• 한국신재생에너지학회:학술대회논문집
• /
• 2008.05a
• /
• pp.186-189
• /
• 2008

Solar simulator를 이용한 메탄의 수증기 개질은 집광된 태양에너지를 이용하기 위한 목적으로 수행되었다. 본 연구에서는 이와 같은 태양열에너지의 화학적 축열을 실시하기 위해 Solar Simulator를 이용한 메탄의 수증기 개질을 연구하였다. 태양열 모사 램프로 1.2kW급 Xenon-arc lamp를 사용하였다. 반응기는 앞면의 Quartz Window와 촉매지지층으로 구성되어 있다. 램프의 빛은 Quartz Window를 통하여 촉매층에 직접적으로 방사되고, 방사된 빛으로 촉매지지층에서 흡열반응이 일어난다.메탄의 수증기개질 반응은 고온에서 일어나기 때문에 촉매지지체를 열에 강한 SiC로 만들어진 Ceramic foam을 사용하였다. 이 촉매지지체에 촉매를 Wash-coat하여 사용하였으며, 담지된 촉매는 Ni을 활성성분으로 하는 ICI 46-6을 사용하였다. 반응기는 318 SUS 재질로 제작되었으며, 반응기 외부는 Insulation을 하여 열손실을 감소시켰다. 실험은 온도와 공간속도에 따른 Solar Steam reforming의 반응특성을 분석하였다.

• Journal of Energy Engineering
• /
• v.12 no.2
• /
• pp.145-153
• /
• 2003

In order to develop the carbonation process as a core technology of zero emission coal power plant, study on characterization of methane steam reforming (MSR) which is main reaction of this process was carried out. The effects of gas hourly space velocity (GHSV), steam/carbon (S/C) ratio and pressure in the MSR using reforming catalyst were investigated. The equilibrium composition of the gases produced in the MSR were obtained below GHSV 7,000 hr$\^$-1/. The operating conditions of carbonation process using hybrid reaction (MSR+CO$_2$ adsorption using CaO) were 700∼800$^{\circ}C$ and S/C ratio of 2.5∼3. The equilibrium mixture of gases composed of 75∼78% H$_2$ and 8∼9％ CO$_2$ at atmospheric pressure and 60∼78% H$_2$ and 9∼l1% CO$_2$ at 1∼30 atm respectively under above operating conditions.

• Journal of the Korean Institute of Gas
• /
• v.20 no.5
• /
• pp.27-33
• /
• 2016

The aim of numerical study is the investigation of the solid and fluid temperatures in a reformer tube and chemical reaction characteristics of different steam-carbon ratio. We considered conjugate heat transfer contain radiation, convection and conductive heat transfers. This is because steam reforming reaction of hydrocarbon occurred high temperature conditions up to 800 K- 1000 K by using commercial computational fluid dynamics (CFD) code (Fluent ver. 13.0). For numerical simulation, the Reynolds-Averaged Navier-Stokes, momentum and energy equation were employed. In addition, inside of reformer tube is assumed as the porous medium to consider the Nichrome-based catalyst. To analysis characteristics of tube temperature in chemical reaction, we changed steam-methane ratio(SCR) from 1 to 6. As increased SCR, the higher tube temperature and methane conversion were observed. It was obtained that the highest hydrogen production held in SCR of 5.

• Journal of Energy Engineering
• /
• v.22 no.2
• /
• pp.226-236
• /
• 2013

The heat distribution and internal flow from the efficiency of actual reformer and specification variation, using the computer simulation and experiment about the steam methane reforming reaction which uses the high temperature reformer. Reaction model from steam refoemer uses the steam response model developed by Xu & Froment.As result we supposed the chemical react Steam Reforming(SR), Water Gas Shift(WGS), and Direct Steam Reforming(DSR) from the inner high temperature reformer dominates the response has dissimilar response. According to result of steam methane reforming reaction exam using high temperature reformer, we figured out when Steam Carbon Ratio(SCR) increase, number of hydrogen yield increases but methane decreases. When comparing and examining between design with one inlet and two inlet, result came out one inlet design is more outstanding at thermal distribution and internal flow, hydrogen yield in one inlet design than two inlet design.

• 한국신재생에너지학회:학술대회논문집
• /
• 2009.06a
• /
• pp.259-261
• /
• 2009

Solar simulator를 이용한 프로판의 수증기 개질은 집광된 태양에너지를 이용하기 위한 목적으로 수행되었다. 본 연구에서는 이와 같은 태양열에너지의 화학적 축열을 실시하기 위해 Solar Simulator를 이용한 메탄의 수증기 개질을 연구하였다. 태양열 모사 램프로 1.24kW급 Xenon-arc lamp를 사용하였다. 반응기는 앞면의 Quartz window와 Absorber로 구성되어 있다. 램프의 빛은 Quartz window를 통하여 촉매층에 직접적으로 방사된다. 프로판의 수증기개질 반응은 고온에서 일어나기 때문에 열에 강한 SiC로 만들어진 Ceramic foam을 Absorber로 사용하였다. 촉매는 Absorber에 Wash-coat하여 사용하였으며, 담지된 촉매는 Ni을 활성성분으로 하는 ICI 46-6와 귀금속 촉매인 Ru/$Al_2O_3$를 사용하였다. 반응기는 SUS 재질로 제작되었으며, 반응기 외부는 Insulation을 하여 열손실을 감소시켰다. Propane과 Steam의 비율은 S/C ratio를 3으로 하여 실험하였다. 실험은 온도와 촉매에 따른 Solar Steam reforming의 반응특성을 분석하였다.

