Making water with hydrogen.

I don't understand. It probably doesn't really matter to your question but I don't know what you're referring to as "dirty energy to produce hydrogen" unless you mean electricity generated by fossil fuels, and I don't know what you mean by "water in water out".

Well, this isn't a question of chemistry so much as one of physical chemistry of climatology. But I'd say any excess water in the atmosphere is cycled out by normal processes involving rain.

 

Yes I was referring to fossil fuel generated electricity. By water in water out I mean both the origin of the energy (or rather storage of it?) and the emissions are water. Could this eventually be an alternative to electric cars and their dirty, inefficient and non sustainable batteries? Assuming the energy to produce the hydrogen was clean in the first place. Does the burning of the hydrogen to release the energy avoid the emission of carbon?

 

Well, I commented on the "dirty energy" issue previously, but the batteries of electric cars cannot be compared to the "dirty, unsustainable" nature of fossil fuels since a battery pack lasts for some 70,000 to 100,000 miles.

The burning of hydrogen does not involve carbon at all. The product of combustion is entirely water and water only. The problem with hydrogen usage in cars is that it requires more energy to produce it than is available from the hydrogen, and only electrolysis of water via solar electricity produces hydrogen without also producing CO2.

So all things considered, hydrogen is not the best choice for transportation. The best we have today is electric vehicles charged by solar panels. But even charging with electricity generated by traditional means is better than burning gasoline or diesel oil in cars due to efficiencies of scale.

 

Thanks for taking the time to answer my questions. One final question, does the electrolysis of water to produce hydrogen use any non-sustainable or dirty materials eg acids or metals? My only knowledge of producing hydrogen with electricity is lead acid batteries which use both.
Batteries in electric cars while improving all the time are still inefficient, dirty and use rare metals etc....I just wondered if in the future hydrogen could become an even better way of transporting us about.

 

There are different electrolytes that can be used depending one products desired. If table salt (NaCl) is used, the products will be hydrogen, chlorine, and lye. But other substances can be used and some will produce just hydrogen and oxygen. I think if you Google it you will find a more complete answer.

 

Cheers, I live off grid with low bandwidth internet access but next time I have access to broadband I'll look it up.

 

IMHO, either using natural gas directly for auto fuel, or using electric cars is the better option. The better batteries are the less potential there is for hydrogen fuel.

 

I pretty much agree. The future will be electric cars, not hydrogen.

 

The near to medium future sure but what will happen when the materials needed to make batteries become rarer and even more expensive? Not to mention the copper needed in electric motors.
I am not suggesting an end to the research and development of electric cars merely asking whether hydrogen engines offer a possible alternative in the more distant future.

 

You are presuming that we won't develop new batteries using new materials.

Hydrogen was a fad for a little while in the 1990s/2000s. I don't see it as practical.

 

Anything is possible in 1,000 years. We can't predict. But I can say that the copper in motors and in anything else is recycled. There is little loss. At $1.80 to $2 per pound, most copper is recycled for cash.

Electric drives are the next major phase in transportation over roads.

 

My farmer friend says they are predicting electric tractors on all large farms within 10 years. Take that oil industry