Olive Kernel and RDF Co-firing with Greek Lignite in Drop Tube Pulverized Fuel Furnace

The purpose of the current work is to present the experimental results from co-firing tests performed at a 20 kWth drop tube pulverized fuel furnace installed at the Institute of Combustion and Power plant Technology (IFK), University of Stuttgart. High ash and moisture low rank lignite utilized in the Megalopolis power plant in Greece was used as the main fuel. Olive kernel produced from a olive mill and drying plant, in the vicinity of the Megalopolis plant, and Refused Derived Fuel (RDF) produced in the Athens Mechanical and Biological Treatment Plant, were chosen as potential substitution fuels, due to their local availability and low cost. Each alternative fuel was tested at thermal shares of 15 and 30%; the experimental campaign included monitoring of gaseous emissions and sampling and analysis of unburnt particles, deposits and fly ash particles from the fabric filter. A comparison of results with the reference case of 100% lignite combustion indicates that co-firing lignite with the investigated fuels has the potential for decreasing some emission types and of improving combustion conditions in the furnace; in addition, despite the higher alkali and chlorine content of the fuels, the deposits formed during co-firing appear to be more easily removed via conventional boiler cleaning equipment, as they are less molten than the lignite deposits. Overall, co-firing with olive kernel or RDF appears to be an interesting candidate for implementation at the lignite­fired power plant using the investigated lignite type.
Proceedings of the 21st European Biomass Conference and Exhibition, 3-7 June 2013, Copenhagen, Denmark, pp. 1180-1185