• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.138-138
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• 2011

GTL(Gas to Liquid) 합성유 생산 공정은 크게 합성가스 개질공정(reformer), FT 반응공정, upgrading 공정으로 구성된다. 본 연구에서는 FT 반응기에 유입되는 합성가스의 생산공정인 개질공정 최적화 시뮬레이션을 수행하였다. 기존에 HYSYS 공정 모사 tool로 구현한 개질공정 모델에 dynamic simulation을 적용하여 공정 운전 시간 변화에 따른 온도/압력/조성의 일정범위 별 생산 가스의 성분비를 모사하고자 한다. Dynamic 공정 시뮬레이션은 모사 대상 공정의 운전 시간 별 결과값 변화를 산출할 수 있는 방법으로 기존 정상상태(steady-state) 시뮬레이션에 비해 현실 공정의 운전 변수를 보다 더 정확하게 반영할 수 있는 장점이 있다. 본 시뮬레이션은 1bpd급 GTL 파일럿 플랜트의 설계 자료를 근거로 수행되었으며, 향후 운전 데이터를 feedback하여 최적의 운전 매뉴얼 도출자료로 활용코자 한다. 아울러, 다음의 시간 변화별 모사 결과 데이터들을 산출하고 공정의 최적운전 조건을 분석하고자 한다. - 시간에 따른 공정의 온도/압력 변화, 이에 연동되는 반응기 출구의 1) $H_2$/CO 비율, 2) $CH_4$ conversion, 3) $CO_2$ conversion 본 연구의 결과 데이터를 1bpd급 GTL 플랜트 내 합성가스 개질공정의 운전조건 최적화에 적용코자 하며, 이는 개질반응기의 안정적인 연속운전을 통한 GTL 통합공정의 운전 효율향상에 기여 가능하리라 기대된다. 향후 개질공정의 후단공정인 FT 합성공정 시뮬레이션 과업과 연계하여 GTL 통합공정 시뮬레이션 및 최적화에 따른 실증 규모의 스케일업 기반 데이터를 마련할 수 있을 것이다.

• Applied Chemistry for Engineering
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• v.21 no.2
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• pp.195-199
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• 2010

The reversible chemical absorption using MEA (monoethanolamine), one of alkanolamine, is generally used as a conventionally method for $CO_{2}$ capture. Even MEA absorbent has excellent reactivity with $CO_{2}$, it has been known to have the decrease of absorption capacity caused by $CO_{2}$, $O_{2}$ or other acid gases in flue gas, corrosion and thermal degradation. In this study, MEA solutions degraded in the steam reforming process of refinery used and the absorption performance were compared for the used of conventional MEA solution. In case of 30 wt% MEA and mixture of 20 wt% thermal degraded absorbent (DP) and 10 wt% PZ, the absorption capacities were $0.5365mol-CO_{2}$/mol-absorbent and $0.5939mol-CO_{2}$/mol-absorbent respectively. PZ added thermally degraded absorbent showed the enhanced absorption capacity. On the contrary, the absorption rates were $1.1610kg_{f}/cm^2{\cdot}min$ for 30 wt% MEA, $0.5310kg_{f}/cm^2{\cdot}min$ for mixture of 20 wt% thermal degraded absorbent (DP) and 10 wt% PZ and $0.3525kg_{f}/cm^2{\cdot}min$ for 30 wt% thermally degraded absorbent only. The absorption rates of PZ added thermally degraded absorbent was higher than that of thermally degraded absorbent only. Therefore, it can be confirmed that thermally degraded absorbent can be reused as an absorbent for $CO_{2}$ by the addition of suitable additives.

• Transactions of the Korean hydrogen and new energy society
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• v.17 no.3
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• pp.293-300
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• 2006

KIER has been developing a Ru-based preferential oxidation catalysts and a novel fuel processing system to provide hydrogen rich gas to residential PEMFCs system. The catalytic activity of Ru-based catalysts was investigated at different Ru loading amount and different support structure. The obtained result indicated that 2 wt% loaded Ru-based catalyst supported on ${\alpha}-Al_2O_3$ showed high activity in low temperature range and suppressed the methanation reaction. The developed prototype fuel processor showed thermal efficiency of 78% as a HHV basis with methane conversion of 92%. CO concentration below 10 ppm in the produced gas is achieved with separate preferential oxidation unit under the condition of $[O_2]/[CO]=2.0$. The partial load operation have been carried out to test the performance of fuel processor from 40% to 80% load, showing stable methane conversion and CO concentration below 10 ppm. The durability test for the daily start-stop and 8 h operation procedure is under investigation and shows no deterioration of its performance after 50 start-stop cycles. In addition to the system design and development.

• Korean Chemical Engineering Research
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• v.45 no.4
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• pp.340-344
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• 2007

Catalytic upgrading of pyrolytic bio-oil produced from Japanes Larch was carried out over MCM-41 catalyst. Oil with enhanced stability was produced by the MCM-41 catalyst due to transform oxygen known as a main cause for the instability of bio-oil into $H_2O$, CO and $CO_2$. In addition, the MCM-41 catalyst produced the larger amount of phenolic compounds in the pyrolytic bio-oil product compared with that in the bio-oil produced without catalyst. Especially, the catalytic activity of Al-MCM-41 for the bio-oil upgrading was higher than that of Si-MCM-41 because Al-MCM-41 has the larger amount of acid sites. Also, the better reforming result was obtained when pyrolytic bio-oil vapor passed through catalytic layer rather than Japanese Larch was mixed with catalyst directly.

