This study was carried out to examine the improvement plan by analyzing the characteristics of imported wastes, operation rate, and benefits of energy recovery for incineration facilities with a treatment capacity greater than 50 ton/ day. The incineration facility capacity increased by 3,280 tons over 15 years, and the actual incineration rate increased to 2,783 ton/day. The operation rate dropped to 76% in 2010 and then rose again to 81% in 2016. The actual calorific value compared to the design calorific value increased by 33.8% from 94.6% in 2002 to 128.4% in 2016. The recovery efficiency decreased by 29% over 16 years from 110.7% to 81.7% in 2002. Recovery and sales of thermal energy from the incinerator (capacity 200 ton/day) dominated the operation cost, and operating income was generated by energy sales (such as power generation and steam). The treatment capacity increased by 11% to 18% after the recalculation of the incineration capacity and has remained consistently above 90% in most facilities to date. In order to solve the problem of high calorific value waste, wastewater, leachate, and clean water should be mixed and incinerated, and heat recovery should be performed through a water-cooled grate and water cooling wall installation. Twenty-five of the 38 incineration facilities (about 70%) are due for a major repair. After the main repair of the facility, the operation rate is expected to increase and the operating cost is expected to decline due to energy recovery. Inspection and repair should be carried out in a timely manner to increase incineration and heat energy recovery efficiencies.

Over the past two decades, the options for solid waste management have been changing from land disposal to recycling, waste-to-energy, and incineration due to growing attention for resource and energy recovery. In addition, the reduction of greenhouse gas (GHG) emission has become an issue of concern in the waste sector because such gases often released into the atmosphere during the waste management processes (e.g., biodegradation in landfills and combustion by incineration) can contribute to climate change. In this study, the emission and reduction rates of GHGs by the municipal solid waste (MSW) management options in D city have been studied for the years 1996-2016. The emissions and reduction rates were calculated according to the Intergovernmental Panel on Climate Change guidelines and the EU Prognos method, respectively. A dramatic decrease in the waste landfilled was observed between 1996 and 2004, after which its amount has been relatively constant. Waste recycling and incineration have been increased over the decades, leading to a peak in the GHG emissions from landfills of approximately 63,323 tCO2 eq/yr in 2005, while the lowest value of 35,962 tCO2 eq/ yr was observed in 2016. In 2016, the estimated emission rate of GHGs from incineration was 59,199 tCO2 eq/yr. The reduction rate by material recycling was the highest (-164,487 tCO2 eq/yr) in 2016, followed by the rates by heat recovery with incineration (-59,242 tCO2 eq/yr) and landfill gas recovery (-23,922 tCO2 eq/yr). Moreover, the cumulative GHG reduction rate between 1996 and 2016 was -3.46 MtCO2 eq, implying a very positive impact on future CO2 reduction achieved by waste recycling as well as heat recovery of incineration and landfill gas recovery. This study clearly demonstrates that improved MSW management systems are positive for GHGs reduction and energy savings. These results could help the waste management decision-makers supporting the MSW recycling and energy recovery policies as well as the climate change mitigation efforts at local government level.

This study examined the potentials for greenhouse gas reduction by material recovery and energy recovery from municipal solid waste between 2017 and 2026 in Daejeon Metropolitan City (DMC), which is trying to establish a material-cycle society by constructing a waste-to-energy town by 2018. The town consists of energy recovery facilities such as a mechanical treatment facility for fluff-type solid refuse fuel (SRF) with a power generation plant and anaerobic digestion of food waste for biogas recovery. Such recycling and waste-to-energy facilities will not only reduce GHGs, but will also substitute raw materials for energy consumption. The emissions and reduction rate of GHGs from MSW management options were calculated by the IPCC guideline and EU Prognos method. This study found that in DMC, the decrease of the amount of MSW landfilled and the increase of recycling and waste-to-energy flow reduced GHGs emissions from 167,332 tonCO2 eq/yr in 2017 to 123,123 tonCO2 eq/yr in 2026. Material recycling had the highest rate of GHG reduction (-228,561 tonCO2 eq/yr in 2026), followed by the solid refuse fuels (-29,146 tonCO2 eq/yr in 2026) and biogas treatment of food waste (-3,421 tonCO2 eq/yr in 2026). This study also shows that net GHG emission was found to be -30,505 tonCO2 eq in 2017 and -105,428 tonCO2 eq, indicating a great and positive impact on future CO2 emission. Improved MSW management with increased recycling and energy recovery of material waste streams can positively contribute to GHGs reduction and energy savings. The results of this study would help waste management decision-makers clarify the effectiveness of recycling MSW, and their corresponding energy recovery potentials, as well as to understand GHG reduction by the conversion.

