Theoretical Analyses of Autothermal Reforming Methanol for Use in Fuel Cell

Hak-Min Wang,Kap-Seung Choi,Il-Hwan Kang,Hyung-Man Kim,Paul A. Erickson 대한기계학회 2006 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.20 No.6

As fuel cells approach commercialization, hydrogen production becomes a critical step in the overall energy conversion pathway. Reforming is a process that produces a hydrogen-rich gas from hydrocarbon fuels. Hydrogen production via autothermal reforming (ATR) is particularly attractive for applications that demand a quick start-up and response time in a compact size. However, further research is required to optimize the performance of autothermal reformers and accurate models of reactor performance must be developed and validated. The design includes the requirement of accommodating a wide range of experimental set ups. Factors considered in the design of the reformer are capability to use multiple fuels, ability to vary stoichiometry, precise temperature and pressure control, implementation of enhancement methods, capability to implement variable catalyst positions and catalyst arrangement, ability to monitor and change reactant mixing, and proper implementation of data acquisition. A model of the system was first developed in order to calculate flowrates, heating, space velocity, and other important parameters needed to select the hardware that comprises the reformer. Predicted performance will be compared to actual data once the reformer construction is completed. This comparison will quantify the accuracy of the model and should point to areas where further model development is required. The end result will be a research tool that allows engineers to optimize hydrogen production via autothermal reformation.

메탄올-과산화수소를 이용한 MEMS 자열 개질기 개발

정은상(Eun Sang Jung),권세진(Sejin Kwon) 한국연소학회 2011 KOSCOSYMPOSIUM논문집 Vol.- No.43

Development of MEMS reformer by autothermal reforming process was carried out. Autothermal reforming uses simple, small reactors with relatively high efficiency. Decomposition of hydrogen peroxide for autothermal reforming of methanol is presented. Cu/ZnO was selected as a catalyst for hydrogen peroxide decomposition and methanol autothermal reforming. For fabricating autothermal reformer, we choose the material as photosensitive glass. Photosensitive glass is chosen as a structural material since the thermal insulation and gas sealing can be achieved easily with a material. The experiment using MEMS reformer was performed. At 230℃, activation of catalyst was occurred.

Autothermal reforming over a Pt/Gd-doped ceria catalyst: Heat and mass transport limitations in the steam reforming section

Lim, Sungkwang,Bae, Joongmyeon Elsevier 2010 INTERNATIONAL JOURNAL OF HYDROGEN ENERGY - Vol.35 No.13

<P><B>Abstract</B></P><P>Autothermal reforming (ATR) has several advantages for fuel cell applications, such as a compact reactor structure and fast response. Using oxidation reactions inside the reactor, ATR does not have the external heat transfer limitations associated with steam reforming. However, mass and heat transfer limitations inside and outside the catalyst particles are still anticipated. In this study, transport limitations in the steam reforming section of ATR over a Pt/Gd-doped ceria catalyst are analyzed by numerical simulations based on a reaction rate equation in which parameters are adjusted to measured kinetic data. The simulation results show that significant transport limitations characterize the steam reforming section of packed-bed ATR reactors. The activity per catalyst bed volume is highly dependent on the particle size, and only the thin exterior layer of the particles is involved in catalyzing the reactions. Based on the results, it is shown that an eggshell type catalyst particle could reduce catalyst material significantly without a considerable decline in the activity per catalyst bed volume.</P>

디젤자열개질 반응기의 자립운전에 관한 실험적 연구

강인용(Inyong Kang),윤상호(Sangho Yoon),배중면(Joongmyeon Bae) 한국자동차공학회 2006 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

An on-board diesel reformer for producing hydrogen-rich gases can be applied for not only a fuel cell system, but also an internal combustion engine for low emission vehicles. Diesel is reformed by autothermal reforming (ATR) reaction due to its high reforming efficiency comparing with steam reforming (SR) and catalytic partial oxidation (CPOX). ATR is a slightly exothermic reaction. If we control the reaction exothermicity, it is possible to design a self-sustaining diesel reformer. In previous researches, we have already studies about the factors to affect the exothermicity of the ATR reaction such as O₂/C (oxygen to carbon ratio), S/C (steam to carbon ratio), GHSV (gas hourly space velocity). In this paper, we will introduce an actual self-sustained 100We-c1ass diesel reformer. Especially, startup protocol of the diesel reformer and product distributions in steady-state operation will be presented. The diesel reformer was continuously operated for about 1 day with stable manner. But eventually, severe carbon deposition was happened after the period.

