95년도 LPG산업 및 가스 안전관리 정책방향

김은규,Kim, Eun-Gyu 대한석유협회 1995 석유와 에너지 Vol.1995 No.3

용매 추출을 사용한 바닐린 생산공정의 개념 설계

김은규,송대성,Kim, Eunkyu,Vu, Thang Toan,Song, Daesung 한국화학공학회 2022 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.60 No.4

본 연구에서는 크라프트 리그닌(Kraft Lignin)을 사용해 바닐린을 생산하는 공정의 개념 설계를 진행하였다. 기존 크라프트 리그닌은 대부분 저품질의 보일러 연료로 사용되거나 폐수로 버려지고 오직 2% 이하의 리그닌만 고품질의 제품으로 정제된다. 버려지는 크라프트 리그닌을 활용하기 위해 새로운 공정을 제안하였다. 기존 바닐린 생산 개념 공정은 NaOH를 사용한 알칼리 산화, 여과, 크로마토그래피, 결정화 단계로 진행됐다. 이중 상용화가 어려운 크로마토그래피를 용매 추출 공정으로 변경하였다. 제안된 용매 추출 공정의 바닐린 회수율 92.9%, 순도 99.5%이며, 이는 기존 크로마토그래피 공정과 유사한 수준이다. 크로마토그래피와 비슷한 결과를 보이는 용매 추출 공정이 기존 크로마토그래피 공정을 대체할 수 있는 이유를 분석하였다. This study presents a conceptual design of vanillin production from Kraft lignin. Most of the existing Kraft lignin is used as low-quality boiler fuel or discarded as wastewater, and only 2% or less of lignin has been refined into high-quality products. We propose the process developed in this study to utilize discarded Kraft lignin. The existing vanillin production concept process consisted of alkali oxidation using NaOH, filtration, chromatography, and crystallization. Chromatography, which is difficult to commercialize, was changed to a solvent extraction process. The recovery rate of vanillin of the proposed solvent extraction process is 92.9%, and the purity is 99.5%, which is similar to the existing chromatography process. The reason why the solvent extraction process showing similar results to chromatography can replace the existing chromatography process was analyzed.

LPG 수급동향과 정책방향

김은규,Kim, Eun-Gyu 대한석유협회 1997 석유와 에너지 Vol.1997 No.5

동북아시아 지역에서 MODIS와 MI에 의한 에어로졸 광학두께 비교

김은규,이규태,정명재,Kim, Eun-kyu,Lee, Kyu-Tae,Jung, Myeong-Jae 대한원격탐사학회 2017 大韓遠隔探査學會誌 Vol.33 No.5

본 연구에서는 동북아시아($15{\sim}55^{\circ}E$, $90{\sim}150^{\circ}N$) 영역에 대하여 극궤도 위성 Terra와 Aqua에 탑재된 Moderate Resolution Imaging Spectrometer (MODIS) 센서와 우리나라 정지궤도 위성인 통신해양기상위성(Communication, Ocean and Meteorological Satellite, COMS)에 탑재된 Meteorological Imager (MI) 센서에 의한 에어로졸 광학두께(AOT) 산출 결과와 지상의 Aerosol Robotic Network (AERONET) 관측 자료를 비교 분석하였다. 그 결과 MODIS와 MI에 의한 에어로졸 광학두께는 해양에서 비교적 잘 일치하였으나 구름 가장자리와 육지에서는 두 센서의 에어로졸 광학두께 차이가 크게 나타났다. 그 이유로서 MODIS는 가시 채널과 적외 채널을 혼용하는 반면 MI는 오직 가시채널 만 사용하기 때문에 구름 가장자리의 옅은 구름을 에어로졸로 인식할 수 있고 육지에서는 지표면 특성에 따라 MODIS와 MI에 의한 에어로졸 광학두께 산출 차이가 발생된다. 따라서 MI 에어로졸 광학두께는 구름 가장자리와 지표면 특성의 영향을 주는 지표면 반사도의 정확성 개선을 통해 에어로졸 광학두께 산출 결과를 개선할 수 있다고 사료된다. The aerosol optical thickness data retrieved by Moderate Resolution Imaging Spectrometer (MODIS) of Terra & Aqua and Meteorological Imager (MI) of Communication Ocean and Meteorological Satellite (COMS) are analyzed and compared with the measurement data of Aerosol Robotic Network (AERONET) in Northeast Asia. As the result, the aerosol optical thickness retrieved by MODIS and MI were well agreed at ocean region but quite different at cloud edge and barren surface. The reason was that MODIS aerosol optical thickness was retrieved using the visible and infrared channels but MI was retrieved with the visible channel only. Consequentially, the thin cloud be misinterpreted as aerosol by MI and the difference between MODIS and MI aerosol optical thicknesses could be occurred with Normal Distribution Vegetation Index (NDVI) and land surface property. Therefore, the accuracies of clear/cloud region and surface reflectivity are required in order to improve the aerosol optical thickness algorithm by MI.

