Widespread Use of Hydrogen May Hurt Ozone Layer

Saeger writes "The AP has a story about a CalTech study which has found that the Hydrogen Economy may deplete the ozone layer by 'as much as 8 percent' on the assumption that '10 percent to 20 percent of the hydrogen would leak from pipelines, storage facilities, processing plants and fuel cells in cars and at power plants.'" CalTech's press release has more information.

Comments

Re:overblown

[sweeney37]

They had a discussion about this topic on Talk of the Nation on NPR today. One of the scientists that was on claimed that this report focused mainly on the extremes. For instance the 20% leakage they've been using is a worldwide amount. The national amount in the US is about 2%.

Mike

Re:And then... one spark...

[tmasssey]

And this is why 10 to 20% of H2 will not leak out like it might with Gasoline. First of all, you don't pump hydrogen out of the ground. You have to make it, and you can control how you do so. Second, because it can be made anywhere there's an electric power plant, you don't have to ship it halfway around the world in supertankers. Second, it's *extremely* explosive. The cost of leaking even a small part of the amount you're moving is death in a fiery inferno.

All-in-all, I think they'll reduce the leakage before H2 becomes practical...

Re:overblown

[Mr_Matt]

Not only that, but unlike catalytic destruction of ozone (as with CFCs and such) the oxidation of this hydrogen means that the hydrogen is consumed. So I can't see how a hydrogen sink could approach the ozone loss levels attributed to CFCs and such - naively, I would say that it's probably not as big a deal. Naively, of course - this still merits some attention.

But hey, publish publish publish, whatever the cost, right? :)

Only applies to pure hydrogen

[worst_name_ever]

One would hope that the "hydrogen-based economy" would not be operating on pure gaseous - or even liquid - hydrogen! Gaseous hydrogen is annoying to keep sealed inside a system with any number of fittings (those tiny molecules like to leak out of anything) not to mention is extremely flammable.

I was under the impression that the "hydrogen-based economy" would actually transport its energy around in a more easily handled form, e.g. methanol which can be trucked around and handled more easily than pure hydrogen.

To me, this paper appears to be saying: "If the hydrogen economy is based around this arbitrary and unworkable assumption we made, bad things would happen!" Well, okay...

Re:overblown

[Anonymous Coward]

That's only one problem with the future "hydrogen economy".

Sure, hydrogen is in abundance, in outer space. Who's going to go get it?

What's the major source for hydrogen right now? Natural Gas. What's the major byproduct of extracting hydrogen from Natural Gas? Carbon Dioxide.

Sure, you can do electrolysis. Unfortunately, you need a lot of electricity to do that. Until nuclear power becomes popular again, there's not enough capacity in our power infrastructure. Not to mention that, in the US, most power is generated from coal.

Have you seen the price of Natural Gas lately?

It will be interesting to watch how we overcome these hurdles.

It's an engineering problem

[panurge]

I spent some time some years ago in a facility that handled a hydrogen mixture.
It is indeed very hard to prevent hydrogen leaks (the small molecule goes straight through even slightly porous metal) and it is difficult to detect, except when you get up to a couple of percent when a very small spark can cause a very interesting experience (like the roof being embedded in the car park.) On the other hand, that's the reason why a lot of work has to go into preventing gross leaks.

The same problem existed with the original town gas, which was practically odorless (CO + hydrogen + nitrogen) and of course the solution was to put in an odorous tracer gas. I am sure that with modern sensor technology a suitable tracer could be found that would be detectable in even minute quantities

Given that in the past we've been cavalier about low BP compounds and their ill effects - benzene in gas, CFCs, - it would be really good if this time governments and environmental scientists got their act together in advance. Leakage is not a reason not to use hydrogen, any more than the possibility of a leak is a reason not to put in plumbing. It's just a potential problem to be prevented.

Sure, if you treat it like oil

[Chairboy]

This really applies if you treat it like Oil with centralized production, pipelines to sub-stations, etc.

The reason this article might not reflect what actually happens is that hydrogen production might be done on a decentralized local scale. There's no technological reason you can't make hydrogen gas AT the fill station or home, it's just a matter of the economy of scale. Initially, you might see factories extracting hydrogen for shipment, but the logical next step would be to have extraction facilities at the fill stations that crack water. It's not feasible right now because the easiest way for a small operation to make hydrogen is by electrically seperating the hydrogen from water, but there are other catalytic or new tech (insert trek speak here) ways that could get it to a point where you have a box the size of an airconditioner that takes water in one end, and pumps compressed hydrogen out the other.

Also, the article doesn't take into account another likely source of hydrogen that might be used, and that's natural gas. There are already devices that crack natural gas catalytically to extract the hydrogen for use in fuel cells, so it's conceivable that until the technology reaches the 'gas station hydrogen extraction' level, we might all be using CNG for our fuel cells. Since CNG has big fat molecules, it won't leak like hydrogen.

Soooo... while the article is interesting, the problems it describes can be overcome and probably would need to be to make it economical in the first place.

Problems

[WatertonMan]

There have already been a lot of criticisms of this. For instance they determine leakage as about 20% based upon existing hydrogen leaks. But that uses all existing pipelines including many very old pipelines in Russian and China. In the United States existing leakage is estimated at 2%.

The other problem is that the ozone hole is repairing itself while the paper calculates problems in I believe 2060 - but uses the existing ozone levels. The amount of hydrogen needed to have the effects the authors discuss thus takes place many decades after the type of ozone hole analyzed.

There were a few other problems as well. (A perhaps overly optimistic estimate of when hyrdogen would be the dominant energy transmission method, for instance)

Thie paper is full of bogus assumptions

[Ponder]

1. leakage of 20% a figure based on world wide natural gas industry which includes places like the Russia, and other former eastern block countries with notoriously poor maintenance records. actual leakage from modern hydrogen systems is of the order of 2%
2. article assumes 100% hydrogen based economy by 2050. the most optimistic estimates put hydrogen use at 30% by 2050.

looks like they are off by a factor of 30 minimum.

Re:And then... one spark...

[Sylver Dragon]

Of course, this is ignoring the fact that gasoline is actually worse than hydrogen about this. Also, the H2 will probably disapate into the atmosphere too fast to get to any sort of useful concentration. Remember, that while (2H2 + O2 -> 2H20 + energy) if there isn't much of the H2 in one place, there isn't going to be much energy. This is why H2 is usually held in ballons before it is used, its just not useful while its spaying out of the wine bottle. It just disapates way too fast.

Re:Fossil Fuels

[terraformer]

IAAES (I am an environmental scientist/policy analyst) and it is definitely better than fossil fuels. The thing is, if this study is correct, and that is a big if based on how little is known about hydrogen in the environment, it will slow Hydrogen adoption by increasing costs associated with it's use and through fear of creating damage to the ozone layer, thereby extending how long fossil fuels continue to remain dominant. Hydrogen (more specifically hydrogen rich fuels) is seen as the next step in portable fuel. As time has moved forward from the industrial age, the hydrogen:caron ratio in fuels has swung from being very carbon rich (wood,coal) to less carbon rich (natural gas).