Also, the oxygen reduction reaction orr is considered in both of them. Acetaldehyde, acetic acid and mixtures of them with ethanol were also tested as. However, to provide practical defcs power source there are several issues that still must be addressed. Hence, direct ethanol fuel cells defcs have recently received. Ethanol electrooxidation, pd catalyst, alkaline media 1.
This has lead to a considerable interest in developing fuel cell systems operating directly on bioethanol. A direct ethanol fuel cell offers an attractive, fairly high density, energy source, if an electrochemical system can be developed that efficiently carries out the 12electron oxidation of ethanol to carbon dioxide and water. Experimental investigation of a passive direct ethanol fuel cell defc is presented in this work. An alkaline direct ethanol fuel cell with a cation.
Introduction direct ethanol fuel cell is an electrochemical device which converts the energy through chemical reactions. In direct alcohol fuel cells dafcs, alcohol is directly oxidised at the anode in an acidic. Characterization and analysis of new catalysts for a. The direct methanol fuel cell dmfc enables the direct conversion of the chemical energy stored in liquid methanol fuel to electrical energy, with water and carbon dioxide as byproducts. The fuel cell stack utilizes a hydrogen rich gas stream, and there are several approaches to supplying the hydrogen onboard the vehicle. An alkaline direct ethanol fuel cell with a cation exchange. The authors highlight that the theoretical effi ciencies for methanolair and ethanolair fuel cells are actually higher than.
This fuel cell does not use any auxiliary devices such as pumps, gas compressors, and gas blowers. Chapter 6 deals with the description of different membranes used in direct alcohol fuel. This power density is about four times higher than any other sofc. A direct methanol fuel cell dmfc is an electrochemical cell that generates electricity based on the oxidation of methanol and reduction of oxygen. Fuel cells are divided into two types of alcohol fuel cell that are direct methanol fuel cell dmfc and ethanol fuel cell defc. Directmethanol fuel cell their main advantage is the ease of transport of methanol, an energydense yet reasonably stable liquid at all environmental conditions.
Ethanol is the most used biofuel worldwide with an existing supply chain and infrastructure in many parts around the world. Feb, 2012 the direct ethanol fuel cell defc represents one of the most exciting future clean energy solutions in modern research, because ethanol can be sustainably produced from biomass, is relatively nontoxic and, most importantly, has a high energy density. Analytical models provide useful information for researchers to study fuel cell function. To that end, new catalyst systems must be developed along with fuel cell operating conditions that encourage the complete oxidation of ethanol, as. Electrooxidation of ethanol on pt in the absence of water. Oliveira et al performance evaluation of a platinumfree microscale alkaline direct ethanol fuel cell operating for long periods hamish a. Direct alcohol fuel cells for portable applications 1st. Direct ethanol fuel cells defcs, which use ethanol as a fuel, have.
Direct alcohol fuel cells dafcs have attracted enormous attention as powerful sources for portable electronic devices and transportation due to the much higher energy density than gaseous fuels such as hydrogen and natural gas. Long term performance study of a direct methanol fuel cell. The demand for energy, coupled with concerns about. The results showed that fuel cells have a high performance at. Energy conversion using pdbased catalysts in direct. Hards johnson matthey technology centre the direct methanol fuel cell dmfc has been considered as the ideal fuel cell system since it produces electric power by the direct conversion of the methanol fuel at the fuel cell anode. Direct ethanol fuel cells def cs linkedin slideshare. A micro alkaline direct ethanol fuel cell with platinum. Defc uses ethanol in the fuel cell instead of the more toxic methanol. Additional electrochemical data, tem images, and xps spectra pdf. Also the high efficiency makes defc attractive, but the absence of cells and prototypes tested and evaluated in terms of vehicle demands makes the technology more challenging. A selective electrocatalystbased direct methanol fuel cell operated at high concentrations.
Study on the performance of the micro direct ethanol fuel cell. The sufficient feeding of aqueous ethanol solution into direct ethanol fuel cell stack exhibited very high voltage and high current level of 1. A micro alkaline direct ethanol fuel cell with platinumfree catalysts. However, since the crossover of ethanol as a fuel in defcs can deteriorate the cell performance due to the oxidation of ethanol etoh at the cathode during oxygen reduction. The effect of acetaldehyde and acetic acid on the direct. Direct ethanol fuel cell using hydrotalcite clay as a. Fuel cells are of tremendous interest, from both energy and environmental considerations. Direct ethanol fuel cells for transport and stationary applications a. Direct ethanol fuel cells defcs, which use ethanol as a fuel, have attracted considerable attention due to their relatively high energy density, the nontoxicity of ethanol, and the abundance of ethanol sources. Pdf a micro alkaline direct ethanol fuel cell with platinum. Ive seen a lot of fuel cells that run on methanol, but the igen data sheet pdf was the first time ive seen a company make specific promises about.
