• Journal of Korean Society of Environmental Engineers
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• v.38 no.7
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• pp.353-363
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• 2016

In this study, traditional treatment scenario of food wastes that collected and transported food waste is recycled in large treatment facilities and suggested treatment scenario of onsite zero discharge system that food waste is treated in housing complex were supposed. The scenarios were compared and analyzed by capital expenditure, oil consumption, $CO_2$ emission quantity, operating expenditure and management expenses. The capital expenditure, oil consumption and $CO_2$ emission quantity of small scale dispersion dealing method is the lowest compared to traditional treatment method. As a results, it is possible to obtain the effect that operating expenditure was reduced by 91% and management expenses was reduced by 40% with suggested treatment method. The treatment method that have low capital expenditure is tend to lower oil consumption and $CO_2$ emission quantity. The small scale dispersion dealing method have the lowest capital expenditure, oil consumption and $CO_2$ emission quantity and the linked method with sewage treatment have the highest expenditure and $CO_2$ emission quantity. Eventually, the optimal model of onsite zero discharge system in housing complex is small scale dispersion dealing method.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.396-396
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• 2023

기후 위기에 대한 대응으로 현재 많은 국가에서 2050년 탄소중립을 목표로 하고 있으며, 우리나라도 2050년까지 탄소중립을 선언하고 다양한 부문의 배출 절감 계획을 내세웠다. 현재 건물 부문에서는 2050년의 목표배출량을 6.2 백만톤 CO2eq으로 설정하고 관련 정책적 수단을 검토 중이지만 달성 방안 등에 대해서는 구체적으로 제시하지 못하고 있다. 본 연구에서는 국내 건물 부문의 이산화탄소의 배출량 산정 모델을 개발하여, 2050년까지 이산화탄소 배출 저감 시나리오를 시뮬레이션하였다. 이를 토대로 국내의 건물 부문 탄소중립 가능성을 검토한 통합 시나리오를 제시하고, 향후 정책 및 기술 개발의 방향성을 제시한다. 탄소배출량 산정모델은 연면적 예측 및 사용 에너지의 원단위 환산, 탄소배출계수 등을 고려해 개발하였고, 이를 활용하여 4가지 탄소배출 시나리오를 분석하였다. 먼저 현재 정책 기반 탄소 배출 시나리오는 탄소중립에 이르지 못하여 더 강화된 시나리오의 필요성을 보여준다. 신규 건물을 대상으로 한 제로 에너지화 제도 기반 시나리오는 전체 탄소배출량에 큰 기여를 하지 못하며, 기존 건물 대상의 그린 리모델링 제도 기반 시나리오에서는 10년 이상 건물에 50% 이상의 높은 에너지 효율 개선을 시행해야 한다는 결과를 도출하였다. 또한 전기화 시나리오에서는 화석연료와 전력의 탄소배출계수를 비교하여 적절한 에너지 전환 시점을 계산하였다. 그 결과, 건물 부문에서 2050년까지 탄소배출량 감축 목표 달성을 위해 신축 건물의 에너지 자립율 100%, 에너지 전환 계획과 연동한 건물의 전기화, 그리고 그린리모델링을 통한 효율 개선 기준을 47% 이상 달성하는 조건을 만족해야 한다는 결과를 얻었다. 이 연구는 도전적인 온실가스 감축 마련의 필요성을 제시하였으며, 탄소중립 가능성을 제시하여 실질적인 감축정책에 기여할 것으로 기대한다.

• Journal of Energy Engineering
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• v.18 no.4
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• pp.221-229
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• 2009

This study develops the optimized operation program which enables effective and economic operation between individual and connected branch offices by analyzing the current status and influential indicators of district heating companies' capital branch offices. Accordingly, the study examines the efficiency of optimized operation program. In doing so, this study has diagnosed and analyzed various factors, such as boilers, pumps, and relevant tags (temperature, pressure, fuel amount) through investigation of individual branch offices, and finally succeeded in developing wide-ranging data base by factor covering one-year time period. Additionally, after running the optimized operation program, different branch offices, optimum preference has turned out "incinerator receiving heat from KEPCO>CHP >PLBs>PLBw." Meantime, except the connected offices, there has been no big difference between actual and optimum operation program in branch offices. Meanwhile, the integrated optimum operation program has made it possible the most optimal result only via the connecting supply and demand heat without changing received Heat from KEPCO which is the same as total productive heat. The result has showed that the reduction percentage per day is 2.45~6.80%, and the reduction cost per day is 22,727~60,077 thousand won given the randomly selected sample days. In particular, winter time shows the highest demand with the largest reduction cost whereas summer time illustrates the lowest demand with the smallest reduction cost. Given this result, reduction cost per year compared to actual heat production cost for one year theoretically would be 84 hundred million won. Also, the economic effect showed that the reduction cost percentage per year is more than 2.74% on heat production cost per year for all capital branch offices.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.7
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• pp.877-882
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• 2014