An investigation of reaction progression through the catalyst bed inmethanol autothermal reformation

김형만,최갑승,윤형철,J. Lars Dorr,Paul A. Erickson 대한기계학회 2008 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.22 No.2

This study investigates autothermal reforming of fuel cell-grade methanol as a method for producing hydrogen for transportation applications. A previous study on the effects of oxygen-to-carbon ratio on ATR reactor performance showed that the optimum of O2/CH3OH=0.30 found in the experimental tests is 30% higher than the theoretical optimum of 0.23. In this study, the influence of catalyst bed length is investigated to give insight into the reaction progression through the catalyst bed in methanol autothermal reformation. The effect of reaction progression through the catalyst bed is experimentally investigated in relation to reactor output parameters of fuel conversion, temperature profile, and reactor efficiency. The results from this study serve as a baseline for future research of autothermal reforming of hydrocarbon fuels as a method for producing hydrogen.

Theoretical Analyses of Autothermal Reforming Methanol for Use in Fuel Cell

Wang Hak-Min,Choi Kap-Seung,Kang Il-Hwan,Kim Hyung-Man,Erickson Paul A. The Korean Society of Mechanical Engineers 2006 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.20 No.6

As fuel cells approach commercialization, hydrogen production becomes a critical step in the overall energy conversion pathway. Reforming is a process that produces a hydrogen-rich gas from hydrocarbon fuels. Hydrogen production via autothermal reforming (ATR) is particularly attractive for applications that demand a quick start-up and response time in a compact size. However, further research is required to optimize the performance of autothermal reformers and accurate models of reactor performance must be developed and validated. The design includes the requirement of accommodating a wide range of experimental set ups. Factors considered in the design of the reformer are capability to use multiple fuels, ability to vary stoichiometry, precise temperature and pressure control, implementation of enhancement methods, capability to implement variable catalyst positions and catalyst arrangement, ability to monitor and change reactant mixing, and proper implementation of data acquisition. A model of the system was first developed in order to calculate flowrates, heating, space velocity, and other important parameters needed to select the hardware that comprises the reformer. Predicted performance will be compared to actual data once the reformer construction is completed. This comparison will quantify the accuracy of the model and should point to areas where further model development is required. The end result will be a research tool that allows engineers to optimize hydrogen production via autothermal reformation.

Autothermal reforming of heavy-hydrocarbon fuels by morphology controlled perovskite catalysts using carbon templates

Jeon, Y.,Lee, C.,Rhee, J.,Lee, G.,Myung, J.h.,Park, M.,Park, J.I.,Einaga, H.,Shul, Y.G. Elsevier Ltd 2017 Fuel Vol.187 No.-

A novel synthesis of morphology-controlled perovskite networked with LaCr<SUB>0.8</SUB>Ru<SUB>0.2</SUB>O<SUB>3</SUB> nanoparticles was introduced using activated carbons as sacrificial templates. These catalysts were used for the hydrogen production by heavy-hydrocarbon autothermal reforming. To investigate the effect of the carbon templates, morphology-controlled perovskites using activated carbons and a non-templated catalyst were prepared to determine how carbon templates influence the chemical structure of the perovskite. The carbon templates produced a crystalline structure with the well incorporation of Ru under mild calcination conditions. The morphology of the hollow fibers provided a higher specific surface area than that of the porous grain catalyst with a similar average particle size (~80nm). It was found that the hollow fibers showed a unique pore structure with large macropores from 1 to 100μm, which might offer a higher surface area and enhanced mass transfer of the reactants. This provided a higher activation energy for H<SUB>2</SUB> production than the porous grain and non-templated catalysts during the autothermal reforming of heavy hydrocarbons. As a result, the fibrous feature and well-defined chemical structure were crucial factors when cracking the hydrocarbon chain. The hollow fiber catalyst showed high reforming efficiency for H<SUB>2</SUB> production (>65mol%) from heavy-hydrocarbon fuels during long-term experiments, featuring substantial durability with low carbon deposition and no structural changes.

