Ni-based bimetallic nano-catalysts anchored on BaZr0.4Ce0.4Y0.1Yb0.1O3−δ for internal steam reforming of methane in a low-temperature proton-conducting ceramic fuel cell

2021 ◽  
Author(s):  
Kyungpyo Hong ◽  
Stephanie Nadya Sutanto ◽  
Jeong A. Lee ◽  
Jongsup Hong
Keyword(s):  
Steam Reforming ◽  
Low Temperatures ◽  
Operating Conditions ◽  
Hydrogen Yield ◽  
Carbon Formation ◽  
Long Term Stability ◽  
Ceramic Fuel Cell ◽  
Ceramic Fuel ◽  
Nano Catalysts

Ni–Rh and Ni–Co nano-scale alloys exhibit high methane conversion, hydrogen yield, resistance to carbon formation, and long-term stability at low temperatures, allowing them to cope with the various operating conditions of direct methane-fueled PCFCs.

scholarly journals Exposure of Ceramics and Ceramic Matrix Composites in Simulated and Actual Combustor Environments

2000 ◽  
Vol 122 (2) ◽  
pp. 212-218 ◽  
Author(s):  
Karren L. More ◽  
Peter F. Tortorelli ◽  
Mattison K. Ferber ◽  
Larry R. Walker ◽  
James R. Keiser ◽  
...  
Keyword(s):  
Ceramic Matrix Composite ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Surface Damage ◽  
Operating Conditions ◽  
Matrix Composites ◽  
Long Term Stability ◽  
Recession Rates ◽  
Combustor Liner

A high-temperature, high-pressure, tube furnace has been used to evaluate the long term stability of different monolithic ceramic and ceramic matrix composite materials in a simulated combustor environment. All of the tests have been run at 150 psia, 1204°C, and 15 percent steam in incremental 500 h runs. The major advantage of this system is the high sample throughput; >20 samples can be exposed in each tube at the same time under similar exposure conditions. Microstructural evaluations of the samples were conducted after each 500 h exposure to characterize the extent of surface damage, to calculate surface recession rates, and to determine degradation mechanisms for the different materials. The validity of this exposure rig for simulating real combustor environments was established by comparing materials exposed in the test rig and combustor liner materials exposed for similar times in an actual gas turbine combustor under commercial operating conditions. [S0742-4795(00)02402-9]

scholarly journals Long-Term Stability of Ferroelectret Energy Harvesters

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 42 ◽  
Author(s):  
Muhammed Kayaharman ◽  
Taylan Das ◽  
Gregory Seviora ◽  
Resul Saritas ◽  
Eihab Abdel-Rahman ◽  
...  
Keyword(s):  
Output Power ◽  
Operating Conditions ◽  
Constant Stress ◽  
Center Frequency ◽  
Term Stability ◽  
Energy Harvesters ◽  
Long Term Stability ◽  
Stress Cycling ◽  
Piezoelectric Charge

Cellular polypropylene (PP) has been recently used in energy harvesting applications. In this work, we investigate its viability and long-term stability under various operating conditions. Specifically, the effect of constant stress and stress cycling on output power and long-term stability of ferroelectret energy harvesters is analyzed. Our findings show that after 112 days constant stress significantly increases the piezoelectric charge constant d 33 and output power from 0.51 μW for a stress-free harvester to 2.71 μW. It also increases the harvester center frequency from 450 to 700 Hz and decreases its optimal resistance from 7 to 5.5 M Ω .

Modeling and Analysis of a Bio-Fuelled Ceramic Fuel Cell Stack

2004 ◽  
Author(s):  
Jinliang Yuan ◽  
Bin Zhu ◽  
Ramesh K. Shah ◽  
Bengt Sunde´n
Keyword(s):  
Fuel Cell ◽  
Gas Flow ◽  
System Modeling ◽  
Operating Conditions ◽  
Intermediate Temperature ◽  
Innovative Technology ◽  
Direct Oxidation ◽  
Modeling And Analysis ◽  
Ceramic Fuel Cell ◽  
Ceramic Fuel

Recent development in the advanced ceramic fuel cell (CFC), working at intermediate temperature 600–700°C, brings up feasibility and new opportunity to employ renewable fuels with this innovative technology. It may offer a better solution concerning environment, natural resources and development of our civil society. Moreover, direct oxidation of hydrocarbon fuels at intermediate temperature possesses great advantage in avoiding complex and expensive external reforming process. This paper presents modeling and analysis of an intermediate temperature CFC stack. The model is a general one to evaluate the stack performance for the purpose of optimal design and/or configuration based on the specified electrical power or fuel supply rate, except that the Tafel coefficients are adjusted and/or obtained to match experimental data. The energy and gas flow data obtained from the investigation can be further used to identify the heat exchanger network configurations and optimal operating conditions using process integration techniques. The model can be applied as a stand alone one, or implemented into an overall energy system modeling for the purpose of system study.

