Straw Combustion: Pilot and Laboratory Studies on a Straw-Fired Grate Boiler

This paper presents the results of work carried out by the project "Development of the Methods for Pretreatment of Agricultural Biomass Used for Production of Energy" supported by the national program Innovative Economy. The research includes the analysis of several factors related to utilization of straw for energy purposes. The main points of interest were a decrease of ash-sintering potential using inorganic additives, application of alloy steels in boiler construction, and leaching of mineral compounds to minimize corrosion risk. This paper also provides a review of the results of experiments, including the combustion of two different types of straw in a grate boiler, with a capacity of 3.5 MW_th. The testing was carried out for rape and wheat straw with and without the addition of kaolin. The energy balance and emission factors of pollutants [CO, NO_x, SO₂, and total suspended particles (TSP)] were derived. The obtained results show that application of mineral additives gives satisfactory results in terms of the increase of the ash-softening point. High-quality materials could be used in the manufacturing of the boiler parts exposed to a corrosive environment.