The use of mechanical treatment (MT) for preparing solid refuse fuel (SRF) using municipal solid waste has been growing in Korea. One of the problems with using this treatment measure is the generation of residual waste from the MT, which will not be contained in the SRF. Most of this waste will be dumped into landfill instead of being used for the production of SRF. Much of the waste will be organic portions originating from food and biodegradable wastes. Consequently, the organic portion dumped into the landfill generates methane gas, which is a strong greenhouse gas. In this paper, the waste from MT was investigated directly at the MT facility located at Su-Do-Kwon landfill site to develop proper treatment measures to avoid disposing of the MT waste in landfill, which is prohibited in Germany and England.

Depending on the steam pressure and temperature balance, it is possible to increase the power generation efficiency of the steam turbine by increasing the heat loss of the turbine by increasing the temperature and pressure. As the high temperature and high pressure increase, the boiler main steam amount is reduced by about 10%, but the increase rate of the heat drop is larger than the decrease rate of the steam flow rate, leading to improvement of power generation efficiency. Utilizing the US Department of Energy Steam Turbine Calculator, we calculated the electricity produced by steam temperature and pressure changes. In this study, the steam temperature was increased from 50℃ to 500℃ at the steam temperature of 20 kg/cm²×300℃, and increased by 10 kg/cm² at the pressure of 20 kg/cm² at the pressure of 60 kg/cm² to investigate the changes in electricity production. Electricity production increased with increasing temperature and pressure. The electricity production was increased by 40.11% at 40 kg/cm²×400℃ and 75.56% at 60 kg/cm²×500℃ compared to the standard condition of 20 kg/cm²×300℃ for comparison.

Energy can be reduced by reducing the exhaust gas temperature at the catalyst inlet and reducing or not using the amount of steam to reheat the exhaust gas. At this time, it is a method to improve the power generation efficiency by using the saved energy for power generation. When the exhaust gas temperature at the inlet of the catalytic reaction tower is operated at about 210℃, it is necessary to increase the temperature of the flue gas downstream of the bag filter at 165℃ to 45℃ to 210℃ required for the catalytic reaction. In the case of low temperature catalyst application, the temperature required for the catalytic reaction tower may be 185℃ and the temperature may be raised only 20℃. Therefore, the amount of steam for heating can be reduced. If the exhaust gas temperature of the bag filter inlet can be increased to 190℃, it can be combined with the low-temperature catalyst to reduce the energy consumed by removing exhaust gas ash. On the other hand, since the high-pressure steam is used as the heat source for reheating the exhaust gas, the reheating temperature is limited. According to such conditions, the exhaust gas temperature at the inlet of the catalytic reaction tower is often designed at about 200 to 220℃.

Emissions of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurnas (PCDFs) in stack gas were analyzed from 21 municipal solid waste incinerators (MSWs) using high resolution gas chromatography equipment with a high resolution mass spectrometer (HRGC/HRMS) in 2015. The concentration of PCDDs/DFs was in the range 0.09 ~ 354.54 pg-TEQ/Sm3 based on the International Toxicity Equivalency Factor (I-TEF) and all MSWs complied with emission standards. The congener distribution of PCDDs/DFs was categorized into one group and two outliers via principal component analysis (PCA). Among the 17 PCDDs/DFs, 1,2,3,4,6,7,8-HpCDD showed the highest mass fraction (20.8%) and 2,3,4,7,8-PeCDF showed the largest TEQ contribution (42.9%).

