• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.520-520
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• 2016

석유 화학공장에서 발생하는 spent sulfidic caustic (SSC) 폐수는 액화석유가스(LPG)나 천연가스(NG)의 정제과정에서 발생되는 것으로 고농도의 sulfide와 cresylic, phenolic 그리고 mercaptan 등이 포함된 독성과 냄새를 유발하는 물질이다. 이러한 물질들은 LPG나 NG의 정제과정에서 높은 산도를 가진 휘발성 황화합 물질들을 제거하기 위해 사용된 NaOH가 $H_2S$와 반응하여 발생하는 것이다. 진한 갈색 또는 검은색을 띄는 SSC 폐수는 12 이상의 높은 pH를 가지고 있으며 5~12 wt%의 높은 염분도를 가지고 있다. 또한 강한 부식성과 독성을 가진 황화합물의 농도가 1~4 wt%이며, 방향족 탄화수소 물질 (i.e. methanethiol, benzene, tolune and phenol)들도 다량 함유되어 있다. 따라서 이러한 유해 물질들은 기존의 하수처리 공정으로 방류하기 전에 완벽하게 처리해야만 하수처리 공정의 오염 부하량을 줄일 수 있다. 습식산화공정은 SSC 폐수를 처리하기 위해 흔히 사용되고 있는 물리-화학적 처리 공정이지만 고비용, 고에너지가 필요하며, 고온 및 고압에서만 작동되어 안전상의 문제점을 갖고 있다. 또한 습식산화공정을 거친 폐수는 배출허용기준을 만족하기 위해 생물학적 2차 처리가 반드시 필요하다. 철-과산화수소를 이용하는 펜톤산화 공정, 그리고 sulfide를 sulfate로 전환시키는 생물학적 처리 공정은 황화합물의 완전한 무기물화가 힘들며, 현장 적용 시 기술적 경제적 부담이 크다. 이러한 단점을 극복하고, SSC 폐수를 효과적으로 처리하기 위해 본 연구는, 높은 흡착력과 광산화력을 가진 흡착광산화 반응 시스템(Adsorption Photocatalysis System, APS)을 개발하였다. APS는 SSC 폐수를 시스템 내부로 유입하여 수중의 오염물질을 흡착광산화제로 구성된 반응구조체가 흡착하고, 흡착된 오염물질을 UV에너지와 이산화티타늄 광촉매의 광화학반응에 의해 최종적으로 무해한 물질로 환원시키는 폐수처리시스템이다. APS의 반응구조체는 태양에너지 및 인공에너지원에 의해 활용 가능하며, 난분해성 유기화합물질을 물과 이산화탄소로 분해할 수 있는 친환경적이고 경제적인 소재로서 널리 쓰이고 있는 이산화티타늄 광촉매와 화력발전소의 높은 소성온도에 의해 연소된 후 발생되는 bottom ash를 이산화티타늄의 지지체로 사용하여 높은 흡착력과 광촉매 산화력을 가진 복합물이다. 개발된 APS에 의해 SSC 폐수를 처리한 결과, COD 86.1%, 탁도 98.4%, sulfide 99.9%의 높은 처리효율을 보여주고 있다. 따라서 본 연구를 통해 개발된 APS는 강한 부식성과 독성 그리고 높은 농도를 가지고 있는 SSC 폐수를 효과적으로 처리할 수 있다.

• Korean Chemical Engineering Research
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• v.46 no.5
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• pp.922-930
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• 2008

The selective non-catalytic reduction(SNCR) performance is sensitive to the process parameters such as flow velocity, reaction temperature and mixing of reagent(ammonia or urea) with the flue gases. Therefore, the knowledge of the velocity field, temperature field and species concentration distribution is crucial for the design and operation of an effective SNCR injection system. In this work, a full-scale two-dimensional computational fluid dynamics(CFD)-based reacting model involving a droplet model is built and validated with the data obtained from a pilot-scale urea-based SNCR reactor installed with a 150 kW LPG burner. The kinetic mechanism with seven reactions for nitrogen oxides($NO_x$) reduction by urea-water solution is used to predict $NO_x$ reduction and ammonia slip. Using the turbulent reacting flow CFD model involving the discrete droplet phase, the CFD simulation results show maximum 20% difference from the experimental data for NO reduction. For $NH_3$ slip, the simulation results have a similar tendency with the experimental data with regard to the temperature and the normalized stoichiometric ratio(NSR).

