How do you measure oxidative stability?

How do you measure oxidative stability?

Methods of Oxygen Absorption (RapidOxy): the RapidOxy method consists of an accelerated oxidation process by increasing the pressure of oxygen and temperature, allowing us to determine the oxidative stability of the samples.

What is oxidation stability?

“Oxidation stability” refers to the tendency of fuels to react with oxygen at temperatures nearer ambient—mechanism (i) and describes the relative susceptibility of the fuel to degradation by oxidation. These reactions are much slower than those that would occur at higher temperatures.

How is oxidation stability of biodiesel measured?

The oxidation stability was measured by the Induction Period (IP) using a Metrohm 873 Biodiesel Rancimat® at 110 °C with an airflow of 10 L h−1, according to EN14112. Samples of 3 g were weighed in the Rancimat flask.

How is oxidation tested?

The majority of analytical tests that measure oxidation protection measure the amount of oxidation that has occurred to the lubricant. The Linear Scanning Voltammetry (LSV) (D6971) and FTIR are two tests capable of measuring the concentration of the antioxidant additive(s) present in the oil to control oxidation.

What is oxidative stability index?

Oxidative Stability Index (OSI) is a method that determines the relative resistance of fats or oils to oxidation. The air stream flushes the volatile acids from the oil into a conductivity cell containing water where the acids are solubilized.

What is thermal oxidative stability?

Thermal stability refers to the ability of a material to maintain desirable mechanical properties such as strength, toughness or elasticity at a given temperature. The structure-property relationships of polymers are provided. The oxidative degradation of polymers involves free-radical chain reactions.

What is high oxidative stability?

Oxidation stability is a chemical reaction that occurs with a combination of the lubricating oil and oxygen. The rate of oxidation is accelerated by high temperatures, water, acids and catalysts such as copper. Oxidation will lead to an increase in the oil’s viscosity and deposits of varnish and sludge.

What does high oxidative stability mean?

The more an oil can resist reacting with oxygen and breaking down, the better for cooking. This quality is measured as oxidative stability and is considered by many oil experts as the best predictor of how an oil performs during cooking. Oxidative stability is measured via induction time.

Why is oxidation stability important?

The oxidation stability of fats, oils and their products plays an important role in determining the quality and so is an important parameter for quality assessment of fats and oils and biodiesels derived from them. It is defined as the resistance of oil/fats/biodiesel to degrade by oxidation with air.

Why is biodiesel prone to oxidation?

They concluded that biodiesel is more prone to oxidation in higher temperature due to the formation of oxidation products, such as aldehydes, alcohols, shorter-chain carboxylic acids, gum, and sediment, which are often responsible for fuel filter plugging, injector fouling, and deposit formation during fuel combustion.

What is oxidation in hydraulic oil?

Oxidation is the chemical union of oil and oxygen. This is one of the primary sources for decreasing the stability of hydraulic oil. When the reaction starts, an increase of rate in the chemical reaction happens due to the participation of an additional substance.

What is grease oxidation?

Oxidation stability: This is the ability of a grease to resist a chemical union with oxygen. The reaction of grease with oxygen produces insoluble gum, sludges, and lacquer-like deposits that cause sluggish operation, increased wear, and reduction of clearances.

What is the petrooxy method?

The PetroOXY method was developed from the bomb method (ISO 7536—ASTM D 525—IP 40). As with the bomb method, the test results are directly measured as the pressure drop inside the test chamber as the oxidation process is accelerated by heat and oxygen at pressure.

How to test the oxidation stability of petrodiesel?

Presently, the most important test methods for the oxidation stability testing of petrodiesel are ISO 12 205 and ASTM D 2274. These methods require a 16-hr-long aging process at 95 °C under oxygen flow.

What is the induction period in petrooxy?

In the PetroOXY method, the oxidation stability is characterized by the induction period. The induction period is the elapsed time between starting the test and the breaking point, which is defined as a pressure drop of 10% below the maximum pressure as detected in the pressure versus time curve ( Figure 1 ).

What are the advantages of the petrooxy method over Rancimat?

An important advantage of the PetroOXY method over the Rancimat method is the significantly shorter duration of that test for determining the oxidation stability of a given sample. This is very important when testing and developing new additives for fuels.