WtE of MSW plays a crucial role in renewable energy production in Korea. Municipal solid waste (MSW) is an important energy resource for combined heat and power (CHP) production. This study investigated an increasing method to the power generation efficiency by MSW to energy (WtE) plants in South Korea and discussed the issues related to energy efficiency improvement. To achieve energy efficiency improvement is used to lower temperature for emission gas at catalyst inlet, or to reduce/stop using steam to reheat emission gas. Saved energy from this process can be used as power source in order to increase generation efficiency. It is possible to increase denitrification efficiency by maintaining the temperature of emission gas for catalyst denitrification. The temperature of emission gas of which moisture is increased to saturation point (relative humidity of 100%) at the exit of wet scrubber is between 50 and 60℃. This means there should be reheating of emission gas with the approximate temperature of 150℃. Dry emission gas treatment, on the other hand, is the technology to increase generation efficiency by using highly efficient desalination materials including highly-responsive slaked lime and sodium type chemicals in order to comply with air pollution standards and reduce used steam volume for reheating emission gas. If dry emission gas is available, reheating is possible only with the temperature of 45℃ in order to expect generation efficiency by reducing steam volume for reheating.

When adopting drain close system, the temperature of emission gas at the boiler exit is set high by spraying and evaporating drained water on quencher tower. According to applying drain close system boiler and power generation efficiency were decreased. In case of the water close system is not applied to treat the wastewater from incineration facility, the economizer outlet temperature can be reduced to 190∼220℃. And this leads to the increased ability of boiler's heat recovery. However, the temperature of emission gas at economizer exit should be set at 250℃ or higher if applying drain close system (minor conditions can affect as well). Boiler efficiency and generation efficiency can be improved by comparing the temperature of emission gas at economizer exit at 190℃ without the introduction of drain close system and 250℃ with drain close system. There are three types of white plume reduction equipment: one is offline type to blow air into chimney through heat source and exchange points after heating the air by using steam from equipment like boiler; another is in-line type to blow air into chimney through heat exchanger of combustion emission gas (mainly boiler exit); and the other is to blow air into chimney through hot wind burner by using fuels including kerosene. At a facility with white plume reduction equipment equipped with 5℃ of outdoor temperature and 60% of humidity, power generation volume and generation efficiency can be improved by using leftover steam for steam turbine from suspension of using white plume reduction equipment.

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.

This study examined how OECD countries treat municipal solid waste (MSW) and how their methods of recovering energy after waste incineration changed as leaders prepared to resource circulation and reduce greenhouse gas emissions. The results showed that Korea, with its per capita MSW of 350 kg and recycling rate of 59%, was the most efficient among the 14 countries studied in regards to waste management. In Korea, the rate of waste reclamation dropped from 71% in 1995 to 15.7% in 2014. However, the rate of waste incineration is expected to increase, allowing the rate of waste reclamation to decrease to less than 1%. In addition, the study showed that the average rate of waste incineration was 49.8% in the OECD-EU countries and Japan, where reclamation rates are relatively low, and this average rate was higher than Korea’s rate of 25.3%. Therefore, Korea needs to identify ways to increase the rate of waste incineration and recover more energy from existing and future incineration plants. Such measures, along with the 3Rs of municipal solid waste and energy recovery, would help Korea become a society of both low carbon and resource circulation.

지금껏 안정적으로 폐기물을 처분해왔던 방법에 변화를 가져올 정책과 국제협정이 최근 제정 및 체결되었다. 첫 번째는 2016년 5월 29일 자원순환기본법이 제정･공포되어 2018년 1월 1일부터 시행될 예정으로 자원순환사회 기반을 구축하기 위한 제도적 기틀을 마련한 것이다. 지금까지 자원의 절약과 재활용촉진에 관한 법률에 의해 추진해오던 것에 비하면 자원순환에 관해서는 다른 법률에 우선하기에 폐기물 처분방법에 있어 변화가 있을 것으로 본다. 두 번째는 2015년 12월 프랑스 파리에서 열린 2020년 이후의 신기후체제가 논의되어 모든 국가가 온실가스 감축에 참여하는 파리협정을 체결하였다. 이로 인해 폐기물부문도 온실가스 감축을 위한 방안과 실행계획 마련이 있을 것으로 본다. 이 같은 정책과 국제협정이 지금껏 안정적으로 처분해왔던 폐기물관리에 일정부분 변화를 가져올 수밖에 없는 상황이다. 감량 목적의 단순 소각처분이 아닌 자원이 순환하고 온실가스 감축을 위해 에너지를 최대한 회수하기 위한 방안 마련이 필요한 것이다. 우리나라는 선진화된 폐기물정책 시행으로 인해 폐기물 감량이나 재활용에 있어서는 선도적 역할을 담당해오고 있으나 소각에너지 회수에 있어서는 미흡한 면이 있다. 이에 본 연구에서는 우리나라의 시도별 도시폐기물의 발생 및 처분 그리고 소각시설에 대한 현황을 2000년 이후 2014년까지 5년 주기의 변화 추이를 살펴봄으로써 앞으로 자원순환 정책과 기후변화 협약에 대응할 수 있는 방향성을 제언하고자 한다.

