.5/0.2 g/s powder feed rate, and a 29.1 kJ/cm heat input. The exhibited mass loss ratio was attributed to M3C, M7C3, and FeSiC carbides in the microstructure. The results conclude that TIG can be used effectively for surface alloying with SiC/C powders to improve the wear resistance of the AISI 4140 steel surface.
Fatty acid methyl esters (FAMEs) from castor oil have been synthesized by methanolysis catalyzed by sodium methoxide and the optimal transesterification conditions have been found. However, some properties of the castor FAME render it... more
Fatty acid methyl esters (FAMEs) from castor oil have been synthesized by methanolysis catalyzed by sodium methoxide and the optimal transesterification conditions have been found. However, some properties of the castor FAME render it unsuitable in pure state for its direct use as fuel in internal combustion engines. Thus, blends with reference diesel have been prepared and their properties have been evaluated. Among these properties, the oxidative stability of the blends shows a negative anti-synergistic effect, that is, all the blends have an induction period lower than the pure reference diesel and the pure castor FAME. On the contrary, the lubricity shows a positive synergistic effect, the wear scar of the blends being always lower than those of the pure components. The cold-filter plugging point of the blends shows also a singular effect, since the filterability remains identical to that of the reference diesel until around 50 vol% of castor FAME has been blended with it. The b...
The four-ball tester was used in this analysis to demonstrate the lubricity of tire pyrolysis oil (TPO). The tribological performance of the tire pyrolysis oil was compared with diesel fuel (DF) and their blends, DT10 (TPO 10%, Diesel... more
The four-ball tester was used in this analysis to demonstrate the lubricity of tire pyrolysis oil (TPO). The tribological performance of the tire pyrolysis oil was compared with diesel fuel (DF) and their blends, DT10 (TPO 10%, Diesel 90%) and DT20 (TPO 20%, Diesel 80%). A scanning electron microscope (SEM) was used to investigate the wear scar. In contrast to diesel fuel, TPO demonstrated better antiwear behaviour in terms of higher load-carrying capacity. DT10, DT20, and TPO’s wear scar diameter (WSD) was 22.35%, 16.01%, and 31.99% smaller than that of diesel at 80 kg load, respectively. The scanning electron microscope micrographs showed that the TPO and DT10 had less wear than their counterparts.
The main point of interest when discussing lubrication is to understand what lubricants do in a compound, particularly during processing. Among lubricants, we can find metal soaps, which are often heat stabilizers of PVC. In order to... more
The main point of interest when discussing lubrication is to understand what lubricants do in a compound, particularly during processing. Among lubricants, we can find metal soaps, which are often heat stabilizers of PVC. In order to study the influence of lubricants on the flow properties, it is of particular interest to analyse the behaviour of the material at the die walls, where slip may be observed. Then, in the present paper, the lubricating ability of a lead stabilizer during extrusion of a plasticized PVC formulation was investigated through an instrumented die, which allowed us to have the apparent flow properties at the wall. Rough and smooth surfaces of the die were used in order to prevent or promote slip at the metal surface. From this method, it was possible to observe the slip phenomenon above a critical concentration, whereas the analysis of the die surface through SEM coupled energy dispersive x-ray spectroscopy shows that lead stabilizer migrates even at low concentration. So, slip occurs when the lubricant layer forms a continuous solid layer which modifies the polymer–metal interface properties.