• Proceedings of the Korean Society of Crop Science Conference
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• 2022.04a
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• pp.6-6
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• 2022

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.464-464
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• 2023

최근 이산화탄소(Carbon Dioxode, CO₂) 배출량 증가로 인하여 지구온난화와 같은 기후변화 문제가 심각한 사회 문제로 대두되고 있다. 이에 따라 2015년 12월 12일 프랑스 파리에서 열린 제21차 유엔기후변화협약에서 교토의정서를 대체하는 파리협정(Paris Agreement)을 채택하였으며, 국내에서는 이러한 국제사회의 기후변화 대응에 동참하고 온실가스 감축을 이행하기 위한 2050 탄소중립 정책을 추진하였다. 이산화탄소를 다량으로 발생시키는 철강·산업·건설·에너지 분야 중건설 분야에서 배출되는 이산화탄소는 전체 배출량의 19.9%로 특히 시멘트를 제조하는 과정에서 많은 양의 이산화탄소가 배출되고 있다. 기존의 건설 분야 에서는 이산화탄소를 저감하기 위해 콘크리트 배합 또는 양생과정에서 챔버 내 이산화탄소를 가스 형태로 주입하여 탄산화 반응을 통해 콘크리트 내부에 이산화탄소를 영구히 저장시키고자 하였다. 그러나 이는 챔버 사용, 양생조건 등 적용 조건이 제한적이며, 콘크리트 내 이산화탄소 흡수 효율이 높지 않아 이를 개선할 수 있는 기술이 필요하다. 이를 개선하기 위해 최근에는 콘크리트 배합수 내 이산화탄소를 용해시켜 배합과정에서 콘크리트 내부로 이산화탄소를 강제로 인입시키는 연구들이 진행되고 있다. 그러나 콘크리트 배합수로 사용되고 있는 일반물이나 지하수의 경우 가압을 하여도 약 1,400mg/L의 이산화탄소를 용해시키며, 가압을 통해 용해된 이산화탄소는 쉽게 대기 중으로 방출되는 한계점을 지니고 있어 현장에서 사용하기 어려운 문제가 있다. 이러한 한계점을 극복하기 위해서 본 연구에서는 200nm 이하의 크기를 가지는 나노버블기술을 이용해 압력을 가하지 않은 상태에서 수중에 이산화탄소를 용해시킬 수 있는 시스템을 개발하고자 한다. 나노버블기술을 이용한 수중 이산화탄소용해 시스템을 통해 수중에 이산화탄소를 용해시켜 콘크리트 배합수로 활용하기 위한 기초 연구가 될 것으로 판단된다.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.436-436
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• 2023

산업혁명을 거치면서 높은 화석연료를 사용하는 제조업 중심의 산업구조와 많은 자원을 필요로 하는 도시의 집중 현상으로 지구 온난화에 따른 이상기후 발생이 증가하고 있다. 이러한 기후변화는 홍수, 태풍, 폭염 및 폭설 등의 자연재해 발생 빈도 및 규모를 증가시켜 피해가 커지고 있다. 특히 인구 및 시설들이 집중해 있어 도시의 집중 현상은 이러한 재해에 더욱 취약한 구조가 됨에 따라 피해의 규모를 가중 시키고 있는 실정이다. 전 세계적으로 기후변화 문제의 심각성을 인식하고 이를 해결하기 위해 선신국에 의무를 부여하는 교토의정서(1997년) 채택에 이어, 선진국과 개도국이 모두 참여하는 파리협정(2015년)을 채택하였고 2016년 협정이 발효되었다. 파리협정의 목표는 산업화 이전 대비 지구 평균온도 상승을 2℃보다 아래로 유지하고, 나아가 1.5℃로 억제하기 노력하는 것을 강제하는 것으로 2050년까지 탄소 순배출량을 '0'으로 만든다는 탄소중립사회로의 전환이 본격적으로 시작되었다. 본 연구에서는 기후변화로 인한 물부족 및 수실오염과 같은 도시의 수자원 문제 해결을 위해 IoT 기반 센서 및 네트워크 기반 수자원 플랫폼을 개발하였다. 도시 수자원 시설 데이터를 기반으로 대체 수자원 확보 및 수요 중심의 물 관리를 통해 효율적인 물 배분이 될 수 있도록 하였으며 이러한 스마트 물 관리에 따른 대체 수자원 확보 및 효율적 물 배분이 탄소 저감에 미치는 효과에 대해 분석하였다. 연구대상 지역은 세종 6-4구역으로 LID 특화지구로 조성되었으며 1,000 세대의 주민이 생활하는 공동주택이다. 물 순환(LID) 시설에서 확보된 물을 물 공급 시설과 연계하여 공동주택에서 활용함으로써 감소된 상수 사용량을 온실가스 배출량으로 환산하여 탄소 저감량을 계산하였다. 실제 주민들(1,000세대)이 사용하고 있는 상수량 데이터와 전력거래소 온실가스 배출계수를 활용하였으며 물순환(LID) 시설로 확보하여 대체할 수 있는 상수량은 10%로 가정하였다. 연구대상 지역(1,000세대)의 연간 상수공급량은 331,603m³이며, 연간 전력사용량은69,637kWh이다. 온실가스 배출량은 31.963tCO₂eq이며, 온실가스 저감량은 3.2tCO₂eq로 산정되었다. 추후 LID 시설에 대한 상수 대체량과 온실가스 저감효과 정량화가 필요하다.

