Fuel Cells 2014

Fuel Cells

Fuel CellsDr Ijaz Ahmad ChaudhryPhD, DIC (CAM), (UK), MEng(Energy) AIT, BSc Mechanical Engineering UET, Post-Doctral Research Fellow Newcastle UponTyne (UK), PE, Member ASME, Member IEP, Member Pakistan Engineering CongressProfessor Mechanical Engineering DepartmentUniversity of Engineering and Technology, Lahore, PakistanPhone: +92 (42) 9902 9465Email: [email protected]

23 April, 20141Prof Dr Ijaz Ahmad ChaudhryDevices that convert chemical energy directly into electricity are called voltaic cells, a subgroup of electrochemical cells, which also include devices that use an electric current to promote a chemical reaction. Such devices are called electrolytic cells or electrolyzers. Flashlight batteries, automobile batteries, and fuel cells are examples of voltaic cells. Because voltaic cells transform chemical energy directly into electricity without requiring an intermediate degradation into heat, they are not limited by the Carnot efficiency.23 April, 20142Prof Dr Ijaz Ahmad ChaudhryIf the battery is not worth preserving after its first discharge, it is an expendable (also called primary) battery. If the device is reusable after discharge, it may fall into one of two categories:Rechargeable (also called secondary) devices, in which the activity is restored by means of an electric charging current, as is the case of automobile batteries. Refuelable devices (fuel cells), which deliver a sustained output because their consumables are replenished. To facilitate such replenishment, these consumables are usually fluids, although some fuel cells use solid consumables as is the case of zinc-air cells

23 April, 20143Prof Dr Ijaz Ahmad ChaudhryAlthough fuel cells date back to 1839 when Sir William Groves demonstrated his gaseous voltaic battery, until recently they remained in their technological infancy. NASA revived fuel cell research: both Gemini and Apollo used fuel cells, and so does the space shuttle. Their most important applications in the near future are as power sources for buses and automobiles, as central utility power plants, as dispersed (including residential) power suppliers, and as power sources for cell phones and other small electronic devices.23 April, 20144Prof Dr Ijaz Ahmad ChaudhryVoltaic CellsThe purpose of voltaic cells is to provide a flow of electrons in an external circuit where useful work can be done. To this end, the cells must consist of a source and a sink of electrons.The reactions used in electrochemical cells are called reduction-oxidation (redox) reactions, because the buzz word for releasing electrons is oxidation and that for capturing electrons is reduction. Numerous old scientific terms are confusing or at least not self explanatory. The terms reduction and oxidation require explanation.23 April, 20145Prof Dr Ijaz Ahmad ChaudhryThe word oxygen stems from oxus = acid or sharp and means generator of acids, a name that appears in de Morveau and Lavoisiers Nomenclature Chimique in 1787, when chemists were under the wrong impression that oxygen was an essential element in acids. Actually, it is hydrogen that is essential. When an acid is dissolved in water, some of its hydrogen atoms lose their electronthe water becomes acidic; the hydrogen is oxidized. By extension, any reaction that involves the loss of electrons is called oxidation. The reverse reactiongaining electronsis called reduction.23 April, 20146Prof Dr Ijaz Ahmad ChaudhryThe simplest way of thinking of a voltaic cell is as a combination of an electron source or anode in which some chemical is oxidized delivering a flow of electrons to an external load. The latter is connected to a sink of electrons, i.e., a cathode in which a chemical is reduced thus taking up the electrons exiting from the load. In practical electrochemical cells, the full reaction is broken down into two half-cell reactions or half-reactions that occur in physically separate regions of the device. These regions are interconnected by an electrolyte that conducts ions but not electrons.23 April, 20147Prof Dr Ijaz Ahmad ChaudhryFigure 1 A voltaic cell must consist of a source and a sink of electrons.

23 April, 20148Prof Dr Ijaz Ahmad ChaudhryThe electrons, having (in voltaic cells) been released by the oxidizing half-reaction, can move to the reduction side only via an external circuit, establishing the external current that is the purpose of the cell. The conventional direction of this external current is from the reduction to the oxidizing sidethe current exits the device from the reduction side, which thus becomes the cathode, and enters the device at the oxidizing side, which becomes the anode. As in any source of electricity, the cathode is the positive electrode and the anode the negative one, the opposite of what happens in sinks of electricity (loads).23 April, 20149Prof Dr Ijaz Ahmad ChaudhryAs an example of an electrochemical cell, consider a membrane capable of acting as an electrolyte. Put hydrogen in contact with one side of this membrane. At ambient conditions, most of the gas will be in the form of H2 molecules; however, a small amount will dissociate:and some of the resulting H will oxidize (ionize)that is, lose an electron:

Since the membrane does not conduct electrons, the electrons will remain on its surface, while the positive ions will diffuse through it and arrive at the other side. Because the ions carry a positive charge, the hydrogen side becomes negative owing to the excess electrons that remain on it, and the opposite side becomes positive owing to the positive ions that arrived there. The resulting electric field causes some of the positive ions to drift back to the hydrogen side. A dynamic equilibrium is established when the diffusion exactly equals the returning drift. It is easy to calculate the potential developed23 April, 201410Prof Dr Ijaz Ahmad Chaudhry

Fig 2 Fuel Cell

23 April, 201411Prof Dr Ijaz Ahmad ChaudhryFuel Cell ClassificationAFCAlkaline fuel cellDMFC Direct methanol fuel cellMCFCMolten carbonate fuel cellPAFCPhosphoric acid fuel cellSAFCSolid acid fuel cellSOFCSolid oxide fuel cell (ceramic)SPFCSolid-polymer fuel cell23 April, 201412Prof Dr Ijaz Ahmad ChaudhryFuel cells can be classified according to several criteria, as follows.Temperature of OperationState of the ElectrolyteType of FuelChemical Nature of the Electrolyte

23 April, 201413Prof Dr Ijaz Ahmad ChaudhryTypical Fuel Cell ConfigurationsAll fuel cells are basically a sandwich of two electrodes separated by an electrolyte. Numerous variations of this theme have been tried, but as we have pointed out, the dominant variable is the nature of the electrolyte. Early fuel cells used liquid electrolytesalkaline or acidbut the current trend is in the direction of solidsmostly polymers or ceramics. In the subsections that follow, we will briefly describe configurations that have had some success, many of which have now been abandoned.23 April, 201414Prof Dr Ijaz Ahmad ChaudhryTypical Fuel Cell Configurations1. Demonstration Fuel Cell (KOH)2. Phosphoric Acid Fuel Cells (PAFCs)2.1 A Fuel Cell Battery (Engelhard)2.2 First-Generation Fuel Cell Power Plant 3. Molten Carbonate Fuel Cells (MCFCs)3.1 Second-Generation Fuel Cell Power Plant4. Ceramic Fuel Cells (SOFCs)4.1 Third-Generation Fuel Cell Power Plant4.2 High-Temperature Ceramic Fuel Cells4.3 Low-Temperature Ceramic Fuel Cells

23 April, 201415Prof Dr Ijaz Ahmad Chaudhry5. Solid-Polymer Electrolyte Fuel Cells5.1 Cell Construction5.2 Membrane9.5.5.3 Catalysts9.5.5.4 Water Management6 Direct Methanol Fuel Cells (DMFCs)7 Direct Formic Acid Fuel Cells (DFAFCs)8 Solid Acid Fuel Cells (SAFCs))9 Metallic Fuel CellsZincAir Fuel Cells

23 April, 201416Prof Dr Ijaz Ahmad Chaudhry

The demonstration fuel cell described here illustrates the ideas that perhapsoriginated in the 1950s. The design is self-evident from Figure The six holes near the rim of the two Lucite covers allow the passage of screws that hold the system together. The diameter of the device is8 cm. Fuel sources are two toy balloons (not shown), one containing oxygenand the other hydrogen. Excess gas is vented into a beaker withwater.

Demonstration Fuel Cell (KOH)23 April, 201417Prof Dr Ijaz Ahmad ChaudhryProton exchange membrane fuel cells (PEMFCs)In the archetypical hydrogenoxide proton exchange membrane fuel cell design, a proton-conducting polymer membrane (the electrolyte) separates the anode and cathode sides. This was called a "solid polymer electrolyte fuel cell" (SPEFC) in the early 1970s, before the proton exchange mechanism was well-understood. (Notice that the synonyms "polymer electrolyte membrane" and "proton exchange mechanism" result in the same acronym.)

23 April, 201418Prof Dr Ijaz Ahmad ChaudhryOn the anode side, hydrogen diffuses to the anode catalyst where it later dissociates into protons and electrons. These protons often react with oxidants causing them to become what are commonly referred to as multi-facilitated proton membranes. The protons are conducted through the membrane to the cathode, but the electrons are forced to travel in an external circuit (supplying power) because the membrane is electrically insulating. On the cathode catalyst, oxygen molecules react with the electrons (which have travelled through the external circuit) and protons to form water.In addition to this pure hydrogen type, there are hydrocarbon fuels for fuel cells, including diesel, methanol (see: direct-methanol fuel cells and indirect methanol fuel cells) and chemical hydrides. The waste products with these types of fuel are carbon dioxide and water.

