Evaluation of the Performance Characteristics of a Direct Methanol Fuel Cell With Multifuels

Author(s):  
Sujith Mohan ◽  
S. O. Bade Shrestha

Direct methanol fuel cells are one of the alternate power sources for the field of power electronics because of their high energy density. The benefits of a fuel cell toward the environment can be greatly improved if the fuel used for its application comes from renewable sources. In this study, the performance of a direct methanol fuel cell was investigated under five different methanol concentrations. The effect of methanol concentration on the cell operating temperature is studied. Impedance spectroscopy was conducted to measure the ohmic, activation, and mass transport losses for all concentrations. The cell performance was evaluated using methane and ethanol fuels and this was compared with methanol operation.

Author(s):  
Sujith Mohan ◽  
S. O. Bade Shrestha

Direct methanol fuel cells are one of the alternate power sources for the field of power electronics because of their high energy density. The benefits of a fuel cell towards the environment can be greatly improved if the fuel used for its application comes from renewable sources. In this study, the performance of a direct methanol fuel cell was investigated under five different methanol concentrations. The effect of methanol concentration on the cell operating temperature is studied. Impedance spectroscopy was conducted to measure the ohmic, activation and mass transport losses for all concentrations. The cell performance was evaluated using methane and ethanol fuels and this was compared with methanol operation.


2014 ◽  
Vol 11 (6) ◽  
Author(s):  
S. O. Bade Shrestha ◽  
Sujith Mohan

Direct methanol fuel cells (DMFCs) are becoming a choice of a power source in the field of power electronics, and portable devices because of their high energy density. The benefits of using a fuel cell toward the environment will be enhanced if the fuel used for its application comes from renewable sources such as ethanol. A method of modeling of the performance of DMFC was developed and validated with the experimental data obtained from a passive DMFC operated under varying methanol and ethanol concentrations. Impedance spectroscopy was employed to measure ohmic, activation and mass transport losses for all concentrations. Improved performance of the cell was observed when the concentrations of the solutions were closer to stoichiometric values. The model predicted results were compared to the corresponding experimental values and found satisfactory.


Author(s):  
Antonio Villalba-Herreros ◽  
Teresa J. Leo ◽  
Ricardo Abad

Autonomous underwater vehicles (AUVs) are versatile machines capable of more and more complex missions including the offshore industry. The ability to carry out some missions relies on the endurance the vehicle is provided with. In this sense, fuel cells are found to be very adequate devices to enlarge AUVs endurance because of the high energy density and specific energy they can achieve, but the application of fuel cell technology to AUVs faces specific challenges that need to be overcome. The present work describes the conceptual design process of a typical AUV powered by a direct methanol fuel cell. Methanol is a high available fuel and its handling system is simple. The obtained results indicate that the manufacturing of such a vehicle is possible within several constrains, being the carbon dioxide treatment system the most critical component of the energy plant. The projected vehicle is compared to current vehicles on the market showing the improved endurance.


2020 ◽  
Vol 5 (8) ◽  
pp. 822-827
Author(s):  
Govindarasu Ramasamy ◽  
R. Kavitha ◽  
M. Nambiraj ◽  
R. Praveen Kumaar ◽  
N. N. Harish Kumar

Fuel cells are the devices that convert chemical energy into electrical energy through an electrochemical reaction. Direct Methanol Fuel cell (DMFC) is a proton exchange membrane fuel cells in which methanol is used as fuel. Its high energy density makes it suitable for fuel cells. Even though carbon dioxide is produced, there is no production of sulfur or nitrogen oxides. The problems usually occurred while working with DMFC are methanol crossover, condensation of methanol, water management and carbon dioxide release. In that the uneven flow distribution, accumulation of carbon dioxide bubbles in the fuel cell are the major issues in DMFC. To prevent these issues, this work focuses on the theoretical and experimental studies on development of fuel cells with special importance to geometry of the manifold. This paper provides the optimal solution for preventing uneven flow distribution that is the usage of squoval shaped manifold which is the combination of both square and circle. Performance of DMFC with squoval shape manifold is evaluated experimentally and is compared with square shape manifold and rectangle shape manifold geometry design.


Author(s):  
Nastaran Shakeri ◽  
Zahra Rahmani ◽  
Abolfazl Ranjbar Noei ◽  
Mohammadreza Zamani

Direct methanol fuel cells are one of the most promisingly critical fuel cell technologies for portable applications. Due to the strong dependency between actual operating conditions and electrical power, acquiring an explicit model becomes difficult. In this article, the behavioral model of direct methanol fuel cell is proposed with satisfactory accuracy, using only input/output measurement data. First, using the generated data which are tested on the direct methanol fuel cell, the frequency response of the direct methanol fuel cell is estimated as a primary model in lower accuracy. Then, the norm optimal iterative learning control is used to improve the estimated model of the direct methanol fuel cell with a predictive trial information algorithm. Iterative learning control can be used for controlling systems with imprecise models as it is capable of correcting the input control signal in each trial. The proposed algorithm uses not only the past trial information but also the future trials which are predicted. It is found that better performance, as well as much more convergence speed, can be achieved with the predicted future trials. In addition, applying the norm optimal iterative learning control on the proposed procedure, resulted from the solution of a quadratic optimization problem, leads to the optimal selection of the control inputs. Simulation results demonstrate the effectiveness of the proposed approach by practical data.