Miller et althis content was downloaded from ip address 207. The direct ethanol fuel cell performance scientific. Box 110, dalian 116023, pr china b department of mechanical. Pdf direct ethanol fuel cells defcs are a promising carbonneutral and sustainable power source for portable, mobile, and stationary applications find.
Jan 01, 2008 ive seen a lot of fuel cells that run on methanol, but the igen data sheet pdf was the first time ive seen a company make specific promises about both power output and fuel consumption. Direct ethanol pemfuel cells performance on binary catalysts direct ethanol fuel cell operation over different bimetallic anode catalysts at 90 c. A passive direct formate fuel cell using ambient air is designed, fabricated, and tested. They have been used as a model to investigate a range of fuel cell concepts including the use of pem. A dualcell passive direct ethanol fuel cell defc stack with single ethanol tank was designed and tested to obtain the voltage requirement of electronics and to reduce weight and volume for. Direct alcohol fuel cells for portable applications. The effect on performance of single direct ethanol cell due to ethanol solution concentrations 5%, 10% and 15% by volume, ambient temperature and, continuously changing of ambient temperature and, load resistance and and air circulation through the cell were investigated experimentally in this research. In direct alcohol fuel cells dafcs, alcohol is directly oxidised at. This paper assesses the beha viour of a direct methanol fuel cell fed with aqueous methanol, aqueous ethanol and aqueous methanolethanol blends in a long term. Experimental investigation of a passive direct ethanol fuel cell.
Origin of low co2 selectivity on platinum in the direct. Pdf an alkaline direct ethanol fuel cell with a cation. Performance of alkaline electrolytemembranebased direct. Direct ethanol fuel cells are able to burn ethanol without first reforming it to hydrogen. Catalysts for alcoholfuelled direct oxidation fuel cells. The most attractive direct ethanol fuel cell defc technology for vehicle applications is based on alkaline, aaem, enabling the usage ofmembranes ptfree catalysts. Pdf experimental investigation of a passive direct. However, the presence of a large amount of water on the effect of the ethanol feed concentration on fuel cell perfor the cathode due to the oxygen reduction reaction along with water mance. Ethanol as fuel for fuel cells comparison methanol and ethanol methanol ethanol physical properties energy density mjkg 19,7 30,0 boiling point c 64,7 78,0 vapour pressure at 20c mbar 129 58 other properties permitted form of distribution packaged only bulk availability special supply chain super market. Dec 20, 2017 hydrogen is very difficult to deal with.
Environmental 46 2003 273285 pt based anode catalysts for direct ethanol fuel cells weijiang zhoua, zhenhua zhoua, shuqin songa, wenzhen lia, gongquan suna, panagiotis tsiakarasb, qin xina,c. Special attentions are given to direct ethanol fuel cells defcs and direct methanol fuel cells dmfcs. In the anode side a mixture of ethanol and naoh aqueous solution is inserted as fuel, in the cathode, the inlet of humidified oxygen closes the system. Direct ethanol fuel cell acetaldehyde acetic acid ptsno 2c electrocatalysts abstract ptsno 2c with pt. Ethanol 27, 2propanol 8,9, ethylene glycol 10 and glycerol 14 have all been considered for fuel cell applications. The direct ethanol fuel cell that we proposed herein uses natural clay as the electrolyte. An aqueous methanol solution of low molarity acts as the reducing agent that traverses the anode flow field. In alkaline fuel cells of this type, the metal cations react with dissolved co 2 in alcohol fuels producing metal carbonate precipitates that decrease the fuel cell performance.
The direct methanol fuel cell dmfc has been considered as the ideal fuel cell system since it produces electric power by the direct conversion of the methanol fuel at the fuel cell anode. Efficiency is quite low for these cells, reaching around 10% 1, so they are targeted especially to portable applications, where energy and power density are more important than. Direct ethanol fuel cells defcs are attractive as a power source options because ethanol is a nontoxic, leading to ease of handling and a high energy density fuel, leading to high system energy density. Pdf direct ethanol fuel cells defcs are attractive as a power source options because ethanol is a nontoxic, leading to ease of handling and. Direct ethanol fuel cells with superior ethanoltolerant. Energy conversion using pdbased catalysts in direct ethanol. Oct 12, 2006 a direct ethanol fuel cell offers an attractive, fairly high density, energy source, if an electrochemical system can be developed that efficiently carries out the 12electron oxidation of ethanol to carbon dioxide and water. The model included equations inside diffu sion layer, catalyst layer, and ethanol crossover through membrane, which all have been solved.