The reduction of CO2 emission has been discussed in the Marine Environment Protection committee in the International Maritime Organization as the biggest causes of GHG for the purpose of indexing CO2 amounts released into the atmosphere from ships. Accordingly, various methods including the change in the hull design to improve energy efficiency, the coating development to reduce friction resistances, the additives development for improving thermal efficiency in an engine, the low-speed operation to reduce fuel consumptions, and etc. have been applied. The main engine of a ship is an electronic engine for improving the efficiency of the whole load area. However, marine generator engines still use mechanical drive engines in intake, exhaust, and fuel injection valve drive cams. In addition, most of marine generator engines in ships apply a part-load operation of less then 80% due to an overload protection system. Therefore, marine auxiliary diesel engine set at 100% load is necessary to readjust in order to efficient operation because of part-load operation. The objective of this study is to report the results of the part-load fuel consumption improvement by injection timing readjust to identifying the operational characteristics of a marine generator engine currently operated in a ship.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.2
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• pp.131-140
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• 2010

Zero waste clean city was visualized by designing the environmental fundamental facilities such as automated waste collection and bio-energizing system of domestic waste, which was categorized into food and combustible waste from urban area. The biomass circulation position was applied to the domestic waste collection position combined with bio-energizing system in the zero waste clean city. Bio-energizing system consisted of bio-gasification, bio-fuel and bioenergy-circulation process. Food wastes were treated by bio-gasification with anaerobic digestion, and combustible wastes were made of bio-fuel with pyrolysis/drying. Biogas and bio-fuel was utilized into the electric generation or boiler heat in bioenergy-circulation process. The emission of carbon dioxide(CO2) and construction fee of the environmental fundamental facilities related with domestic waste was estimated in the existing city and zero waste clean city, assuming the amount of food waste 35 ton/day, combustible waste 20 ton/day from domestic area. Consequently, 2.7 times lower carbon dioxide emission and 15% construction fee of the environmental fundamental facilities related with domestic waste were obtained from the zero waste clean city by comparing with existing city.

• Journal of Bio-Environment Control
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• v.32 no.4
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• pp.278-284
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• 2023

Recently, a closed-type plant factory has been receiving attention as a advanced agricultural method. It has diverse advantages such as climate-independence, high productivity and stable year-round production. However, high energy cost caused by environmental control system is considered as a challenges of a closed-type plant factory. In order to reduce the energy cost, investigation about energy load which is directly connected to energy consumption needs to be conducted. In this study, energy load changes of a plant factory have been analytically analyzed according to the environmental changes. The target plant factory was a lettuce growing container farm. Firstly, the impact of photoperiod, set temperature and relative humidity change were examined. Under the climate condition of Daejeon in South Korea, increase of photoperiod and set temperature rose a yearly energy demand of a container farm. However, increase of set relative humidity decreased a yearly energy demand. Secondly, the climate environment effect was compared by investigating the energy demand under 9 different climate conditions. As a result, the difference between maximum and minimum value of the yearly energy demand showed 21.7%. Lastly, sensitivity analysis of each parameter (photoperiod, set temperature and relative humidity) has been suggested under 3 different climate conditions. The ratio of heating and cooling demand was varied depending on the climate, so the effect of each parameter became different.

