Combustion of Reeds in a 3 MW District Heating Plant

Abstract

Reed (phragmites australis) from the Lake Neusiedl in Austria is investigated as energy source for thermal utilization. Reeds represent a cheap, locally available and renewable feedstock which is not used today. This paper presents the investigations and experimental results of thermal utilization of reeds in a 3 MWth commercial district heating plant dedicated for combustion of wood chips. The results of fuel analysis show that reed is a high quality straw-type biomass with an ash deformation temperature of over 1400° C. For the test runs, chopped reed was mixed with wood chips in various ratios. The results show that the higher sulphur and chlorine content in reed causes slightly higher SO2 (25 ppm) and HCl (1.6 ppm) content in the flue gas. However, with higher ratios of reed in the feedstock no increasing of environmental harmful components such as dioxins and heavy metals can be measured. At the end of the test runs a short period of combustion with pure reed was carried out. It could be proven that reed is a suitable feedstock for commercial district heating plants.