Ni-Ru/Al2O3-MgO 금속 모노리스 촉매체를 이용한 메탄의 자열 개질반응

이창호 ( Chang Ho Lee ),이태준 ( Tae Jun Lee ),신장식 ( Jang Sik Shin ),이종대 ( Jong Dae Lee ) 한국유화학회 2011 한국응용과학기술학회지 Vol.28 No.3

The autothermal reforming reaction of methane was investigated to produce hydrogen with Ni/CeO2-ZrO2, Ni/Al2O3-MgO and Ni-Ru/Al2O3-MgO catalysts. Honeycomb metallic monolith was applied in order to obtain high catalytic activity and stability in autothermal reforming. The catalysts were characterized by XRD, BET and SEM. The influence of various catalysts on hydrogen production was studied for the feed ratio(O2/CH4, H2O/CH4). The O2/C H4 and H2O/CH4 ratio governed the methane conversion and temperature profile of reactor. The reactor temperature increased as the reaction shifted from endothermic to exothermic reaction with increasing O2/CH4 ratio. Among the catalysts used in the experiment, the Ni-Ru/Al2O3 -MgO catalyst showed the highest activity. The 60% of CH4 conversion was obtained, and the reactor temperature was maintained 600℃ at the condition of GHSV=10000h-1 and feed ratio S/C/O=0.5/1/0.5.

공정폐기물상의 메탄올을 이용한 비상 PEM 연료전지용 과산화수소 자열 개질 반응

정은상 한국폐기물자원순환학회 2015 한국폐기물자원순환학회지 Vol.32 No.2

Development and performance evaluation of the hydrogen generator by autothermal reforming process for emergency PEM fuel cell using methanol from process waste were carried out. Supply of gaseous hydrogen has been a technical barrier for its wide application. As a result, conventional reformer has either a separate heat source such as a catalytic combustor or a parallel process in the same reactor to generate heat. The later device is called ATR (Autothermal reforming). Typical product gas of ATR still contains a large amount of carbon monoxide that poisons electro-catalyst of the MEA. In the present study, we used the decomposition of hydrogen peroxide as a parallel exothermic reaction in the same reactor as the reformer. The decomposition of hydrogen peroxide releases water vapor and gaseous oxygen with enormous heat. The heat sustains the reforming reaction and the oxygen is used to recombine the carbon monoxide by oxidation. By parametric study, at the condition of 200oC and the rate of methanol to 40% of hydrogen peroxide is 4 to 1, the Carbon monoxide contents are reduced by less than 800 ppm. Using the present concept we could reduce the concentration of carbon monoxide in the product gas of the reformer by more than 80%. At that carbon monoxide contents, we can be possible to load the methanol-hydrogen peroxide ATR system without any devices.

과산화수소를 이용한 메탄올 자열 개질 반응

정은상(Eun Sang Jung),김태규(Taegyu Kim),권세진(Sejin Kwon) 한국연소학회 2009 KOSCOSYMPOSIUM논문집 Vol.- No.38

Development and performance evaluation of the on-board hydrogen generator by autothermal reforming process were carried out. Supply of gaseous hydrogen has been a technical barrier for its wide application. As a result, conventional reformer has either a separate heat source such as a catalytic combustor or a parallel process in the same reactor to generate heat. The later device is called ATR (Autothermal reformer). Typical product gas of ATR still contains a large amount of carbon monoxide that poisons electro-catalyst of the MEA. In the present study, we used the decomposition of hydrogen peroxide as a parallel exothermic reaction in the same reactor as the reformer. The decomposition of hydrogen peroxide releases water vapor and gaseous oxygen with enormous heat. The heat sustains the reforming reaction and the oxygen is used to recombine the carbon monoxide by oxidation. By parametric study, at the condition of 200℃and the rate of methanol to 40% of hydrogen peroxide is 4 to 1, the Carbon monoxide contents are reduced by less than 800ppm. Using the present concept we could reduce the concentration of carbon monoxide in the product gas of the reformer by more than 80%. At that carbon monoxide contents, we can be possible to load the methanol-hydrogen peroxide ATR system without any devices.