Biomass Gasification 공정에서 발생하는 Tar 제거연구

김주회(Ju-Hoe Kim),조영민(Young-Min Jo),김종수(Jong-Su Kim),김상범(Sang-Bum Kim) 한국산학기술학회 2018 한국산학기술학회논문지 Vol.19 No.8

화석연료의 고갈과 환경문제를 대응하기 위한 대체에너지 중 재생가능하고 탄소중립(Carbon-neutral)자원인 바이오매스 (Biomass)를 연료로 이용하는 연구가 진행되고 있다. 바이오매스를 사용하는 대부분의 에너지 생산 시스템은 열화학전환 방법이 대표적이다. 이 가운데 가스화 기술을 이용해 합성가스 (syngas)를 생산해 보일러나 엔진 등에 적용하여 열과 전기를 생산한다. 하지만 합성가스 (syngas)를 생산하는 과정에서 타르 (tar)가 발생되며 낮은 온도에서 응축되기 때문에 배관 및 엔진 등에 막힘 현상을 일으켜 공정 효율을 감소시키는 문제를 야기한다. 타르를 제거하기 위해 대부분의 가스화 공정에서 물을 이용한 wet scrubber를 사용하고 있는데 효율이 낮은 문제점이 있다. 이에 본 연구에서는 물과 oily material (soybean oil, waste cooking oil, mineral oil)을 이용하여 제거효율이 높은 순으로 나타내자면 Soybean oil> Waste Cooking Oil> Mineral oil>Water 순서로 나타났고 제거효율은 각각 약 97%, 약 70%, 약 63%, 약 30%의 효율을 보여주었으며 식물성 오일 종류인 soybean oil을 사용하였을 때 타르 제거 효율이 가장 높았다. Biomass, a carbon-neutral resource, is an alternative energy source for exhaustion of fossil fuel and environmental problems. Most of energy production systems using biomass operate with a thermal chemical conversion method. Amongst them, gasification generates syngas and applies to boilers or engines for the production of heat and electricity. However, Tar could be formed during the production of syngas and it is condensed at low temperature which may cause to clog the pipelines and combustion chamber, ultimately resulting in decrease of process efficiency. Thus this work utilized water and oily materials such as soybean oil, waste cooking oil and mineral oil for scrubbing liquid. The removal efficiency of Tar appeared 97%, 70%, 63% and 30% for soybean oil, waste cooking oil, mineral oil and water respectively.

물의 전기 분해를 위한 전극 표면적 및 구조적 변화특성에 관한 연구

김주회(Joowoi Kim),안형환(Hyungwhan An),허문회(Munwoe Hur) 한국가스학회 2016 한국가스학회 학술대회논문집 Vol.2016 No.6

색상차이에 따른 FRC-포스트와 코어 사이의 구별

김주회(Jou-Hwe Kim),김진우(Jin-Woo Kim),조경모(Kyung-Mo Cho),박세희(Se-Hee Park) 대한턱관절교합학회 2015 구강회복응용과학지 Vol.31 No.2

브라운가스 생산을 위한 DC형 소형장치의 개발

김주회(Joowoi Kim),안형환(Hyungwhan An),허문회(Munwoe Hur) 한국가스학회 2015 한국가스학회 학술대회논문집 Vol.2015 No.11

