• 한국수소및신에너지학회논문집
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• 제18권2호
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• pp.132-139
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• 2007

Popular techniques for producing synthesis gas by converting methane include steam reforming and catalyst reforming. However, these are high temperature and high pressure processes limited by equipment, cost and difficulty of operation. Low temperature plasma is projected to be a technique that can be used to produce high concentration hydrogen from methane. It is suitable for miniaturization and for application in other technologies. In this research, the effect of changing each of the following variables was studied using an AC Glidarc system that was conceived by the research team: the gas components ratio, the gas flow rate, the catalyst reactor temperature and voltage. Glidarc plasma reformer was consisted of 3 electrodes and an AC power source. And air was added for the partial oxidation reaction of methane. The result showed that as the gas flow rate, the catalyst reactor temperature and the electric power increased, the methane conversion rate and the hydrogen concentration also increased. With $O_2/C$ ratio of 0.45, input flow rate of 4.9 l/min and power supply of 1 kW as the reference condition, the methane conversion rate, the high hydrogen selectivity and the reformer energy density were 69.2%, 36.2% and 35.2% respectively.

• Environmental Engineering Research
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• 제17권2호
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• pp.89-94
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• 2012

Pyrolysis/gasification technology utilizes an energy conversion technique from various waste resources, such as biomass, solid waste, sewage sludge, and etc. to generating a syngas (synthesis gas). However, one of the major problems for the pyrolysis gasification is the presence of tar in the product gas. The tar produced might cause damages and operating problems on the facility. In this study, a gliding arc plasma reformer was developed to solve the previously acknowledged issues. An experiment was conducted using surrogate benzene and naphthalene, which are generated during the pyrolysis and/or gasification, as the representative tar substance. To identify the characteristics of the influential parameters of tar decomposition, tests were performed on the steam feed amount (steam/carbon ratio), input discharge power (specific energy input, SEI), total feed gas amount and the input tar concentration. In benzene, the optimal operating conditions of the gliding arc plasma 2 in steam to carbon (S/C) ratio, 0.98 $kWh/m^3$ in SEI, 14 L/min in total gas feed rate and 3.6% in benzene concentration. In naphthalene, 2.5 in S/C ratio, 1 $kWh/m^3$ in SEI, 18.4 L/min in total gas feed rate and 1% in naphthalene concentration. The benzene decomposition efficiency was 95%, and the energy efficiency was 120 g/kWh. The naphthalene decomposition efficiency was 79%, and the energy yield was 68 g/kWh.

• 한국응용과학기술학회지
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• 제20권4호
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• pp.289-295
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• 2003

Synthesis gas is produced commercially by a steam reforming process. However, the process is highly endothermic and energy intensive. Thus, this study was conducted to produce synthesis gas by the partial oxidation of methane to cut down the energy cost. Supported Ni catalysts were prepared by the impregnation method. To examine the activity of the catalysts, a differential fixed bed reactor was used, and the reaction was carried out at $750{\sim}850^{\circ}C$ and 1 atm. The fresh and used catalysts were characterized by XRD, XPS, TGA and AAS. The highest catalytic activity was obtained with the 13wt% Ni/MgO catalyst, with which methane conversion was 81%, and $H_2$ and CO selectivities were 94% and 93%, respectively. 13wt% Ni/MgO catalyst showed the best $MgNiO_2$ solid solution state, which can explain the highest catalytic activity of the 13wt% Ni/MgO catalyst.

• Journal of Microbiology and Biotechnology
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• 제26권4호
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• pp.717-724
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• 2016

Methane (CH₄) is the most abundant component in natural gas. To reduce its harmful environmental effect as a greenhouse gas, CH₄ can be utilized as a low-cost feed for the synthesis of methanol by methanotrophs. In this study, several methanotrophs were examined for their ability to produce methanol from CH₄; including Methylocella silvestris, Methylocystis bryophila, Methyloferula stellata, and Methylomonas methanica. Among these methanotrophs, M. bryophila exhibited the highest methanol production. The optimum process parameters aided in significant enhancement of methanol production up to 4.63 mM. Maximum methanol production was observed at pH 6.8, 30℃, 175 rpm, 100 mM phosphate buffer, 50 mM MgCl₂ as a methanol dehydrogenase inhibitor, 50% CH₄ concentration, 24 h of incubation, and 9 mg of dry cell mass ml^-1 inoculum load, respectively. Optimization of the process parameters, screening of methanol dehydrogenase inhibitors, and supplementation with formate resulted in significant improvements in methanol production using M. bryophila. This report suggests, for the first time, the potential of using M. bryophila for industrial methanol production from CH₄.

• Korean Chemical Engineering Research
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• 제50권2호
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• pp.358-364
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• 2012

철 촉매를 이용한 Fischer-Tropsch 합성 반응과 수성 가스 전환 반응에 대한 반응 메커니즘과 반응 속도식을 5 채널 고정층 반응기를 이용하여 조사하였다. 실험 조건은, 반응물 합성가스 $H_2$/CO 비 0.5~2, 반응물 공급 유량 60~80 ml/min, 반응 온도 $255{\sim}275^{\circ}C$로서 반응 압력은 1.5 MPa을 유지하였다. F-T 합성 반응의 반응 속도식($r_{FT}$)은 반응 속도 결정 단계로서 분자로 흡착된 CO와 기상의 수소 분자와의 반응을 바탕으로 하는 Eley-Rideal 반응 메카니즘을 통해 계산되었고, WGS 반응의 반응 속도식($r_{WGS}$)은 formate 중간체 생성 반응을 반응 속도 결정 단계로 가정하여 결정되었다. 실험 결과, F-T 합성 반응의 반응 속도식과 WGS 반응의 반응 속도식은 각각 탄화수소 생성과 $CO_2$ 생성에 대한 반응 속도 실험값을 잘 모사하였고, 또한 power law에 근거한 CO 전환 반응에 대한 반응 속도식도 실험값과 잘 일치하였다. 이처럼, 각각의 반응 메카니즘을 바탕으로 도출된 반응 속도식($r_{FT}$, $r_{WGS}$, $-r_{CO}$)은 실험값과 여러 가지 기존 문헌에서 보고된 반응 속도식 모델과 잘 일치하였다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.2232-2237
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• 2007