최근 급속한 경제 성장과 소비 수준의 상승으로 폐기물 배출량이 급격히 증가했고, 질적으로도 다양화 되고 있다. 우리나라 폐기물 처리정책의 주요내용은 자원을 효율적으로 이용함으로써 자연으로부터의 자원채취를 최소화함과 동시에 자연으로 되돌려지는 폐기물을 최소화함으로써 자연환경을 보호하고 사람의 건강을 보존하는 것이다. 선․후진국을 막론하고 폐기물관리정책의 변화과정은 비슷하다. 이러한 폐기물의 적정처리와 국가 에너지자원의 활용측면에 있어서 매우 중요한 역할을 담당하고 있는 소각시설은 현재 정부가 추진 중에 있는 ｢자원순환사회전환촉진법｣ 제정에 따라 적지 않은 변화가 있을 것으로 판단된다. ｢자원순환사회전환촉진법｣은 자원 및 에너지 소비량의 증가에 따라 계속적으로 폐기물 발생량이 증가하고 있는 국내의 사회적 구조를 고려할 때 폐기물의 발생억제 및 순환이용 촉진 등 자원순환사회 실현을 위한 기반 마련을 위하여 반드시 필요한 제도임에 틀림없다. 자원순환 성과관리제를 통하여 검토되고 있는 폐기물처분부담금(소각 또는 매립)은 에너지를 회수하지 않는 단순 소각시설의 경우 재활용비용에 버금가는 소각세를 부과한다. 그러나 일정기준 이상 에너지를 회수하여 사용하는 소각시설은 폐기물처분부담금의 감면혜택이 부여됨으로써 폐기물로부터 에너지를 회수하는 에너지회수시설과 단순 소각시설의 차별화가 뚜렷이 구분될 것으로 판단된다. 이에 본 연구에서는 생활폐기물 소각처리 시설(2개소, 3호기)을 대상으로 2015년 ｢폐기물관리법｣ 시행규칙 제3조제2항에 따른 “폐자원에너지 회수･사용률 산정방법”에 따라 에너지회수율을 산정하였다. 각각의 저위발열량 및 에너지회수･사용률 산정인자(Ep, Ew, Ei, Ef)는 3개월 동안의 계측기 측정값과 현장측정(배출가스 조성, 방열손실, 바닥재 보유열 등)결과를 바탕으로 산출하였다. 폐자원에너지 회수･사용률 산정결과로는 A시설(1호기･2호기)의 경우 생산량 기준 98.6 %, 사용량 기준 26.9 %로 산정되었다. B시설(1호기)에서는 생산량 기준 99.0 %, 사용량 기준 81.9 %로서 생산량 및 사용량 모두 높은 비율을 나타났다. 반면, A시설에서는 생산량 대비 사용량 기준 27.3 %로서 낮은 유효사용률을 나타내었으며, 유효사용률을 높이기 위해서는 다양한 방안(소내 소비감소, 소각시설의 효율적 가동, 폐열보일러의 효율 향상, 안정적인 수요처 확보 등)을 강구할 필요가 있을 것으로 판단된다.

