The growing use of liquid biofuels in industrial power equipment has increased the need for effective fuel testing to confirm that bio content levels remain within required limits.

With the introduction of new environmental standards and directives aimed at improving air quality, the low sulphur content and reduced CO2 and greenhouse gas emissions associated with biofuels has increased their use in a range of emergency and stand-by power generation applications.

Although many different types of biofuels can be produced from a wide variety of biomass, the term biodiesel usually refers to Fatty Acid Methyl Esthers (FAME) produced from bio-oils generated from feedstocks that include rapeseed, palm oil and soya bean.

Although 100% biodiesel (B100) sometimes is used as a fuel by itself, it is more commonly used as a blend component in conventional diesel. Biodiesel blends are therefore defined as a blend of biodiesel and conventional diesel such that the final blended fuel will meet all the technical requirements of conventional diesel grades.

However, engine tolerance of higher levels of biofuel content in diesel blends can vary enormously. Most engine manufacturers set their own standards for liquid fuels. While lower level blends may not require engine modifications or adjustments, the variations in fuel quality associated with some higher levels of biofuels can impair engine performance and power output.

In addition, the physical properties of biofuels can also cause damage to components so that the service life of the engine and manufacturers’ warranty conditions can be affected.

In the circumstances, to prevent potential reductions in power output and damage to engine filters, fuel injection systems and other components, specific biofuel content threshold limits are imposed for different power generation applications.

In the industrial engines sector, manufacturers of gensets also set recommended biofuel limits of typically 2%, but individual users can decide to vary the standards of fuel they prefer, in some circumstances even specifying no allowable bio content even though it may be allowed by the manufacturer.

All of these considerations mean that it has become essential for users of blended diesel to be able to accurately determine the biofuel content of the fuel feedstocks they are using.

Given the critical importance of biofuel content advanced sensor technology has been developed as a first stage screening tool to check diesel blend quality and composition. DieselProve test kits utilise patented radio frequency technology to analyse the electromagnetic properties of the material under test to detect the number of particulates present.

The technology exploits radio frequency spectroscopy to measure certain characteristics of a material such as real and imaginary magnetic susceptibility and permittivity.  Once calibrated, products incorporating this technology can be used to rapidly analyse composition.

In this way the electronic hand held unit and integral probe provides accurate, real time in-field measurement of biodiesel content with the same accuracy as laboratory sampling methods. As well as detecting the proportion of biofuel present, other contaminants such as white spirit, petrol and water can also be detected.

The advanced RF sensor is used as a quick on the spot screening tool to determine whether further sample analysis is required. As well as testing against specific 0, 2 and 7% content limits for different applications, the sensor system can also detect less than 100% biofuel content in those B100 applications where it is being used on its own.

Reliable and robust test results are displayed in seconds and can be downloaded to a supporting software program for formal record keeping and reporting options.

With some fuel blends having the potential to cause permanent harm to engines, accurately assessing biofuel content using innovative sensor technology is a fundamental preventative maintenance requirement of assessing fuel quality.