Synergies of Biomass and Solid Recovered Fuel in grate type Energy from Waste Plants

摘要

Solid Recovered Fuels made from commercial/industrial and MSW type waste streams containing high heat value plastics do offer a number of synergies for biomass combustors1. The paper covers technical and operational synergies to increase biomass combustion efficiency in a grate fired system typical for waste to energy technology. Results from small laboratory scale tests have proven a more stable and homogeneous bed combustion behaviour. Due to the sometimes poor biomass fuel quality in biomass combustion facilities the following unfavourable operating conditions occur: boiler incrustation, fouling and slaging on the furnace /boiler walls. These effects lead to lower operating hours due to more frequent cleaning cycles2. The low and medium priced biomass available from the market has very low heat values (5 GJ/t) and high alkali metal content. Biomass availability in most EU countries lead to an increased amount of low grade biomass fed into grate type combustors. The efforts of the American Chemistry Council, the Institute of Technical Chemistry and Plasticsiswrope have assessed the synergies through laboratory scale experiments and have continued to demonstrate the biomass and SRF synergies on a large scale pilot grate type incinerator. The results from the pilot scale confirm that SRF addition of 20 - 40 wt.-% lead to more homogeneous combustion behaviour and an increase of energy efficiency.