영상 몽타주의 예술적 미학

김주회(ju hoi kim) 한국콘텐츠학회 2019 한국콘텐츠학회지 Vol.17 No.4

디젤자동차 용 소형 브라운가스 발생장치의 개발을 위한 가스 생성 특성에 관한 연구

김주회(Joohwi Kim),안형환(Hyunghwan An) 한국가스학회 2016 한국가스학회지 Vol.20 No.5

디젤자동차용 소형브라운가스 생성 장치의 개발을 위하여 전극 셀의 재료로서 SuS와 Ni 및 Ag기반 셀을 제조하고 셀의 면적과 전해질의 농도 및 전류의 세기를 변화시켜 브라운가스 생성특성을 실험적으로 분석하였다. 전기분해 반응기는 셀의 표면적 및 전극 –극과 +극 배치를 다르게 하여 SMT30, SMT50, SMT50-1, SMT70, SMT90로 제조하였다. 이 때 각 반응기의 따른 브라운가스 생성특성은 셀의 접촉 면적이 클수록 생성특성이 증가하는 경향을 보였으며 전극배치의 경우는 같은 전극면적에서도 극의 배치 따라 차이가 있는 것을 보였다. 또한 전해질의 농도에 대한 영향은 NaOH를 1∼3‰로 변화시켰을 때 농도가 적을수록 생성특성이 증가하였고, 전류의 세기의 따른 생성특성은 SMT30 , SMT50 , SMT50-1 , SMT70 , SMT90에서 각각 0.74ℓ/10min, 1.0ℓ/10min, 1.10,ℓ/10min, 0.97ℓ/10min, 1.13ℓ/10min가 얻어졌다. This study is experimentally investigated brown gas generative properties with the changes of cell areas, a electrolyte concentration and ampere current for the developments of small brown gas generation equipments usable in diesel cars. Electrolysis reactors have been manufactured as SMT30, SMT50, SMT50-1, SMT70, SMT90, respectively on various surface areas and different positions anode and cathode. Thus, the brown gas generative properties on reactors tended to increase as surface area increase, and show differences in different electrode positions. However, the effect on electrolyte concentration had increased with a decreasing electrolyte concentration of NAOH 3∼1‰, and the brown gas generative properties on ampere of SMT30, SMT50 , SMT50-1 , SMT70 , SMT90 have shown to be 0.74ℓ/10min, 1.0ℓ/10min, 1.10,ℓ/10min, 0.97ℓ/10min, 1.13ℓ/10min.

싸이클론 재순환, 냉각공정을 이용한 공정가스 정제 연구

김주회(Ju-Hoe Kim),조우진(Woo-Jin Jo),최영태(Young-Tae Choi),조영민(Young-Min Jo),김상범(Sang-Bum Kim) 한국산학기술학회 2018 한국산학기술학회논문지 Vol.19 No.1

화석 연료의 고갈과 온난화 현상으로 인해 새로운 에너지원에 대한 관심이 급증하고 있다. 그 중에서 바이오가스는 유기성 폐기물 및 바이오매스를 혐기성 소화과정인 가수분해(hydrolysis), 산발효(acidogenesis), 유기산발효(acetogenesis), 메탄발효(methanogenesis)의 단계를 거쳐 발생되기 때문에 친환경적인 에너지자원으로 각광받고 있다. 그러나 바이오가스는 기존의 정제설비로는 제거할 수 없는 높은 미세분진 및 수분 함량으로 인해, 직접연소, 도시가스, 자동차용 연료 등 효율적인 이용을 위해서 정제시스템이 필요하다. 따라서 본 연구는 미세분진과 수분을 동시에 제거할 수 있는 정제과정의 전처리 방법으로써 원심력을 이용하는 냉각공정을 설계하였다. 원심력을 이용하여 분진을 제거하는 Cyclone 내·외부에 열교환기와 ID fan을 구성하여 주입되는 가스를 어는점 이하로 냉각시킴으로써 물안개를 형성시켜 분진입자를 제거하고, 일부 가스를 ID fan을 이용하여 재순환시켜 제거하는 고효율 냉각제어공정을 개발하였다. 수분제거는 유량(25~150L/min) 및 상대습도(60~95%)의 조건에서 시험하였다. 수분제거율은 상대습도 95±5%일 때 평균 80.8%, 입자제거율은 입자크기 2.5 ㎛에서 평균 99.78%의 제거효율을 보였고, 수분과 입자의 동시제거효율은 수분 70.86%, 입자 99.67%의 평균 값을 보여주었다. Renewable energy has been of interests in the area of modern alternative fuels. Biogas is produced in waste landfill sites through anaerobic digestion processes, including hydrolysis, acidogenesis, organic acid fermentation (acetogenesis), and methane fermentation (methanogenesis). High contents of fine dust and moisture limited its utilization for direct combustion, town gas and vehicle fuel. Thus, this study proposed a new design for a cooling device using a centrifugal cyclone for simultaneous removal of fine dust and moisture as a pretreatment in the purification processes. A heat exchanger and an ID fan, which are installed inside and outside of the cyclone, in order to cool the humid gas below the freezing point and form a foggy mist. Such an atmosphere enhanced to capture fine dust as recirculating the cold mist flow. The water removal rate was 80.8% at a relative humidity of 95%, and the particle removal efficiency was 98.3% for 2.5 μm. Simultaneous removal efficiency was 70.8% and 99.6% for particle and moisture respectively.

