According to IPCC Guidelines for Greenhouse Gas Inventories Volume 2 (energy) and Volume 5 (waste), waste incineration facilities are both energy production facilities and GHG emission facilities. The methods for calculating the emission are Tier 1, Tier 2, Tier 3. Tier 4, which recognizes the trend factor with Continuous Emission Measuring system(CEMS). Korea is currently in the process of transition from Tier 1 to Tier 3 and is reviewing Tier 4 on a trial basis. Under the IPCC and the Korean Environment Corporation's guidelines for calculating Greenhouse Gas emissions, waste incineration facilities are mixed combustion facilities for biogenic carbon fraction(BCF) and fossil carbon fraction(FCF), with carbon dioxide accounting for most of the emissions, and only carbon dioxide generated from FCF. Methods for calculating biogenic carbon fraction are accepted by the default value of IPCC guideline based on waste characteristics (Tier 1, 2) and the ASTM D6866 test method for measuring radioactive isotopes ( 14C) among combustion gases. There are uncertainties to check 14C content in atmosphere, which is an important factor in measuring biogenic carbon fraction. In Korea, where TMS is installed at the exhaust gas stack for real-time and long-term monitoring, Tier 3 levels can be applied when calculating emissions. This is why the FCF requires a standard for an appropriate atmospheric concentration of 14C. This paper reviewed the Fossil Carbon Fraction (FCF) for textiles and diapers and obtained the adjusted default factors and the Korean index of percent Modern Carbon (pMC), a key factor in the BCF calculation, among the factors that lead to uncertainty in the emission calculation of emissions.

Most of the greenhouse gas reduction results will be recovered from energy when calculating emission reductions. There are two approaches to calculating energy recovery efficiency: thermodynamic approaches and indirect greenhouse gas emission coefficients. Thermodynamic approaches include the measurement of energy recovery efficiency under the first law, the calculation of exergy efficiency under the second law, the measurement of power loss coefficient, and the measurement of the exergy/energy fraction by combining the first and second laws. Indirect emission factors calculation method calculates the sum of the energy obtained by multiplying each social average emission coefficient for fuel, electricity, heat, etc. As a standard for calculating energy recovery efficiency, the Energy Recovery Efficiency Index (R1) was introduced in Korea from 2018 as well as in EU from 2008. The R1 index is a formula consisting of a fraction of the energy produced divided by the energy injected (R1 = Eproduct/Einput). When obtaining the sum of the energy used by production, an equivalent factor(EF) of 2.6 times the electricity production and 1.1 times the heat production are given EF. Electricity production contributes more to energy recovery efficiency than heat use.

Among the ways to increase energy recovery effectiveness and reduce greenhouse gas emissions in waste incineration facilities, it is most efficient to increase electricity production. For power generation only, the efficiency of the ACC and how much the use of the reheat cycle in the EU to increase the heat efficiency of incinerators could increase the electricity output.

The objectives of the study set out in this paper are three: the calculation of emissions from incineration facilities in Korea, the formula for calculating the energy recovery efficiency derived from the ratio of electricity/heat, and measures to increase the amount of energy reduction through the efficiency of electricity production. Data was selected from three WtE facilities equipped with energy efficiency formulas were reviewed for efficient use of energy. Firstly, Chapter 3 used the data on the operation status of the national incinerator issued by the Ministry of Environment from 2014 to 2018, and among them, it was verified using the actual data of Plant I. Based on ASTM methodologies, trends for PMC concentrations in the atmosphere were analyzed to estimate trends for applicable PMC concentrations in Korea. The trend curves obtained here were compared with those of the Korea Institute of Geoscience and Mineral Resources(KIGAM), which had the dataes in 14C research in Korea, to verify logical convergence. In addition, the bio-based carbon ratio of textile oil, which has been increasing its share of domestic waste in Korea, was adjusted to examine the emissions of the three facilities, Plant N, S, I. The basis for adjustment was to use research data from the Korea Environment Corporation, which calculated FCF values by analyzing the 14C fraction among domestic household waste emissions. The trend curve obtained above may be used as an indicator of the concentration of 14C in the atmosphere, a major source of uncertainty in calculating emissions at Korean Waste-to Energy facilities. Chapter 4 presents a adjusted model of energy recovery efficiency system R1 based on the equivalent coefficient of electricity/heat in the post-generation cogeneration cogeneration section under cogeneration conditions combined with district heating for three incineration facilities. To compare and analyze this, one of the facilities that were inspected in Korea was added to calculate each energy/exergy efficiency for Plant N, S, and I. The revised energy recovery efficiency (R2) was derived from this calculations, and the revised energy recovery efficiency (R2') obtained by comparing indirect emission coefficients for comparative analysis. The convergence between R1, R2 and indirect emission coefficients used in reducing greenhouse gases was reviewed. Chapter 5 studied a computational simulation to maximize electricity production by increasing energy recovery efficiency based on the emission of Plant S, N, and I obtained in Chapter 3 and 4. According to the current status of heat use in the three facilities above, Plant S and N, which are operated as Combined Heat and Power (CHP), and Plant I, which is a power-only facility, reflect various types of energy use of domestic waste incineration facilities.