• Journal of the Korean Institute of Gas
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• v.7 no.1 s.18
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• pp.1-9
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• 2003

A Multi-distinction Equipment Screening Algorithm (MESA) is proposed. It selectively integrates Dow's F&EI as its process hazard index technique and ESA (Equipment Screening Algorithm) as qualitative hazard classification technique, and retrieves a detailed list of hazardous equipments with the total hazard indices of those equipments. The inherent expert system, which includes the accident scenarios of the equipments and processes and experts' views of them, narrows further down the list of hazardous equipments and recommends only the most notable candidates. Through the case study of distinguishing the hazardous ranking of the equipments of the LPG underground storage process, using the expert system or not, the applicability of MESA has been validated. Taking the characteristics of the process equipments with hazardous ranking in the point of process intrinsic safety, this proposed algorithm would contribute to providing engineers or managers with information on constructing safely devices and mitigation devices and on scheduling emergency response planning.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.2
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• pp.590-596
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• 2010

Through this study, we have attempted the thermodynamic analysis on the dimethyl ether (DME) separation process, which can be used for diesel alternative fuel, additive to LPG and natural gas. And we also have completed the simulation of DME separation process using PRO/II with PROVISION. As an appropriate thermodynamic models, we selected NRTL liquid activity coefficient model to describe the non-ideality between methanol and water. To estimate the vapor phase non-idealities, we have chosen the Peng-Robinson equation of state model. And we also use the Henry's law option to predict the solubilities of non-condensible gases like CO, $CO_2$, $H_2$, $CH_2$ and $N_2$ in methanol solvent. Case study showed that optimal solvent to feed molar ratio was 3.40

• Journal of the Korean Institute of Gas
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• v.14 no.3
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• pp.41-45
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• 2010

The physical properties of DME(Dimethyl Ether) are very similar to LPG and well-mixed. As cetane number of DME is similar to diesel fuel that can replace diesel fuel and alternative energy. DME is a clean energy source that can be manufactured from various raw materials such as natural gas, CBM(Coal Bed Methane) and biomass. DME has no carbon-carbon bond in its molecular structure and its combustion essentially generates no soot as well as no SOx. The development of DME process in KOGAS have 4 section. First, syngas section can be manufactured various syngas ratio. This completes the tri-reforming process for the synthesis gas ratio of approximately 4.0 to 1.0 range can be adjusted. Second, $CO_2$ is removed from the $CO_2$ removal section of about 92~99%, so the maximum concentration of $CO_2$ entering the DME synthesis reactor should not exceed 8%. Third, in the DME synthesis section, if the temperature of DME reactor increases, the activity of DME catalyst increased. but for the long-term activity is desirable to maintain the proper temperature. Finally, the purity of DME in the DME purification section is over 99.6%.

• Korean Chemical Engineering Research
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• v.52 no.6
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• pp.720-726
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• 2014

PEM fuel cell vehicles have been getting much attraction due to a sort of highly clean and effective transportation. The onboard fuel processor, however, is inevitably required to supply the hydrogen by conversion from some fuels since there are not enough available hydrogen stations nearby. A lot of studies have been focused on analyses of ATR reactor under the assumption of thermo-neutral condition and those of the optimized process for the minimization of energy consumption using thermal efficiency as an objective function, which doesn't guarantee the maximum hydrogen production. In this study, the analysis of optimization for 100 kW PEMFC onboard fuel processor was conducted targeting various fuels such as gasoline, LPG, diesel using newly defined hydrogen efficiency and keeping simply synthesized heat exchanger network regardless of external utilities leading to compactness and integration. Optimal result of gasoline case shows 9.43% reduction compared to previous study, which shows the newly defined objective function leads to better performance than thermal efficiency in terms of hydrogen production. The sensitivity analysis was also done for hydrogen efficiency, heat recovery of each heat exchanger, and the cost of each fuel. Finally, LPG was estimated as the most economical fuel in Korean market.

