Fuel cell Definition and 56 Threads

I happen to be modelling PEMFC and accounted for various transport equation including mass, heat, species and charge. I was able to validate my stationary model based on a published reference. In validating its voltage dynamic response, I was expecting at a potentiometric conditions that an...

The quantity (dE_dP)_T can be derived using the Gibbs-Helmholtz equation which states that dE = TdS - PdV + μdN where E is the internal energy of the system, S is the entropy, V is the volume, N is the number of particles and μ is the chemical potential. Differentiating this equation with...

Can someone explain me what does the underlined part of the following passage mean? "The reversible operation of a fuel cell implies that the external circuit exactly balances its emf, with the result that its current output is negligible. In actual operation under reasonable load, internal...

Hello, I'm taking an energy class and I'll be giving a presentation on fuel cells. I was wondering if I could get some help understanding the whole process of the paper below. Unfortunately, I can't post the article because of copyrights. To summarize, it's a one compartment H2O2 fuel cell with...

Fuel cells quickly provide electricity from H2 when switched on. But what exact steps get to Grid voltage? Are there many small inverters, and if so, how do they keep the output in step? What sort of efficiencies are there?

Hello, Can you tell me please the mass flow rate of hydrogen and oxygen per unit of area of electrodes in fuel cells? Or if you have information on the mass flow rate of hydrogen and air per volume of fuel cell stack? I understand this may vary, but I am looking for publications or other...

I am trying to understand the working of simple hydrogen fuel cell. We have anode (negative terminal), cathode (positive terminal), catalyst at anode to separate negative and positive ions of hydrogen atoms and electrolyte which allows only positive ions. We will be sending hydrogen fuel at...

greetings, here I found a Simulink model on mathswork, I want to replace the battery with a fuel cell, so I'm stuck at the level of the energy management block. here is the link of the model: https://www.mathworks.com/matlabcentral/fileexchange/28441-hybrid-electric-vehicle-model-in-simulink...

Hello! I've been working on a few soil based MFCs and I have been monitoring my voltage and energy output for a week now. I've made the electrodes by covering stainless steel metal meshes with activated carbon using epoxy. I've gotten some funky results as attached. As you can see... the...

I am aware of laminar flow but would like to look for some other ways. Is it possible to block ions from flowing in the "wrong" direction by applying a magnetic field to the electrolyte and let neutral molecules pass through?

I was just wondering if there is an easy way to recombine hydrogen in a fuel cell style but effectively by doing electrolysis in reverse. Splitting is really easy but is there a way to get the HHO to recombine into water and release electricity effectively by reverse electrolysis? I get that...

I know theoretically fuel cell efficiency decreases as temperature increases. But in practice it is vice versa. What is the reason of that? I couldn't find enough sources. Any kind of help is much appreciated.

Essentially, I'm wondering (knowing virtually nothing at present), what is at the front of modern research in the realm of energy. Whether this be renewable energy, or simply more efficient ways of using energy (e.g. fuel cells?). I assume nuclear fusion will be mentioned too, so what obstacles...

Hi! Recently, I got a hobby grade mini- fuel cell after watching a youtube video. Sometimes the fuel cell doesn't perform steadily. What effect does the surrounding air temperature have on PEMs? will it work better if i run in near an AC? (:wink:) I've seen some really complex images on...

Hello, Just as the title asks, what sort of applications would series and parallel connections of Direct Methanol Fuel Cell suit the best? Based from my understanding of Fuel Cells and experimental results, one cell is not enough to power anything, hence they are used in stacks, in addition...

Hello, I have some questions regarding the nernst equation at open circuit voltage. We know E(OCV) = E0+ ln (PH2*PO2^0.5 / PH2O) I have some trouble with this: If I have dry gas (both for O2 and H2), and my circuit is open at 25°C and 1 atm I have no water in the circuit so what become the...