23 April, 201419Prof Dr Ijaz Ahmad ChaudhryThe different components of a PEMFC are (i) bipolar plates, (ii) electrodes, (iii) catalyst, (iv) membrane, and (v) the necessary hardware. The materials used for different parts of the fuel cells differ by type. The bipolar plates may be made of different types of materials, such as, metal, coated metal, graphite, flexible graphite, CC composite, carbonpolymer composites etc. The membrane electrode assembly (MEA) is referred as the heart of the PEMFC and is usually made of a proton exchange membrane sandwiched between two catalyst-coated carbon papers. Platinum and/or similar type of noble metals are usually used as the catalyst for PEMFC. The electrolyte could be a polymer membrane.

23 April, 201420Prof Dr Ijaz Ahmad ChaudhryComparison of fuel cell typesFuel cell nameElectrolyteQualified power (W)Working temperature (C)Efficiency (cell)Efficiency (system)StatusCost (USD/W)Alkaline fuel cellAqueous alkaline solution10000 !10 100 kW79 !< 8065% !6070%62%Commercial / ResearchDirect borohydride fuel cellAqueous alkaline solution

70

CommercialDirect carbon fuel cellSeveral different

775 !70085080%70%Commercial / ResearchDirect formic acid fuel cell (DFAFC)Polymer membrane (ionomer)49 !< 50 W39 !< 40

Commercial / ResearchDirect methanol fuel cellPolymer membrane (ionomer)0.1 !100 mW 1 kW105 !9012025% !2030%15% !1020%Commercial / Research125Direct-ethanol fuel cellPolymer membrane (ionomer)0 !< 140 mW/cm26 !> 25? 90120

ResearchElectro-galvanic fuel cellAqueous alkaline solution

39 !< 40

Commercial / ResearchEnzymatic Biofuel CellsAny that will not denature the enzyme

39 !< 40

ResearchMagnesium-Air Fuel CellSalt water

-20 !20 to 5590% !90%

Commercial / ResearchMetal hydride fuel cellAqueous alkaline solution

0 !> -20(50% Ppeak @ 0C)

Commercial / Research23 April, 201421Prof Dr Ijaz Ahmad ChaudhryMicrobial fuel cellPolymer membrane or humic acid

39 !< 40

ResearchMolten carbonate fuel cellMolten alkaline carbonate100000000 !100 MW625 !60065055%47%Commercial / ResearchPhosphoric acid fuel cellMolten phosphoric acid (H3PO4)999999 !< 10 MW175 !150-20055%40% !40%Co-Gen: 90%Commercial / Research44.50Planar Solid oxide fuel cellO2--conducting ceramic oxide99999999 !< 100 MW975 !500110063% !6065%57% !5560%Commercial / ResearchProton exchange membrane fuel cellPolymer membrane (ionomer)100 !100 W 500 kW125 !50100 (Nafion)[44]125220 (PBI)60% !5070%40% !3050%Commercial / Research50100Protonic ceramic fuel cellH+-conducting ceramic oxide

700

ResearchReformed methanol fuel cellPolymer membrane (ionomer)5 !5 W 100 kW200 !250300 (Reformer)125200 (PBI)55% !5060%33% !2540%Commercial / ResearchRegenerative fuel cellPolymer membrane (ionomer)

49 !< 50

Commercial / ResearchRFC RedoxLiquid electrolytes with redox shuttle and polymer membrane (Ionomer)1000 !1 kW 10 MW

ResearchTubular solid oxide fuel cell (TSOFC)O2--conducting ceramic oxide99999999 !< 100 MW975 !850110063% !6065%57% !5560%Commercial / ResearchUpflow microbial fuel cell (UMFC)

