Boat powered by Hydrogen from Seawater? 2

[SparkyBear]

Am I being naive to ask whether a boat [say 10m in length] could be powered by using hydrogen [as a result of seawater electrolysis] in an internal combustion engine as a direct feed thereby removing the need for mass storage [and losses involved in pressurising it]? Obviously, one would need to store a quantity but I was wondering whether the rate of production of hydrogen could be high enough to run the engine direct [let's say to power a 305cu in Chevy V8 - just to give an example of power]?

I appreciate there are many question arising from this and I would appreciate all feedback?

 

[IRstuff]

How would you get the more than 100% efficiency you need to make that work?

TTFN

 

[HydroScope]

better off having a small floating raft that you drag around with you, to much equipment to fit in one boat and use it practically even for fishing!. First you need to remove nacl from the water then add another electrolyte find a source of natural energy exam. solar/tidal/thermal/wind. then use it to electrolis the water and produce hydrogen which would then need to be compressed.

If you wish to drive your boat and produce the hydrogen at the same rate of consumption then as you can see you would need a large uninterupted source of natural energy. If you had that you would be better of using it, in other words using the solar energy to drive an electric motor rather than producing hydrogen as any transfer of energy process is not without losses

personally I like the idea of the raft you can leave it behind or take it with you on long trips (overnight) and it can be set up to produce hydrogen from all tidal/solar/thermal/wind/wave. best thing about a boat you don't use them all day every day, make sure your raft has a large tank and high compression limit and you should always have some hydrogen for a trip up and down the river.

Also even if you got your raft in order, then runing a IC engine on hydrogen is not that easy it will require some serious mods or a rotary engine is much more practical.

 

[SparkyBear]

I'm sorry ... I didn't make it very clear, I wasn't after driving continuously without any other form of energy. As I have seen comments regarding the energy in pressurising plus the safety aspect of having large qty of hydrogen on board a boat!! I focused my question without being very thorough!

Let's say there were batteries to provide the energy for electrolysis ... I have seen a comment saying the actual voltage to start H2 production is low so assume 12v [0r 24v?] was available from batteries.

I need your experience to tell me how feasible is this?

Another option would be to produce the H2 from a shorepower supply [while the boat is moored] and then pressurise it into tanks? What would be the amount of electricity required to produce 100 litres? How dangerous would that be in a boat? Compared to gasoline or LPG [which sinks when it escapes whereas H2 doesn't?]

I did hear that the planned attempt to break the 'round the world' record set by 'Challenger' was going to use this technology but they have changed to green diesel - wondered what changed their plans?

 

[IRstuff]

Do the math. The energy you get from the hydrogen is less than or equal to the energy available in the battery. How much energy is in a battery?

Let's say it's one of those Die-Hards with 400 A-hr capacity. Times 12V, that's 4800 W-hr, divide by 745 W/hp, results in 6.4 hp-hr. In other words, it drive a 1-hp vaccuum cleaner for about 6 hrs.

TTFN

 

[moltenmetal]

What you're proposing would be very energy inefficient. Better to use the energy in the batteries to drive an ~ 85% efficient electric motor directly, rather than electrolyzing water (~30-60% efficient) then using the hydrogen to run an engine (max 15% efficient)...but see IRStuff's post about the energy storage capacity of the average battery...

 

[SparkyBear]

Maybe if I approach this from a different angle?

I have a fast motor boat and live in the UK. Gasoline is £0.75+/litre. LPG is 35p/litre and rising. My TWO Chevy V8 305's drink about 54 litres/hour - do the math!
I am using my 'imagination' to see whether there is a viable way of using hydrogen from seawater as a cheaper alternative, working on the assumption that it must be cheaper than gasoline and LPG because the raw product is free and plentiful? So, if it costs me £1 to extract 3 litres or more then it is worth looking at ...
NOW - can anyone comment on this concept?

I am not trying to get free energy, something for nothing, invent perpetual motion, etc!

Electric motors are not an option for driving a boat at anymore than a few knots [mph]. The QE2 has electric motors but it also has many diesel generators [each the size of a London double decker bus] to supply it with electricity!!!

 

[IRstuff]

Firstly, you're running about 600 hp or 1.6 gigajoule/hr, which roughly correlates with your fuel consumption and the energy density of gasoline. That's about 466 kWhr of energy per hour, which is no more than twice the energy consumption of a typical household for a month.

Using the same 400 A-hr battery model, that equates to draining about 100 batteries PER HOUR.

You already have the highest practical energy density fuel, and you're only paying about 2/3 what it would cost as electricity.

