고온건식탈황 유동층 반응기에서 아연계 탈황제의 재생반응에 미치는 산소농도의 영향

조성호,이봉희,진경태,이창근 한국화학공학회 2001 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.39 No.6

Zinc titanate 탈황제를 사용하여 내경 4.5㎝인 소형유동층 반응기에서 재생반응특성을 연구하였다. 산소농도를 5%에서 21%까지 변화시키면서 재생실험을 수행하였다. 산소의 농도변화에 따라 배출되는 SO_2의 최대농도는 양론적으로 이론치와 일치하였다. 발열반응으로 인한 재생반응기의 온도상승은 산소농도가 증가함에 따라 증가하였다. 2차 황화반응 초기에 SO_2가 발생되지 않는 것으로 보아 sulfate가 형성되지 않았다는 것을 확인할 수 있었다. 재생반응 후 시료의 물리-화학적 특성 분석결과 zinc titanate 탈황제는 부반응 및 물성변화가 없는 것으로 판단할 수 있었다. 이와 같은 실험으로 분무 건조법으로 성형된 zinc titanate 탈황제는 유동층 반응기에서 산소농도 21%의 공기로 재생 가능성을 보여 주었다. The regeneration characteristics of spray-dried zinc titanate sorbent in a fluidized bed reactor were examined at temperatures of 650℃ and 700℃ with the regenerated gas of the oxygen concentrations from 5% to 21%. The outlet SO_2 peak concentrations were coincided with the theoretical values depending on inlet O_2 concentration. As the oxygen concentration was increased, the temperature rise in the regeneration reactor was increased due to the heat of exothermic reaction. During the initial stage of the second sulfidation reaction, SO_2 was not detected in the outlet gases. It was an indirect indication that zinc sulfate had not been formed during the first regeneration reaction. The various analysis results showed little differences in physical and chemical properties between fresh and regenerated sorbent.

매체순환식 가스연소기 적용을 위한 Ni계 및 NiO계 산소공여입자의 반응특성

류호정,배달희,조성호,진경태 한국화학공학회 2004 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.42 No.1

매체순환식 가스연소기에 적용하기 위한 최적의 산소공여입자를 결정하기 위해 금속산화물(NiO)의 함량 변화에 따라 네 가지 (NiO 26, 44, 58, 78wt%)의 산소공여입자를 제조하여 열중량 분석기에서 환원반응특성을 측정 및 비교하였다. 제조된 입자들 중에서 NiO 약 60wt%인 입자가 산소전달능력 및 반응속도 면에서 다른 입자들에 비해 우수한 성능을 나타내었다. 산소공여입자의 제조과정에서 금속산화물 형태의 영향을 살펴보기 위해 금속산화물의 출발물질로 Ni과 NiO를 사용하여 NiO 함량이 동일한(약 60%) 두 종류의 입자를 제조하였으며 열중량 분석기와 고정층 반응기를 이용하여 반응속도, 재생성, 환원반응 유지시간 및 CO_(2) 선택도 등을 측정 및 고찰하였다. 금속산화물의 출발물질로 NiO를 사용한 입자가 Ni을 사용한 입자에 비해 반복 실험시에 정상반응조건에 빨리 도달하였고 반응속도와 CO_(2) 선택도가 높았으며 환원반응 유지시간인 길게 나타났다. 실험결과에 의해 본 연구에서 고려한 산소공여입자 중에서 금속산화물의 출발물질로 NiO를 사용한 NiO 함량이 60wt%인 입자를 최적의 산소공여입자로 선정하였다. To find a suitable oxygen carrier particle for chemical-looping combustor, four kinds of particles (NiO 26, 44, 58, 78wt%) were prepared and the reactivity of the reduction was measured and investigated by a thermo-gravimetrical analyzer. From the viewpoint of oxygen transfer capacity and reaction rate, the particle containing 60wt% of NiO showed better performance than the other particles. Also, we have prepared two kinds of oxygen carrier particles to investigate the effect of the starting material for a metal oxide component(i.e., Ni based and NiO based particles, where the weight percents of both samples were set at 60wt% as NiO). The reaction rate, regenerative ability, duration of the reduction, and CO₂ selectivity were easured and investigated by a thermo-gravimetrical analyzer and a fixed bed reactor. The results obtained here indicated that the NiO based oxygen carrier particle containing 60wt% of NiO showed better regenerative ability, reaction rate, CO₂ selectivity, and duration of the reduction, compared with the other particles, therefore we selected this particle as an optimum oxygen carrier particle.