• Applied Chemistry for Engineering
• /
• v.24 no.4
• /
• pp.375-381
• /
• 2013

Kinetics data were obtained for steam reforming of methane and natural gas over the commercial nickel catalyst. Variables for the steam reforming were the reaction temperature and partial pressure of reactants. Parameters for the Power law rate model and the Langmuir-Hinshelwood model were obtained from the kinetic data. As a result of the reforming reaction using pure methane as a reactant, the reaction rate could be determined by the Power law rate model as well as the Langmuir-Hinshelwood model. In the case of methane in natural gas, however, the Langmuir-Hinshelwood model is much more suitable than the Power law rate model in terms of explaining methane reforming reaction. This behavior can be attributed to the competitive adsorption of methane, ethane, propane and butane in natural gas over the same catalyst sites.

• Journal of the Korean Solar Energy Society
• /
• v.21 no.4
• /
• pp.29-35
• /
• 2001

The chemical heat storage as the one way of utilization for high temperature solar energy was considered. The stram reforming reaction of methane was chosen for endothermic reaction. The reactor was made of stainless steel tube and it's dimension was 0.635 cm I.D. and 30 cm long, coiled tube because of the geometry requirement of solar receiver The effects of space velocity and reactants mole ratio on the methane conversion and CO selectivity were examined. From the experimental results, the optimum steam/methane mole ratio was determined.

• Proceedings of the Korean Environmental Sciences Society Conference
• /
• 2007.05a
• /
• pp.526-529
• /
• 2007

본 연구에서는 일정선량(600kGy)에서 전자빔 에너지(0.7, 1, 2 MeV)를 달리하여 조사한 $Ni/g-Al_2O_3$ 촉매를 이용하여 세 가지 다른 종류의 합성가스 전환반응(메탄의 이산화탄소 개질반응, 메탄의 수증기 개질반응, 메탄의 부분산화반응)을 수행하였다. 전자빔 조사는 He 분위기, 실온에서 수행하였으며, 조사된 촉매의 표면상태 변화를 살펴보기 위하여 XRD, XPS 분석을 수행하였다. 고에너지 전자빔 처리된 $Ni/g-Al_2O_3$ 촉매의 표면 특성분석 결과 촉매 표면의 Ni종은 metallic Ni, NiO, $NiAl_2O_4$의 3가지 상태로 존재함을 알 수 있었으며, 전자빔 에너지 증가에 따라 촉매 표면의 전체적인 Ni 함량과 촉매 표면의 Ni 분산도를 나타내는 Ni/Al ratio가 증가하였다. 또한, 전자빔 에너지 증가에 따라 Ni에 결합된 산소가 더 크게 감소되어 표면에서 산소 vacancy가 증가하는 결과를 가져왔으며, 이는 결국 세 가지 Ni의 상태 중 metallic Ni과 $NiAl_2O_4$를 증가시켰다. 이러한 결과들은 메탄의 이산화탄소 개질 반응과 메탄의 수증기 개질반응에서 반응물($CH_4$, $CO_2$)의 전환율과 생성물(CO, $H_2$)의 수득율을 증가시켰으며 메탄의 부분산화반응은 반응의 특성상 메탄의 전환율은 증가하나 생성물인 CO, $H_2$는 오히려 감소하는 결과를 가져옴을 알 수 있었다.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.36 no.9
• /
• pp.885-894
• /
• 2012

A numerical study of a microchannel steam methane reforming reactor has been performed to understand the characteristics of heat and mass transfer. The integration of Rh-catalyzed steam methane reforming and Pt-catalyzed methane combustion has been simulated. The reaction rates for chemical reactions have been incorporated into the simulation. This study investigated the effect of contact time, flow pattern (parallel or counter), and channel size on the reforming performance and temperature distribution. The parallel and counter flow have opposite temperature distribution, and they show a different type of reaction rate and species mole fraction. As the contact time decreases and channel size increases, mass transfer between the catalyst layer and the flow is limited, and the reforming performance is decreased.

• Applied Chemistry for Engineering
• /
• v.35 no.2
• /
• pp.134-139
• /
• 2024

In the steam reforming of methane reactions, the effect of adding noble metals Ru and Pd to a Ni-based catalyst as promoters was analyzed in terms of catalytic activity and hydrogen production. The synthesized catalysts were coated on the surface of a honeycomb-structured metal monolith to perform steam methane reforming reactions. The catalysts were characterized by XRD, TPR, and SEM, and after the reforming reaction, the gas composition was analyzed by GC to measure methane conversion, hydrogen yield, and CO selectivity. The addition of 0.5 wt% Ru improved the reduction properties of the Ni catalyst and exhibited enhanced catalytic activity with a methane conversion of 99.91%. In addition, reaction characteristics were analyzed according to various process conditions. Methane conversion of over 90% and hydrogen yield of more than 3.3 were achieved at a reaction temperature of 800 ℃, a gas hourly space velocity (GHSV) of less than 10000 h^-1, and a ratio of H₂O to CH₄ (S/C) higher than 3.