In recent years, waste-to-energy conversion using municipal solid waste (MSW) has been gaining attention in municipalities. Such conversion can reduce the dependency of non-renewable energy such as fossil fuels by generating solid refuse fuel (SRF) and diverting landfilling of the waste, although there is debate over the efficiency and economic aspect of the practice. With a growing interest in the conversion, D city is trying to adopt all possible measures towards achieving a material-cycle society by constructing a waste-to-energy town by 2018. The waste-to-energy town will be comprised of energy recovery facilities such as a mechanical treatment facility for fluff-type SRF with a power generation plant, and anaerobic digestion of food waste for biogas recovery. In this paper, we focus on estimating the energy recovery potentials and greenhouse gas (GHG) reduction of MSW by waste-to-energy conversion under three different scenarios. The data required for this study were obtained from available national statistics and reports, a literature review, and interviews with local authorities and industry experts. The lower heating value was calculated using the modified Dulong equation. Based on the results of this study, the energy recovery potential of MSW was calculated to be approximately 14,201-51,122 TOE/y, 12,426-44,732 TOE/y, and 8,520-30,673 TOE/y for Scenarios 1, 2, and 3, respectively. The reduction of GHG by such conversion was estimated to range from 10,074-36,938 tonCO2eq/y, depending on scenario. This study would help determine the production rate of fluff-type SRF to be converted into a form of energy. In addition, this study would aid waste management decision-makers to clarify the effectiveness of recycling of MSW and their corresponding energy recovery potentials, as well as to understand GHG reduction by the conversion.

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.

The purpose of this study was to analyze the physicochemical characteristics of bottom-ash recycling from municipal solid waste incineration (MSWI) and investigate the possibility of the use of bottom ash for Lightweight Aggregate for Structural Concrete and Bottom Ash Aggregate for Road Construction according to Korean Industrial Standards (KS). Samples were taken from the MSWI bottom ash collected at the resource recovery facilities “A” and “B.” In the results, both samples did not satisfy the criteria of the particle sizes. In particular, the two samples failed to comply with the physical and chemical characteristics criteria of the Lightweight Aggregate for Structural Concrete. On the other hand, both bottom ash samples met the physical characteristics criteria of the Bottom Ash for Road Construction. Therefore, the recycling of Bottom Ash Aggregate for Road Construction can be more a suitable method for recycling, provided that proper pre-treatment as a screening process for bottom ash is performed.

Due to the problems on BW (Bulky Waste) from SRF (Solid Refused Fuel) facilities in terms of operation andmaintenance, we investigated the characteristics of bulky waste about physical composition ratio, discharge type and ratio,etc. BW are 5.83% in MSW (Municipal Solid Waste) and composition ratio is as below; fiber (28.22%), plastic (19.18%),paper (17.95%), wood (17.02%), metal (11.49%), vinyl (3.3%), styrofoam (2.84%). Paper was mostly packing box, wood;chipboard, pieces of wood, branch, vinyl; big vinyl bag, plastic; home appliance, toy, big piece of plastic, fiber; clothing,mattress, sponge, styrofoam; pieces of styrofoam box, metal; broken metal stuff. BW has characteristics that is bulky andmainly consist of recycle waste compared with general MSW. We compare the composition ratios of only BW, MSWincluding BW and not including BW in order to extend to which variation in BW affects on physical composition ratioof general MSW. As a result of these researches, physical composition ratio between MSW not including BW and BWhas some difference but correspond closely with MSW including BW. This is because BW component ratio is so smallthat have little effect on composition ratio of total waste. Conclusively BW component and physical composition ratio,discharging type should be investigated for characterizing BW. But BW composition ratio needs not to be included onlyfor analyzing physical composition ratio of waste.

Municipal Solid Wastes (MSW) are disposed of three types (recycling, incineration, landfill). The ashes made after the incineration are also recycled to minimize the volume of waste owing to reducing the amount of landfill. However, MSW incinerations (MSWI) in Seoul are not satisfied with the policy of Korea as a result of experiments about the chemical characteristics of the ash (Ignition loss, pH, Chloride, Cyanide, metals leaching). So, according to the policy, the MSWI in Seoul must be pretreated so as to recycle the MSWI. There are many pretreatments, three pretreatments (washing, weathering, CO2 aging) of which are selected through the literature review. Through Washing, the value of pH and chloride decrease. The optimal ratio (S/L) and time of Washing treatment is 1 : 10 (S/L) and 60 minutes, respectively. The CO2 aging method compensates the defect of weathering method which is required to react long-period time. After CO2 aging, pH and some Heavy metals decrease. So, We will compare and evaluate pre-treatment methods and we find the best method or new method.