I have also posted this question here: Relationship between surface area of electrode and reaction rate of hydrogen in fuel cells, but I really need an answer before tomorrow morning so I hope you don't mind me posting it here as well! I am looking at the effects of increasing the surface area...

Hi, I haven't posted anything on here in a long time, but thought somebody here could help me out. I am building a fuel system for an endurance sports car. I have a sealed 0.6 gallon collector in the fuel cell with three 75gph pumps, capable of 95psi feeding it, through 3/8" hose. It then...

Homework Statement Calculate the open cell voltage for an H2/O2 fuel cell operating at P=1atm and T = 100°C Homework Equations Nernst Eq: Eo+(RT/nF)*ln[(aH2)*(aO2^1/2)/(aH2O)] The Attempt at a Solution E=1.17V+((8.314J/mol-K)*(373K))/((2e-)*(96486C/e-))*ln[(PH2*PO2^1/2)/PH2O]...

Hi As I am preparing for a presentation about modern http://scopewe.com/tag/fuel-cell-2/ I need some reference books or articles about fuel cells and the technology of these cells. I appreciate any information about these cells: 1.Solid oxide fuel cell (SOFC) 2.Alkaline fuel cell (AFC)...

Hi all, one last question for today - Given steam reforming of natural gas to generate hydrogen, what is the major difficulty with it with respect to most fuel cells? Thank you,

Can anyone help me explain the elements of the fuel cell polarization curve. Please be sure to include Etn, Er, and the various polarizations. I am interested by the use of thermodynamics as well... Thank you-

I've heard fuel cells being called energy storage devices. However, unlike batteries, they only convert energy. They don't store anything unless you consider the brief moment of converting chemical energy to electrical energy storage time? Are there fuel cell types that store let's say hydrogen...

Let's say I have a balloon full of Hydrogen that is STP, and outside this balloon I have normal air (containing oxygen) which is also STP. Is there a way to produce energy by turning these 2 items into a fuel cell, if so how practical is it (in a DIY setting) and is there anything that would...

Fuel cells means chem engineering, right? (move to the right section if necessary) Anyway this sounds great, except that it still uses gasoline: http://www.technologyreview.com/energy/39203/

I'm given a fuel cell that uses methane as fuel: (CH4) + 2(O2) --> 2(H2O) + (CO2) And I'm asked to find (a) the electrical work I can get out for each mole of methane, and (b) the amount of waste heat produced. I understand that ΔG is defined as the amount of useful non-mechanical work...

Hey everyone, I was just wondering, in a PEM fuel cell the Hydrogen ion diffusion through the membrane is an important step. But don't these ions need to diffuse through the anode as well to reach the membrane? Also, if this is the case and the anode is a metal like Pt, wouldn't the diffusion...

Could one really big hydrogen fuel cell battery replace a nuclear reactor in providing power to millions of people? This may end up being a safer option for generating power.

Basically as the title says, is it possible to build a DB fuel cell stack? Something that could output 100W (to power a laptop or for power outages). I actually have access to a couple of kilos of sodium borohydride and while looking at what I can do with the stuff I came across this type of...

Is there a way to make the atoms in HHO gas (Browns gas) to separte into it's elements; so the Hydrogen atoms go one way and the Oxygen in another way. By doing this I'm hoping to generate electricity from the reaction by bringing them together again. What kind of fuelcell do I need?

I understand that generating the hydrogen that powers a typical fuel cell is (prohibitively?) energy intensive at this point, but I was curious about the following: Assuming a sufficiently efficient catalyst was obtained that allowed large-scale production of pure hydrogen without...

Hey folks, I am currently doing some research on hydrogen fuel cells as part of a project. I just wanted to clear up some confusion I am having with the whole *platinum issue.* Very generally speaking, this is what I have gathered on H2 Fuel cell vehicles: 1) Electrolysis is needed to...

I think I got a and b, the rest I did my best on, and I could use some guidance! Thanks!Homework Statement 1. [6] Methane (Natural Gas) Fuel Cell. Consider a fuel cell that uses methane as fuel. The chemical reaction is CH4 + 2O2 = 2H2O + CO2 + energy (a) [0.5] Measurements reveal that...

