Using the waste(sand wastr and boiler ash) in fluidized bed inciverator, lightweight aggregate concrete was produced and a recycling plan was prepated. The first, the result of the leaching test shows that the waste fluid sand and boiler ash did not exceed the effluent standard. This indicates that there is no harmful effect for recycling. The second, in the lightweight aggregate test using waste fluid sand and boiler ash, the sample that combined cement, waste fluid sand, and sand showed the highest compressive strength, and the mix proportion was 10: 7: 3. Lightweight aggregate concrete that combined cement, waste fluid sand, boiler ash, and sand had a low compressive strength by and large. The third, the same results were identified in the relation between the content of SiO2 and that of Na2O. As the SiO2 content is lowered, the overall viscosity and plasticity of the concrete also decrease, which is not a good condition to form concrete. As for Na2O, as the content increases, the viscosity of the sample and the viscosity of the cement are remarkably lowered, and the strength of the finished concrete is lowered. Therefore, it was concluded that the higher the content of SiO2 and the lower the content of Na2O, the more suitable it is to mix with cement to produce concrete. Fourth, from the fluidized bed incinerator currently operated by company A in city B, a total of 14,188 tons/year were discharged as of 2016, including 8,355 tons/year of bottom ash (including waste fluid sand) and 5,853 tons/year of boiler ash. The cost for landfill bottom ash and boiler ash discharged is 51,000 won/ton, and the total annual landfill cost is 723,588,000 won/ year. Assuming that the landfill tax to be applied from the year 2018 is about 10,000 won/ton, and if there is no reduction in waste disposal charge, an additional landfill tax of 141,880,000 won/year will be imposed. Consequently, the sum total of the annual landfill cost will be 865,468,000 won/year. Therefore, if the entire amount is used for recycling, the annual savings of about 8.7 billion won can be expected.
우리나라에서 폐기물을 처리하는 방법에는 크게 매립, 소각, 재활용이 있으며 일반적으로 폐기물을 수거하여 재활용 할 수 있는 부분을 제외한 나머지는 소각한 뒤 매립을 하는 방식을 택하고 있다. 매립은 계속적인 매립지 확보에 어려움을 겪고 있으며 폐기물의 배출량이 갈수록 증가됨에 따라 예상되는 매립지의 기대수명이 점점 감축되고 있다. 이러한 상황에서 우리나라에서는 폐기물을 짧은 시간 안에 매우 안정적으로 처리할 수 있는 소각기술로 시야를 넓혀야 한다. 소각은 대부분 재활용할 수 있는 폐열 및 고형화연료를 확보할 수 있을뿐더러 매립지의 수명도 효과적으로 늘릴 수 있다. 또한 소각이 완료된 후의 소각재는 수분까지도 거의 제거된 상태이기 때문에 바로 매립이 가능한 정도에 이르렀다. 환경부에서 발행한 ‘전국 폐기물 발생 및 처리 현황(2015년도 수정본)에 따르면 소각과정에서 발생된 연소재의 일일배출량은 점점 증가하는 추세이다. 따라서, 소각재를 매립하는 방법 외에 재활용할 수 있는 방안을 모색하여 매립지의 수명연장은 물론 효율적인 재활용자원으로 사용할 수 있게 만드는 것이 필요하다. 그러나 소각재는 현행 폐기물 관리법상 중금속 농도가 비교적 낮기 때문에 일반폐기물로 관리되고 있었으나 유해성 논란이 끊이질 않고 있다. 따라서, 소각재에 들어있는 유해중금속의 농도를 효과적으로 처리하여 낮추면 다른 분야에서 즉각 활용할 수 있는 좋은 재료로 사용할 수 있을 것이다. 본 연구에서는 소각재의 처리 실태를 알아보고 재활용되고 있는 방법들을 검토, 비교하고 현재 유동상식 소각로에서 배출되는 폐유동사의 재생골재로의 재활용 가능성에 대해 알아보았다. 추가적으로 유동상식 소각로에서 배출되는 보일러재와의 배합 가능성, 그리고 성분분석을 이용한 함유성분의 함량과 재활용 목표의 관계도 연구하였다. 이는 기존에 활용되고 있는 재활용 방법과 새롭게 이용할 수 있는 방법에서 원재료로 사용되고 있는 것들을 대체할 수 있는가에 대한 것이다. 기존에 사용되고 있는 원재료만큼의 효율이 나온다면 원가절감은 물론 폐기물 재활용, 나아가서는 자원재이용에 따른 환경문제 감소에 도움이 될 수 있을 것이라 판단된다.