TTFN

 

[SparkyBear]

Thanks for all your input ... I have found that the storage of H2 in pressurised tanks is not too feasibel for the consumption I require and the case of the battery model has been clearly stated ...

Hey! It was just a thought ...

 

[HydroScope]

electrolysis of water is generally around 80% efficient and you can use hydrogen in a IC engine up to 40% efficient the flamability limits of hydrogen allow you to lean out the mixture far leaner than gasoline engine or even LPG, as for having a 305 chev engine then running it with a supercharger would lean out the mixture well and your engine would have identical power out to it's gasoline cousin without a supercharger. ford did this recently with there model U and obtained 38% effic no drop in power.

Easist Hydrogen production is steam reformation from natural gas. and you can always run your 305 chev on a mixture of hydrogen gas and natural gas AKA hythane, this will keep your costs down as natural gas is independent of crude oil prices.and natural gas is substantially cheaper than gasoline on energy basis. As a mechanical eng. student this is my area of interest. This basically means you have a cheaper than natural gas running engine as with hydrogen addition any engine petrol engine will run at high efficency.

As for the storage the natural gas/ hydrogen can be stored in all carbon composite tanks at up to 10 000 psi (50Kg), such tanks with 20% Vol hydrogen/nat gas would hold close to same amount of energy stored in equiv. volume of petrol, with engine running at higher efficency you will be able to drive your boat further than if running on petrol. tank made of carbon fibre is safe. and when on water likely hood of impact crash is minimal and involve lower speeds than on land and not risk puncher of tank

If safety your biggest worry then metal hydride storage of hydrogen may be the answer as it sound to me like you are keen on water skiing or even wake boarding, if so then as you would know a nicely formed wake is what you want and can be obtained from extra weight in the back, metal hydride tanks are heavey but they can hold a lot of hydrogen, and the risk of hydrogen storge is substaintialy reduced as metal hydrides do not store hydrogen at high pressure instead low pressure or atmospheric pressure.

obvisouly it is possible to reduce you fuel cost by running on hythane but you will need to spend money first hydrogen by steam reformation unit can be bought from BOC gas and engine mods and tank fitting can be done my yourself or reputable auto engineering joint. Thus you need to add the numbers up carefully before doing. But certainly you are correct you can reduce your fuel bill by the use of hydrogen.

for the sake of lowering human impact of the air we breath I would not be supprised if this is where the technology in the near future is going to take us as NOx emissions are almost obsilute when running lean equiv ratio .4 or lower and this is well worth considering. sulfur content of nat gas is lower than petrol and desiel.

hydrogen production from renewable energy i.e electrolysis from tidal or wave or solar or wind energy is not as cheap as you first might think as the equipment you need can get expensive and considering the sun doesn't shine 24hrs7days wind/tidal/wave they all stop at some time. compare that to oil rig that pulls 1000 times the flow of energy out of ground aka cruel oil for years and years at time then you begin to realise why renewables have had problems getting of the ground. you should look at recycling parts i.e second hand equip. to obtain electricity from renewables i.e using a refrigerant cycle in reverse etc. thermal energy from sun. It may not give you power 24.7 but will not cost much if you catch my drift. and you can store it via hydrogen for later use in your boat ;O)

hope that helps . . . .

 

[moltenmetal]

So- you're looking for something cheaper than fossil fuels to drive your boat, and you're looking toward hydrogen?

Think again! Hydrogen is NOT a cheaper fuel than ANY fossil fuel. Period! And it's only a CLEANER fuel if it's made the right way.

How cheap the thing is that you're taking the hydrogen from is pretty much irrelevant. The cost in hydrogen generation is in the process of making the hydrogen from the raw materials- and of storing it in sufficient quantities to do the job. The easiest materials to make hydrogen from (i.e. natural gas) are also the most expensive, because they're already FUELS, rather than mere synthetic energy carriers like hydrogen. Water is relatively easy to make energy from in technical terms, but it's a very energy-intensive process. It takes electricity (i.e. high grade energy, essentially "work-on-tap&quot, and a lot of it, to make hydrogen from water via electrolysis. The overall energy efficiency in terms of watts of energy equivalent hydrogen in the tank per watt of electricity into the electrolyzer, is nowhere near 80%- it's closer to 60%- and then you need the work of compression, which is not negligible or trival at reasonable storage densities for hydrogen. A figure of 80% for electrolysis energy efficiency takes into account the energy in the (useless) oxygen which you can get for free from the air if all you're doing is running an internal combustion engine- it would never pay to carry compressed feed oxygen around with you in a tank, unless your boat's a submarine...

