• Journal of Industrial Convergence
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• v.22 no.6
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• pp.13-23
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• 2024

In this study, the optimal level of CER issuance price in the energy industry was estimated using a real options considering the uncertainty of emission price. As a result of the analysis, the break-even point for CDM projects in the energy industry registered by UNFCCC from December 2012 to the end of 2021 was 0.64-36.69 euros per ton of CO2 for each individual project. More closely, the emission permit price that reaches the break-even point when NPVw/o CER+ NPVCER ≥ 0 is estimated to be 12.10 euros on average, and the emission permit price that reaches the break-even point when NPVw/o CER + NPVCER ≥ option value is estimated to be 12.63 euros on average. Meanwhile, the option value using real options to reduce business uncertainty is about 19% at the 1-5 euro per ton level, about 11% at the 5-10 euro per ton level, and about 5% at the 10-15 euro per ton level. It was analyzed that there was an effect of increasing emissions prices due to uncertainty reduction. The results of this study may be useful to greenhouse gas reduction project entities, including investors, project operators, and companies with potential mandatory reductions.

• Transactions of the Korean hydrogen and new energy society
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• v.18 no.4
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• pp.382-390
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• 2007

To check the feasibility of SMART(Steam Methane Advanced Reforming Technology) system, an experimental investigation was performed. A fluidized bed reactor of diameter 0.052m was operated cyclically up to 10th cycle, alternating between reforming and regeneration conditions. FCR-4 catalyst was used as the reforming catalyst and calcined limestone(domestic, from Danyang) was used as the $CO_2$ absorbent. Hydrogen concentration of 98.2% on a dry basis was reached at $650^{\circ}C$ for the first cycle. This value is much higher than $H_2$ concentration of 73.6% in the reformer of conventional SMR (steam methane reforming) condition. The hydrogen concentration decreased because the $CO_2$ capture capacity decreased as the number of cycles increased. However, the average hydrogen concentration at 10th cycle was 82.5% and this value is also higher than that of SMR. Based on these results, we could conclude that the SMART system can replace SMR system to generate pure hydrogen without HTS (high tempeature shift), LTS (low temperature shift) and $CO_2$ separation process.

• Proceedings of the KSME Conference
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• 2001.11b
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• pp.682-687
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• 2001

This study represents effect of exhaust performance by according to active muffler valve spring. The experimental parameter were divided engine speed and torsion coil spring constant. The sound pressure level was generally low at engine speed 2000-2500rpm but That was showed the lowest at spring constant k=0.75. Flow speed of exhaust gas was showed the fast at spring constant k=0.75 but the low value was showed at k=0.97. It was contained a rather low concentration of carbon monoxide(CO) at engine speed 2000-2500rpm and k=0.81, low concentration of hydrocarbon(HC) at spring constant k=0.81 but that was high at spring constant k=0.97. A conclusion based on FFT analysis was generally low concentration value at k=0.79 and k=0.81. The temperature distributions into the muffler was shown similar conditions. Heat transfer was well spreaded at thermocouple No.8 because valve was opened.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1999.11a
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• pp.23-29
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• 1999

Experimental studies are conducted to investigate the flame stability and the thermal/fuel NOx formation characteristics of the low calorific value (LCV) coal derived gas fuel. Synthetic LCV fuel gas is produced by mixing carbon monoxide, hydrogen, nitrogen and ammonia on the basis that the thermal input of the syngas fuel into a burner is identical to that of natural gas. The syngas mixture is fed to and burnt with air on flat flame burner. With the variation of the equivalence ratio for specific syngas fuel, flame behaviors are observed to identify the flame instability due to blow-off or flashback and to define stable combustion range. Measurements of NOx content in combustion gas are made for comparing thermal and fuel NOx from the LCV syngas combustion with those of the natural gas one. In addition, the nitrogen dilution of the LCV syngas is preliminarily attempted as a NOx reduction technique, and its effects on thermal and fuel NOx production are discussed.

