• 한국연소학회:학술대회논문집
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• 한국연소학회 2005년도 제31회 KOSCO SYMPOSIUM 논문집
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• pp.64-68
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• 2005

Methane reforming processes to obtain hydrogen were investigated experimentally by using atmospheric plasma source. Among possible reforming processes, such as a $CO_2$ reforming(dry reforming), a partial oxidation (POx), a steam reforming(SR), and a steam reforming with oxygen(SRO or auto-thermal reforming), partial oxidation and the steam reforming with oxygen were considered. We choose a rotating arc plasma as an atmospheric plasma source, since it shows the best performances in our preliminary tests in terms of a methane conversion, a hydrogen production, and a power consumption. Then, the effects of a feeding flow-rate, an electrical power input to a plasma reaction, an $O_2/C$ ratio and a steam to carbon ratio in the case of SRO on the reforming characteristics were observed systematically. As results, at a certain condition almost 100% of methane conversion was obtained and we could achieve the same hydrogen production rate by consuming a half of electrical power which was used by the best results for other researchers.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회B
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• pp.2892-2897
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• 2008

Plasma techniques have been proposed to generate a hydrogen enrich gas to investigate a feasibility of plasma techniques on a fuel reforming, we considered a dry reforming and a partial oxidation with methane in the atmospheric pressure. For these experiments, we employed an arc jet plasma reactor. The effects of input power and oxidizer in each process were investigated by product analysis, including carbon monoxide, hydrogen, ethylene, propane, and acetylene as well as methane and carbon dioxide. In both processes, input electrical power activated the reactions significantly. The increased ratio of the carbon dioxide to methane in the dry reforming doesn't affect to a methane conversion, whereas increased ratio of oxidizer to methane in the partial oxidation was very effective for the reaction. Moreover, for a simultaneous treatment of methane and carbon dioxide, a feasibility of a dry reforming combined with partial oxidation also has been investigated.

• 한국수소및신에너지학회논문집
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• 제26권1호
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• pp.1-7
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• 2015

In this study, characteristics of reforming process of automotive liquefied petroleum gas (LPG) fuel using plasma reactor are investigated. Because plasma reformer technology has advantages of a fast start-up and wide fuel/oxidizer ratio of operation, and reactor size is smaller and more simple compared to typical combustor and catalytic reactor, plasma reforming is suitable to the on-board vehicle reformer. To evaluate the characteristics of the reforming process, parametric effect of $O_2/C$ ratios, reactant flow rate and metal form on the process were investigated. In the test of varying $O_2/C$ ratio from partial oxidation to stoichiometry combustion, conversion of LPG was increased but selectivity of $H_2$ decreased. The optimum condition of $O_2/C$ ratio for the highest $H_2$ yield was determined to be around 1.0 for 20~50 lpm, and 1.35 for 100 lpm. Specific energy density (SED) was major factor in reforming process and higher SED leads to higher $H_2$ yield. And metal form in the reformer increased $H_2$ yield of about 34 % as compared to the case of no metal form. The result can be a guide to map optimal condition of reforming process.

• 한국연소학회지
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• 제11권2호
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• pp.15-21
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• 2006

Characteristics of a plasma reactor for partial oxidation of methane, especially focused on the role and effectiveness of plasma chemistry, are investigated. Partial oxidation of methane is investigated using a rotating arc which is a three dimensional version of a typical gliding arc. Three different modes of operation were found. Each mode shows different reforming performance. The reason for the difference is due to the difference in relative role of thermal and plasma chemistry in overall process. A mode with high temperature results higher methane conversion and hydrogen selectivity in contrast to the mode with lower temperature where poor methane conversion and higher selectivity of $C_2$ species are observed. In this way, we can confirm that by controlling characteristic of process or controlling relative strength of plasma chemistry and thermal chemistry, it is possible to map an optimal condition of reforming process by rotating arc.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2006년도 제32회 KOSCO SYMPOSIUM 논문집
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• pp.144-148
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• 2006

Characteristics of a plasma reactor for partial oxidation of methane, especially focused on the role and effectiveness of plasma chemistry, is investigated. Partial oxidation of methane is investigated using a rotating arc which is a three dimensional version of a typical glidingarc. The rotating arc has both the characteristics of equilibrium and non-equilibrium plasma. Non-equilibrium characteristics of the rotating gliding arc can be increased by rotating an elongated arc string attached at both the tip of inner electrode and the edge of outer electrode. In this way, plasma chemistry can be enhanced and hydrogen selectivity can reach almost 100% that is much higher than thermal equilibrium condition. As a result, the present study enables the strategic approach of the plasma reforming process by means of appropriate reactor design to maximize plasma effect and resulting in maximized reaction efficiency.

