Online fuel characterization - a prerequisite for fuel flexibility in biomass fired boilers

How can we increase fuel flexibility? How can we optimize process stability in biomass combustion when facing solid biomass with inhomogeneous characteristics and quality? One decisive step is to know more about the fuel and its characteristics, right before it is transported into the furnace. So some kind of online fuel characterization is needed to give the process control of any biomass-fired plant the chance to react in time to changing fuels and fuel qualities. In our project Digital Fire (funded by the German Federal Ministry of food and agriculture) an innovative approach for online fuel characterization is being developed. The concept is based on the idea, that different fuels will behave differently when exposed to hot air convective drying. Simple measurement equipment is used to measure temperature, water content and pressure drop and create profiles and key parameters from their functions over time. With a sufficient large database, it will be possible not only to distinguish between different fuels, but also to calculate water content and estimate energy and ash content.