PILOT PLANT EXPERIMENT OF ORGANIC SLUDGES CO-INCINERATION WITH MUNICIPAL SOLID WASTE USING OXYGEN-ENRICHED AIR

摘要

In this study, pilot-plant experiments were performed to evaluate the effect of oxygen enrichment on the co-incineration of municipal solid waste and organic sludge from a waste water treatment facility. The design capacity of the stoker-type incinerator pilot-plant was 150 kg/h. Combustion chamber temperatures, as well as the stack gas concentrations, i.e., NOx and CO, and the residual oxygen were measured. The maximum ratio of organic sludge waste to total waste input was 30%. Oxygen-enriched air, 22% oxygen, was used for stable combustion. As the co-incineration ratio of the sludge increased, the primary and secondary combustion chamber temperatures were decreased to 900 and 750 ℃, respectively, approximately 100 ℃ below the proper incineration temperatures (primary: l,000 ℃, secondary: 850 ℃). However, if the supplied air was enriched with 22% oxygen content, the incinerator temperature was high enough to burn the waste mixture containing 30% sludge, with an estimated heating value of 1,600 kcal/kg. There are two main benefits of using oxygen enrichment in the co-incineration; first, the sensible heat can be reduced as the quantity of nitrogen in the flue gas will be decreased. However, this has been shown to not be significant, based on the results from computer simulation, including a heat balance calculation. Secondly, the unburned carbon formation is reduced due to the oxygen-enriched burning of the waste, despite an increase in the sludge co-incineration ratio.