Recently, the concept of “waste minimization and a sustainable resource circulation society” has become a global issue as the key term waste management policy, the effective use of waste, has been emphasized. Research that converts wastes from incinerators into energy is actively underway as a countermeasure for this issue. The most important factor, the lower heating value (LHV), is the amount of heat (excepting the latent heat of water vapor) generated when the fuel is completely burned, and it is necessary to analyze the combustion performance and economic efficiency of waste incineration facilities. The current LHV estimation methods of the Dulong equation and calorimeter through sampling cannot produce results that reflect the operation status of the incineration facility and the waste characteristics. Consequently, an objective and quantitative LHV formula (LHVKorea) was derived based on the operating data from the domestic municipal solid waste incineration facilities in this study. Additionally, by comparing LHVKorea and LHVEU, the error range of the two formulas is analyzed. The average result of LHVKorea is 2,318kcal/kg (1,788 ~ 2,734 kcal/kg), and an error range of 5% appears between LHVKorea and LHVEU.
Municipal solid waste incinerator (MSWI) fly ash was used for accelerated carbonation via bubbling of gaseous carbon dioxide (CO2) after treatment with sodium hydroxide (NaOH). The influence of alkaline concentration and volumetric flowrate of CO2 was investigated. Experimental results showed that carbonation reduced the leaching of Cu, Pb, Zn, and Cr. The pH of leachate decreased from around 12 to 10.5. The content of soluble chlorides was also decreased after carbonation. Additionally, the application of accelerated carbonation enhanced the sequestration of CO2 from MSW incineration plants. The TG/DSC analysis indicated that MSWI fly ash sequestrated approximately 185 g CO2/kg waste.
Comparing predicted PCDF isomer patterns with those obtained from a municipal waste incinerator assessed the role of two-phenol condensation pathways in the formation of PCDFs. Complete PCDF homologue and isomer distributions were obtained from a Fluidized Bed Incinerator (FBI). Two-phenol condensation model, dependent only on the distributions of phenols, was developed to predict the PCDF congeners produced from phenol precursors. R-squared values from linear correlations are presented for the dichlorinated through hexachlorinated isomer distributions between measured and predicted. They range from 0.003 to 0.1 for the dichlorinated through hexachlorinated isomer sets. Agreement between predicted and measured PCDF isomer distributions was very poor for all homologues. Two-phenol condensation pathways are not likely to be the predominant pathways in the formation of PCDF in a FBI. However, dibenzofuran (DF) is likely to be produced from a condensation of two phenols. This work demonstrates the use of PCDF homologue and isomer patterns for testing PCDF formation mechanism from two-phenol condensation pathways in municipal waste incinerators.
A Numerical simulation on the thermal flow performance was carried out to propose the incinerator type for the domestic refuses and to investigate the design factor and operating conditions. The SSTI(Standard Stoker Type Incinerator) proposed in this study was modified from the type with central flow. It has the characteristics of good mixing between refuse and hot combustion gas in primary combustion chamber and between unburned gas inflowing and secondary air jet in secondary chamber.
By predictive results, the SSTI was no recirculation zone in secondary chamber so that mixing time was increased with high residence time. It has good characteristics of combustion and low emission. Parametric screening studies have been understood with phenomenon of combustion in incinerator.