A miniaturized methanol reformer with Si-based microreactor for a small PEMFC

Kawamura, Yoshihiro; Ogura, Naotsugu; Yamamoto, Tadao; Igarashi, Akira

doi:10.1016/j.ces.2005.08.014

Cited by 116 publications

(64 citation statements)

References 19 publications

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“…The decoupling of syngas generation from the SOFC-membranes has the advantage of allowing an easier and more precise optimization of the fuel-processing unit, leading to an increase in the overall efficiency of such a system. Studies on micro-scale fuel processors for small-scale fuel cell devices have been primarily focused on steam reforming of hydrocarbons and alcohols [12][13][14][15][16][17] mostly at temperatures below 350 °C. Tanaka et al [18] introduced a micro-fuel reformer system able to reform methanol at temperatures as low as 180°C.…”

Section: Introductionmentioning

confidence: 99%

A nanoparticle bed micro-reactor with high syngas yield for moderate temperature micro-scale SOFC power plants

Santis-Alvarez

Nabavi

Jiang

et al. 2012

Chemical Engineering Science

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This work introduces and investigates the a novel compact catalytic nanoparticle bed microfabricated reactor suitable for utilization in small-scale intermediate-temperature micro-SOFC systems. It is shown that the presented micro-reactor is able to produce syngas (CO + H 2 ) efficiently from n-butane and propane at temperatures between 550 -620 °C by means of catalytic partial oxidation (CPOX) using Rh-doped nanoparticles embedded in a foam-like porous ceramic bed as a catalyst. The novel micro-fabricated reactor system is experimentally tested using a carrier specially designed for heating the reactor as well as feeding the fuel and receiving the reaction product gases. Optimization of the syngas production is performed by varying fuel dilutions and reactor temperatures. The performance of the micro-reactor was investigated in two modes: (1) Continuous heating mode, in which two built-in heaters underneath the carrier are kept on throughout the reforming reaction. This simulates the operating state of a micro-SOFC system where the post-combustor provides heat to the microreformer continuously. (2) Thermally self-sustained mode, in which the heaters are turned off after the CPOX has been ignited. An estimation of the heat losses of both testing modes is also given. The present micro-reactor is able to achieve syngas yield as high as 60 % for nbutane and 50 % for propane in the continuous heating mode, which is a substantial improvement to state-of-the-art micro-reactors.

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Section: Introductionmentioning

confidence: 99%

A nanoparticle bed micro-reactor with high syngas yield for moderate temperature micro-scale SOFC power plants

Santis-Alvarez

Nabavi

Jiang

et al. 2012

Chemical Engineering Science

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“…As a rough guide, the deviation from the flat profile of velocity assumed in plug flow is not more than 20%, provided that the tube diameter is at least 30 × the particle diameter (Trimm, 1980). To guarantee that the flow pattern in the membraneless reactor was plug flow, we established that the smallest dimension of the microchannel should be 50 times greater than the catalyst bed particle diameter; this leads to d p = 1×10 −5 m because the microchannel had H = 5×10 −4 m. Many published papers that used metal catalysts supported on alumina have catalyst densities in the range of 1-2×10 6 g/cm 3 (Falco and Gallucci, 2010;Kim et al, 2005;Kawamura et al, 2006;Wang and Rodrigues, 2005;Lee et al, 2006). The value of the catalyst density used in this work (ρ cat =1.35×10 6 g/cm 3 ) was adjusted to obtain a space time equivalent to that used by Comas et al (2004b) in his experimental measurements.…”

Section: Resultsmentioning

confidence: 99%

“…Both reactants (water and ethanol) contain H atoms which contribute to the hydrogen yield and, furthermore, ethanol is nontoxic and easy to store and transport (Fatsikostas and Verykios, 2004;Iulianelli et al, 2009;Kawamura et al, 2006;Mariño et al, 2001;Sun et al, 2005). This technology is particularly interesting for a country such as Brazil, which is one of the largest ethanol producers and exporters in the world and where ethanol from sugarcane is produced at extremely competitive prices.…”