• New & Renewable Energy
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• v.18 no.2
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• pp.60-72
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• 2022

The environmental, social, and governance (ESG) score is gaining recognition as important nonfinancial investment criteria. With climate change emerging as a global issue, energy companies must pay attention to the ESG impact on corporate performance. In this study, the ESG impact on the performance of energy companies was analyzed based on 23 companies selected from the S&P 500. The panel corrected standard error methodology was used. The Refinitiv ESG score was the independent variable, and financial performance metrics, such as Tobin's Q, return on assets, and return on equity, were the dependent variables. It was found that the ESG score is positively associated with long-term corporate value but not with short-term profitability in the electricity utility industry. Among the subcategories of ESG, the environmental and social scores also showed positive correlations with long-term corporate value. A direct incentive policy is recommended that can offset expenses for ESG activities to reduce carbon emission in the energy sector.

• Journal of Korean Society on Water Environment
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• v.35 no.4
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• pp.316-331
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• 2019

Carbon dioxide($CO_2$) emission from rivers to the atmosphere is a key component in the global carbon cycle. Most of the rivers are supersaturated with $CO_2$. At a global scale, the amount of $CO_2$ emission from rivers is reported to be five-fold greater than that from lakes and reservoirs, but relevant data are rare in Korea. The objectives of this study is to estimate the $CO_2$ net atmospheric flux(NAF) from the upstream of Gangjeong-Goryeong Weir(GGW), Dalseong Weir(DSW), Hapcheon-Changnyeong Weir(HCW), and Changnyeong-Haman Weir(CHW) located in Nakdong River South Korea) using field and laboratory experiments and to apply data mining techniques to develop parsimonious prediction models that can be used to estimate $CO_2$ NAF with physical and water quality variables that can be collected easily. As a result, the study sites were all heterotrophic systems that often released $CO_2$ to the atmosphere, except when the algal photosynthesis was active.The median $CO_2$ NAF was minimum $391.5mg-CO_2/m^2$ day at GGW and maximum $1472.7mg-CO_2/m^2$ day at DSW. The $CO_2$ NAF showed a negative correlation with pH and Chl-a since the overgrowth of the algae consumed $CO_2$ in the water and increased the pH. As the parsimonious multiple regression model and random forest model developed, this study showed an excellent performance with the $Adj.R^2$ value higher than 0.77 in all weirs. Thus, these methods can be used to estimate $CO_2$ NAF in the river even if there is no $pCO_2$ measurement data.

• Korean Journal of Remote Sensing
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• v.28 no.1
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• pp.145-157
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• 2012

In this study, we simulated a carbon flux model, so called Vegetation Integrated Simulator for Trace gases (VISIT) using Spatio-temporal Environmental Information, to estimate carbon budgets of vegetation ecosystem in South Korea. As results of the simulation, the model estimated that the annual-average gross primary production (GPP), net primary production (NPP) for 10 years were $91.89Tg\;C\;year^{-1}$, and $40.16Tg\;C\;year^{-1}$, respectively. The model also estimated the vegetation ecosystems in South Korea as a net carbon sink, with a value of $3.51Tg\;C\;year^{-1}$ during the simulation period. Comparing with the anthropogenic emission of South Korea, vegetation ecosystems offsets 3.3% of human emissions as a net carbon sink in 2007. To estimate the carbon budget more accurately, it is important to prepare reliable input datasets. And also, model parameters should be calibrated through comparing with various independent method. The result of this study, however, would be helpful for devising ecosystem management strategies that may help to mitigate global climate change.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.5
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• pp.728-733
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• 2010