• Journal of Korean Society of Transportation
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• v.20 no.1
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• pp.19-38
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• 2002

To evaluate the effects of transportation system operation, usually measures of effectiveness(MOE) such as travel time, space mean speed, stop/delay ratio have been used. But, energy consumption as well as the existing MOE in transportation receives more attention as an alternative MOE in transportation operation. The purpose of this study is a development of procedure, which could measure the relative energy consumption for each alternative and compare the results. A mesoscopic simulator called INTEGRATION is used to evaluate the operation of high occupancy vehicle lane, signal optimization, lane expansion, and the application of ITS. Among those, the application of ITS shows the greatest effectiveness in energy reduction, and then lane expansion, signal optimization, and the operation of high occupancy vehicle lane in the order named. Because we don't consider the characteristics of vehicle class, Potential demand and the simulation time is just for an hour. it is recommended that a procedure for precise economic analysis and an improvement in methodology are needed in the future for the expanded application of this study.

• Applied Chemistry for Engineering
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• v.26 no.6
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• pp.686-691
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• 2015

A basic research for utilizing solid refuse fuel (SRF) based on changing SRF properties (RDF, RPF) and types (pellet, fluff) is demonstrated. Physicochemical characteristics of SRF and also changes in thermal decomposition depending on combustion time and emission gas (NOx, CO, HCl, etc) concentration were investigated for applications to waste energy sources. In conclusion, RPF is easy to pelletize, and has better combustion efficiency, higher LHV, higher thermal reduction, and short combustion time because it is composed of plastic wastes homogeneously. Also, fluff type samples have better combustion efficiency, and short combustion time because it has wider exposed surface area for combustion. It can also save energy consumption for pelletizing.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.33 no.6
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• pp.210-215
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• 2023

Raw mix burnability is an especially crucial factor in cement manufacturing technology, and it depends on the physical, chemical and mineralogical properties of each raw material. In this article, we compared the difference of burnability between the domestic and Japanese fly ash as cement raw materials by using Lafarge and Polysius evaluation method. Regardless of the type or amount of fly ash used, it was found to be more combustible when using fly ash. In both case, burnability improves as the amount of fly ash increases, especially the improvement in bunarbility is remarkable up to 3%. In conclusion, as the amount of fly ash increases within the range allowed by cement quality, burnability of raw materials improves, and thus the fuel cost required for the firing of clinker can also be expected to be reduced.

• Bulletin of Korea Environmental Preservation Association
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• s.389
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• pp.8-24
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• 2010

도시생활과 관련된 교통 주택부문의 온실가스 배출량은 43%를 차지하고 있어 도시에서의 온실가스 저감대책 마련이 시급하며, 저탄소 녹색성장의 시대적 요구에 따라 기후변화 위기에 적극적으로 대응할 수 있는 저탄소 녹색도시 조성이 필요한 실정이다. '저탄소 녹색도시'는 지구온난화 등 기후변화의 주요 원인인 이산화탄소의 배출을 획기적으로 감축하고, 지속가능한 도시기능을 확충하면서 자연과 공생하는 도시를 말한다. 최근의 '저탄소 녹색도시'는 기존의 녹색도시와 또 다른 양상을 보이고 있다. 자원순환과 신재생에너지원의 도입을 주장하고, 탄소상쇄를 위한 에너지 및 자원절감 전략을 중요시 하고 있다. 선진국에서는 이미 주거단지내 소비되는 난방과 전력은 단지내에서 생산되는 신재생에너지를 활용하고 있으며, 모든 주택의 지붕위에 태양광 패널을 설치하고 단지 내 열병합 자가발전소에서 산업폐기물을 소각하여 에너지를 생산함으로써 제로 에너지(Zero Energy)를 실현하고 있다. 선진국 뿐 아니라 전 세계의 이목이 '저탄소 녹색도시'에 집중되고 있으며 저탄소 녹색도시를 조성해야 하는 것은 선택이 아닌 의무가 되고 있다. 우리나라도 2020년 그린홈 100만호 보급을 목표로 주택분야 보급가능 신재생 에너지원을 태양열, 지열, 소형풍력, 연료전지 등으로 다양화하여 안정적 보급 기반을 확보해 가고 있다. 녹색도시를 조성하기 위해서는 저탄소 주택, 저탄소 에너지, 녹색교통, 생태녹지, 물 및 자원순환등 핵심요소들의 적용방안이 검토되어져야 한다. 이에 본지에서는 "저탄소 녹색도시의 해외사례와 국내 적용방향", "그린홈 100만호 보급사업 그간 성과와 발전방향", "온라인 전지자동차의 기술 개발 동향" 내용에 대하여 살펴보고자 한다.