scholarly journals Changes of Insulation Properties of Photovoltaic Cables Caused by Ageing Treatment

2020 ◽  
Vol 6 (1) ◽  
pp. 6-9 ◽  
Author(s):  
Juraj Packa ◽  
Vladimir Kujan ◽  
Daniel Štrkula ◽  
Vladimír Šály ◽  
Milan Perný
Keyword(s):  
Power Plants ◽  
Real Life ◽  
Life Time ◽  
Operating Conditions ◽  
Solar Panels ◽  
Font Size ◽  
Long Term Stability ◽  
Cable Systems

<span style="font-family: 'Times New Roman',serif; font-size: 10pt; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;" lang="EN-US">An important part of the photovoltaic power plants are cable systems. The dielectric properties of cables, reliability and durability depend on quality of production processes, operating conditions and degradation factors, as well. Expected lifetime of cable systems is more than 20-30 years in general. Their failure free operation and long-term stability of properties has a direct impact on the economic return of the investments. According to our experiences the tests in compliance with valid standards are not adequate to verify real life time during operation. Photovoltaic cables intended for use in outdoor applications for the connection between the solar panels and possible connection between panels and inverter were chosen for our experiments. <span style="-ms-layout-grid-mode: line;">The changes </span>of insulation resistance and breakdown voltage caused by some degradation factors, mainly water, are presented. This research was inspired by real failure in operation.</span>

Steam reforming of ethanol over bimetallic RhPt/La2O3: Long-term stability under favorable reaction conditions

2013 ◽  
Vol 38 (14) ◽  
pp. 5580-5593 ◽  
Author(s):  
Martha Cobo ◽  
Diana Pieruccini ◽  
Ricardo Abello ◽  
Laura Ariza ◽  
Luis Fernando Córdoba ◽  
...  
Keyword(s):  
Steam Reforming ◽  
Reaction Conditions ◽  
Term Stability ◽  
Long Term Stability ◽  
Steam Reforming Of Ethanol ◽  
Favorable Reaction

Evaluation of PBTS and NBTS in SiC MOS Using In Situ Charge Pumping Measurements

2013 ◽  
Vol 740-742 ◽  
pp. 545-548 ◽  
Author(s):  
Daniel B. Habersat ◽  
Aivars J. Lelis ◽  
Ronald Green ◽  
Mooro El
Keyword(s):  
Charge Trapping ◽  
Operating Conditions ◽  
Degradation Mechanisms ◽  
Power Devices ◽  
Charge Pumping ◽  
Long Term Stability ◽  
Accelerated Degradation ◽  
Mos Devices

Since power devices such as DMOSFETs will operate at higher temperatures with accelerated degradation mechanisms, it is essential to understand the effects of typical operating conditions for power electronics applications. We have found that SiC MOSFETs when gate-biased at 150 °C show an increasing charge pumping current over time, suggesting that interface traps (or perhaps near-interface oxide traps) are being created under these conditions. This trapping increase occurs slightly above linear-with-log-time and mimics previously observed threshold voltage instabilities, though a causal relationship has not yet been determined. We found the charge trapping after 104 s of BTS increased at a rate of 1x1011 cm-2/dec for NBTS (-3 MV/cm), 0.7x1011 cm-2/dec for PBTS (3 MV/cm), and 0.3x1011 cm-2/dec when grounded. The observed increase in charge trapping has negative implications for the long term stability and reliability of SiC MOS devices under operating conditions.

scholarly journals Exposure of Ceramics and Ceramic Matrix Composites in Simulated and Actual Combustor Environments

1999 ◽  
Author(s):  
Karren L. More ◽  
Peter F. Tortorelli ◽  
Mattison K. Ferber ◽  
Larry R. Walker ◽  
James R. Keiser ◽  
...  
Keyword(s):  
Ceramic Matrix Composite ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Surface Damage ◽  
Operating Conditions ◽  
Matrix Composites ◽  
Long Term Stability ◽  
Recession Rates ◽  
Combustor Liner

A high-temperature, high-pressure, tube furnace has been used to evaluate the long term stability of different monolithic ceramic and ceramic matrix composite materials in a simulated combustor environment. All of the tests have been run at 150 psia, 1204°C, and 15% steam in incremental 500 h runs. The major advantage of this system is the high sample throughput; >20 samples can be exposed in each tube at the same time under similar exposure conditions. Microstructural evaluations of the samples were conducted after each 500 h exposure to characterize the extent of surface damage, to calculate surface recession rates, and to determine degradation mechanisms for the different materials. The validity of this exposure rig for simulating real combustor environments was established by comparing materials exposed in the test rig and combustor liner materials exposed for similar times in an actual gas turbine combustor under commercial operating conditions.

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