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From: herbie@watdcsu.UUCP (Herb Chong [DCS])
Newsgroups: net.misc,net.physics
Subject: Re: perpetual motion
Message-ID: <1183@watdcsu.UUCP>
Date: Thu, 28-Mar-85 11:34:32 EST
Article-I.D.: watdcsu.1183
Posted: Thu Mar 28 11:34:32 1985
Date-Received: Fri, 29-Mar-85 00:03:18 EST
References: <608@vortex.UUCP> <491@spp2.UUCP> <455@cepu.UUCP>
Reply-To: herbie@watdcsu.UUCP (Herb Chong [DCS])
Distribution: net
Organization: U of Waterloo
Lines: 63
Xref: watmath net.misc:7679 net.physics:2332
Summary: 

In article <455@cepu.UUCP> scw@cepu.UUCP (Stephen C. Woods) writes:
>>While I tend to agree with Lauren that there is a lot of garbage being
>>passed around as truth, I have to wonder why our cars aren't powered
>>by liquid hydrogen (a non-polluting fuel) rather than gasoline.
>
>Well there's a whole bunch of reasons:
>(1) It's MUCH MUCH MUCH (is that enough MUCHes?) more hazardious than Gasoline.
>     Remember that you're going to have grade school dropouts pumping this
>     stuff into your car.
>(2) It's about 4 times as bulky as the energy equivalent ammount of gasoline.
>     Most people would not appreciate having to fill their tank with $10/Gal
>     LH2 every 50-100 miles.  Not to mention the insulation on your tank to
>     keep it from evaporating.
>(3) It's much more expensive to make.
>    (a)extraction from H2O (about 50% efficency?)
>    (b)Cooling it to (whatever degrees K 10? 20?).
>	Totally lost energy here (it's not useable to make your car go).
>    (c)Keeping it COLD.
>
>-- 
>Stephen C. Woods (VA Wadsworth Med Ctr./UCLA Dept. of Neurology)

well, i have a friend who is converting his van to hydrogen power this summer.
he thinks that there will be little problems with it.  so, i will attempt
to reply to the above based upon what he has told me:
1)	it is more explosive than gasoline in the sense that it doesn't
	need to evaporate first before mixing with air (see point 3).
	however, since it is less dense than air, it will rise, and any 
	flames and stuff will rise also.  because it is a gas to begin with
	there will be a flash explosion and nothing else except possibly
	nearby debris that ignites.  natural gas and gasoline are denser
	than air and will pool, forming flames that will be underneath any
	vehicle and burning anything above.  since they also burn less rapidly
	than hydrogen, there is a higher likelyhood of igniting nearbly
	inflammable material.  propane and natural gas powered cars pull up
	at the nearest source of supply (some gas stations sell propane for
	these cars) and fill up.  there's a station about 1 km from where
	i write this.  you also buy leaded and unleaded gas from the same
	person.

2)	propane and natural gas powered cars suffer from this same problem
	but no-one around here notices it much.  most of these cars that i
	know of have cruising ranges of about 300 km before requiring
	refilling.  remember that these engines are more efficient than
	gas engines and don't need as much total energy input to get
	the same amount out.  mind you, the old gas tank is just removed
	and the trunk essentially becomes useless for putting all but the
	smallest things into.

3)	it is not sold as liquid hydrogen, but as compressed gas.  
	it is mostly extracted from byproducts of natural gas wells, though
	electrolysis is another way of getting it.  since it's a gas, no
	problem with refrigeration.  it's cleaner burning than gasoline
	though it still produces oxides of nitrogen.

Herb Chong...

I'm user-friendly -- I don't byte, I nybble....

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