• Transactions of the Korean hydrogen and new energy society
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• v.34 no.3
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• pp.316-326
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• 2023

Development of carbon-neutral fuel production technologies to solve climate change issues is progressing worldwide. Among them, methane can be produced through the synthesis of hydrogen produced by renewable energy and carbon dioxide captured through a CO₂ methanation reaction, and the fuel produced in this way is called synthetic methane or e-methane. The CO₂ methanation reaction can be conducted via biological or thermochemical methods. In this study, a 30 Nm³/h thermochemical CO₂ methanation process consisting of an isothermal reactor and an adiabatic reactor was used. The CO₂ conversion rate and methane concentration according to the temperature measurement results at the center and outside of the adiabatic reactor were analyzed. The gas flow into the adiabatic reactor was found to reach equilibrium after about 1.10 seconds or more by evaluating the residence time. Furthermore, experimental and analysis results were compared to evaluate performance of the reactor.

• Clean Technology
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• v.27 no.2
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• pp.124-131
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• 2021

As declarations of carbon neutrality are spreading throughout the world, much research is being conducted on biodegradable polymers. In this study, nanocellulose, which comprises the largest amount of natural polymer currently available in the world, was proposed as a substitute for non-biodegradable polymers. We chose to modify the surface functional group of crystalline nanocellulose using glycidoxypropyl trimethoxysilane (GPTMS), which is a silane coupling agent, and the product was then used to form a film with low density polyethylene (LDPE). We then conducted measurements using a Fourier transform infrared spectrophotometer (FT-IR) in addition to measuring hydrophilic/lipophilicity of the surface functional group modification of crystalline nitrocellulose as well as that of a polymer composite using the hybrid nanocellulose (H-NC). For compatibility with petroleum-based polymers, the best tensile strength and transparency was found when the H-NC was reacted at pH 14 and 1 wt% compared with LDPE. From the test results, we found that it is possible to modify the surface functional groups of nanocellulose using a silane coupling agent. In addition, the high compatibility of nanocellulose with petroleum-based polymers is expected to help in reaching carbon neutrality by reducing the use of fossil fuels.

• 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 ℃.

• Membrane Journal
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• v.33 no.4
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• pp.168-180
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• 2023

H₂ generation from renewable sources is crucial for ensuring sustainable production of energy. One approach to achieve this goal is biohydrogen production by utilizing renewable resources such as biomass and microorganisms. In contrast to commercial methods, biohydrogen production needs ambient temperature and pressure, thereby requiring less energy and cost. Biohydrogen production can reduce greenhouse gas emissions, particularly the emission of carbon dioxide (CO₂). However, it is also associated with significant challenges, including low hydrogen yields, hydrodynamic issues in bioreactors, and the need for H₂ separation and purification methods to obtain high-purity H₂. Various technologies have been developed for hydrogen separation and purification, including cryogenic distillation, pressure-swing adsorption, absorption, and membrane technology. This review addresses important experimental developments in dense polymeric membranes for biohydrogen purification.

• Membrane Journal
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• v.34 no.3
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• pp.172-181
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• 2024

Many countries have passed laws to achieve Nationally Determined Contribution (NDC) which is a climate action plan to reduce greenhouse gas emissions and adapt to climate impacts. Although there are various technologies to achieve NDC targets, membrane technologies pose dramatical attractions for the purification of gaseous greenhouse gases or energy sources. Therefore, this review will provide the technological trends of polymeric membranes among various materials due to the advantages of the feasible fabrication process and easy scale-up.

• 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.

• Clean Technology
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• v.28 no.3
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• pp.203-209
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• 2022

An environmental evaluation was conducted by employing LCA methodology for a mechanical seal manufacturing process that uses recycled silicon recovered from end-of-cycle PV modules. The recycled silicon was purified and reacted with carbon to synthesize β-SiC particles. Then the particles underwent compression molding, calcination and heat treatment to produce a product. Field data were collected and the potential environmental impacts of each stage were calculated using the LCI DB of the Ministry of Environment. The assessment was based on 6 categories, which were abiotic resource depletion, acidification, eutrophication, global warming, ozone depletion and photochemical oxidant creation. The environmental impacts by category were 45 kg CO₂ for global warming and 2.23 kg C₂H₄ for photochemical oxide creation, and the overall environmental impact by photochemical oxide creation, resource depletion and global warming had a high contribution of 98.7% based on weighted analysis. The wet process of fine grinding and mixing the raw silicon and carbon, and SiC granulation were major factors that caused the environmental impacts. These impacts need to be reduced by converting to a dry process and using a system to recover and reuse the solvent emitted to the atmosphere. It was analyzed that the environmental impacts of resource depletion and global warming decreased by 53.9% and 60.7%, respectively, by recycling silicon from end-of-cycle PV modules. Weighted analysis showed that the overall environmental impact decreased by 27%, and the LCA analysis confirmed that recycling waste modules could be a major means of resource saving and realizing carbon neutrality.