Electrical Study on Indium-Rich InGaN/GaN Multi-Quantum-Well System

김은규,윤의준,김희진,J. S. Kim,권순용 한국물리학회 2006 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.49 No.5I

We studied the electrical properties of a 10-period InGaN/GaN multi-quantum-well (MQW) structure by using capacitance-voltage (C-V) and deep-level transient spectroscopy (DLTS) methods. Two energy states of the InGaN QW appeared, are at about 0.37 eV and the other at 0.43 eV from the conduction band edge of the GaN barrier. Band-to-band transition energies of 3.10 eV and 3.18 eV were found by using the PL measurements. A defect with an activation energy of 0.39 eV and a cross-section of 3.96 × 10.18 cm2 was also found in the GaN buffer layer. The energyband diagram of InGaN/GaN QW structure is discussed using the PL and the DLTS parameters, considering the existence of a electron capture barrier.?서`

Electrical Properties of Vertically Stacked InGaAs/InGaAsP/InP Self-Assembled Quantum Dots

김은규,Il-Woo Park,Jin Soak Kim,W. G. Jeong 한국물리학회 2005 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.47 No.3

We used capacitance-voltage (C-V) and deep-level transient spectroscopy (DLTS) methods to investigate dependence of the electrical properties of the vertically stacked InGaAs/InGaAsP/InP quantum dot (QD) system on the vertical distance between the InAs QD layers. The DLTS measurements show that two groups of activation energies, 0.33 0.37 eV and 0.39 0.43 eV for low and high temperatures, respectively, appear in QD samples and vary with the thickness of the InGaAaP spacer layer. Also, the activation energy of the 100-nm-thick spacer samples has a lower value than that of the thin-spacer (10 nm) sample. From the bias-dependent DLTS measurements for the 10-nm-spacer sample, the quantum energy states of nearby QDs appear to couple and decouple as the gate bias conditions vary.

Energy Levels of InAs/InP Quantum Dots by Thermal Treatment

김은규,J. S. Kim,K. Park,윤의준,노삼규 한국물리학회 2005 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.46 No.1

We have measured the energy levels of thermally annealed InAs/InP quantum dots (QDs) by deep level transient spectroscopy. The QDs were grown by Stranski-Krastanov mode during low-pressure metal organic chemical vapor deposition. During the thermal annealing in thetemperature range from 500 to 600 ±C, the thermal activation energy and the emission cross-section of thr QD-related signal were varied from 0.47 to 0.60 eV and 1:01 £ 10¡15 to 9:63 £ 10¡14 cm2, respectively. The capture barrier height of the thermally annealed QD system was also obtained from the analysis of carrier capture dynamics, and then it lowered from 0.24 eV to 0.06 eV with increasing annealing temperature. From these results, it is considered that the intermixing between InAs QD and InP barrier layers by thermal treatment also gradually releases the internal strain. We have measured the energy levels of thermally annealed InAs/InP quantum dots (QDs) by deep level transient spectroscopy. The QDs were grown by Stranski-Krastanov mode during low-pressure metal organic chemical vapor deposition. During the thermal annealing in thetemperature range from 500 to 600 ±C, the thermal activation energy and the emission cross-section of thr QD-related signal were varied from 0.47 to 0.60 eV and 1:01 £ 10¡15 to 9:63 £ 10¡14 cm2, respectively. The capture barrier height of the thermally annealed QD system was also obtained from the analysis of carrier capture dynamics, and then it lowered from 0.24 eV to 0.06 eV with increasing annealing temperature. From these results, it is considered that the intermixing between InAs QD and InP barrier layers by thermal treatment also gradually releases the internal strain.

