Synergies Between Biomass and Solid Recovered Fuel in Energy Conversion Processes

摘要

Solid recovered fuels (SRFs) derived from commercial/industrial and municipal solid waste-type streamsncontaining high heat value plastics offer a number of synergies for biomass combustors. This article coversntechnical and operational synergies to increase biomass combustion efficiency in a grate fired system typical fornwaste-to-energy technology. The transfer of laboratory results to pilot scale is presented by a new approachnbased on experimental data in laboratory scale and a mathematical model using key combustion parameters.nAgreement between the experimental data and the mathematical model is sufficient to use the model for scalenup. Because of the sometimes poor biomass fuel quality in biomass combustion facilities, the following unfavorablenoperating conditions occur: fouling and slagging on the furnace and boiler walls. These effects lead tonlower operating hours due to more frequent cleaning cycles. The low- and medium-priced biomass availablenfrom the market has very low heat values (5 GJ/t) and high alkali metal content. Biomass availability in mostnEuropean Union (EU) countries lead to an increased amount of low-grade biomass fed into grate-type combustors.nEfforts of the American Chemistry Council, the Institute of Technical Chemistry, and PlasticsEuropenhave assessed the synergies through laboratory-scale experiments and have continued to demonstrate the biomassnand SRF synergies on a large-scale pilot grate-type incinerator. This article points out that primary airnpreheat influences energy efficiency of the total process for the combustion of wet biomasses positively. Localncombustion behavior of the wet biomass will depend on the degree of mixing and the moisture content. Resultsnfrom this pilot scale confirm that SRF addition of 20–40 wt% lead to more homogeneous combustion behaviornand an increase of energy efficiency from 2% to 3% absolutely.