환경에서의 오존이용 전망

김병호,금경호,서양곤 경상대학교 환경보전연구소 2001 環境保全硏究所報 Vol.9 No.-

Ozone was first used to disinfect water supplies in France in the early 1900s. Its use increased and eventually spread into several Western European countries. Today nearly 1,000 ozone disinfection installations exist (primarily in Europe), almost entirely for treating water supplies. A common use for ozone at these installations is to control taste-producing, odor-producing and color-producing agents. Ozone can also be used in wastewater treatment for odor control and in advanced wastewater treatment for the removal of soluble refractory organics, in lieu of the carbon-adsorption process. Ozone is also very effective virucide and is generally believed to be more effective than chlorine. Ozonation does not produce dissolved solids and is not affected by the ammonium ion or pH influent to the process. For these reasons, ozonation is considered a alternative to either chlorination of hypochlorination, especially where dechlorination may be required.

공기재생용 고온건식탈황제의 가압유동층 반응기에서의 사이클 성능실험

조성호,이봉희,이중범,류청걸,진경태,이창근 한국화학공학회 2002 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.40 No.2

고온고압 기포유동층 반응기에서 분무건조기로 성형제조한 아연계 탈황제(ZAC C)에 대하여 총 6회 황화-재생 반복실험을 500℃, 5atm 조건에서 수행하였다. 1% H_2S를 포함한 석탄모사가스를 반응기에 주입하여 황화반응을 시킨 결과 배출가스 중 H_2S 농도는 10ppmv 이하로 유지되었다. ZAC C의 황흡수력은 6회 황화반응 동안 각각 11.1, 10.9, 11.1, 11.1, 10.9, 10.5g S/100g sorbent으로 유지되어 초기 황흡수력을 유지하였다. 공기를 이용한 500℃ 재생반응에서 배출되는 SO_2의 최대농도는 양론적으로 이론값과 일치하였다. 재생반응에서 탈황제 층의 온도는 발열반응에 의해 500℃에서 최대 750℃까지 상승하였다. 연속 70시간 동안 유동층 반응기내에서 실시된 ZAC C 탈황제의 비산되어 유출된 양은 1.07%이고, 실험 후 탈황제의 크기와 조직특성의 변화도 적었다. 고온고압반응기 multi-cyclone 실험결과 ZAC C 탈황제는 이론 황흡수력의 50% 이상을 유지하였고, 공기를 사용한 500℃의 재생반응이 원활하고 완전히 이루어졌고, 황산염생성과 같은 부반응이 없었다. Two desulfurization-regeneration experiments for a spray-dried zinc-based sorbent(ZAC C) were performed at 500℃ and 5 atm in a fluidized-bed reactor(ID 0.097㎜) facility. The H_S concentration after each desulfurization run was maintained below 10 ppmv from a simulated coal gas of 1% H_2S. The estimated sulfur absorption capacities of ZAC C sorbent were 11.1, 10.9, 11.1, 11.1, 10.9, 10.5 g S/100g sorbent, and the sorption capacity of sorbent was maintained in spite of six times sorption experiments. The maximum SO_2 concentration in regeneration effluent gas agreed with a stoichiometric value of 500℃(ca. 14vol%). In regeneration run, the peak temperature of sorbent bed in the reactor reached up to 750 due to the vigorous exothermicity of regeneration reaction with neat air. While entrainment rate for 70h continuous run in fluidized-bed reactor is 1.07%, the size and the textural properties of ZAC C sorbent also show a little change. Multi-cycle tests in fluidized-bed show that ZAC C sorbent maintains over 50% of its theoretical sorption capacity during 70h run and regeneration reaction undergoes smoothly and completely without side reactions such as sulfate formation.

Cr,Cu,Fe가 첨가된 MgO 단결정의 열자극 발광 스펙트럼 분석

田耕南,兪昇喆,杜夏榮,李春鎬 全北大學校 1994 論文集 Vol.38 No.-

On the MgO single crysital doped artificially with Cr, Cu, Fe we observed thermally stimulated luminescence(TSL) glow curves and spectra, and analyzed them in the temperatured range from 500 to 77 k after excitation with UV or X-ray irradiation. TSL glow curves obtained from these samples show five peaks at 136.5K, 223.5 K, 390 K, 440 K, and their estimated activation energies are 1.08 eV, 0.27 eV, 0.63 eV, 1.19 eV, and 1.33 eV, respectively. When we measured TSL spectrum at the range of 200 nm to 650 nm, we also analysed the peak wavelength which obtained at 345 nm, 375 nm, and 410 nm from measurement of TSL spectrum and described their luminescence mechanisms.

