How much Hydrogen to match Petrol

[Hydro-Cell]

I need to find out how much hydrogen (in LPM) is needed to match the energy of petrol.

Here are some of the figures you may need,

Engine size:           1.8L    4 STROKE
Fuel consumption:   30mpg @ 70mph

I need to know the lower and upper limits, i.e how much hydrogen to tickover at 800-1000rpm and also flat out at 7000rpm.
           
I have looked on the net and figures change from site to site. just thought id see what i get on here

cheers in advance

[Hydro-Cell]

Also, if i were to compress the hydrogen to say 50psi @ room temp, would i be correct in thinking that the hydrogen will occupy 50x less space???

i.e  1000Litres of hydrogen compressed to 50psi = 20Litres of hydrogen @ 50psi

[Cloxxki]

Many such basic questions are simply no answer to be found, I'm glad you asked, similar questions bother me.

50psi is to be compared with 14.7psi ambient (atmospheric) pressure. So, a bit over 3 times as little space as I see it.
You may be confusing 1 bar with 1 psi.

With pure H in a tank, isn't the fuel cell driving a electric engine the most effective solution (todate)?
HHO on demand to me seems much more interesting. Liters per minute are needed compared to gasoline, of course. I never found those.

The mpg to lpm calc, this forum's members will probably not do for you. Ain't no rocket science, and google is our friend :-)

[Hydro-Cell]

how dumb of me, lol, i was thinking "bar" but for somereason wrote it as psi, noway practical.

i have worked out that to run a 1.8l engine @ 70mph at 30mpg this will require approx 420lpm of hydrogen

i agree a fuel cell is the most efficient way of using pure hydrogen, unfortunatly i dont have a spare £10,000 to buy one to run a motor big enough for my car. to just as proof of concept i will run an engine, if it works i would say without doubt it will run on a fuel cell and use less hydrogen.

[Cloxxki]

420lpm. Sounds like you'll need the Hindenburg as a trailing gas tank. Hey, it's less weight on the wheels!
Hydrogen has a unfair bad reputation name for lighting up airships at one bar. It gets really exciting when you up the pressure. At least with straight up H it can be done, with HHO it's just a complicated way of blowing yourself up.
There are such wonderful dynamics to Hydrogen as fuel in an engine, that I bet the efficiency can be much improved with additional systems to harvest the energy put out, let alone H-specific engine designs used. Think not only of the explosing, but also the collaps back to liquid. It's water of of the exhaust, right, not steam! And of course, if it were steam, one would need to be stupid to not use it well. Water is for free, steam and H are seriously rare and expensive to make. When you need it while on the go.
So how much HHO would be needed to power the same car? The O is taking up space, but it goes bang easier, and doesn't even use ambient are to burn with.