• Journal of the Korean Institute of Gas
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• v.3 no.1
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• pp.21-26
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• 1999

Chemical plant's fire and explosion does not only damage to the chemical plants themselves but also damage to people in or near of the accident spot and the neighborhood of chemical plant. For that reason, Chemical process safety management has become important. One of safety management methods is called 'the quantitative analysis', which is used to reduce and prevent the accident. The results of the quantitative analysis could be used to arrange the equipments, evaluate the minimum safety distance, prepare the safety equipments. In this study we make the computer program to make easy to do Quantitative analysis of the accident. The output of the computer program is the magnitude of fire(pool fire and fireball) and explosion(UVCE and BLEVE) effects. We used the thermal radiation as a measure of fire magnitude and used the overpressure as a measure of explosion magnitude. In case of BLEVE, the fly distance of fragment can be evaluated. Also probit analysis was done in every case. As the case study, Buchun LPG explosion accident in Korea was analysed by the program developed. The simulation results showed that the permissible distance was 800m and probit analysis showed that 1st degree bum, 2nd degree burn, and death distances are 450, 280, 260m, respectively the simulation results showed the good agreement with the results from SAFER PROGRAM made by Dupont.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.20-23
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• 2007

가정용 연료전지 수소 공급용 연료변환 장치는 LNG, LPG를 이용하여 수소를 제조하는 수증기 개질과 제조된 합성가스의 정제공정으로 저온/고온 전이 반응 및 선택적 산화 반응을 포함하게 된다. 이중 전체 연료변환 장치 효율은 공정중의 유일한 흡열 반응인 수증기 개질 반응기 구조와 반응열 공급용 버너에 의해 결정된다. 반응열 공급용 버너의 형식, 구조 등의 변수를 통해 본 연구진에 의해 개발된 반응구조의 최적 열원 공급 방식을 산출하고자 하였다. 이를 위하여 본 연구에서는 원통형 개질 반응기에 적용 가능한 버너의 구조, 토출 각도, 토출구의 수 등의 버너 설계 변수가 버너의 성능의 미치는 영향에 대하여 연구하였다. 연구에 사용된 버너는 적용 연료의 혼합 특성을 증가시키기 위해 혼합공간을 충분히 유지 하였으며, 버너의 구조와 연소용 기체의 토출각 및 토출구의 위치 변화를 통한 불꽃의 형태를 변화 시켜 반응기 내의 온도 분포 특성을 비교 분석하였으며, 분석 결과에 의해 원통형 개질 반응기에서 최대 효율을 가지는 버너의 구조로부터 수증기 개질 반응을 평가하였다.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.40 no.1
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• pp.11-19
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• 2003

A micro sensor array with 4 discrete sensors integrated on a microhotplate was developed for identifying the kinds and quantities of explosive gases. The sensor array consisited of four tin oxide-based thin films with the high and broad sensitivity to the tested explosive gases and uniform thermal distribution on the plate. The microhotplate, using silicon substrate with N/O/N membrane, dangling in air by Al bonding wires, and controlling the thickness by chemical mechanical process (CMP), has been designed and fabricated. By employing the sensitivity signal of the sensor array at 40$0^{\circ}C$, we could reliably classily the kinds and quantities of the explosive gases like butan, propane, LPG, and carbon monoxide within the range of threshold limit values (TLVs), employing principal component analysis (PCA).

• 한국신재생에너지학회:학술대회논문집
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• 2005.11a
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• pp.436-445
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• 2005

석탄가스화는 화석연료인 석탄을 기존의 공해물질 발생을 90% 이상 줄이면서 고효율로 활용할 수 있는 방법이다. 3톤/일급 pilot급 석탄가스화 설비에서 생산된 CO와 수소가 주성분인 합성가스를 소형 LPG 엔진과 중형 천연가스 엔진에 연계시켜 발전시스템을 구성하였으며 전기생산까지 구현하였다. 합성가스의 고온 집진과 탈황을 자체기술로 구현하여 합성가스내 $H_2S$와 COS 성분들을 1 ppm 이하 정제와 99% 이상의 고온집진 효율을 확인하였다. 선진국들의 설비 규모에 비해서는 극히 열세인 국내 현황이지만, 고온고압의 석탄가스화로부터 탈황과 집진, 전기 생산까지 전 과정을 pilot 설비규모에서 실증하는 성과를 얻었으며 향후 전체 시스템의 최적화와 연속운전 기술의 개발로 이어진다면 중소형 석탄가스화 부분에서는 선진국과 차별화된 틈새시장 실용화 기술의 확보가 가능할 것이다.