The conclusions obtained in each chapter are as follows: Chapter 3 for calculating emissions in the country and concentrations in flue gas detected pMC at 2020 calculated results derived through the Analysis of Korean atmospheric concentrations of pmc, as 101.3, which is a higher value of 100 in ASTM-2020. ASTM applies the same correction factor (REF) as pMC. However, there is a risk of directly equating PMCs to REFs. PMC is applied to external air in the combustion process, but in the case of wood products subject to combustion, specially major content of waste paper in MSW, the age of growth is about 15 to 20 years on average. When estimating the PMC value of timber at 110, referring to other data, the correction index REF value to be applied in Korea is calculated at 102 +/- 0.5. Based on this, the CO2 emissions generated by waste from the three facilities were calculated as 484.5kg.CO2/waste.ton for Plant N, 439.2kg.CO2/ waste.ton for Plant S, and 662kg.CO2/waste.ton for Plant I. Comparing the results of measurement by the Korea Environment Corporation, which measured 14C in combustion gases, with the results by the ASTM methodology, the results showed a higher fossil-based carbon fraction. This seems to be due to fibers that have recently increased occupancy. According to a recent survey of textile sales statistics to determine the bio-based carbon fraction of textiles, the share of Hwaseong fiber among textiles exceeded 50%, indicating that increasing the fossil fiber fraction from 20 percent set by IPCC to 40 percent reflecting the research results was similar to the results of 14C concentration measurement. Because the Biogenic carbon content of textiles was expressed as a component of the standard emission coefficient for IPCC, it was confirmed that changing the fossil-based carbon fraction for textiles to 40 per cent was not different from the standard for IPCC. The CO2 emissions obtained from FCF correction of fibres were calculated at Plant N, S, and I at 542.1kg.CO2/waste.ton, 482.0kg.CO2/waste.ton, 680kg.CO2/waste.ton. Adding to this, emissions calculated by the standard emission coefficient of CH4. N2O were found to be Plant N 550.6 kg.CO2/waste.ton, Plant S 514.4 kg.CO2/waste.ton and Plant I 687.1 kg.CO2/waste.ton, and this result was determined as the reference emission for greenhouse gas emissions.

Chapter 4 reviewed the second subtopic. The R1 index adopts an equal index of 2.6 times the electricity energy sent out to the outside boundaries and 1.1 times the heat energy to outside. The ratio of elecricity/heat is 2.38, which is an advanced recovery efficiency concept partly citing the Second Law of Thermodynamics. Nevertheless, it is difficult to overcome the fact that large amounts of thermal energy use facilities around them are external environment-dependent indices that are judged to be efficient only when heat is used, and all the focus is on how to set the equivalent coefficients for electricity/heat.