• 한국가스학회지
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• 제16권6호
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• pp.17-22
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• 2012

본 연구에서는 플라즈마 반응기를 이용한 자동차용 LPG 연료의 개질 특성에 대해서 실험하였다. 실험에서 사용된 플라즈마 반응기술은 종전의 촉매반응기술에 비해서 빠른 기동시간 및 연소기 부하변동 응답성, 단순하고 소형화가 가능한 장점을 가지고 있어 차량의 온-보드형 개질에 적합하다. 본 개질 반응의 특성을 평가하기 위해 플라즈마 반응기로 공급되는 $O_2$/C 비와 공급되는 공기와 LPG의 총 유량 및 플라즈마 공급전력을 주요 변수로 실험하였다. 공급되는 전력이 일정할 때, $O_2$/C 비 변화 실험에서는 완전산화 조건으로 갈수록 LPG 전환율은 증가하지만 수소의 선택도는 감소되었다. 높은 수소 선택도와 수율을 동시에 만족시키는 $O_2$/C 비는 20~50lpm 조건에서 0.8~0.9 이었으며, 총 유량이 증가할수록 LPG 전환율과 수소 수율이 감소하는 경향을 나타내었다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.2918-2922
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• 2007

This is a report of a feasibility study on the reduction of harmful substances such as particulate matters and nitric oxides emitted from diesel engines by using a plasma reforming system that can generate hydrogen-rich gas. In this paper, an exhaust reduction mechanism of the non-thermal plasma reaction was investigated to perform its efficiency and characteristics on producing hydrogen-rich gas. Firstly, we explain briefly the chemistry of hydrocarbon reforming. The experimental system is showed in the second part. Finally, we demonstrate the feasibility of producing hydrogen using non-thermal plasma. The experimental results are focused on the influence of the different operating parameters (air ratio, inlet flow rates, voltage) on the reformer efficiency and the composition of the produced gas.

• 한국연소학회지
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• 제11권3호
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• pp.1-7
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• 2006

A reaction mechanism of methane partial oxidation, which consists of thermal and plasma chemistry reaction pathways, has been investigated using with an arc-jet reactor. The reaction zone of the arc-jet reactor is spatially separated into thermal and non-thermal plasma zone. Methane conversion rates, selectivity of $H_2$ and $C_2$ chemicals in each zone are obtained, which reveals clearly different characteristics of reaction pathways depending on the temperature conditions. The conversion rates obtained in thermal plasma zone is higher than those in non-thermal plasma zone. The selectivity, however, obtained in non-thermal plasma zone is significantly higher than those in thermal plasma zone. Further parametric study on $O_2/C$ ratio, arc length and SED shows that the present process is mainly governed by thermal chemistry pathways.

• 대한기계학회논문집B
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• 제31권11호
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• pp.942-948
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• 2007

Popular techniques for producing hydrogen 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 fur 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. Results were obtained for methane and hydrogen yields and intermediate products. The system used in this research consisted of 3 electrodes and an AC power source. In this study, air was added fur 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%, 32.6% and 35.2% respectively.

• 한국수소및신에너지학회논문집
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• 제34권1호
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• pp.8-16
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• 2023

In this work, we report basic performance test results of a lab-scale three phase alternative current (AC) arc plasma torch system for plasma gas reforming applications. The suggested system primarily consists of three graphite electrodes inclined at 12.5° to the central axis, a 𝞥 150 mm cylindrical gas path and a three phase-60 Hz AC power supply. At air flow rate of 50 Lpm and arc currents of 100-175 A, test results revealed that plasma resistances were decreasing from 1.08 Ω to 0.53 Ω with the increase of plasma power from 9.3 kW to 13.8 kW, causing the decrease of power factor and increase of the line voltages. However, the injected air can be heated quickly up to the temperatures of >1,200℃ when injecting AC arc plasma powers of >10 kW.