Hydrogen production

Replies

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  Ramani Aswath

  26.8 amp. hrs will give you about 1 gm (about 12 litres at room temperature) of hydrogen at 100% current efficiency. Work backwards taking into account your engine efficiency and HP required to get the power needed for electrolysis. Why SS? What about the anodic reaction? If SS is used as anode it will dissolve 1 gm of SS for every 1 amp.hr passed. Better use a non consumable anode like graphite. You can use graphite for both electrodes.
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  crazy john

  we are using 24volt battery for the process , so if we use graphite rod will it produce sufficient amount to run an I C Engine ?
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  Ramani Aswath

  crazy john

  we are using 24volt battery for the process , so if we use graphite rod will it produce sufficient amount to run an I C Engine ?

  I suggest that you read up on electrolysis of water. It is the CURRENT that produces the hydrogen. The voltage is needed to drive the current through the cell.
  The best water electrolysis cell runs at about 2 volts. You can therefore run 12 cells in series with 24 volts. The problem is that 26.8 amps passing for one hour will produce 12 litres of hydrogen. A 100 amp hour 24 V battery may give about two and a half hours cycle per charge. It will produce about 500 litres hydrogen/charge in two and half hours.
  
  You will have to work out what you need based on these figures.
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  crazy john

  Sir,
  If i use graphite won't it produce any other gas other than hydrogen because i have heard that it will produce methane gas & if it is so then my project will fail as it deals with environment friendly engine...
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  Ramani Aswath

  I am afraid that your electrochemistry requires some revision. There is no danger of methane production.
  However, I have a different take on this project. Electricity is the highest form of energy. Using it to produce hydrogen (that is, chemical energy) will lead to a degradation and associated entropy increase according to Second Law of thermodynamics. What is worse is that this energy will be used in a heat engine, which has its own entropy (because of inefficiency) issues. If you add to this the poor efficiency of charging and discharging a lead acid battery the overall efficiency will be poor indeed.
  You will be much better off directly driving a DC motor as the main motive power. Also if your electrolysis is to be done on board, designing a suitable sulphuric acid cell that can stand motion vibrations could give trouble. An alkaline cell may be easier to handle.
  Alternatively, have a well designed static electrolytic hydrogen generator and use a compressed hydrogen tank on the vehicle. No moving parts; you can directly use rectified line power with near 100%efficiency; no corrosion problems with acid; and best of all much less weight on board to push around.
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  crazy john

  does hydrogen needs oxygen to burn ??? if it is then what happens in sun & stars ??
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  Ramani Aswath

  crazy john

  does hydrogen needs oxygen to burn ??? if it is then what happens in sun & stars ??

  Hydrogen burns in oxygen to produce water in a chemical reaction to release heat of combustion. In the stars,Hydrogen fuses to Helium in a nuclear fusion to release nuclear energy, which is quite different. In the first case the hydrogen is still hydrogen in the combined state. In the second case Hydrogen becomes Helium.
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  jigarmech

  bioramani

  I am afraid that your electrochemistry requires some revision. There is no danger of methane production.
  However, I have a different take on this project. Electricity is the highest form of energy. Using it to produce hydrogen (that is, chemical energy) will lead to a degradation and associated entropy increase according to Second Law of thermodynamics. What is worse is that this energy will be used in a heat engine, which has its own entropy (because of inefficiency) issues. If you add to this the poor efficiency of charging and discharging a lead acid battery the overall efficiency will be poor indeed.
  You will be much better off directly driving a DC motor as the main motive power. Also if your electrolysis is to be done on board, designing a suitable sulphuric acid cell that can stand motion vibrations could give trouble. An alkaline cell may be easier to handle.
  Alternatively, have a well designed static electrolytic hydrogen generator and use a compressed hydrogen tank on the vehicle. No moving parts; you can directly use rectified line power with near 100%efficiency; no corrosion problems with acid; and best of all much less weight on board to push around.

  very well said sir!!
  the more you will convert the energy from one form to other, the more it will loose. So try to make out an electric car and if you are still on to hydrogen car then it is better to have a hydrogen cylinder(tank) in it rather than using an electrolysis process.
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  crazy john

  sir storing hydrogen will need heavy tanks which will increase the weight of car which will decrease its efficiency ....because its very difficult to store hydrogen & if we want to store it which tank we should use to make it efficient ??
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  jigarmech

  crazy john

  sir storing hydrogen will need heavy tanks which will increase the weight of car which will decrease its efficiency ....because its very difficult to store hydrogen & if we want to store it which tank we should use to make it efficient ??

  i guess carbon fiber material will be useful...
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  Ramani Aswath

  crazy john

  sir storing hydrogen will need heavy tanks which will increase the weight of car which will decrease its efficiency ....because its very difficult to store hydrogen & if we want to store it which tank we should use to make it efficient ??

  TATA is planning to introduce a compressed air car with a range of about 200 KM between refills. Obviously the tank for a compressed air car has to be more robust than a hydrogen cylinder. The solution to the technical problem is available.
  Jigarmech is right.
  Carbon fibre or other fibre reinforced plastic tanks will be adequate for storing hydrogen, if you are still interested in a hydrogen driven engine. No issue with increased weight. These tanks are light.
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  crazy john

  bioramani sir , can you tell me which will be more efficient compressed air cars or hydrogen cars ??
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  jigarmech

  crazy john

  bioramani sir , can you tell me which will be more efficient compressed air cars or hydrogen cars ??

  efficient will be hydrogen but the cost of producing it is high and it is considered dangerous too as it is highly flammable...
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  crazy john

  but if we are using electrolysis process with water+NaOH as electrolyte do you think cost will be more ??
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  Ramani Aswath

  crazy john

  bioramani sir , can you tell me which will be more efficient compressed air cars or hydrogen cars ??

  Are you going to use hydrogen in an IC engine or in a fuel cell and electric driven car? Both are low energy vehicles.
  If electrolysis is on board, battery weight and efficiency will figure in efficiency calculations. Air engine is less hazardous. Both are indirect energy sources. . The expanding air in an air engine cools and may be used for air conditioning the car.
  The problem is multidimensional. Unless all factors are considered, it may not be possible to say which is superior.
  
  An efficient electrolysis cell will give you 250 litres hydrogen/KWHr. However, a hydrogen IC engine will give about 0.2 KWHr output /KWHr input.