• Applied Chemistry for Engineering
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• v.33 no.6
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• pp.613-617
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• 2022

The equipment for fabricating the large-area PTFE nanofiber coated-PTFE foam filter for use as filtration parts of the baghouse that removes particulate matter (PM) in industrial sites was designed and manufactured in this study. The PTFE nanofiber was coated on a commercial PTFE foam filter to increase its PM collection efficiency. The equipment and fabrication processes using a roll-to-roll system were proposed to continuously coat PTFE nanofibers on the surface of the PTFE foam filter. The electrospinning and annealing parts were designed and made by optimizing the equipment for the roll-to-roll system. The surface morphology, composition, and filtration characteristics of the large-area filter fabricated by this equipment were confirmed. PTFE nanofibers were uniformly coated on the large-area filter, and the PTFE nanofiber coated-PTFE foam filter showed PM_2.5 collection efficiency of 91.79% and an appropriate pressure drop of 62 Pa with a face velocity of 1 m/min at 280 ℃.

• Environmental and Resource Economics Review
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• v.31 no.4
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• pp.777-799
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• 2022

This study examined the latest EU regulatory strengthening trends for refrigerant gases with very large global warming potential (GWP) and derived implications for carbon neutrality. The European Commission recently unveiled an amendment that significantly strengthens the F-gas Regulation. This study presented the meaning of the main contents related to refrigerants in the amendment by comparing them with the current regulations. The main contents of the amendment include drastically reducing the maximum amount of HFCs that can be placed on the market, strengthening regulations related to HFCs allocation, adding products and equipment that use high GWP refrigerants, adding regulated F-gas and updating the GWP of existing gases, and other stricter regulatory designs. This movement of the EU will affect the policy stance of advanced countries such as the United States and Japan, and Korea's policy will also be further strengthened. Therefore, it will be inevitable for related industries to change to next-generation refrigerant gas. Meanwhile, this study also analyzed the latest policy trends related to per- and polyfluoralkyl substances (PFAS) regulation, which were not noted in previsou studies on refrigerants and F-gas. If PFAS's registration of REACH restricted substances, which are being promoted by five European countries, is made, it will have a very big impact on the industry regarding refrigerant gas. In addition, it will be inevitable to thoroughly review each country's greenhouse gas reduction strategies related to F-gas materials, including refrigerants.

• Clean Technology
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• v.29 no.2
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• pp.151-159
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• 2023

The realization of carbon neutrality requires cooperation from various stakeholders and the utilization of a governance system. The criteria for participating members are crucial for the successful operation of governance, and it is especially necessary for experts who can provide scientific advice for policy implementation to share a framework for successful consensus. In this study, governance model theory and model structure, governance common success factors by case, and the application of governance cases in the climate and environmental sector of Seoul, were investigated and analyzed to derive common success factors in order to present the activity standards of the science and technology experts participating in governance. The study of the model theory suggested that the model structure is commonly composed of a basic condition-process-result structure, and it was confirmed that common success factors can be derived at the process stage which is the activity period of members. Through the case study of common success factors, overlapping factors were found to be reliability, accountability, transparency, networks, and related factors. The validity of the common success factors was verified using the analysis results of satisfaction survey data from Seoul Governance Committee participants. The results confirmed that reliability was the most valuable factor followed by networks, transparency, and responsibility, and it was found that the related factors were appropriately derived. The findings of this study are expected to be used as an activity factor for science and technology experts to increase the acceptability and effectiveness of carbon-neutral policies in the future.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.33 no.6
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• pp.226-233
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• 2023

In this study, the basic physical properties and microstructure of concrete interlocking blocks with amount of different CO₂ gas injection were analyzed according to determine the applicability of In-situ carbonation technology to construction secondary products. The amount of carbon dioxide gas injection was selected as 0, 0.1, 0.3, 0.5, 0.7 wt.% compared to cement amount. A lab-scale press equipment was designed to apply developed carbonation technology to real construction site. And mixer for stable CO₂ gas injection was designed. Using the designed devices, CO₂ gas injected samples were created and physical property of samples were performed. As a result of the physical property test, as the CO₂ injection amount increased to 0.3 %, it showed higher strength behavior compared to the original mix. And more than 0.5 % samples showed lower strength behavior than original sample, but they satisfied the standard of concrete interlocking block. This results were determined that CO₂ injection contributed to the creation of hydrates such as C-S-H. Therefore, the possibility of applying carbonation technology, which injects CO₂ during mixing, to various secondary construction products was confirmed.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.34 no.2
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• pp.66-72
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• 2024

In this study, the applicability of CCMs (Carbondioxide conversion capture materials) manufactured by reacting carbon dioxide gas with DG (Desulfurization gypsum) as a cement substitute for secondary concrete products were evaluated and the basic physical properties of CCMs-mixed mortar and concrete specimens were measured to derive the optimal mixing ratio. The main chemical oxides of CCMs were CaO and SO₃, and the main crystalline phases were CaSO₄·2H₂O, Ca(OH)₂, CaCO₃, and CaSO₄. In addition, by the results of particle size analysis and heavy metal measurement, the applicability of CCMs as a cement substitute for secondary concrete products was confirmed. As a result of measuring the strength behavior using mortar and concrete specimens with CCMs, the compressive and flexural strength decreased as the mix ratio of CCMs increased, but requirements by the standards for interlocking blocks and retaining wall blocks, which are target products in this study, were satisfied up to the optimal mixing ratio of 10 wt.% substitution. Therefore, its applicability as a cement substitute for secondary concrete products was confirmed.