This study was carried out to estimate carbon emission using LCA and to establish LCI database of potato production system. Potato production system was categorized into the fall season potato and the spring season potato according to potato cropping type. The results of collecting data for establishing LCI D/B showed that input of fertilizer for fall season potato production was more than that for spring season potato production. Input of pesticide for spring season potato production was much more than that for fall season potato production. The value of field direct emission ($CO_2$, $CH_4$, $N_2O$) were 2.17E-02 kg $kg^{-1}$ for spring season potato and 2.47E-02 kg $kg^{-1}$ for fall season potato, respectively. The result of LCI analysis focussed on the greenhouse gas (GHG), it was observed that carbon footprint values were 8.38E-01 kg $CO_2$-eq. $kg^{-1}$ for spring season potato and 8.10E-01 kg $CO_2$-eq. $kg^{-1}$ for fall season potato; especially for 90% and 6% of $CO_2$ emission from fertilizer and potato production, respectively. $N_2O$ was emitted from the process of N fertilizer production (76%) and potato production (23%). It was observed that characterization of values of GWP were 8.38E-01 kg $CO_2$-eq. $kg^{-1}$ for spring season potato and 8.10E-01 kg $CO_2$-eq. $kg^{-1}$ for fall season potato.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.1185-1194
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• 2011

This study was carried out to estimate carbon emission using LCA (Life Cycle Assessment) and to establish LCI (Life Cycle inventory) DB for lettuce production system in protected cultivation. The results of data collection for establishing LCI DB showed that the amount of fertilizer input for 1 kg lettuce production was the highest. The amounts of organic and chemical fertilizer input for 1 kg lettuce production were 7.85E-01 kg and 4.42E-02 kg, respectively. Both inputs of fertilizer and energy accounted for the largest share. The amount of field emission for $CO_2$, $CH_4$ and $N_2O$ for 1 kg lettuce production was 3.23E-02 kg. The result of LCI analysis focused on GHG (Greenhouse gas) showed that the emission value to produce 1 kg of lettuce was 8.65E-01 kg $CO_2$. The emission values of $CH_4$ and $N_2O$ to produce 1 kg of lettuce were 8.59E-03 kg $CH_4$ and 2.90E-04 kg $N_2O$, respectively. Fertilizer production process contributed most to GHG emission. Whereas, the amount of emitted nitrous oxide was the most during lettuce cropping stage due to nitrogen fertilization. When GHG was calculated in $CO_2$-equivalents, the carbon footprint from GHG was 1.14E-+00 kg $CO_2$-eq. $kg^{-1}$. Here, $CO_2$ accounted for 76% of the total GHG emissions from lettuce production system. Methane and nitrous oxide held 16%, 8% of it, respectively. The results of LCIA (Life Cycle Impact assessment) showed that GWP (Global Warming Potential) and POCP (Photochemical Ozon Creation Potential) were 1.14E+00 kg $CO_2$-eq. $kg^{-1}$ and 9.45E-05 kg $C_2H_4$-eq. $kg^{-1}$, respectively. Fertilizer production is the greatest contributor to the environmental impact, followed by energy production and agricultural material production.

• Agricultural and Biosystems Engineering
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• v.3 no.2
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• pp.59-64
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• 2002

Odor generated during composting of livestock manure is mainly due to ammonia emission. Biofiltration is a desirable method to control composting odor. This study was conducted to analyze the efficiency of using fresh compost as a biofilter. A mixture of cattle manure and recycled compost was composted in a bin equipped with a suction-type blower. The exhaust gas was filtered through the fresh compost. Residence time was controlled by the flow rate of exhaust gas and the depth of filtering materials. At the aeration rate of 30 L/min(experiment I), ammonia reduction rate varied from 100% to -15% for biofilter A(residence time 56.5 s) and almost 100% for biofilter B(residence time 113 s). At the aeration rate of 30 L/min, the cumulative ammonia reduction rate was 80.5% for biofilter A and 99.9% for biofilter B. At the aeration rate of 50 L/min(experiment II), the lowest reduction rate showed a negative value of -350% on the 8th and 9th day for biofilter A(residence time 33.9 5), and 50% on the loth day for biofilter B(residence time 67.8s). At the aeration rate of 50 L/min, the cumulative ammonia reduction rate was 82.5% fur biofilter A and 97.4% for biofilter B. Filtering efficiency was influenced by residence time. The moisture content(MC) and total nitrogen(T-N) of the filtering material were increased by absorbing moisture and ammonia included in the exhaust gas, while pH was decreased and total carbon(T-C) remained unchanged during the filtering operation.