Comparative study of biodiesel oxidation stability using Rancimat, PetroOXY, and low P-DSC

Valle, M. L. Murta; Leonardo, R. S.; Dweck, Jo

doi:10.1007/s10973-014-3706-6

Cited by 35 publications

(3 citation statements)

References 40 publications

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“…It has been reported that oxidation is the first step in the formation of deposits in jet fuels via a free-radical chain mechanism . Therefore, a high degree of oxidation stability is very important for suppressing the deposit buildup and reducing its impact on the performance of advanced aerospace vehicles. , …”

Section: Introductionmentioning

confidence: 99%

Regioselective Synthesis of Methyl-Substituted Adamantanes for Promoting Oxidation Stability of High-Density Fuels

et al. 2020

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Alkyl-adamantane fuels have drawn tremendous attention for aerospace vehicles due to their high density and high oxidation stability. Here, we reported a regioselective route to synthesize methyl-substituted adamantanes including 1,3,5-trimethyladamantane and 1,3,5,7-tetramethyl-adamantane with single configuration via alkylation of 1,3-dimethyl-adamantane, with yields of ∼60 and ∼80%, respectively. The reaction kinetics of alkylation has been investigated, and the reaction rate constants and apparent activation energies were calculated based on the experimental kinetic data. The oxidation stability of methyl-substituted adamantane family were first evaluated via pressure differential scanning calorimetry and rapid small-scale oxidation test, and the results indicate that the oxidation stability is correlated to the carbon type available on the molecule in the order of 1,3,5,7-tetramethyl-adamantane > 1,3,5-trimethyl-adamantane > 1,3-dimethyl-adamantane > 1-methyl-adamantane. Notably, 1,3,5,7-tetramethyl-adamantane with four quaternary carbons and no tertiary carbon presents supreme oxidation stability than JP-10 and decalin. Finally, we used 1,3,5,7tetramethyl-adamantane as an additive and achieved in improving the oxidation stability of JP-10. This work presents methylsubstituted adamantanes as good high-density and high-oxidation-stability fuel components and suggests that methyl groups substituted on tertiary carbon of adamantane has a beneficial effect on improving oxidation stability.

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Section: Introductionmentioning

confidence: 99%

Regioselective Synthesis of Methyl-Substituted Adamantanes for Promoting Oxidation Stability of High-Density Fuels

et al. 2020

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“…There are many established accelerated fuel stability measurement methods currently in use, namely, ASTM D2274, ASTM D4625, active oxygen method, and oxidation stability index. , In these methods, biodiesel is exposed to higher temperature, higher pressure, or enhanced oxygen supply in order to accelerate the auto-oxidation process. , As the temperature increases, the rate of oxidation is found to increase exponentially . The relationship between temperature and oxidation rate depends upon the activation energies of the rate-controlling steps in the oxidation reactions.…”

Section: Introductionmentioning

confidence: 99%

Investigations on Gradual and Accelerated Oxidative Stability of Karanja Biodiesel and Biodiesel–Diesel Blends

2019

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One of the major limitations that hinder widespread application of biodiesel in automotive engines is its poor oxidative stability, which in turn depends upon methyl ester constituents of biodiesel as well the storage conditions. Hence, a relative assessment of the oxidative stability of biodiesels across the different parts of the world is rather difficult. In the present work, oxidative stability of biodiesel based on the ASTM D4625 accelerated oxidative stability test is compared with that of gradual oxidation under two different long-term storage conditions, namely, open to air and sunlight and closed to air and sunlight. Neat Karanja biodiesel and its blends with diesel at 25, 50, and 75% by volume are used for the present study. The important physicochemical properties of fuel samples are measured at regular time intervals to evaluate the rate of oxidation and the extent of fuel quality degradation. The results obtained show that neat Karanja biodiesel stored under open to air and sunlight conditions has the highest rate of oxidation and fuel quality degradation with a 32% increase in kinematic viscosity, 1.5% increase in density, and 3% decrease in calorific value. The acid value of all the tested fuel samples increased beyond ASTM and EN standard specification limits within the first 3 months of storage period. The peroxide value showed a steep increase during the first 6 months of storage period and decreased afterward. The effects of adding the TBHQ antioxidant in Karanja biodiesel at varying concentrations are also evaluated based on the measured Rancimat induction period, and it is observed that 250 ppm TBHQ is required to meet EN 41214 standard specifications for biodiesel. No correlations are found to exist between the properties of fuel samples stored under gradual and accelerated oxidation conditions. However, adopting the ASTM D4625 standard test method to evaluate the storage stability of biodiesel avoids any ambiguity owing to the variations in the storage and the ambient conditions across the different parts of the world.

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“…Presented in the article are issues concerning dynamic operating conditions of the combustion engine. Complete knowledge in area of dynamic states can contribute to the ability to power supply of combustion engines by other fuels [3,[6][7][8] allowing the optimization of the operation under these conditions.…”

Section: Introductionmentioning

confidence: 99%

Thermodynamic analysis of indexes of operation of the engine with direct fuel injection for idle speed and acceleration

Pielecha

Cieślik

2016

J Therm Anal Calorim

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Contemporary requirements for combustion engines are aimed mainly at obtaining significant parameter values of their operation at simultaneously low fuel consumption and reduced exhaust emission. Despite the fact that combustion engines utilize diverse load conditions, the idle speed share in the whole range of their operation is significant. The percentage of combustion engines with spark-ignition direct injection (SI DI) in the total number of spark-ignition engines is increasing. It means that the method of the mixture preparation is an important factor in SI DI engine, also for idle speed. In the tests was analysed the SI engine preparing the mixture with a dose of injected fuel (air-guided type) in conditions of the idle speed. Idle speed control is a critical issue in engine control fields. Essentially, it is a highly nonlinear and timevarying problem. Its performance has a significant impact on fuel economy and emission levels. The engine operation indexes were determined, and with the use of coefficient of variation, the variation of the cycle was estimated. Article contains the three-stage division, taking into account the variable measuring modes where was analysed the work condition during the idling, free acceleration of combustion engine and car acceleration. From numerous operational indexes of the engine operation were selected those, which in the best way characterize engine operation for idle speed.

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Comparative study of biodiesel oxidation stability using Rancimat, PetroOXY, and low P-DSC

Cited by 35 publications

References 40 publications

Regioselective Synthesis of Methyl-Substituted Adamantanes for Promoting Oxidation Stability of High-Density Fuels

Regioselective Synthesis of Methyl-Substituted Adamantanes for Promoting Oxidation Stability of High-Density Fuels

Investigations on Gradual and Accelerated Oxidative Stability of Karanja Biodiesel and Biodiesel–Diesel Blends

Thermodynamic analysis of indexes of operation of the engine with direct fuel injection for idle speed and acceleration

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