At 01:38 am 23-10-04 -0800, you wrote:
>At 1:18 AM 10/23/4, Grimer wrote:
>>At 03:23 pm 22-10-04 -0800, you wrote:
>>
>>>............. Hydrogen pipelines, like gas pipelines, carry some major
>>>risks. Since their engineering and implementation would be fairly new, and
>>>hydrogen is more difficult to manage, I would assume hydrogen risks to be
>>>higher than those for natural gas, both in transmission and delivery.
>>
>>When I was a boy my older brother used to make model airships out of balsa
>>wood and tissue paper. He filled them with "coal gas" from the gas stove and
>>they flew around the kitchen OK so I presume coal gas must contain a lot of
>>hydrogen. A search on the web gives the following data on "coal gas".
>>
>> ==================================================================
>> A typical composition of town gas would be about 51% hydrogen,
>> 15% carbon monoxide, 21% methane, 10% carbon dioxide and nitrogen,
>> ==================================================================
>>
>>They seemed to be able to handle toxic coal gas without killing too many
>>people*
>>in those early days of the 20th century. I can't see why handling a gas
>>which is
>>100% hydrogen would be much of a problem in the 21st century. Even in the most
>>famous accident involving hydrogen (the Hindenburg disaster) two thirds of the
>>nearly one hundred people on board escaped.
>>
>>Cheers
>>
>>Grimer
>> * apart from those distraught housewives who
>> deliberately put their head in the gas oven.
>
>
>Yes, and I've seen lots of support for limited exposure to explosion when
>filling tanks and in accidents, etc. However, I would still expect
>transmission lines to have some surprises due to hydrogen embrittlement.
When they dug up my road to replace the old gas pipes they used what
looked like a yellow plastic pipe. Would that kind of pipe suffer from
hydrogen embrittlement? Did the metal gas pipes of the old town gas
transmission system suffer from hydrogen embrittlement. Mind you, in
those days they probably wouldn't have known about hydrogen
embrittlement anyway. ;-) When ignorance is bliss.......
>This would especially be a problem for the gas turbines which would be
>hydrogen fueled and for the compressor blades used to push hydrogen
>upstream in the pipeline.
Would it be a problem for carbon-fibre blades?
>High pressure valves, bearings, seals and
>lubricants would have to be tested long term, etc.
>
>In addition, a lot of engineering related to operations would have to be
>done, like modeling linepack, supercompressibility effects, jet engine
>performance, storage reservoir performance, and other parameters used in
>gas transmission simulations and operating models currently. Transmission
>lines are considerably different from distribution systems, and a lot more
>dangerous. Broken natural gas transmission lines can and have wiped out
>very large areas by explosion.
I know that there was one famous case in Russia. There must have been
others presumably. How bad were they?
I suppose I can google to find out.
==============================================================
12. The impacts of pipeline accidents are usually only
environmental, i.e. release of hydrocarbon liquid to surface
and groundwater and release of gas to the atmosphere. There
have been no recorded fatal accidents involving inhabitants
following gas releases from transmission pipelines over the
period 1970-2000 in those countries included in the EGIG
database (all within Western Europe). However, fatal incidents
can certainly occur, as illustrated horrendously by an accident
near Ufa, Russia on 4 th June 1989, when two trains, each
carrying more than 500 passengers, passed each other within a
cloud of natural gas arising a pipeline leak (see Table 1).
The gas exploded and most of the passengers in one train were
killed outright; hundreds of passengers in the other (many of
them children) suffered severe burns.
==============================================================
That's from a United Nations Economic Commission for Europe document.
I know Yanks aren't keen on the UN - or Europe for that matter - but
I would think that's pretty reliable info, wouldn't you Horace? ;-)
>Hydrogen transmission lines might be able >to do the same thing.
Hydrogen does have the advantage over methane, though, that it is
lighter than air. Presumably that is why so many Hindenburg passengers
survived. If the gas had been heavier than air they would all have been
roasted. Mind you - the airship would have needed a good anti-grav
engine or it would never have got off the ground. <G>
Cheers
Grimer
