Hydrogen knowledge lybrary

General H2 technology

What is a Fuel Cell ?


Basically fuel cell in common language, is a device which converts chemical energy from a fuel into electrical energy which happens by undergoing a chemical reaction where positively charged hydrogen ions reacts with oxygen or any other oxidizing agent. Released electrons travel through wire-creating electric current. Ions travel through the electrolyte to the cathode side. Once reaching cathode-ions reunited with electrons-react with third chemical (usually oxygen), create water. (or carbon dioxide in a case of Methane Fuel Cells). In another simple word, FC is a device that uses hydrogen as s fuel to produce electricity and heat.




What kind of Fuel Cells are being used?


Fuel Cells are devided on the basis of used kind of electrolyte. Most common are these: 1. Alkaline Fuel Cell - alkaline solution electrolyte such as potassium hydroxide (KOH). 2. Phosphoric Acid Fuel Cells (PAFC - electrolyte is phosphoric acid. 3. Solid Proton Exchange Membrane (PEM) Fuel Cell-electrolyte is polymer electrolyte membrane fuel cells and its electrolyte consist of the proton exchange membrane. (e.g. NafilonTM) 4. Molten Carbonate Fuel Cells (MCFC) - electrolyte is molten carbonate. 5. Solid Oxide Fuel Cells (SOFC) - electrolyte is ceramic ion-conducting electrolyte in solid oxide form. 6. Regenerative Fuel Cell There are several other experimental methods and we can write about them in another section. LOMINA uses AFC or ALE method for Hydrogen production and PEM FC method for power production at Fuel Cells




How does most common PEM Fuel Cell work?


Advantages of PEM are especially - high power density and relatively low operating temperature (ranging from 60 to 80 degrees Celsius. Low operating temperature means that it doesn't take very long time for the fuel cell to warm up and begin generating electricity. Fast start up is an important factor. PEM FCs are built out of membrane electrode assemblies (MEA) which include the electrodes, electrolyte, catalyst, and gas diffusion layers (GDL). An important part of the cell is the triple phase boundary (TPB) where the electrolyte, catalyst, and reactants mix and thus where the cell reactions actually occur. Importantly, the membrane must not be electrically conductive so the half reactions do not mix.




How does a fuel cell differ from a battery?


A fuel cell is different from a battery cell in that reactants are constantly supplied to a fuel cell making it an open system whereas a battery cell is a closed system that stores the reactants within it. A fuel cell works as long as fuel is supplied to it whereas a battery cell requires regular replacements.




What are the benefits of using a fuel cell?


Low-to-Zero Emissions High Efficiency Reliability High Quality Power Fuel Flexibility Energy Security Lightweight Technology Compatibility Quiet Operation Scalability Durability




Why use a fuel cell?


Fuel cells offer a variety of benefits compared to traditional power generators. They are generally more fuel-efficient, operate with very little noise and produce no harmful emissions at point of use (fuel cells which use renewable hydrogen as fuel produce only water). They have no moving parts and are thus easy to maintain. In addition to electrical power, they produce high-quality heat which can be used for heating (or to drive refrigeration cycles for cooling), so improving the overall efficiency of fuel use.




What can fuel cells power?


In principle, fuel cells could power anything that requires electrical energy to function. This could range from a mobile phone up to a city. Current commercial applications include off-grid power for telecoms stations; back-up power for buildings; drives for forklift trucks; residential heat and power; and portable generators and recharging devices.








Why not burn hydrogen instead of using it in a fuel cell?


Hydrogen is an extremely clean-burning fuel, and offers a good alternative to gasoline or diesel for internal combustion engines. However it is also good alternative to Natural gas heating. New HCHP (Hydrogen Combined Heat and Power) are already on a market where integrated Fuel Cell producess electricita and low grade heat (<80°C) and H2boiler supply heat when Fuel Cel thermal capacity is over limit. For comparison hete is a table of CO2 emmisions produced per 293 kWh H2 (Hydrogen) 0 kg (ZERO) Coal (anthracite) 103 kg Coal (bituminous) 93 kg Coal (lignite). 97 kg Coal (subbituminous) 97 kg Diesel fuel and heating oil. 73 kg Gasoline (without ethanol). 71 kg Propane 63 kg Natural gas 53 kg





Fuel cell types


Electrolyzers

How is the hydrogen produced?


Although there are huge quantities of hydrogen in the universe, very little of it here on Earth is in a freely-available form - it is usually present in a compound with other elements , most achievable is water. Most industrial hydrogen is currently produced from oil or gas, by reforming of the hydrocarbon feedstock to produce synthesis gas (syngas), primarily a mixture of hydrogen and carbon monoxide. However this is not CO2 free technology and therefore we mainly focuss on electrolysis which aloves to produce hydrogen with zero carbon emissions. This can be done by using renewable energy (particularly solar, and wind) to power an electrolyser to split water into hydrogen and oxygen. The hydrogen is then compressed, stored and transported from the site of production to the point of use. Running a fuel cell on this hydrogen produces zero carbon emissions.





H2 Storage


© 2007 - 2020 by LOMINA A.G.

  • Facebook LOMINA
  • YouTube LOMINA