Traceable online moisture content in wood chips

The aim of the project is to develop a method for improvement of the quality of the measurement of the water content in wood chips used for biomass boilers for district heating. An improvement of online equipment and sampling methods will be made. The present experience with commercially available online measurement systems is that it is not possible to perform a representative calibration with wood chips due to the inhomogeneity of the fuel. This entails that the measurements are unreliable and cannot be used as control parameter nor for quality control of the wood chips. The inhomogeneity of the wood chips requires numerous samples for analysis, which is cost-intensive.

To accommodate the above mentioned issues the project addresses the following main activities:

• Identification of a reference analysis method
• Investigation of the composition of the fuel (wood, bark, branches, needles, impurities)
• Optimisation of the sampling procedure
• Development of a representative calibration procedure
• Establishment of a measurement system
• Onsite evaluation efficiency and accuracy of the measurement systems.

Through the project activities the use of wood chips and mixed fuels in biomass fired boiler plants is supported by providing the possibility for optimising the combustion process and for correct settlement of accounts. The goal is a to achieve a significant improvement of the uncertainty of the determination of the water content in wood chips with online measurement equipment and to validate the basis of the reference method.