The use of alcohol blends in direct alcohol fuel cells may be a more environmentally friendly and less toxic alternative to the use of methanol alone in direct methanol fuel cells. What are the advantages of direct methanol fuel cells. A dual cell passive direct ethanol fuel cell defc stack with single ethanol tank was designed and tested to obtain the voltage requirement of electronics and to reduce weight and volume for. Direct methanol fuel cells technological advances and further requirements by m. This is an important subject and the authors general description can easily be followed by students in chemistry or related subjects. This is more attractive than the conventional hydro gen fuelled cells. Direct ethanol fuel cells have attracted much attention recently. Ethanol is the most used bio fuel worldwide with an existing supply chain and infrastructure in many parts around the world. Direct methanol fuel cells dmfcs, however, are powered by pure methanol, which is usually mixed with water and fed directly to the fuel cell anode. An alkaline direct ethanol fuel cell with a cation exchange membrane liang an and t. The direct ethanol fuel cell defc represents one of the most exciting future clean energy solutions in modern research, because ethanol can be sustainably produced from biomass, is relatively nontoxic and, most importantly, has a high energy density. Characterization and analysis of new catalysts for a direct. However, since the crossover of ethanol as a fuel in defcs can deteriorate the cell performance due to the oxidation of ethanol etoh at the cathode during oxygen reduction reaction. The major benefit to this type of fuel cell is that an ethanol supply chain is already available and there are a number of sources from which ethanol can be generated.
Protonexchangemembranebased direct ethanol fuel cell single cell tests with online ms analytics of the anolyte for single cells with a ptsnc anode with 3. Direct ethanol fuel cells or defcs are a category of fuel cell in which ethanol is fed directly into the cell. The recent developments of platinum and nonplatinumbased catalysts as methanol and ethanol tolerant oxygen reduction catalysts for direct alcohol fuel cells are described in chap. Zhao received 4th january 2011, accepted 30th march 2011 doi. Pdf performance of a passive direct ethanol fuel cell. However, conventional defcs that use acid protonexchange membranes typically nafion type and platinumbased catalysts exhibit low performance i. Direct methanol fuel cells do not have many of the fuel storage problems typical of some fuel cell systems because methanol has a higher energy density than hydrogenthough less than gasoline or. The energy produced from a direct ethanol fuel cell defc is theoretically higher than the pioneer direct methanol fuel cell dmfc. First, it has a lower density than any other fuel compare liquid hydrogens 70. Direct ethanol proton exchange membranes fuel cells depemfc. Principles and materials aspects of direct alkaline alcohol.
Pdf a micro alkaline direct ethanol fuel cell with. At 75 c, the single ethanol fuel cell with pt3sn2c as anode catalyst showed a comparable performance to that with pt2sn1c, but at higher temperature of 90 c, the latter presented much better performance. Two important features can be obtained with the use of this membrane. The performance of three alkaline direct ethanol fuel cells adefcs is investigated. The practical efficiencies of fuel cells with ethanol as the anode fuel are still low in comparison with other investigated fuels, such as hydrogen. Portable fuel cells powered directly by ethanol could soon be practical, thanks to a new catalyst that breaks a strong bond at the heart of ethanol molecules, freeing electrons and generating. Comparison of alkaline direct ethanol fuel cells with and without.
To evaluate the effect of the membrane thickness on the that permeates from the anode. Pt based anode catalysts for direct ethanol fuel cells. All three use identical anode and cathode electrodes, but one uses an. Fundamentals, engineering and advances presents the fundamental concepts, technological advances and challenges in developing, modeling and deploying fuel cells and fuel cell systems for portable devices, including micro and mini fuel cells. Principles of direct methanol fuel cells for portable and. In this paper, its aimed to pre sent a 2d analytical model for direct ethanol fuel cell defc performance. Jun 14, 2016 the greater range comes from the more efficient process of reforming ethanol into hydrogen and using that in a fuel cell to produce electricity, which generates more energy to turn the wheels than. The operation principle of an anion exchange membrane direct ethanol fuel cell aemdefc is illustrated in figure 15. By comparison, ethanol is more environmentally friendly and can be easily produced in large quantities from agricultural products or biomass. Direct methanol fuel cell dmfc performanceworcester polytechnic institute. Direct methanol fuel cell their main advantage is the ease of transport of methanol, an energydense yet reasonably stable liquid at all environmental conditions. Pdf anionexchange membrane direct ethanol fuel cells. The voltage drop of the direct ethanol fuel cell was observed with increasing current in fig 5. Direct ethanol fuel cells defcs are a promising carbonneutral and sustainable power source for portable, mobile, and stationary applications.
This paper assesses the beha viour of a direct methanol fuel cell fed with aqueous methanol, aqueous ethanol and aqueous methanol ethanol blends in a long term. The greater range comes from the more efficient process of reforming ethanol into hydrogen and using that in a fuel cell to produce electricity, which generates more energy to turn the wheels than. Direct alcohol fuel cells for portable applications 1st edition. To that end, new catalyst systems must be developed along with fuel cell operating conditions that encourage the complete oxidation of ethanol, as opposed to the. Electrochemical characterization of lowtemperature direct.