Progress in measuring solid biofuels

Measuring the quality of solid biofuels, particularly forest residue, is a tricky business and far from an exact science. Typically you’re interested in two parameters; how much energy the fuel actually contains and how moist it is since the amount of water will affect your combustion process.

Determining these parameters is currently a challenge. Moisture measurements need a lot of preparation and take around 24 hours to dry in an oven. There is a limit as to how many samples can be taken to represent a delivery – and there is still a high degree of uncertainty. Ash content is even harder to measure and is usually based on a table of similar material with data from previous lab tests.

Solid biofuel is fast becoming an important trading commodity and there is a demand for an easy, accurate, and reliable measurement method to let buyers and sellers agree on a price based on the quality of fuel they trade.

Analyse a sample in 3 minutes

Skogfors is the central research authority for the Swedish forestry industry and is investigating alternative measurement technologies. This autumn Mantex was commissioned to test some 300 samples of various types from across Sweden, using a prototype Desktop Scanner with XRF – our advanced dual X-Ray technology (qDXA). This enabled analysis of a 3 litre sample in a few minutes with no sample preparation or complex procedure. Samples were tested for moisture, ash, and energy content and sent to Skogfors’ laboratory for verification.

Now the results are in and the Desktop Scanner performed with half the error of current methods. Not bad for a first attempt! You will have to await the full official report from Skogfors for the details (watch this space) but this indicates that an alternative measurement method could be present in terminals up and down the country before long. So you can take more samples, with a higher accuracy, in order to get a better idea of the true energy value of your solid biofuel delivery – and a fairer valuation.