Heat transfer enhancement in methanol steam reforming for a fuel cell

Nagano, Susumu; Miyagawa, Hiroshi; Azegami, Osamu; Ohsawa, Katsuyuki

doi:10.1016/s0196-8904(01)00043-7

Cited by 46 publications

(13 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To investigate the effects of methanol slip the performance mapping has been done by varying the concentration between 100% reformer conversion ratio and 90% conversion. These test points were chosen due to the trade-off in a methanol reformer between methanol conversion rate and CO formation, i.e., as reformer temperature increases, methanol conversion rate increases, and at the same time the rate of reverse water gas shit reaction increases producing more CO [27]. Kim [21] achieved a methanol conversion higher than 90% at temperature higher than 250 C and at feed rate of methanol of 2 ml/h.…”

Section: Performance Characterizationmentioning

confidence: 99%

Performance and endurance of a high temperature PEM fuel cell operated on methanol reformate

Araya

Grigoras

Zhou

et al. 2014

International Journal of Hydrogen Energy

View full text Add to dashboard Cite

This paper analyzes the effects of methanol and water vapor on the performance of a high temperature proton exchange membrane fuel cell (HT-PEMFC) at varying temperatures, ranging from 140 C to 180 C. For the study, a H 3 PO 4 e doped polybenzimidazole (PBI) e based membrane electrode assembly (MEA) of 45 cm 2 active surface area from BASF was employed. The study showed overall negligible effects of methanol-water vapor mixture slips on performance, even at relatively low simulated steam methanol reforming conversion of 90%, which corresponds to 3% methanol vapor by volume in the anode gas feed. Temperature on the other hand has significant impact on the performance of an HT-PEMFC. To assess the effects of methanol-water vapor mixture alone, CO 2 and CO are not considered in these tests. The analysis is based on polarization curves and impedance spectra registered for all the test points. After the performance tests, endurance test was performed for 100 h at 90% methanol conversion and an overall degradation rate of À55 mV/ h was recorded.

show abstract

Section: Performance Characterizationmentioning

confidence: 99%

Performance and endurance of a high temperature PEM fuel cell operated on methanol reformate

Araya

Grigoras

Zhou

et al. 2014

International Journal of Hydrogen Energy

View full text Add to dashboard Cite

show abstract

“…However both of conversion ratio and CO concentration increase with reforming temperature (6) . Therefore one of research subjects is to improve the trade-off relationship between conversion ratio and CO concentration.…”

Section: Introductionmentioning

confidence: 90%

“…In this context, numerical analysis plays an important role for these investigations. In our previous study (6) , it was found that the methanol steam reforming catalyst supported by metal honeycomb had several advantages such as heat transfer enhancement, low pressure loss and low heat capacity.…”

Section: Introductionmentioning

confidence: 99%

Numerical Study on Honeycomb Type Methanol Steam Reformer

Yamamoto

Nagano

Asano

et al. 2008

JEE

Self Cite

View full text Add to dashboard Cite

Experimental and numerical analysis of methanol steam reforming for a fuel cell have been carried out. The reforming catalyst is supported by metal honeycomb to decrease the heat capacity. Conversion performances are improved by segmenting the honeycomb catalyst into several blocks due to the enhancement of mixing of gases and heat transfer at the front edges of segmenting catalyst. Numerical simulation model for methanol steam reforming is developed by changing chemical reactions in the model for exhaust catalyst of internal combustion engines and using a smaller mass transfer coefficient for methanol steam reforming. The calculated results for a plate type methanol steam reformer which generates hydrogen of 7 kW (LHV) are also in good agreement with the measurements. The pattern of heat supply to catalysts and the reformer configuration affect conversion performances. It is predicted that the optimized methanol steam reformer for a 50 kW size fuel cell vehicle has a sufficient compactness.

show abstract

“…The catalytic reforming of methanol using Cu/ZnO catalysts has been energetically investigated as a promising process for the production of hydrogen in new power generation systems, such as polymer electrolyte fuel cells (PEFCs) [45,46]. In particular, autothermal reforming (ATR), which is a combined process consisting of endothermic steam reforming and exothermic partial oxidation, has recently attracted much attention, because of high energy conversion efficiency.…”

Section: Methanolmentioning

confidence: 99%

On-paper Synthesis of Metal Nanoparticles for Catalytic Applications

Koga

Kitaoka²

2011

Sen-i Gakkaishi

View full text Add to dashboard Cite

Metal catalysts have played essential roles in a wide range of chemical industrial processes [1][2][3]. For example, the copper/zinc oxide (Cu/ZnO) catalyst has been especially important for methanol synthesis [4] and alcohol reforming to produce hydrogen for fuel cell applications [5]. Energy, environmental and resource problems have escalated in recent times. Therefore, the development of high-performance catalytic materials that can effectively and selectively promote desired reactions is required for sustainability. Metal nanocatalystsNanosized metal particles have received an increasing amount of attention in various fields, such as in electronic [6], optical [7] and biomedical [8] applications, because of their unique and specific properties. In particular, the extremely large specific surface areas of metal nanoparticles (NPs) are very advantageous for effective catalytic reactions [9]. This has led to the active use of metal NPs as heterogeneous catalysts for a variety of industrial processes [9] including energy conversion, fine chemical synthesis and environmental cleanup. For example, gold (Au) nanocatalysts have received considerable interest for use in various reactions, including the reduction of 4-nitrophenol (4-NP) in the liquid phase [10] and low-temperature carbon monoxide (CO) oxidation [11] in the gas phase, even though bulk Au is typically regarded as an ineffective catalyst. However, the practical implementation of metal NPs is difficult, because they are difficult to handle and they aggregate easily, which minimizes their surface area. The aggregation of metal NPs results in the formation of ordinary bulk metals, and this consequently deteriorates their excellent functionalities. Therefore, catalytic metal NPs are generally attached to various support materials, such as polymers [9,12] and metal oxide powders [9,13]. Since these supported catalysts are fine and are handled with difficulty in practice, they are generally fashioned as beads or pellets. This eventually decreases their catalytic reactivity, because of the poor contact efficiency between the reactants and the catalytically active sites [14]. In addition, filling a reactor with solid catalysts can cause a high pressure drop, local reactant flow and an uneven thermal environment inside the catalyst layer, leading to an inefficient overall process, particularly for flow-type reactions. Therefore, establishing an efficient and practical immobilization technique that enables highly active metal NPs to be attached to and exposed on easyto-handle porous matrices is a challenge. On-paper Synthesis of Metal Nanoparticles for Catalytic ApplicationsDepartment of Agro-environmental Sciences, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan ( † Present address : Department of Biomaterials Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan)Abstract: We discuss the successful in ...

show abstract

Heat transfer enhancement in methanol steam reforming for a fuel cell

Cited by 46 publications

References 6 publications

Performance and endurance of a high temperature PEM fuel cell operated on methanol reformate

Performance and endurance of a high temperature PEM fuel cell operated on methanol reformate

Numerical Study on Honeycomb Type Methanol Steam Reformer

On-paper Synthesis of Metal Nanoparticles for Catalytic Applications

Contact Info

Product

Resources

About