• Journal of the Korean Recycled Construction Resources Institute
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• v.12 no.1
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• pp.82-93
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• 2024

Since the cement industry generates more than 60 % of CO₂ during the clinker production process, supplementary cementitious materials are used worldwide to reduce CO₂ efficiently. Mainly used supplementary cementitious materials such as blast furnace slag and fly ash, which are used in various industries including the cement industry, concrete admixtures, and ground solidification materials. However, since their availability is expected to decrease in the future according to the carbon neutrality strategy of each industry, new supplementary cementitious materials should be used to achieve the cement industry's goal for increasing the additive content of Portland cement. Limestone is a material that already has a large amount in the cement industry and has the advantage of high grinding efficiency, so overseas developed countries established Portland limestone cement standards and succeeded in commercialization. This study was an experimental study conducted to evaluate the possibility of utilizing domestic PLC, the effect of fineness and replacement ratio on the physical properties of cement was investigated, and the environmental impact of cement was evaluated by analyzing CO₂ emissions.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.191-191
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• 2023

기후변화 대응을 위한 탄소 중립의 중요성이 대두되는 요즘, 생태계의 가장 큰 메탄 저장소로서 지구의 탄소 순환에 주요한 영향을 미치는 습지에 대한 이해는 필수적이다. 전지구 지면 모델인 Community Land Model(CLM)에 Functionally Assembled Terrestial Ecosystem Simulator(FATES) 외부 모듈을 함께 구동한 지면 생태계 모델 CLM-FATES는 지면 heterogeneity와 다양한 식생 종류를 고려하여 에너지 플럭스, 토양 수문, 생화학적 과정 등을 모의함으로써 탄소 동태 변화를 포함한 장기적 생태계 동태 변화 모의를 가능하게 한다. 본 연구는 CLM-FATES 모델을 미국 캘리포니아주 Mayberry Wetland (US-Myb)와 Twitchell East End Wetland (US-Tw4)에 적용하였다. 모델의 대기 입력 자료로는 FLUXNET-CH4에서 제공하는 에디 공분산 기반 플럭스 관측 자료를 사용하였다. 기존 CLM-FATES 모델은 토양이 장기간 포화 혹은 침수되어 지표 위 혹은 지표면 가까이 발달한 지하수면을 가지고 있는 습지의 수문학적 특성을 잘 반영하지 못해 정밀한 습지 생태계 동태 변화 모의에 한계를 가지고 있다. 본 연구에서는 CLM-FATES를 통한 보다 정확한 습지 생태계 모의를 위해 모델 내 토양 수문 관련 모듈을 수정하여 모델이 습지의 수문학적 특성을 반영할 수 있도록 하였다. 모델 구동 결과 도출한 잠열, 총일차생산량(Gross Primary Production: GPP)과 순생태계생산량(Net Ecosystem Production, NEP) 플럭스, 메탄 플럭스, 엽면적지수(Leaf Area Index; LAI)와 지표수 높이에 대해 관측값 대비 RMSE 및 R² 값을 계산하여 모의 결과의 적절성을 분석하였다. 이러한 모델 개선 경험을 바탕으로 추후 우리나라 습지 사이트에 모델을 적용하여 습지 탄소 동태 예측에 활용할 계획이다.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.6
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• pp.382-390
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• 2012

Global warming has been hot issue world wide. Korea has been dealing with the global issue under the slogan of low carbon and green-growth such as setting national greenhouse gas (GHG) reduction targets and allocation to each industrial sector. Infrastructure construction, in which enormous social overhead capital (SOC) is input, has great role as one of the actions. Road is one of the representative infrastructure and large amount of resources is utilized in its construction, operation and maintenance stage. The estimation methodology of life cycle carbon emissions was developed and applied to a case study of highway currently under construction in this study. Also, total carbon emissions of all the highway in South Korea at present (2009) and cumulative carbon emissions from 2009 to 2020 were estimated using the results of case study.

• Journal of the KSME
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• v.50 no.9
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• pp.39-42
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• 2010

바이오가스는 세계적으로 풍부한 바이오매스 자원에서 발생하고 지구온난화 문제에 대응할 수 있는 탄소중립 청정에너지원이다. 이 글에서는 유럽의 바이오가스 생산 및 시작동향 중에서도 EU 생산량의 35%를 차지하는 독일의 현황에 대해 살펴보고자 한다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2022.06a
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• pp.1218-1221
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• 2022

최근 전세계의 탄소중립 요구에 따른 에너지 효율 증대를 통한 에너지 절감을 위한 효율성 관련 연구가 확대되고 있다. 방송과 미디어 분야에는 에너지 효율이 더욱 시급하다. 이에 본 연구에서는 효율적인 에너지 시스템 구축을 위해 난방 에너지 시계열 데이터를 기반으로 한 수요 예측 모델을 선정하고, 설명하는 인공지능 모델을 도입하여 수요 예측에 영향을 미치는 원인을 파악하는 프레임워크를 제안한다.