39 !< 40

ResearchZinc-air batteryAqueous alkaline solution

39 !< 40

Mass production23 April, 201422Prof Dr Ijaz Ahmad ChaudhryProton exchange membrane fuel cell design issuesCosts. In 2013, the Department of Energy estimated that 80-kW automotive fuel cell system costs of US$67 per kilowatt could be achieved, assuming volume production of 100,000 automotive units per year and US$55 per kilowatt could be achieved, assuming volume production of 500,000 units per year. In 2008, professor Jeremy P. Meyers estimated that cost reductions over a production ramp-up period will take about 20 years after fuel-cell cars are introduced before they will be able to compete commercially with current market technologies, including gasoline internal combustion engines. Many companies are working on techniques to reduce cost in a variety of ways including reducing the amount of platinum needed in each individual cell. Ballard Power Systems has experimented with a catalyst enhanced with carbon silk, which allows a 30% reduction (1mg/cm to 0.7mg/cm) in platinum usage without reduction in performance. Monash University, Melbourne uses PEDOT as a cathode. A 2011 published study documented the first metal-free electrocatalyst using relatively inexpensive doped carbon nanotubes, which are less than 1% the cost of platinum and are of equal or superior performance.

23 April, 201423Prof Dr Ijaz Ahmad ChaudhryProton exchange membrane fuel cells (PEMFCs)

23 April, 201424Prof Dr Ijaz Ahmad ChaudhryWater and air management (in PEMFCs). In this type of fuel cell, the membrane must be hydrated, requiring water to be evaporated at precisely the same rate that it is produced. If water is evaporated too quickly, the membrane dries, resistance across it increases, and eventually it will crack, creating a gas "short circuit" where hydrogen and oxygen combine directly, generating heat that will damage the fuel cell. If the water is evaporated too slowly, the electrodes will flood, preventing the reactants from reaching the catalyst and stopping the reaction. Methods to manage water in cells are being developed like electroosmotic pumps focusing on flow control. Just as in a combustion engine, a steady ratio between the reactant and oxygen is necessary to keep the fuel cell operating efficiently.

23 April, 201425Prof Dr Ijaz Ahmad ChaudhryTemperature management. The same temperature must be maintained throughout the cell in order to prevent destruction of the cell through thermal loading. This is particularly challenging as the 2H2 + O2 -> 2H2O reaction is highly exothermic, so a large quantity of heat is generated within the fuel cell.23 April, 201426Prof Dr Ijaz Ahmad ChaudhryDurability, service life, and special requirements for some type of cells. Stationary fuel cell applications typically require more than 40,000 hours of reliable operation at a temperature of 35C to 40C (31F to 104F), while automotive fuel cells require a 5,000-hour lifespan (the equivalent of 240,000km (150,000mi)) under extreme temperatures. Current service life is 7,300 hours under cycling conditions. Automotive engines must also be able to start reliably at 30C (22F) and have a high power-to-volume ratio (typically 2.5kW per litre).Limited carbon monoxide tolerance of some (non-PEDOT) cathodes.23 April, 201427Prof Dr Ijaz Ahmad Chaudhry Fuel Cell Applications1. Stationary Power Plants. Stationary power plants of various types include central utility-operated power plants of large capacity (say, up to 1 GW), dispersed utility-operated power plants (perhaps in the tens of MW sizes), and on-site electrical generators (some 10 to 100 kW). For these applications, fuel cells present the following advantages over conventional heat engines:23 April, 201428Prof Dr Ijaz Ahmad Chaudhry1. Absence of noise.2. Little pollution.3. Ease of expansion (owing to modular construction).4. Susceptibility to mass production (again, owing to modularity).5. Possibility of dispersion of power plants. Owing to the low pollution and low noise, plants can be operated even in residential areas, thus economizing transmission lines.23 April, 201429Prof Dr Ijaz Ahmad Chaudhry6. Possibility of using reject heat for ambient heating because fuel cells can be near populated areas where there is a demand for hot water.7. Possibility of cogeneration, using the high-temperature exhaust gases in some types of plants.8. Fast response to demand changes.9. Good efficiency at a fraction of rated power.10. Extremely good overload characteristics.11. Small mass/power ratio, in some types of plants.12. Small volume/power ratio, in some types of plants.13. Great reliability (potentially).14. Low maintenance cost (potentially).23 April, 201430Prof Dr Ijaz Ahmad ChaudhryOwing to modular construction, plant capacity can be easily expanded as demand grows. Capital investment can be progressive, lessening the financial burden. Not all advantages can be realized simultaneously. Cogeneration can only be achieved with high-temperature fuel cells such as MCFCs and SOFCs. With cogeneration, low noise advantage may be lost.23 April, 201431Prof Dr Ijaz Ahmad Chaudhry2 Automotive Power PlantsPowerCogenerationFuel cell electric vehicles (FCEVs)AutomobilesBusesForkliftsMotorcycles and bicyclesBoats