국내 폐기물 소각시설의 에너지 회수효율 관련 규정으로는 「폐기물관리법 시행규칙」 제3조(에너지 회수 기준 등)에 명시되어 있으며, 에너지 회수효율 기준으로는 75 % 이상(생산량 기준) 회수된 열에너지를 스스로 이용하거나 다른 사람에게 공급할 것으로 규정하고 있다. 또한, 2016년 5월 제정된 「자원순환기본법」 내 제21조에서는 폐기물을 순환이용할 수 있음에도 불구하고 소각・매립방법으로 처분하는 경우 폐기물처분부담금을 부과하도록 명시하였으며, 동법 제24조에 따르면 소각열에너지를 50 % 이상 회수하여 이용하는 경우 폐기물처분부담금을 감면할 수 있도록 규정하고 있다. 그러나 현행 에너지 회수효율 기준은 생산에너지를 기준으로 산정하고 있어 실제 유효하게 이용된 에너지의 평가가 곤란하며, 에너지원으로는 전력에너지가 반영되지 못하여 에너지 회수효율 증진을 위한 유인방안이 부족한 실정이다. 국내의 폐기물 소각시설의 저위발열량 산정방법으로는 원소분석법(Dulong, Steuer 등), 단열 열량계(Bomb Calorimeter)를 이용하여 측정・분석하고 있으나 소량의 시료 채취를 통하여 폐기물의 대표성을 확보하기에는 많은 어려움이 따른다. 또한, 소각로에 투입되는 폐기물의 특성(성상의 다양성, 계절적 영향 등) 및 시설의 특성 등을 반영하지 못하고 있는 실정이다. 이에 본 연구에서는 지역적 특성 및 소각로・보일러의 형태(stoker, Rotary Kiln, FBC )등을 고려하여 현재 운영 중인 폐기물 소각시설(생활, 사업장) 11개소(17호기)를 대상시설로 선정하여 계측기 측정데이터 및 현장측정(배출가스 조성, 바닥재 배출온도 및 강열감량, 소각로 및 보일러 방열손실)을 통하여 해당 시설의 저위발열량 및 에너지 회수효율을 산정하였다. 이와 같은 산정결과를 바탕으로 향후 에너지 회수효율 향상 제고를 위한 기초자료로 활용하고자 한다.
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.
Since 1987, the use of CFCs and HCFCs in various fields such as refrigerant of a refrigerator and a vehicle, a propellant for a spray, and a urethane foaming agent has been prohibited by Montreal protocol related to ozone depletion materials. Instead of the CFCs having a high ozone depletion potential (ODP), HFC-based refrigerants without a chlorine content were developed but determined as global warming materials. Therefore, to reduce greenhouse gas such as HFCs, including CFCs and HCFCs, having a global warming potential (GWP) of 150 or more, which is abandoned from the existing apparatus, it is required to develop a new eco-friendly, economic, and stable treatment technology. When the auxiliary fuel LPG was used at a flow of 1.0 kg/h with an air ratio of 1.1, the average temperature at the vertical section in the combustion chamber was 1,300 K, which is sufficient to destroy waste HFCs. In the waste refrigerant destruction test, the destruction ratio of waste HFCs was 100% when waste HFCs were injected at a flow of 2.8 kg/h.
Recently, many countries have been interested in waste-to-energy policy and technology due to the economic crisis from high oil price and the demands on securing the sustainable energy sources. As one of the efforts to achieve the sustainable society and maintain low impact of global warming in Korea, the act on the promotion of saving and recycling resources was enacted to implemetnt the effective reduction of waste at source level, reduce, recycling and recovery of waste to energy. Attaining an efficient recovery of waste heat in a cogeneration plant from incineration facilities is important as a resource recovery of waste to energy. In this study, the waste heat recoveries changed by reducing feed pressure in incineration conditions were analyzed. As results, changing the operating condition in steam header resulted in stable heat supply and increase of waste heat recovery.