A Study on properties of a-Si:H layers by photoelectron spectroscopic

양현훈(Yang, Hyeon-Hun),김한울(Kim, Han-Wool),김주회(Kim, Joo Hoe),김철중(Kim, Chul Joong),이창권(Lee, Chang Gwon),소순열(So, Soon-Youl),박계춘(Park, Gye-Choon),이진(Lee, Jin) 한국신재생에너지학회 2011 한국신재생에너지학회 학술대회논문집 Vol.2011 No.11

We report on a detailed study on gap-state distribution in thin amorphous silicon layers(a-Si:H) with film thickness between 5 nm and 20 nm c-Si wafers performed by UV excited photoelectron spectroscopy(UV-PES). We measured how the work function, the gap state density, the position of the Fermi-level and the Urbch-energy depend on the layer thickness and the doping level of the ultra thin a-Si:H(n) layer. It was found, that for phosphorous doping the position of the Fermi level saturates at E_F-E_V=1.47 eV. This is achieved at a gas phase concentration of 10000 ppm PH₃ in the SiH₄/H₂ mixture which was used for the PECVD deposition process. The variation of the doping level from 0 to 20000 ppm PH₃ addition results in an increase of the Urbach energy from 65 meV to 101 meV and in an increase of the gap state density at midgap(E_i-E_V=0.86eV) from 3{times}10^{18} to 2{times}1019cm^{-3}eV^{-1}.

Non-linear optical properties of PECVD nanocrystal-Si nanosecond excitation

양현훈(Yang, Hyeon-Hun),김한울(Kim, Han-Wool),김주회(Kim, Joo Hoe),김철중(Kim, Chul Joong),이창권(Lee, Chang Gwon) 한국신재생에너지학회 2011 한국신재생에너지학회 학술대회논문집 Vol.2011 No.11

A study of the non-linear optical properties of nanocrystal-Si embedded in SiO2 has been performed by using the z-scan method in the nanosecond and femtosecond ranges. Substoichiometric SiOx films were grown by plasma-enhanced chemical-vapor deposition(PECVD) on silica substrates for Si excesses up to 24 at/%. An annealing at 1250?C for 1 hour was performed in order to precipitate nanocrystal-Si, as shown by EFTEM images. Z-scan results have shown that, by using 5-ns pulses, the non-linear process is ruled by thermal effects and only a negative contribution can be observed in the non-linear refractive index, with typical values around -10-10cm²/W. On the other hand, femtosecond excitation has revealed a pure electronic contribution to the nonlinear refractive index, obtaining values in the order of 10-12 cm2/W. Simulations of heat propagation have shown that the onset of the temperature rise is delayed more than half pulse-width respect to the starting edge of the excitation. A maximum temperature increase of {Delta}T=123.1?C has been found after 3.5ns of the laser pulse maximum. In order to minimize the thermal contribution to the z-scan transmittance and extract the electronic part, the sample response has been analyzed during the first few nanoseconds. By this method we found a reduction of 20% in the thermal effects. So that, shorter pulses have to be used obtain just pure electronic nonlinearities.

대규모 젖소목장의 임상형 유방염 발생에 관한 후향적 연구

강주회 ( Ju Hoe Kang ),김선득 ( Seon Deuk Kim ),박준영 ( Jun Young Park ),조인영 ( In Young Cho ),허태영 ( Tai Young Hur ),정영훈 ( Young Hun Jung ),최창용 ( Chang Yong Choi ),정지영 ( Ji Young Jung ),신성식 ( Sung Shik Shin ) 한국가축위생학회 2011 韓國家畜衛生學會誌 Vol.34 No.4

Incidence of mastitis is highest in dairy cows and it is a leader of all diseases and the economic losses, in dairy farms. The objective of this study is to analyse the incidence of clinical mastitis using the lactation number, lactation month and season of calving. In this study, we used 3,779 lactation data and animal health records collected from 1990 to 2006 at the National Institute of Animal Science. Out of 3,779 cows, a total of 1,721 cows were reported with clinical mastitis, which was 46.3%. The frequency of mastitis increased from 36.9% from first lactation to 56.0% by the fifth lactation. As many as 766 cows (46.9%) showed a recurrence of mastitis after 14 days, apart for two or more and chronic mastitis that were recorded for 657 cows (20.3%). This came to a total of 3,010 cases that had clinical mastitis in the herd for sixteen years. The distribution of incidence of clinical mastitis was highest during the first month of lactation at 24.4%, and it reached to 43.4% by the third month. The incidence of mastitis was even higher for cows in first lactation, showing 28.6% in the first month, and 42.9 percent by third month of lactation. Cows calved during the summer and winter months showed higher rate of incidence with 59.9% and 57.9% within 30 days of lactation, respectively. It is urgently needed to establish a preventative management for heifer cows during their expected first lactation and the clinical specific dry-period management strategies that influence the rate of clinical mastitis during the next lactation. The aim of this study is to present information that might be useful to improve clinical mastitis prevention.