[alancalverd]

Additionally hydrogen is the most flammable and most explosive gas there is and, charmingly, it also burns with an invisible but extremely hot flame. People walk into flames they can't see. The idea of piping it around the whole UK fills me with dread, particularly through a network that was never designed for it.

It was indeed designed for it, 150 years ago, and currently provides half of the UK energy needs . The 20th - 21st  century expansion of the grid was mostly done with plastic pipes.

Baffles me why they still deliver hydrogen in steel tanks, and why it is the most-produced heavy chemical. Does industry never learn that it is impossible and dangerous?  A bit like bumble bees - too busy flying to realise it can't be done!

[Bored chemist]

It was indeed designed for it, 150 years ago

In the intervening years, quite a lot of the pipes have been replaced with things like steel and plastic.
In reality, those were designed to contain methane, not town gas.

Baffles me why they still deliver hydrogen in steel tanks, and why it is the most-produced heavy chemical. Does industry never learn...

Industry does lots of things that we don't trust "the man in the street " to do.
Many of your posts indicate that you don't understand this.
https://en.wikipedia.org/wiki/Risk%E2%80%93benefit_ratio
If you read about it, you may be less baffled in future.
This related idea may also ease your perpetual bafflement.

https://en.wikipedia.org/wiki/Cost%E2%80%93benefit_analysis

[alancalverd]

Oh well, I'd better tell Toyota and Audi that they are wasting their time.  Beats me how those idiots ever get to make anything that works. As for NASA, using ridiculous stuff like hydrogen as rocket fuel and in their fuel cells - no wonder nobody really believes they flew to the moon.

Bumblebees, bumblebees.....why don't they listen to the voice of science?

[Bored chemist]

As for NASA, using ridiculous stuff like hydrogen as rocket fuel

Their vehicles run about 5 inches per gallon.
Did you somehow think they were relevant?

[Bored chemist]

Oh well, I'd better tell Toyota and Audi that they are wasting their time.  Beats me how those idiots ever get to make anything that works.

By the same stupid argument, you need to tell Tesla that their cars don't work.

[Bored chemist]

Bumblebees, bumblebees.....why don't they listen to the voice of science?

Science caught up with how bumblebees fly some time ago.
https://www.livescience.com/33075-how-bees-fly.html
Why haven't you?

[alancalverd]

Oh well, I'd better tell Toyota and Audi that they are wasting their time.  Beats me how those idiots ever get to make anything that works.

By the same stupid argument, you need to tell Tesla that their cars don't work.

My point precisely. But I'll leave it to you to pass on the bad news.

[alancalverd]

As for NASA, using ridiculous stuff like hydrogen as rocket fuel

Their vehicles run about 5 inches per gallon.
Did you somehow think they were relevant?

Are you suggesting that they would fly better with an electric motor?

[wolfekeeper]

Oh well, I'd better tell Toyota and Audi that they are wasting their time.  Beats me how those idiots ever get to make anything that works.

Yeah, about that:

https://pressroom.toyota.com/toyota-to-debut-three-new-electrified-vehicles-for-u-s-market/

Doesn't look like their hydrogen strategy has worked out.

As for NASA, using ridiculous stuff like hydrogen as rocket fuel and in their fuel cells - no wonder nobody really believes they flew to the moon.

Oh I know something about that. Liquid hydrogen is MUCH denser than compressed hydrogen. It's also EXTREMELY inefficient to manufacture. First you have to make the hydrogen. This is not particularly hard. Then you have to liquefy it. This takes an ENORMOUS amount of energy. Bet you thought water had a high heat capacity, well, hydrogen, it's much worse.  And in the overwhelming majority of cases, that heat of liquefaction is wasted.

This means that liquid hydrogen is extremely inefficient to manufacture. And it has nothing to do with cars. It has to be stored in vacuum containers, and even then long-term storage requires active cooling. Even aeroplanes would have difficulty handling it and would have to store it in the fuselage, wing tanks have too much surface area, it would boil off too quickly.

So, no, not the same thing at all. Even with the extra density from liquefaction it's only marginally worth it even for rockets. The main issue is the remarkably low density of the hydrogen, makes the tankage extremely heavy for rockets. There's a sizeable fraction of the space industry that claim that hydrogen is an expensive mistake even in rocketry, still, and you'll note that the Falcon 9 doesn't use it.

As for NASA, using ridiculous stuff like hydrogen as rocket fuel

Their vehicles run about 5 inches per gallon.
Did you somehow think they were relevant?

Are you suggesting that they would fly better with an electric motor?

Electric pumps are a decent choice:

https://en.wikipedia.org/wiki/Rocket_Lab_Electron

They use lithium ion batteries for power.

