As a result, the mineral oil industry and vehicle manufacturers are faced with new requirements for the quality assurance of fuels. For a fuel to be “fit for purpose,” it must be extensively tested before it is launched on the market. This includes, for example, checking
- possible interactions between the materials of fuel-carrying components and the fuels, and
- between biogenic or synthetic and conventional fuels in different blending proportions
- and combustion behavior.
- In addition, there are long-term tests of fuels under laboratory conditions and
- field tests and tests of closed vehicle fleets in model regions.
Tec4Fuels has developed special test methods that can be used to validate new fuels quickly and reliably.
Static test procedures for quality assurance of fuels
In principle, all alternative fuels placed on the market with admixtures of biogenic or synthetic components that can replace petroleum-based fuels must comply with the respective standards. Examples include bioheating oil (containing up to 10% fatty acid methyl ester, FAME) in the space heating market, superfuel E10 (containing up to 10% ethanol) and diesel fuel (containing up to 7% fatty acid methyl ester, FAME). The aim is to ensure that their quality on delivery is sufficiently high to guarantee the operational reliability of components in technical systems such as engines or heating appliances. A statement about the storage stability of the fuels cannot be made on the basis of the tests of the requirements according to the standards. Depending on their composition, fuels age at different rates and also behave differently during aging. In aging tests, various fuel samples are stored at Tec4Fuels under defined conditions that approximate the loads in real applications. To test their long-term stability, the samples are tested over varying periods of time and temperature levels. Depending on the test design, the duration of storage can range from 1 to 24 months and temperatures can vary between 8° and 80 °C. In general, the tests show that the addition of FAME as an alternative component to diesel fuel or heating oil without stabilization measures can intensify possible aging reactions. As a result, the oxidation stability of the fuel decreases and sediments form during storage. However, suitable additivation of the fuel mixture with antioxidants significantly delays aging reactions.
BigOxy: Testing the storage stability of fuels more quickly
The BigOxy test method is suitable for making an initial and rapid statement about the long-term storage stability of a fuel. This is a forced aging test that “stresses” the fuel under variable conditions in such a way that the autoxidation reaction is forced. This rapid aging reaction occurs at pressures between 1.2 and 5 bar and temperatures of up to 250 °C. As a rule, the tests are designed to last 64 or 128 hours, depending on requirements. The BigOxy test method is suitable for both heating oil and diesel fuel as well as gasoline, also with different blends of alternative fuels and additives.