Incineration allows for the recovery of energy from combustible waste. It would be highly beneficial to society if this heat could be used efficiently. However, due to the difficulties involved with storing and transporting heat energy, consumers would need to live near incineration facilities in order to make efficient use of this heat energy. Moreover, it is usually difficult to achieve a balance between heat demand and supply. For instance, although there is a significant demand for heat in Northern Europe, the demand for electricity in that region is larger than the demand for heat in Central/Southern Europe. Hence, the preferred form of energy recovery differs depending on the nation or regional conditions. However, there are no limitations with regard to electricity because it can be used in a variety of ways. As a result, leading countries such as those in the European Union and the United States have been developing technologies and building facilities to recover electricity. In Korea, stable operation (steam condition 200-300℃, 20-25bar) was given priority over energy recovery because the country’s background with regard to the measure for dioxin is different from that of Europe or the United States. In addition, the produced energy has been mostly self-consumed rather than sold. While Korea is implementing incineration energy recovery, the country’s incineration power generation is considerably lower than that of leading nations. According to the 6thbasic plan for power supply(2013–2027), which was announced in 2013, the government of Korea is planning to secure a power generation capacity of 688 MW (as of 2012, a level of 74 MW was attained) from waste. Accordingly, this paper examined trends and efficiency improvements for incineration power generation in leading countries.

현재 폐기물 자원회수시설은 폐기물을 감량화‧무해화하고 소각처리시 발생되는 열을 이용하여 지역 기저 난방부하를 담당하고 있으며, 주민들에게 각종 편의를 제공하는 등 지역의 중요한 에너지원으로 자리하고 있다. 2012년 신재생에너지 통계에 따르면 전체 신재생에너지의 원별 공급비중에 있어서 폐기물에너지가 차지하는 비중은 67.8%로 나타나며, 그 중 산업폐기물 및 생활폐기물의 자원회수시설로부터 회수되는 에너지 생산량이 차지하는 비중은 전체 폐기물 에너지 생산량의 약 35%로 신재생에너지의 전체 공급비중을 고려할 경우 23.6%에 해당할 만큼 매우 중요한 비중을 차지하고 있다. 그러나 폐기물의 발생 및 성상이 불균일하고 특히 계절별로 상당한 차이가 있으며, 난방 열수요 또한 계절별로 큰 차이를 가지고 있다. 그로인해 에너지자원으로의 활용도는 감소한다. 본 연구에서는 폐기물 중간처리시설로서 자원회수시설들의 에너지 생산 및 활용실태를 파악하고 이를 효율적으로 이용하기 위한 기초자료를 확보하고자 한다. 에너지 전환효율을 평가하기 위해 수도권 소재 생활폐기물 자원회수시설 5곳을 대상으로 2011년 ~ 2013년 월별 에너지 생산, 손실, 공급량 등을 조사하였으며, 회수율법, R1, 손실율법을 이용하여 에너지 회수효율을 산정하였다. 5개 시설 전체 에너지 회수효율을 산정한 결과, 2013년 기준 회수율법 69.8%, R1 80.9%, 손실율법 68.8%를 나타내어 산정방식별로 큰 차이가 있음을 알 수 있었다. 본 연구에서는 회수된 여열을 사용량 기준으로 산정하였으며, 4개 시설(2012년 가동된 E 시설 제외) 3년간 평균 71.1%로 기존의 여열 생산량 기준으로 산정된 회수효율 75.5%와 다소 차이가 있었다. 각 시설별로 회수율법을 이용하여 최근 3년간 평균 에너지회수효율을 산정한 결과, A, B, C, D, E시설은 각각 74.6%, 69.3%, 71.7%, 64.6%, 61.0%을 나타내었으며, 시설규모가 가장 작은 E시설이 가장 회수효율이 낮았다. D시설의 경우, 대기오염방지시설 규모가 크고 옥외에 노출되어 있어 방열 및 기타 열손실이 많았으며, 이로 인해 에너지 회수효율이 비교적 낮았다. 계절별로는 하절기에 5개 시설 평균 63.4% ~ 68.9%의 회수효율을 나타낸 반면, 하절기를 제외한 연평균 회수효율은 71.2% ~ 76.1%를 나타내었는데, 이는 하절기에 열수요가 감소하여 생산된 에너지를 제대로 활용하지 못 했기 때문인 것으로 판단된다. 전기를 생산하는 시설은 2곳이었으며, 이들 시설은 하절기에 에너지 회수효율이 비교적 높게 나타나 에너지 회수방법을 다양화하였을 경우 그 효율도 높아짐을 확인할 수 있었다.