Section: Ethanol Steam Reformingmentioning

confidence: 99%

“…Because of their small size, light weight, fast start-up, and rapid response, PEM fuel cells are suitable for portable power sources, capable of delivering power in the 1-100W range (Delsman, 2005;Hu et al, 2003;Palo et al, 2002). Three types of small PEM fuel cells systems have been proposed: systems that use stored hydrogen, direct methanol or ethanol systems and on-board reforming systems (Kawamura et al, 2006). Hydrogen storage methods are currently limited by their inability to meet the practical requirements of safety, weight, and cost considerations (Winter, 2009).…”

Section: Introductionmentioning

confidence: 99%

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Parametric study of hydrogen production from ethanol steam reforming in a membrane microreactor

DeSouza

Zanin

Moraes

2013

Braz. J. Chem. Eng.

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-Microreactors are miniaturized chemical reaction systems, which contain reaction channels with characteristic dimensions in the range of 10-500 μm. One possible application for microreactors is the conversion of ethanol to hydrogen used in fuel cells to generate electricity. In this paper a rigorous isothermal, steady-state two-dimensional model was developed to simulate the behavior of a membrane microreactor based on the hydrogen yield from ethanol steam reforming. Furthermore, this membrane microreactor is compared to a membraneless microreactor. A potential advantage of the membrane microreactor is the fact that both ethanol steam reforming and the separation of hydrogen by a permselective membrane occur in one single microdevice. The simulation results for steam reforming yields are in agreement with experimental data found in the literature. The results show that the membrane microreactorpermits a hydrogen yield of up to 0.833 which is more than twice that generated by the membraneless reactor. More than 80% of the generated hydrogen permeates through the membrane and, due to its high selectivity, the membrane microreactor delivers high-purity hydrogen to the fuel cell.

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“…The length of the microchannel was determined through simulations of methanol reforming using mass and heat balance equations based on a one-dimensional model for an incompressible fluid 15) . The rate equation of methanol steam reforming (1), as described before, for the simulation is expressed as Eq.…”

Section: Determination Of Microchannel Design For Miniaturized Methanmentioning

confidence: 99%

Hydrogen Production by Methanol Steam Reforming Using Microreactor

Kawamura¹,

Ogura²,

Igarashi³

2013

J. Jpn. Petrol. Inst.

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A microreactor technology, in which a microchannel is used as a catalytic reaction field in order to supply hydrogen to a small polymer electrolyte fuel cell (PEFC) for portable electronic devices, was described. The reduction of heat loss in the microreactor is the primary requirement for improving system efficiency, since heat release in microreactors is higher than in conventional reactors due to the increased specific surface area. Therefore, the methanol steam reforming, operated below 300 , is an appropriate process for the hydrogen production using the microreactor. First, the high-performance Cu/ZnO/Al2O3 catalyst for methanol reforming at low temperature was developed under the optimized preparation condition. The miniaturized methanol reformer was then developed to utilize this Cu/ZnO/Al2O3 catalyst. The length of the microchannel was determined based on one-dimensional mass and heat balance analyses. The microreactor was fabricated from silicon and glass substrates using a number of microfabrication techniques. Methanol reforming using this reactor has been demonstrated to reach the levels necessary to power a 1 W-class small PEFC system. The multilayered integrating the miniature methanol reformer with a CO remover, a catalytic combustor as a heat source for methanol reforming, vaporizers, and several necessary functional elements for hydrogen production has also been successfully fabricated. Finally, the microreactor system has been demonstrated to produce hydrogen at a rate sufficient to generate electrical power of 2.5 W.

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A miniaturized methanol reformer with Si-based microreactor for a small PEMFC

Cited by 116 publications

References 19 publications

A nanoparticle bed micro-reactor with high syngas yield for moderate temperature micro-scale SOFC power plants

A nanoparticle bed micro-reactor with high syngas yield for moderate temperature micro-scale SOFC power plants

Parametric study of hydrogen production from ethanol steam reforming in a membrane microreactor

Hydrogen Production by Methanol Steam Reforming Using Microreactor

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