전자기 바이스태이블 래칭 액추에이터를 이용한 저전력 이산 연동식 마이크로펌프

김은규(E. K. Kim),김지용(J. Kim),Salman Khan,강보민(B. M. Kang),이효건(H. G. Lee),윤형민(H. M. Yoon),김재현(J. H. Kim),정재우(J. W. Jung),김우철(W. Kim),윤준영(J. Y. Yoon) Korean Society for Precision Engineering 2023 한국정밀공학회 학술발표대회 논문집 Vol.2023 No.5

황산기가 도입된 감마 알루미나를 이용한 자일로즈 탈수화 반응을 통한 푸르푸랄의 생성

김은규(Eun Gyu Kim),김샛별(Saet Byul Kim),박은덕(Eun Duck Park),김상욱(Sang-Wook Kim) 한국청정기술학회 2011 청정기술 Vol.17 No.1

산성, 중성, 염기성의 감마알루미나에 (3-mercaptopropyl) trimethoxysilane (3-MPTMS)를 알루미나 기공 내에 도입하고 30 wt% 과산화수소수를 이용하여 황산기가 결합된 감마알루미나를 합성하였다. 1 M HCl용액을 이용하여 3-MPTMS의 도입을 좀 더 용이하게 하였다. 합성된 촉매는 자일로즈 탈수화 반응을 통한 푸르푸랄 생성반응에 적용하여 촉매 특성을 분석하였다. 모든 촉매 반응에서 우수한 자일로즈 전환률을 보였고, 황산기가 도입된 촉매가 푸르푸랄의 선택도를 높이는 결과를 보였다. All types of γ-Al₂O₃ such as acidic, neutral and basic forms were chemically modified with (3-mercaptopropyl) trimethoxysilane (3-MPTMS) and oxidized by 30 wt% H₂O₂ solution. As a result, sulfonic acid modified γ-Al₂O₃ catalysts were obtained. Their formation was achieved more easily by treating 1M HCl solution. Their catalytic performance was tested by dehydration reaction of D-xylose to furfural. The sulfonic acid modified γ-Al₂O₃ catalysts showed high conversion (>90%) of Dxylose, and the selectivity to furfural was increased with the amount of sulfonic acid anchored on the catalyst.

황산 표면개질 메조다공 실리카를 이용한 푸르푸랄 제조에 관한 연구

김은규(Eun Gyu Kim),김샛별(Saet Byul Kim),박은덕(Eun Duck Park),김상욱(Sang Wook Kim) 한국청정기술학회 2010 청정기술 Vol.16 No.2

MCM 41, HMS, SBA 15와 같은 메조다공 실리카에 post-synthesis와 co-condensation 방법으로 황산이 결합된 촉매를 제조하였다. 이 메조다공 실리카들을 자일로즈 탈수화반응의 촉매로 사용하여 푸르푸랄을 합성하였으며 관련된 반응특성을 연구하였다. 그 결과, 친환경적 용매인 물을 사용한 경우에도 양호한 전환율과 선택도를 얻을 수 있었다. 아울러 실리카 표면에 황산의 양이 증가할수록 자일로즈의 전환율이 증가하는 것을 알 수 있었고, 동일한 반응 조건에서 다른 고체산 촉매인 제올라이트와 감마알루미나를 사용했을 때 보다 양호한 선택도 결과를 얻었다. Sulfonic acid (-SO₃H) functionalized mesoporous silica containing HMS, SBA 15(S15), MCM 41(M41) were synthesized by post-synthesis and co-condensation method. Their catalytic performance is tested by dehydration reaction of D-xylose to furfural. As a result, good conversion and selectivity was obtained using water as an environmentally friendly solvent. Additionally, increased amounts of sulfuric acid in catalysts resulted in improved conversion of D-xylose. All of the acid-functionalized mesoporous silica showed higher selectivity than other solid acids such as γ-Al₂O₃ and zeolite.