23 April, 201432Prof Dr Ijaz Ahmad ChaudhrySubmarinesPortable power systems

23 April, 201433Prof Dr Ijaz Ahmad ChaudhryMarkets and economicsIn 2012, fuel cell industry revenues exceeded $1 billion market value worldwide, with Asian pacific countries shipping more than 3/4 of the fuel cell systems worldwide. However, as of October 2013, no public company in the industry had yet become profitable.] There were 140,000 fuel cell stacks shipped globally in 2010, up from 11 thousand shipments in 2007, and from 2011 to 2012 worldwide fuel cell shipments had an annual growth rate of 85%. Tanaka Kikinzoku Kogyo K.K. expanded its production facilities for fuel cell catalysts in 2013 to meet anticipated demand as the Japanese ENE Farm scheme expects to install 50,000 units in 2013 and the company is experiencing rapid market growth23 April, 201434Prof Dr Ijaz Ahmad ChaudhryApproximately 50% of fuel cell shipments in 2010 were stationary fuel cells, up from about a third in 2009, and the four dominant producers in the Fuel Cell Industry were the United States, Germany, Japan and South Korea. The Department of Energy Solid State Energy Conversion Alliance found that, as of January 2011, stationary fuel cells generated power at approximately $724 to $775 per kilowatt installed. In 2011, Bloom Energy, a major fuel cell supplier, said that its fuel cells generated power at 911 cents per kilowatt-hour, including the price of fuel, maintenance, and hardware23 April, 201435Prof Dr Ijaz Ahmad ChaudhryIndustry groups predict that there are sufficient platinum resources for future demand, and in 2007, research at Brookhaven National Laboratory suggested that platinum could be replaced by a gold-palladium coating, which may be less susceptible to poisoning and thereby improve fuel cell lifetime. Another method would use iron and sulphur instead of platinum. This would lower the cost of a fuel cell (as the platinum in a regular fuel cell costs around US$1,500, and the same amount of iron costs only around US$1.50). The concept was being developed by a coalition of the John Innes Centre and the University of Milan-Bicocca. PEDOT cathodes are immune to monoxide poisoning23 April, 201436Prof Dr Ijaz Ahmad Chaudhry

23 April, 201437Prof Dr Ijaz Ahmad Chaudhry38

Schematic Diagram of a Fuel Cell 23 April, 2014Prof Dr Ijaz Ahmad Chaudhry39

Fuel Cell Stack23 April, 2014Prof Dr Ijaz Ahmad Chaudhry40Electrosorption (forming Pt-CH2OH, Pt2-CHOH species) of methanol onto Platinum layer deposited on MEA

Addition of oxygen to adsorbed carbon containing intermediates generating CO2 Mechanism for Methanol Oxidation 23 April, 2014Prof Dr Ijaz Ahmad Chaudhry41Operation of Fuel Cell



23 April, 201443Prof Dr Ijaz Ahmad ChaudhryTypes of Fuel Cells Fuel Cell Operating ConditionsAlkaline FC (AFC)Operates at room temp. to 80 0CApollo fuel cellProton Exchange Membrane FC (PEMFC)

Operates best at 60-90 0CHydrogen fuelOriginally developed by GE for spacePhosphoric Acid FC (PAFC)

Operates best at ~200 0CHydrogen fuelStationary energy storage device Molten Carbonate FC (MCFC)

Operates best at 550 0CNickel catalysts, ceramic separator membraneHydrocarbon fuels reformed in situSolid Oxide FC (SOFC)

Operates at 900 0CConducting ceramic oxide electrodesHydrocarbon fuels reformed in situDirect Methanol Fuel Cell (DMFC)Operates best at 60-90 0CMethanol FuelFor portable electronic devices23 April, 201444Prof Dr Ijaz Ahmad Chaudhry

Summary of Reactions and Processes in Various Fuel Cells23 April, 201445Prof Dr Ijaz Ahmad Chaudhry

Block Diagram of the Component Parts of a Fuel Cell23 April, 201446Prof Dr Ijaz Ahmad Chaudhry

Depiction of Components of Complete Fuel Cell System23 April, 201447Prof Dr Ijaz Ahmad ChaudhryPolyelectrolyte Membrane Fuel Cell (PEMFC)

23 April, 201448Prof Dr Ijaz Ahmad Chaudhry49Technology Limitations with DMFCPoor Electrode Kinetics Large activation work potential200-300 mV Cell Voltage LossCatalyst DevelopmentMass TransportCO2 RejectionLow MeOH concentrationElectrode Structure25-150mVCell Voltage LossElectrode Material Development23 April, 2014Prof Dr Ijaz Ahmad Chaudhry50Technology Limitations with DMFC CathodeElectrode Material DevelopmentPoor Electrode KineticsMethanol CrossoverMass TransportLarge Activation OverpotentialMixed Cathode PotentialReduced GasPermeability200-300mVCell Voltage Loss25-100mV LossAbove 100mV LossCatalyst Development 23 April, 2014Prof Dr Ijaz Ahmad Chaudhry Electrode Material: Special conducting carbon Vulcan XE-72 available with Cabot Corporation, USA.

