Hydrogen as Fuel Automotive Uses
Hydrogen Hydrogen is the lightest and most abundant chemical element
Naturally occurring elemental hydrogen is relatively rare on Earth At standard temperature and pressure, hydrogen is a colorless, odorless, nonmetallic, tasteless, highly combustible gas with the molecular formula H2
Hydrogen Production Industrial production is mainly from the steam reforming of natural gas In steam-methane reforming, methane reacts with steam under 3–25 bar pressure (1 bar = 14.5 psi) in the presence of a catalyst (nickel) to produce hydrogen, carbon monoxide, and a relatively small amount of carbon dioxide Methane: CH4 + H2O (+heat) → CO + 3H2
Hydrogen Production cont.
Electrolysis An electrical power source is connected to two electrodes, or two plates (typically made from some inert metal such as platinum or stainless steel) which are placed in the water. In a properly designed cell, hydrogen will appear at the cathode (the negatively charged electrode, where electrons enter the water), and oxygen will appear at the anode (the positively charged electrode).
Hydrogen Production cont.
Currently- It costs about $2.50 just to produce 1 Kg of Hydrogen. Delivery and storage is difficult and expensive Virtually no H2 infrastructure exists.
Energy Content Assuming equal weights H2 contains approximately 3 times the energy of gasoline. 1 Kilogram (2.2 lbs.) of H2 is considered roughly equivalent to 1 gallon of gasoline (approx. 6lbs.)
Emissions When burned in an internal combustion engine Hydrogen will create temperatures high enough to create Oxides of Nitrogen (NOx) gasses. The NOx gasses are less than those emitted by current Near Zero emission vehicles. Other typical automotive emissions are essentially non-existent from Hydrogen burning vehicles
Emissions cont. Currently –
The production of 1 Kg of H2 develops as much pollution as a standard automobile
Hydrogen Storage A gram of hydrogen gas occupies about 11 liters (2.9 gallons) of space at atmospheric pressure (14.7 psi) Remember that 1 Kg of H2 has the same energy as 1 gallon of gasoline. So, at atmospheric pressure, 2900 gallons of H2 is needed to equal the energy content of one gallon of gasoline.
Hydrogen Storage cont. The gas must be intensely pressurized to several hundred atmospheres and stored in a special tank. OR In liquid form, hydrogen can only be stored under cryogenic temperatures. -423 degrees F
Hydrogen Storage cont. Storage of hydrogen in hydride form.
This method uses an alloy that can absorb and hold large amounts of hydrogen by bonding with hydrogen and forming hydrides. A hydrogen storage alloy is capable of absorbing and releasing hydrogen without compromising its own structure. Currently only viable for small scale use.
BMW H2R Hydrogen Car Basically the same engine used in the carmaker's 760i luxury sedans Running on hydrogen, it develops 286 horsepower Zero to 60 mph in under six seconds 187 mph top speed Bi-Fuel Gasoline or H2 at the push of a button
BMW H2R Hydrogen Car cont.
Use liquid hydrogen Must be kept very cold, below -423F. The car's onboard cryogenic system takes care of this automatically If the vehicle isn't started up for three or four days, the liquid will begin to boil, and hydrogen gas will escape through a vent. Hydrogen is less dangerous than gasoline. It disperses quickly, so even when a container leaks explosions are next to impossible.
Hydrogen as a Supplement
HHO, or Brown Gas, generators are quite popular on the web. These small scale generators produce enough H2 to act as a supplemental fuel in gasoline powered cars. Most use hydrolysis produced through battery/alternator voltage. H2 is pumped directly into the intake ducting before the throttle plate. How effective is this?
Assignment Given the equipment available here at HVCC, and your knowledge of fuel systems and computer controls, how can we test the impact of adding H2 to the intake stream? Develop a test procedure and bring it to our next lab session.