[alancalverd]

Science caught up with how bumblebees fly some time ago.
https://www.livescience.com/33075-how-bees-fly.html
Why haven't you?

Because it was always pretty obvious to me that bumblebees knew enough about the aerodynamics of powered flight to ignore the opinion of experts. 

[Bored chemist]

Are you suggesting that they would fly better with an electric motor?

No, that's just you making up irrelevant nonsense again.

[Bored chemist]

Because it was always pretty obvious to me that bumblebees knew enough about the aerodynamics of powered flight to ignore the opinion of experts. 

The opinion of the experts was (as is often the case) " We need to do more work on this".
They knew that the problem lay with their analysis, not the bee.
The fact that they published the disparity shows that they knew their models were inadequate.

[Jolly2 (OP)]

What is the pollution from alcohol like for cars? All Ford cars were originally run on alcohol due to prohibition in America Ford ended up converting all his cars to petroleum.

[hamdani yusuf]

Elon Musk shows how to easily convince a room full of oil giants at the Oil and Gas Summit in Norway 2014.

[alancalverd]

What is the pollution from alcohol like for cars? All Ford cars were originally run on alcohol due to prohibition in America Ford ended up converting all his cars to petroleum.

CO2 and H2O, same as any other organic molecule. These are "emissions" rather than "pollution" because they are natural constituents of the atmosphere.

Possible less nitrogen oxides (pollutants) due to the lower combustion temperature compared with gasoline or hydrogen, but low combustion temperature = low efficiency with low molecular weight alcohols.

Problems arise with water content and the fact that alcohols dissolve various rubber compounds and do not lubricate steel surfaces (hence "no biodiesel" on some filler caps), but these can be overcome with a bit of modification. There's a fine example of a Top Gear episode where they raced a BMW diesel against all comers in an endurance event: the greater range of the diesel gave them an advantage but their nod to the environment made them late for the start because the biodiesel had destroyed several seals in the fuel line. 

[Bored chemist]

These are "emissions" rather than "pollution" because they are natural constituents of the atmosphere.

By your definition, there pretty much aren't any pollutants.

Alcohol tends, in general, to burn more cleanly than diesel or petrol.
Once it has been through a catalytic converter, the exhaust fumes are fairly well scrubbed.

The big advantage to alcohol is that you can make it from plants. If you are careful you can have a "carbon negative" fuel (albeit that it's zero carbon once you burn it). It's a renewable energy source.

These days a fuel cap that says "No Biodiesel" might as well say "Bad Design".
The specifications for biodiesel limit the alcohol and water present.

[alancalverd]

By your definition, there pretty much aren't any pollutants.

Good point! Plenty of sulfur compounds are emitted by volcanoes and rotting vegetation, methane from anaerobic bacteria, etc. and it would be interesting to know how much NO_x is generated by thunderstorms.

However the "good stuff" is simply nitrogen, oxygen, water and CO₂ - AFAIK none of the other constituents is essential to life and most of that which is not inert, is poisonous.

[hamdani yusuf]

By your definition, there pretty much aren't any pollutants.

Good point! Plenty of sulfur compounds are emitted by volcanoes and rotting vegetation, methane from anaerobic bacteria, etc. and it would be interesting to know how much NO_x is generated by thunderstorms.

However the "good stuff" is simply nitrogen, oxygen, water and CO₂ - AFAIK none of the other constituents is essential to life and most of that which is not inert, is poisonous.

At least they are not highly concentrated in a densely populated area where many people breathe the air, such as city streets.

[wolfekeeper]

CO2 and H2O, same as any other organic molecule. These are "emissions" rather than "pollution" because they are natural constituents of the atmosphere.

Just because they're natural, doesn't make it a good thing if you double the amount! Plenty of things are NATURAL, but kill you just fine.

Coroners have a saying: it's the dose that makes the poison

The Earth's climate hasn't changed this fast in millions of years. Very few species have the ability to react to significantly higher temperatures well. Not even humans, a few extra degrees during a heatwave, and you're talking tens of thousands of deaths.

[Bored chemist]

By your definition, there pretty much aren't any pollutants.

Good point! Plenty of sulfur compounds are emitted by volcanoes and rotting vegetation, methane from anaerobic bacteria, etc. and it would be interesting to know how much NO_x is generated by thunderstorms.

However the "good stuff" is simply nitrogen, oxygen, water and CO₂ - AFAIK none of the other constituents is essential to life and most of that which is not inert, is poisonous.

Lots of words.
None of which detracts from the fact that your definition was tosh.

And, as has been pointed out, too much water or oxygen will kill you.