• Journal of Energy Engineering
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• v.19 no.4
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• pp.215-220
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• 2010

Hydrogen is a clean and efficient energy source and is expected to take an important role in future energy demand. A possibly good route to produce hydrogen is by using biomass and organic wastes as a source through thermo-chemical conversion technology. In this study, pyrolysis of wood Pellet(Oregon pine) has been carried out in batch type fixed-bed reactor in $N_2$ atmosphere during 20 minutes to determine the optimum hydrogen generating conditions. At the influence of temperature, hydrogen yield was increased with increasing temperature. For the influence of Steam/Biomass Ratio(SBR), hydrogen yield was increased by steam addition at low temperature condition. However, effect of steam addition was insignificant over at SBR = 1. The hydrogen yield was increased with increasing SBR at high temperature condition. From result of $H_2$/CO and $H_2/CH_4$ ratio, dominant reaction was steam reforming in this experimental condition. The optimum condition for hydrogen production was determined as follows: $H_2$ yield = 38.3 vol.% (56.01 L/min kg) at $900^{\circ}C$, SBR=3.

• Applied Chemistry for Engineering
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• v.3 no.4
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• pp.535-546
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• 1992

The molten carbonate fuel cell(MCFC) has been under Intensive development for the last decade as a second generation fuel cell. The advantages of the MCFC over the phophoric acid fuel cell are higher efficiency, its ability to accept CO and $H_2$ as a fuel, lower material costs, and high operating temperature making internal reforming possible. These features, along with low atmospheric emissions, will open up a significant market as an attractive means of developing highly efficient power plant. This article reviews a status of the MCFC research and development, a principle of the MCFC, and cell and stack technology including the status of electrodes, matrices and electrolytes. Several technical difficulties which must be resolved to be commercialized art mainly focused.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.1
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• pp.23-30
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• 2010

Trends of the automotive market require the application of new engine technologies, which allows for the use of different types of fuel. Since ethanol is a renewable source of energy and it contributes to lower $CO_2$ emissions, ethanol produced from biomass is expected to increase in use as an alternative fuel. It is recognized that for spark ignition (SI) engines ethanol has advantages of high octane number and high combustion speed. In spite of the advantages of ethanol, fuel supply system might be affected by fuel blends with ethanol like a wear and corrosion of electric fuel pumps. So the on-board hydrogen production out of ethanol reforming can be considered as an alternative plan. This paper investigates the influence of ethanol fuel on SI engine performance, thermal efficiency and emissions. The results obtained from experiments have shown that specific fuel consumption has increased by increasing ethanol amount in the blend whereas decreased by the use of hydrogen-enriched gas. The combustion characteristics with hydrogen-enriched gaseous fuel from ethanol reforming are also examined.

• Transactions of the Korean hydrogen and new energy society
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• v.33 no.6
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• pp.660-673
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• 2022

In achieving carbon neutrality and the hydrogen economy, the estimation of H₂ cost is critical in terms of CCU technologies. This study analyzes LCOH of hydrogen produced by the carbon utilization unit with methane reforming and CO₂ from thermal power plant. LCOH for H₂ made with CO is estimated in three ways of Joint Cost Allocations with financial performance risk assessment. Regarding cost analysis, the zero value of LCOH is $6,003/ton. We found that the CCU technology has economic feasibility in terms of profitability. The sensitivity analysis result shows that the input ratio is more influential to the LCOH than other variables. Risk analysis presents the baseline price of zero value of LCOH - $8,408/ton, which is higher than the cost analysis - $6,003/ton. Mainly, the price variability of natural gas primarily affects the LCOH. The study has significant value in analyzing the financial performance risks as well as the cost of H₂ produced by a Plasma-based CCU system.

• Applied Chemistry for Engineering
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• v.8 no.3
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• pp.543-549
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• 1997

The direct reaction of carbon dioxide($CO_2$) with butane($C_4H_{10}$) to obtain synthesis gas and hydrocarbon compounds have been studied on nickel loaded catalysts. In the reaction of $CO_2$ with $C_4H_{10}$, Ni loaded catalysts showed similar activity with Pt catalyst and Coke deposition on the catalyst was severe by dehydrogenation of butane. The main products were carbon monoxide and hydrogen, when alumina and Y type zeolite were used as a support. Instead, a great deal of aromatic hydrocarbons were obtained on the Ni loaded ZSM-5 catalyst. The conversion of $CO_2$ increased with the increasing molar ratio of $CO_2$/$C_4H_{10}$ on Ni/ZSM-5, Ni/NaY and Ni/alumina catalyst, but the conversion decreased again from the ratio of 2. The value of $CO_2$ conversion was the highest at the 5wt% of Ni loading on ZSM-5 catalyst. A part of cokes deposited on the catalysts diminished when only $CO_2$ gas or water steam flowed into the reactor. The coke deposited on the catalysts was very reactive and it may be an important intermediate for the carbon dioxide reforming reaction.

• 한국연소학회:학술대회논문집
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• 2007.05a
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• pp.187-190
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• 2007

A combined hydrogen generator of plasma and catalytic reformers has been developed, and has been applied to stabilize unstable flame of 200,000 Kcal/hr LPG combustor. The role of the plasma reformer is to generate hydrogen in a short period and to heat-up the catalytic reformer during the start-up time. After the start-up period, the catalytic reformer generates hydrogen through steam reforming with oxygen (SRO) reactions. The maximum capacity of the hydrogen generator is 100 lpm that is sufficient to be used to stabilize the flame of the present combustor. In order to reduce NOx and CO emissions simultaneously, 1) FGR (Flue Gas Recirculation) technique has been adopted and 2) the hydrogen has been added into the fuel supplied to the combustor. Test results shows that 25 % addition of hydrogen and 30 % FGR rate lead to simultaneous decrease of CO and NOx emissions. The technique proposed in the present study shows good potential to replace $NH_3$ SCR technique, especially in the case of small-scale combustor applications.