Hi, I'm working on a commercially available PEM fuel cell and I'm trying to calculate the theoretical voltage of the cell: The only electrochemical reaction considered is H2 + 0.5O2 --> H2O And I understand that I need to use the Nernst equation: E = EO - (RT / 2F) ln (PH2O / (PH2 *...

i am learning femlab 3.1...so following the model library given with the set of books.. but i am facing problems with the 3 d modelling.. as in case of fuel cell stack model..the solver is unable to solve even if all the steps are followed according to given instructions.. i have double...

I’m from a group that is current working on the theory of a Hydrogen Economy. Our first area of development is the Hydrogen Highway. We are currently seeking help in the form of freelance / work for hire basically engineer(s) that could aid in design and calculations of internal combustion...

Hello, I'm doing work in Fuel Cells and am having difficulty with a simple issue; the Nernst Voltage (E) is greater than the Standard Potential (EO) The only electrochemical reaction considered is H2 + 0.5O2 --> H2O The Nernst equation for this reaction is E = EO - (RT / 2F) ln (PH2O / (PH2...

Homework Statement 2 H2(g) + O2(g) 2 H2O(l) K = 1.28e83 As temperature increases, does the maximum amount of work obtained from the fuel cell reaction increase, decrease, or remain the same? Homework Equations 1. G = -RTln(K) 2. dG = dH - tdS 3. w_max = dG The Attempt...

I've heard about the units that run on DC and extract O and H from water. The gases are then used on automobles to increase fuel mileage. I'd like to hear the thoughts on energe in and energy out. Also, as hybrids store energy for a finite number of power demands, can these fuel cells do a...

I have just finished my sophomore year at Columbia University with a major in physics. I chose Columbia College instead of the engineering school due to the better reputation/ranking and I was not sure whether to go into physics or engineering. However, after two years of courses, I am very...

Enuma's thread got me thinking why these isn't more buzz for the hydrogen cars like the Honda FCX, GM Sequel, Nissan Frontier, BMW 7...

What is the maximum useful work which can be obtained from a hydrogen-oxygen fuel cell that produces 1.96 kg of water at 25°C? How do we approach this problem? I guess -Ecell x charge = w?

Homework Statement I'm trying to calulate the efficency of a small hydrogen fuell cell that I built. I have all of the measurements, but I'm not coming up with a resonable effiency. Homework Equations \frac{P OUT}{P IN}x 100 The power to electrolyze the water is the P IN. 3.25 W...

http://www.nextenergynews.com/news1/next-energy-news-betavoltaic-10.1.html I cam across this article. It is horribly written from a scientific standpoint and lacks some necessary information on how the device works. But the basics are... Tritium is the beta source, porous silicon matrix...

Can anyone tell me if it is right to say that maximum power of a hydrogen oxygen fuel cell varies directly (with constant efficiency) with gas flow rate at constant pressure at room temperature

I need help thinking of ideas for slides. I have "How it works", "benefits", "challenges", "Physics behind it", "Hydrogen vehicles", "Why Hydrogen", "What is a fuel cell", "Uses", "efficiency", "Fuel cell configurations". I can't think of anything else.

In my school we are developing and investigating the process of generating electricity by means of an hydrogen fuel cell. We have started with an aqueous solution of NaCl and connect it to a 12 volt generator. Then, we waited for 3-4 minutes and disconnected it from the generator and connected...

i recently read in a popular science magizine about a guy inventing a substance that was like a "scafalding" for atoms. that the atoms (gas state) bonded to this structure (assuming this scaffalding is microscopic) making it "semi-solid" i don't know what you would call it. but what if you did...

how do i make a fuel cell which utilises hydrogen and oxygen to make water and in the meantime give out loads of heat. is it possible?:

I got to learn this stuff for my fuel cell project. Anyone know any good websites on it?