| dc.description.abstract | This research investigates using three different sources of Solid Recovered Fuel (SRF)—fiber, plastic, and paper residue—in a fluidized bed boiler for blending tests. The results demonstrate that SRF can be effectively used for boiler fuel charging control, steam output, and temperature regulation, all supporting stable boiler operation. The boiler′s thermal efficiency can exceed 80% with SRF usage. Elemental analyses of the SRFs reveal higher nitrogen and chlorine contents than coal, while the sulfur content is lower. The desulphurization and denitrification systems of the boiler achieve removal efficiencies of over 95% when using SRF, ensuring that emissions of SO2, NOX, and HCl in the stack exhaust meet regulatory standards.
Analysis of fly ash and bottom slag from the SRF-co-fired boiler indicates that the concentrations of metals in the Toxicity Characteristic Leaching Procedure (TCLP) are below 20% of regulatory limits. However, the co-firing of SRF increases the generation of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in fly ash and bottom slag, with fly ash showing higher levels than bottom slag. These compounds are known to be highly toxic and persistent in the environment, which raises concerns about the environmental impact of SRF co-firing. The combustion of SRF contributes only 2.75% to 10% of the total ash, with the main composition of the ash still influenced by coal, Tire-Derived Fuel (TDF), and limestone. Consequently, there is no significant increase in the fly ash slagging index and bottom slag accumulation index compared to scenarios without SRF.
From an economic perspective, the co-firing of all three SRF types can lead to significant cost savings in steam production. For instance, the costs for SRFs made from plastic and plastic-plus-paper residues can drop to 65% of those without SRF. This promising aspect of SRF usage is a key point to consider. However, it′s important to note that the SRFs used in this research lack relevant quality control standards and consistent test data from manufacturers, leading to significant variability in material appearance and test values within the same batch. The use of blended SRF in boilers also results in a marked increase in limestone usage, leading to a 49% rise in ash treatment costs and a 91% increase in pharmaceutical costs compared to scenarios without SRF. The study strongly recommends the establishment of a robust quality control mechanism for SRF materials and products by government agencies. This measure is not just important, it′s crucial in ensuring the production of SRFs with consistent and stable quality. This, in turn, can help reduce medication costs for boiler operators and minimize the risk of damage from abnormal boiler operation. The potential impact of this recommendation on the industry underscores the significance of this research. | en_US |