學校周邊騷音에 대한 學生意識構造 조사 : 대구지역 고등학교 2학년을 대상으로

금경호,김복련,서양곤 경상대학교 환경보전연구소 2000 環境保全硏究所報 Vol.8 No.-

The purpose of this study was to investigate the students' consciousness against noise around nine high schools in Taegu City. It was carried out to make up and analyze a question of noise. The results are summarized as follows : 1. Two schools whose Leq was below 50㏈(A) showed comparatively little noise pollution from noise measurement of schools. Four schools, though their Leq was a little more than 50㏈(A), were supposed to have little complaint about noise because their TNI value was less than 50. Three schools was estimated to have extreme discontentment about noise because their Leq was more than 60㏈(A), so exceeded environmental standard value(50㏈(A)) and their TNI exceeded 70. 2. In questionaire, 61.2% of respondents answered that noise around school was very severe. The main sources of noise were street traffic(45.7%). In season the noise of summer was most severe(81.0%) The responsibility of noise was given to school(21.0%) and community(30.1%). The questionaire showed that damage to study was 56.2% in class, 24.8% in examination. The response to noise during class showed that most students studied bearing noise but 12.3% students gave up studying. About physical damage, 10% students answered 'a little severe' or 'severe', so physical damage was not serious. About mental damage, 30% students-answered 'a little severe' or 'severe', so three times large as the physical damage. As the result, today noise around school in Daegu cause great damage to students in school life, especially study and its psychological effect. Therefore, to live in a good sound environment the study of counterplans to noise around school must be continued.

誤診의 形事責任

秋昊卿 大韓法醫學會 1991 대한법의학회지 Vol.15 No.2

If a physician made a misdiagnosis, which brought about an undesirable result on his patient, he should assume the legly responsibility, nameal the indemnification for damage or the criminal liability for an accidental infliction of injury(homicide) out of duty. The standard of criminal negligence depends on the existence on nonexistence of the punishability of the doer. On the contrary, in judging civil responsibility, the relief of victim is accounted much of on the basis of the principle of equity. So there have been some misdiagnosis cases, the physician's criminal liability being denied, but his civil responsibility admitted. Misdiagnosis is a problem of negligence in the content of diagnosis, therefore it comes under the general thoery of criminal negligence. Due care in medical practice includes duty to anticipation of bad result and duty to avoidance of bad result. If a physician's lack of due care in diagnosis cause the bad result of his patient, he should be punishable. The standard of due care in diagnosis lies on that of an average physician, a specialist in the field of the medical treatment to put it concretely. To judge medical malpractice in diagnosis, the standards of medical science, the discretionary power of phycian and circumstances of medical care should be considered. If a physician's misdiagnosis was irresistible, he would be exempted from criminal liability. However, any physician cannot escape from crininal liability only because of the patient's idiosyncracy. He should be as cautious and circumspect as could be in finding out the idiosyncracy through the medical interview.

ZnSe 단결정에 대한 열자극 발광과 열자극 전류의 동시측정

전경남,유승철,고석룡,신용규,김택성,이춘호 全北大學校 基礎科學硏究所 1994 基礎科學 Vol.17 No.-

두 종류의 ZnSe 분말을 사용하여 sublimation 방법으로 성장한 ZnSe 단결정(as grown)에 대하여 TSC와 TSL을 동시 측정하였으며, PL과 DLTS를 측정하였다. PL 측정으로 I_1, I_2와 DAP 발광을 관측하였으며 DLTS에 의한 깊은준위를 관측하였다. TSL과 TSC의 동시 측정으로부터 얻은 그로우 곡선을 점근 해법으로 분해하여 세개의 준위를 얻었으며 그들의 활성화에너지값은 0.22 eV, 0.30 eV, 0.39 eV이었다. PL spectrum과 열자극 완화과정의 동시 측정 결과로부터 0.22 eV 근방에 impurity에 의한 주게준위와 native defect에 의한 받게준위가 각각 전도대의 아래와 가전자대의 위에 존재하는 것으로 판명되었다. DLTS 측정과 동시측정 결과로부터 0.30 eV와 0.39 eV의 준위는 V_se vacancy와 관련되는 주게 준위임을 알았다. Simultaneous measurements of TSL were carried out on ZnSe single crystals grown by high pressure Bridgman technique and the PL and DLTS signals were observed. Photoluminescence spectrum at 10 K on the ZnSe crystal reveals I_1 and I_2 lines, as well as DAP emission line. DLTS spectrum on the ZnSe crystal show electron trap at 0.33 eV. Two TSC and TSL peaks were observed near 215 K and 230 K, which are identified as having originated from two donor trap levels at 0.30 eV and 0.39 eV, respectively, below the bottom of the conduction band. We also observed single TSL and TSC peaks at 150 K which were identified as having originated from a donor and acceptor trap levels at about 0.22 eV below the conduction band and over the top of the valence band, respectively.