Micromachines ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 658
Author(s):  
Zhu ◽  
Gao ◽  
Li

In order to solve the problem that bolts in traditional packaged direct methanol fuel cells (DMFCs) take up a large area and reduce the specific energy (energy per unit weight) and power density (power per unit area), a new button-type micro direct methanol fuel cell (B-μDMFC) is designed, assembled, and packaged. The cell with four different structures was tested before and after packaging. The results indicate that the button cell with three-dimensional graphene and springs has the best performance. The equivalent circuit and methanol diffusion model was applied to explain the experimental results. The peak volumetric specific power density of the cell is 11.85 mW cm−3. This is much higher than traditional packaged DMFC, because the novel B-μDMFC eliminates bolts in the structure and improves the effective area ratio of the cell.


2010 ◽  
Vol 72 ◽  
pp. 271-276 ◽  
Author(s):  
Antonino Salvatore Arico’ ◽  
Vincenzo Baglio ◽  
Alessandro Stassi ◽  
Vincenzo Antonucci

Direct Methanol Fuel Cells (DMFCs) are promising candidates for portable electric power sources because of their high energy density, lightweight, compactness, simplicity as well as easy and fast recharging. Recently, the attention has been focused on portable applications with passive-feed DMFCs. Under this configuration, DMFCs operate without any external device for feeding methanol and blowing air into the cells. An investigation of properties and operating parameters of a passive DMFC monopolar mini-stack, such as catalyst loading and methanol concentration, was carried out. From this analysis, it was derived that a proper Pt loading is necessary to achieve the best compromise between electrode thickness and number of catalytic sites for the anode and cathode reactions to occurs at suitable rates. Methanol concentrations ranging from 1 M up to 10 M (40 vol%) and an air-breathing operation mode were investigated. A maximum power of 225 mW was obtained at ambient conditions for a three-cell stack, with an active single cell area of 4 cm2 corresponding to a power density of about 20 mW cm-2.


2014 ◽  
Vol 11 (3) ◽  
Author(s):  
Chia-Chieh Shen ◽  
Guo-Bin Jung ◽  
Feng-Bor Weng ◽  
Chia-Chen Yeh ◽  
Chih-Hung Lee ◽  
...  

Increasing interest in utilizing direct methanol fuel cells for portable applications has prompted the need for understanding of their operating characteristics. Approximately 80% of a direct methanol fuel cell stack's volume and weight arise from the bipolar plates. The bipolar plates have grooved anode and cathode flow fields, and have a critical influence on the cell stack performance and stability. However, there is little published data regarding design expansion from single cell to stack, and literature regarding the fuel/oxidant distribution in each cell is especially scant. Hence, this topic is the subject of the present study, which reports the design of a complete direct methanol fuel cell consisting of five single cells including a graphite bipolar plate, as well as an innovative anode and cathode flow channel design. By observing variations in operating parameters, such as applied load and the flow of methanol solution and air, the impact of each parameter on the output performance and stability of the stack was investigated.


Polymers ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1175 ◽  
Author(s):  
Liying Ma ◽  
Guoxiao Xu ◽  
Shuai Li ◽  
Jiao Ma ◽  
Jing Li ◽  
...  

A hyper-branched sulfonated polyimide (s-PI) was synthesized successfully and composited with polyvinylidene fluoride (PVDF) to achieve ultra-high methanol-permeation resistive for direct methanol fuel cell application. The optimized s-PI-PVDF composite membrane exhibited methanol resistivity low to 1.80 × 10−8 cm2/s, two orders of magnitude lower than the value of the commercial Nafion 117 membrane (60 × 10−7 cm2/s). At the same time, the tensile strength of the composite membrane is 22 MPa, which is comparable to the value of the Nafion 117 membrane. Therefore, the composite membrane is promising for application in direct methanol fuel cell.


2014 ◽  
Vol 2 (46) ◽  
pp. 19914-19919 ◽  
Author(s):  
Jianyu Cao ◽  
Hui Zhuang ◽  
Mengwei Guo ◽  
Hongning Wang ◽  
Juan Xu ◽  
...  

Mesoporous graphenes were synthesized via a template-assisted pyrolysis approach and used as a material for a porous diffusion layer in direct methanol fuel cells.


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