im confused, some sites say that hydrogen fuel cell cars are zero emission cars. but others say they emit low amounts of carbon dioxide.
We probably will, eventually. There are still some problems with H2 technology that must be ironed out: 1. Storage: there is a lot less energy per litre of H2 than per litre of gas, in order not to have to pull around a trailer for a gas tank the H2 gas has to be compressed A LOT! The US DOE is studying the use of carbon fibre fuel tanks because of the very high pressures involved. 2. Fuel cells: They are heavy, about 100X the weight of a car engine for the same power output. The catalyst is platinum which is too rare and expensive, they are looking at an iron based catalyst to replace the platinum which would at least solve the price problem for fuel cells. 3. Infrastructure: There are no H2 filling stations, delivery tankers, pipelines etc. No fuelling infrastructure. In the meantime you are more likely to see EVs or electric cars rather than H2 fuelled cars. Most electric cars are designed to be plugged in anywhere. So every wall plug is a gas pump. Much easier to establish a distribution system using the current electrical grid.
Hydrogen cars don't directly emit carbon dioxide. Making hydrogen uses lot of electricity. Since most electricity is made by burning complex hydrocarbons hydrogen cars are responsible for a lot of CO2 even though it doesn't come from the car's tailpipe.
the fuel cell itself doesnt emit CO2. and even if it does, its probably really small compared to a petrol engine the hydrogen (unless you use nuclear power or solar power to make it) may be produced using a process that produces CO2. And also the production fo the fuel cell itself may involve CO2
It dose emit carbon dioxide But where we getting the Hydrogen is not a carbon emit places.
Hydrogen is currently produced by burning natural gas (CH4) in a low oxygen environment to give you hydrogen and carbon monoxide gases (2CH4 + O2 -2CO + 4H2), then they spray in steam so that the carbon monoxide and the water reacts to give you more hydrogen and carbon dioxide (CO+H2O -CO2 + H2). Also, the manufacturing of any new vehicle requires a substantial amount of energy hence imposes a carbon footprint on the environment. Note that hydrogen is at best carbon neutral whereas synthetic gasoline from biomass can be carbon negative without the need to replace any of the nearly 1 billion vehicles on the road or the construction of a separate fuel distribution infrastructure. Even Sandia Labs when investigating how to more efficiently produce hydrogen from H2O concluded that it made more sense to synthesize liquid hydrocarbons then make hydrogen. The cars themselves can be considered zero emissions but they are hardly without environmental impact especially since there are alternatives that are far better for the environment. Of course, you'll see hydrogen cars because the marketing of them presents a growth market for the automobile industry as well as PR since most people erroneously believe that they would be an environmentally friendly choice.