Anodic Catalyst: Platinum-Ruthenium adsorbed on conducting carbon. Procedure of making it is well documented.

Cathodic Catalyst: Platinum adsorbed on conducting carbon. Procedure of making it is well documented.

Membrane: Nafion Membrane available with DuPont USA. They create lot of problems before supplying.Three components of the Fuel Cells

23 April, 201451Prof Dr Ijaz Ahmad Chaudhry52Polystyrene (PS) Membranes Dense membranes used for gas separation and pervaporation

Sulfonated PS membrane used in methanol based fuel cells

Sulfonated PS blended with Nafion membrane

High impact PS blended with polyaniline

Anion exchange membranes prepared by chloromethylation of

polystyrene

Ion Exchange Membranes23 April, 2014Prof Dr Ijaz Ahmad Chaudhry53Experimental SectionPreparation of clay supportCasting of prepolymersyrup on wet clay supportGas phase nitration of the membrane at 1100 CAmination of the membrane using hydrazine hydrateQuaternizationby dichloroethaneand triethylamineStyrene, AIBN, BPO, DMA, Bulk polymerization at 700 C700 C, 12 hMembrane Preparation23 April, 2014Prof Dr Ijaz Ahmad Chaudhry54Clay raw materialComposition(wt. %)Kaolin10.15Ball clay12.90Feldspar4.08Quartz18.85Calcium carbonate22.52Pyrophyllite11.50Water20.00CompositionI CastingClay mixture casted on a gypsum surfaceII DryingAmbient Temp : 24 h100 0C : 12 h250 0C : 12 hIII Sintering900 0C : 6 - 8 hIV Dip CoatingDip coated in polymerized TEOS (tetraethyl orthosilicate)Drying, 100 0C : 24 hSintering, 1000 0C : 5 h

Preparation of Clay SupportSteps of Preparation23 April, 2014Prof Dr Ijaz Ahmad ChaudhrySolid Oxide Electrolyte CeramicsOverpotential OP= AOP COP IRinternal

Perovskite Oxides: La1-aAaM1-bBbO3-x

A=Sr2+, Ln3+, Ce4+M=Fe, Co, Gaa=0.1 to 1molB=Co, Fe, Mgb=0.1 to 0.5 mol

High Temperature Superconductors YBa2Cu3O7-xPiezoelectric material BaTiO3Semiconductor sensors SrTiO3Oxygen Ion Conductors LaGaO3-xProton Conductor doped BaCeO3-xCathode Material La0.8Sr0.2CoO3-x

Working Temperature range: 100-20000C

23 April, 201455Prof Dr Ijaz Ahmad ChaudhryModification of the SupportNOxSupSupNO2Catalyst + NH2NH2SupNH2ImidazoleFeCl3SupNCH2CH2Cl-

NNCH2CH2Cl-

NNSupNCH2CH2FeCl4-

NNCH2CH2FeCl4-

NN23 April, 201456Prof Dr Ijaz Ahmad Chaudhry57Experimental Section

Nitration:2NaNO2+H2SO4 NO + NO2 +H2O+Na2 SO4Amination: Quaternization: Modification Reactions23 April, 2014Prof Dr Ijaz Ahmad Chaudhry58

Membrane CharacterizationScanning electron microscopy (SEM) Crossectional view of the membraneCeramic Support Membrane layer23 April, 2014Prof Dr Ijaz Ahmad Chaudhry59Experimental Setup for ElectrodialysisHCl SolutionNaCl solutionPumpPumpO2 H2 DC Power Supply Catholyte Anolyteanodecathode23 April, 2014Prof Dr Ijaz Ahmad Chaudhry

KWh/mol of NaOH produced Current efficiency Energy consumptionOperating parametersSalt concentrations, flow rate, current density Performance of the Membrane23 April, 201460Prof Dr Ijaz Ahmad ChaudhryEfficiency of leading fuel cell types


Fuel Cells 2014

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