Abstract
Particle concentration and size distribution, in addition to their composition, are essential information not only because of environmental and health concerns but also in order to be able to avoid deposition on heat transfer surfaces which may result in corrosion, fouling and subsequent efficiency reduction and cost increase in biomass combustion plants. For the study of particle concentration and size distribution an ELPI can be used. In this device, already well-developed impactor technology is combined with particle charging and electrical detection allowing accurate real-time measurements and automatic operation. The collection of the size classified particles in the different impactor stages also makes subsequent chemical analysis possible. Gravimetric particle and tar sampling is a relative simple method of measuring particle and tar concentrations against a limit value. Hot filter sampling enable the collection of solid particles by avoiding the condensation of organic compounds, i.e. tars. The STL dust sampler is provided with a heated filter system for temperatures up to 350°C. This temperature is sufficient for the separation of solid particles and tars. The heated filter system is connected to a tar condensation unit. Tars are the main barrier so far for attractive gasification of biomass because they often cause operational problems such as blocking of gas cooler, filter elements and engine suction channels. The ELPI and STL setups described in this report can be used in connection with different experimental setups where particle concentration, size distribution and properties are in focus. This includes the multi-fuel reactor setup at SINTEF Energy Research.