This study surveyed in Korean 4 WtE plants which has combined power and heat utilization by calculating Electricity/heat ratio through exergy/energy efficiency. The equivalent coefficient was calculated and found to be minimum 3.67. The equivalence coefficient by indirect emission coefficient comparison varies depending on how the reference index is determined. Based on the standard emission coefficient of Korean factors to produce electricity and thermal energy production groups, the equivalence coefficient was 3.80, the standard emission coefficient of 3.69 by comparing the ratio of coal-fired electricity generation and LNG heat-producing coefficient of 3.90, and the equivalent coefficient of 3.65 using the latest statistics of the above coal-fired electricity and LNG-heated output, so the equivalence coefficient was 3.80 based on the Korean standard emission coefficient. Consequently, we can derive adjusted energy efficiency formula R2 with equivalent factor of electricity/heat ratio as 3.67 by exergetic approaches, and R2’ with 3.80 by indirecti emission factors.

The relationship between energy recovery efficiency and greenhouse gas reduction (R1/CDM) of R1 and the correlation between adjusted energy recovery efficiency and greenhouse gas reduction (R2/CDM, R2//CDM) were calculated and this effect was analyzed. R2 is a coefficient that is faithful to the Second Law of Thermal Studies and reflects the national oil emission coefficient. The R2/CDM 1.63 index obtained from this could be an index that identifies the correlation between energy recovery efficiency and climate change reduction at all incineration facilities nationwide, making it an efficient index to manage all incineration facilities. R2 was also found to be a formula proportional to the greenhouse gas reduction effect. The above R2 index applies only to heat sources supplied by district heating after generating electricity among cogeneration facilities.

The proportion of solar, wind and nuclear power generation without greenhouse gas emissions continues to increase in Korea. The standard greenhouse gas coefficient in the power generation sector is expected to gradually decrease as renewable energy, which is valid under current standards but has no emissions, increases. In this case, there is a need to reset the equivalent coefficient of electricity/heat based on the social average efficiency among 3.67 under the Exergy Calculation Method or 3.90, the coefficient of electricity emission for coal-fired power and the coefficient of heat production for LNG.

Chapter 5 calculated the increase in efficiency as a computer simulation assuming steam-high efficiency and re-heating cycle are applied among the component technologies for improving energy/exergy efficiency in incinerators. The target facilities included Plant S, which is operated as 100% cogeneration facility among domestic facilities, and Plant I, which is operated exclusively for power generation, in addition to the small amount of heat supply to residents' convenience facilities. First, looking at element-specific technology, Plant I's effect of improving the plural was about 15% and was identified as a very important factor for electricity use. Second, if the Super Critical Steam Condition (130 bar, 440°C) is changed to Super Critical Steam Condition (130 bar, 440°C), the 300°C steam based Plant 2 increased by 43% and 193°C based Plant S by 102%. This is the main reason why the current steam production, the comparison target, is different. Plantnt S's current Turbine inlet and outlet temperatures are 193°C and 104°C respectively, which is only 89°C, but under SC conditions, the thermal drop at the turbine inlet and exit reaches 335°C, which makes a 3.5 times of difference. Comparing the Re-Heat side frames with the SC cycle increased by 28% in Plant I, which is for power generation only, but by 21% in Plant S, which is a cogeneration. Plant S is operated by CHP, so the loss of exergy in the heat exchange process is the result of reducing power generation increase. Third, the correlation between the greenhouse gas reduction effect and energy recovery efficiency R1/R2 was analyzed based on the power production efficiency improvement obtained above. Although the cogeneration facilities applied with the re-heat cycle will be the highest in energy recovery efficiency, they show 0.62 and 0.66, which are very similar for power generation only and cogeneration facilities. It is concluded that the method of reducing GHG emissions caused by injected waste through energy recovery can be sufficiently effective for electricity use alone. In addition, the R2/CDM at Plant I was 1.58, and the R2/CDMat Plant S was 1.63, proving that this figure, or the R2 index, could be used as the facility management own factor.

The energy recovery efficiency in incineration facilities shall be operated under the greenhouse gas reduction policy. Engineeringly obtained recovery efficiency calculations prove that the R2 index based on thermodynamic law is useful, and its association with the calculation method of indirect emission coefficient is proving this. Nevertheless, PMC and REF indexes, which affect emission calculations, are based on countries. The regional standard index shall be presented and corrected from time to time to time to reflect the concentration of CO2 in the atmosphere at home and abroad.