나노 기공의 탄소 멤브레인에서 기체의 선택적 분리를 위한 Monte Carlo 모사

이호수,금경호,서양곤 경상대학교 환경보전연구소 2000 環境保全硏究所報 Vol.8 No.-

The object of this study is to separate hydrocarbon selectively using MC method and carbon membrane. 12-6 Lennard-Jones potential function was used to describe reciprocal action of gas molecules. 10-4-3 potential function suggested by steele was used to calculate reciprocal action of molecules and pore walls. The membrane pore is composed of slit-like pores. it is include high-pressure region(H-region). low-pressure region(L-region) and M-region. between H-region and L-region. In the membrane. the transport of molecules with small size were high when the pore size is small. but in the case of molecules with large size were opposite to the transport of molecules with small size. we have found that the diffusion through surface effected on molecules transport by discussion of snapshots and density profiles. So. if the control of the pore size and surface diffusion were used to obtain high selectivity. it will be very useful method to improve the energy efficiency.

매체순환식 가스연소기 산소공여입자의 최소유동화속도 및 고속유동층으로의 전이유속

류호정,임남윤,배달희,진경태 한국화학공학회 2003 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.41 No.5

기포유동층과 고속유동층의 2탑 연결 가압순환유동층으로 조업되는 매체순환식 가스연소기의 설계와 조업조건 선정을 위해 산소공여입자의 최소유동화속도와 고속유동층으로의 전이유속을 측정 및 고찰하였다. 층물질로 매체순환식 가스연소기의 산소공여입자인 NiO/bentonite (평균입경 : 0.181 mm, 입자밀도 : 4,080 kg/㎥)를 사용하여 가압 기포유동층(내경 0.052 m, 높이 1.66 m)에서 층압력강하를 측정하여 온도(25-1,000℃)와 압력(1-6 atm)의 변화에 따른 최소유동화속도의 변화를 측정 및 고찰하였고 고온순환유동층(내경 0.02 m, 높이 2.0 m)에서 emptying time method에 의해 고속유동층으로의 전이유속(U_(tr))에 대한 온도(25-600℃)의 영향을 측정 및 고찰하였다. 측정된 최소유동화속도는 온도와 압력이 증가함에 따라 감소하였으며, 고속유동층으로의 전이유속은 온도가 증가함에 따라 증가하였다. 최소유동화속도와 고속유동층으로의 전이유속에 대한 본 실험의 측정값을 기존의 상관식과 비교하였으며 기존 상관식을 바탕으로 수정된 상관식을 제시하였다. In order 10 design and select appropriate operating conditions for the practical operation of chemical-loaping combustor, which consists of two interconnected fluidized beds (bubbling fluidized bed and fast fluidized bed), minimum fluidization velocity and transition velocity to fast fluidization were measured and investigated. Oxygen carrier particle of NiO bentonite particle (specific surface mean diameter: 0.181 mm, particle density: 4,080 ㎏/㎥) was used as a bed material. The minimum fluidization velocity was determined by measuring the bed pressure drop in the pressurized fluidized bed (0.052 m i.d. and 1.66 m high) with variations of temperature (25-1,000℃) and pressure (1-6 atm). The transition velocity from bubbling to fast fluidization was determined by means of emptying tim method in the high temperature circulating fluidized bed (0.02 m i.d. and 2.0 m high) with variation of temperature (25-600℃). The measured minimum fluidization velocity was increased with increasing temperature and pressure. The measured transition velocity to fast fluidization was increased with increasing temperature. The previous correlations on the minimum fluidization velocity and transition velocity to fast fluidization were compared with the present measured values to develop new correlation.