Steam reforming and catalytic reforming of $CH_4$ conversion to produce synthesis gas require both high temperatures and high pressure. Non-thermal plasma is considered to be a promising technology for the hydrogen rich gas production from methane. In this study, three phase AC GlidArc plasma system was employed to investigate the effects of gas composition, gas flow rate, catalyst reactor temperature and applied electric power on the $CH_4$ and $H_2$ yield and the product distribution. The studied system consisted of three electrode and it connected AC generate power system different voltages. In this study, air was used for the partial oxidation of methane. The results showed that increasing gas flow rate, catalyst reactor temperature, or electric power enhanced $CH_4$ conversion and $H_2$ concentration. The reference conditions were found at a $O_2$/C molar ratio of 0.45, a feed flow rate of 4.9 ${\ell}$/min, and input power of 1kW for the maximum conversions of $CH_4$ with a high selectivity of $H_2$ and a low reactor energy density.

• 대한환경공학회지
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• 제28권3호
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• pp.323-328
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• 2006

본 논문의 목적은 부채꼴방전(GlidArc) 플라즈마 개질을 이용하여 프로판으로부터 카본블랙의 형성이 없는 합성가스 생산을 위한 개질특성과 최적 운전조건을 연구하였다. 또한 수소 생산 및 프로판 전환율을 항상시키기 위해 반응기 내의 촉매반응 영역에 13 wt%의 니켈촉매를 충진하여 수증기 몰 비, 이산화탄소 몰 비, 입력 전력, 주입 유량 변화의 변수별 연구를 수행하였다. 그 결과, 수증기 몰 비, 이산화탄소 몰 비, 입력 전력, 주입 유량이 각각 1.86, 0.48, 1.37 kW, 14 L/min일 때 프로판 전환율이 62.6%로 최적이었다. 위의 조건에서 합성가스의 건가스 기준에 농도는 $H_2\;44.4%,\;CO\;18.2%,\;CH_4\;11.2%,\;C_2H_2\;2.0%,\;C_3H_6\;1.6%,\;C_2H_4\;0.6%,\;C_3H_4$ 0.4%이며, 이산화탄소 전환율은 29.2%, 합성가스 내의 $H_2/CO$ 농도 비는 2.4이다.

• 한국수소및신에너지학회논문집
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• 제25권3호
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• pp.227-233
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• 2014

Simulated waste-derived synthesis gas has been tested for hydrogen production through water-gas shift (WGS) reaction over supported Cu catalysts prepared by co-precipitation method. $CeO_2$, $ZrO_2$, MgO, and $Al_2O_3$ were employed as supports for WGS reaction in this study. $Cu-CeO_2$ catalyst exhibited excellent catalytic activity as well as 100% $CO_2$ selectivity for WGS in severe conditions ($GHSV=40,206h^{-1}$ and CO concentration = 38.0%). In addition, $Cu-CeO_2$ catalyst showed stable CO conversion for 20h without detectable catalyst deactivation. The high activity and stability of $Cu-CeO_2$ catalyst are correlated to its easier reducibility, high oxygen mobility/storage capacity of $CeO_2$.

• 한국산업융합학회 논문집
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• 제27권2_1호
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• pp.269-276
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• 2024

Many countries across the world are making efforts beyond reducing CO₂ levels and declaring 'net zero,' which aims to cut greenhouse gas emissions to zero by not emitting any carbon or capturing carbon, by 2050. Hydrogen is considered a key energy source to achieve carbon neutrality goals. Korean companies are also interested in building overseas green ammonia production plants and importing hydrogen into Korea in the form of ammonia. Green hydrogen production uses renewable energy sources such as solar and wind power, but the variability of power production poses challenges in plant design. Therefore, optimization of the configuration of a green ammonia production plant using renewable energy is expected to contribute as basic information for securing the economic feasibility of green ammonia production.

• 한국수소및신에너지학회논문집
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• 제25권3호
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• pp.247-254
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• 2014

The synthesis of Fischer-Tropsch oil is the catalytic hydrogenation of CO to give a range of products, which can be used for the production of high-quality diesel fuel, gasoline and linear chemicals. Our cobalt based catalyst was prepared Co/alumina, silica and titania by the incipient wet impregnation of the nitrates of cobalt and promoter with supports. Cobalt catalysts was calcined at $350^{\circ}C$ before being loaded into the FT reactors. After the reduction of catalyst has been carried out under $450^{\circ}C$ for 24hrs, FT reaction of the catalyst has been carried out at GHSV of 4,000/hr under $200^{\circ}C$ and 20atm. From these test results, we have obtained the results as following ; in case of 12wt% Co-supported $Al_2O_3$, $SiO_2$ and $TiO_2$ catalysts, maximum activities of the catalysts were appeared at the promoters of Mn, Mo and Ce respectively. The activity of 12wt% $Co/Al_2O_3$ added a Mn promoter was about 3 times as high as that of 12wt% $Co/Al_2O_3$ catalyst without promoters. When it has been the experiment at the range of reaction temperature of $200{\sim}220^{\circ}C$ and GHSV of 1,546~5,000/hr, the results have shown generally increasing the activities with the increase of reaction temperature and GHSV.