Infectious diseases in domestic animals of carcase were increasing every year. According to the monthly report for infectious disease from Ministry for Food, Agriculture, Forestry and Fisheries, 11,954 heads of cattle, 518,178 heads of pig, 232,850,244 heads of bird were reported in 2011. Infectious diseases of carcase almost spread on a national scale. Dead or emergency preventive carcase are completely treated on bury. Since the treatment of carcase on bury are generating soil, underground water and source water pollution, introduction of new preventive system should be considered. In this study, literature survey and case studies to prevent the spreading of virus for infectious disease and second environmental pollution were investigated. The actual experiments using the existing incineration facilities were also performed to ensure the possibilities of safe treatment of carcase. On the other hand, the moving-type incineration are also being developed and its operation manual will be prepared. Among the investigated incinerators, stoker type incinerator was not suitable for the treatment of carcase, however, other incinerators such as fluidized-bed type incinerator, rotary kiln type incinerator ware shown to be suitable. But even for the stoker type incinerator, if the pre-treatment facilities( grinding, crushing) are installed, it will also be a suitable method. The analytical results for air pollutants(including dioxin) emitted from the final exit were all satisfied to the air pollution emission standards.
The emissions characteristics of particulate matters(PM) according to the types of wastes from industrial waste incinerator of 800 kg/hr treatment capacity were investigated. For this study, the incinerate waste are as follows; waste resin, waste wood, waste urethane, waste gunny, and waste paper. The particulate samples were collected to be emitted in stack and air pollution control(both cyclone and bag filter). In stack, the concentrations of PM were in the range of 2.61 to 26.51 ㎎/S㎥ and the major chemical species were C, Si, Cl, K, Na, Ca in all the wastes. In cyclone fly ash, the mean content of heavy metal were in the order of Fe > Zn > Pb > Cu > Mn > Cr > Ni > Cd > As > Hg and the heavy metal content of waste resin were Zn 34,197.5 mg/kg, Fe 27,587.6 mg/kg, Pb 6,055.8 mg/kg, respectively. In bag filter fly ash, the mean content of heavy metal were in the order of Zn > Pb > Fe > Cu > Mn > Cd > Cr > Ni > As > Hg and the heavy metal content of waste wood were Pb 36,405.2 mg/kg, Fe 15,762.9 mg/kg, Cu 9,989.5 mg/kg, Cd 2,230.1 mg/kg, respectively. Comparing the heavy metal content of both cyclone and bag filter, in cyclone, the Cr, Fe, Ni content were higher than in bag filter and the Cd, Cu, Hg content were lower than in bag filter.
The short-term version of Industrial Source Complex Model(ISCST3) was evaluated for estimating short-term concentrations using criteria pollutant(SO2, NO2, CO, PM10) data form emission inventory of Young Tong area in Suwon for the year 2002. The contribution of pollutant concentration from point, line, area sources was found 21.8, 76.5 and 1.6%. Statistical parameters, such as correlation coefficient, index of agreement(IA), normalized mean square error(NMSE) and fractional bias(FB) were calculated for each pollutants. The model performance were found good for PM10(82%) and NO2(69%), but poor for SO2(34%) and CO(13%).
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.
The purpose of this study is providing basic data to control the air pollutants from solid waste incinerator. Incinerating the waste wood, the electrostatic precipitator had the best collection efficiency. The leather incineration had the same collection efficiency as synthetic resin incineration. And the coarse particle collection efficiency was high. As you know in correlation of leather incineration, pollutants produced a from incinerator are mostly fine particles. If the scrubber used only in the process produced a lot of fine particles. It is adequate to use the above control devices, together with high efficiency collector like bag-filter. To select the adequate control devices, it is required to investigate the size distribution before establishing control devices.
The objectives of this study are to examine combustion characteristics of E.V.A. and rubber wastes by fixed-bed incinerator. The results are as follows. Combustion temperature with time rises rapidly, and mass of E.V.A. reduces at short time in E.V.A. combustion. In variation of air-fuel ratio (m), the ideal values of m of E.V.A. and rubber are 2.5, 1.5 respectively. Mixed-waste combustion is more economic than single E.V.A. combustion, because we can get high combustion efficiency (94.0∼99.0%) at 2.0 air-fuel ratio of mixed-waste combustion. Removal efficiencies of SO2 at cooling tower are about 20%. The combustion efficiencies of rubber are over 98.0% according to the experimental conditions.