You want a cheaper fossil fuel? Switch to diesel from gasoline. Not cheap enough? Rip the IC engines out, replace with a steam engine and run it with coal...Want to do the environment a favour? Dry-dock your boat...

 

[RHuizing]

Sparky...

These sites might be of some interest to you. A Hydrogen powered speedboat would likely be out of the question, but sailboats may someday afford a niche market for fuel cells/hydrogen power. I thought of this awhile back to find someone is already well on top of the idea.

http://www.landfallnavigation.com/fuelcells.html

http://www.haveblue.com/

 

[macroscopic]

FYI:

Iceland is converting their entire infrastructure to hydrogen, first their buses, then passenger vehicles, then FISHING FLEET. This is an internationally funded project, with money coming from the EU in order to advance the technology and bring hydrogen to the masses.

They are using geothermal and hydropower to electrolyse water to make the H2. So you are no the only one who wants a hydrogen powered boat. As for storing on the boat, hydrogen is energy dense on a mass basis, but volumetrically not so good, even as a cryogenic liquid, which is a bit of a hassle.

As for the "cost" of hydrogen vs. fossil fuels, the era of being able to use fossil fuels at the low costs people (particularly americans) have become accustomed to is coming to a quick end. All you need to do is look at the price of oil today and it becomes clear that renewables are not more expensive in the long run. Especially if you factor in external costs like health care, climate change etc.

Today, wind power is competitive even with coal.

For some inspiration, check out the "solar sailor" a solar/wind power boat, in sydney, australia. Not hydrogen powered, but a nice ship.

 

[jsummerfield]

The hydrogen idea is not bad if power is available at the marina. Perhaps 6 hp is more rational than 600. I wonder if wind power can be harnessed on a boat.

Texas Tango, Catalina 25, Galveston Bay

John

 

[macroscopic]

Can wind power be harnessed on a boat?

Ever heard of a sail boat?

Ok, just joking, but seriously...there are probably thousands of small wind turbines in use on boats. For example, the AirX is a 400 watt (peak) model that is relatively quiet and well designed..

http://www.e-marine-inc.com/products/wind_generators/airxmarine.html

this is not the cheapest source..my brother just bought one for about 450 US Dollars. forget where.

john (macroscopic.org)

 

[HydroScope]

400 watts??? check this out . . .

http://foxxaero.homestead.com/files/t36w01.jpg

this sytem is direct drive to the propellors but could easily be made to drive an electrolysis system ;o)

if you had this producing hydrogen, their is no reason why you couldn't have a 600+ HP ICE running on hydrogen. ;o)

let your imagination go!! this boat could servie as ur petrol station for jet ski's and ski boats, hmmm I really really want one. Now just have to spend the next 20 years saving for such a set up :O(

 

[macroscopic]

re:

http://foxxaero.homestead.com/files/t36w01.jpg

HAH HAH!!

oh man..

that has to be a joke...

is that photoshop?

"drop the anchor!! oops.. he dropped his head"

please tell me that's a joke...

oh my god, it's not a joke...

I'm saving that picture...

 

[HydroScope]

I certainly don't think it is a joke, I like it, well not in it's current form, for me to like it you can forget about the direct drive to propellor, electrolys hydrogen and allow the turbine to be brought down when the yaht is under power, then it would make a sweet cruise mobile for the witsundays, never pulling in fuel ;o), here is a better link . . . .

http://foxxaero.homestead.com/indrad_007.html

 

[macroscopic]

I just think it is extremely unelegant design...

My intuition says there is no chance that boat can ever compete with a regular sailboat, either in seaworthiness, speed, safety...

(i mean, my god, can you imagine trying to walk around on the deck of that boat in serious wind conditions?)

unless it is an optical illusion, it looks like you can't walk around on deck while the blade is spinning. Maybe it can compete with a regular sailboat going straight into the wind, which a sailboat can't do..

I don't want to offen anyone.. i mean, hey, they laughed at galileo at first, maybe this is something that just needs to be accepted.. but it just doesn't make sense..if you put the rotor high enough so people can walk on the boat, it will be top heavy. the sail on a sailboat ADDS stability..

i guess it was worth doing just to see if it made sense.. and if you were electrolyzing water with that turbine and then putting it in a fuel cell.. well.. maybe.. maybe..

 

[HydroScope]

I think you are right on the safety issue . . . definetly need them blades way above your head, not sure how sail adds stability to a boat??