Hydrogen Power

[BrilliantBeast]

I am a newbie so go easy on me.

Looking at Bob Park's What's New for last Friday, he discusses the efficiency fallacy of hydrogen fuel, i.e. the energy required to make hydrogen fuel is greater than energy provided.

He uses an analogy of "You can buy an apple for one euro. If you really want an apple, you might pay five euros. You could even pay a thousand euros, but you would never pay two apples."

I think this ignores the value of having a clean, consistant source of energy for vehicles. You may trade 2 apples for 1 apple if that 1 apple has a much longer shelf life, for instance.

If I put on my tie-dyed T shirt and sandals, I could say that using deriving hydrogen from an abundant non mobile resource, say wind powered electricity, definately adds value to the fuel. OK, it is not realistic in the short term that all hydrogen would be generated by this process or even nuclear power.

The most likely source is derived from petroleum, a polluting process. But, what this does do is centralize the problem of controlling emissions. If vehicles burn a clean fuel, it does not need equiptment for emission control. This allows vehicles to be less complex and removes requirements of mobile emission control, weight, size, aesthetics. Several large refineries are easier to inspect, regulate and upgrade than 100 million vehicles. Fuel could be generated at times of lower ozone risk.

I don't have the data to say whether deriving hydrogen is from petroleum is economical, but I don't by the efficiency loss argument.

 

[clusterm2]

So who would want to live near one of these petroleum driven hydrogen creators?... Not bleeding me

 

[hgc]

So who would want to live near one of these petroleum driven hydrogen creators?... Not bleeding me

What's needed is a really, really tall smoke stack -- say 200 miles?

 

[BrilliantBeast]

So who would want to live near one of these petroleum driven hydrogen creators?... Not bleeding me

That's not my point at all or Bob's point. Bob's point is that it is a scam because it takes more energy to make hydrogen fuel than you can get out of the fuel.

Let's assume that you can make this process as clean as your regular oil burning power plant. It has no relevance to the original point.

 

[garys_2k]

Here, please let me try...

I am a newbie so go easy on me.

Looking at Bob Park's What's New for last Friday, he discusses the efficiency fallacy of hydrogen fuel, i.e. the energy required to make hydrogen fuel is greater than energy provided.

He uses an analogy of "You can buy an apple for one euro. If you really want an apple, you might pay five euros. You could even pay a thousand euros, but you would never pay two apples."

I think this ignores the value of having a clean, consistant source of energy for vehicles. You may trade 2 apples for 1 apple if that 1 apple has a much longer shelf life, for instance.

But you traded two "dirty" apples for that clean one. IOW, you had to burn more dirty fuel just to obtain a given amount of hydrogen. Hydrogen is a so-so energy TRANSFER device, that's all. It is not an energy source. Think of it as a chemical battery that can only be charged with another primary fuel.

If I put on my tie-dyed T shirt and sandals, I could say that using deriving hydrogen from an abundant non mobile resource, say wind powered electricity, definately adds value to the fuel. OK, it is not realistic in the short term that all hydrogen would be generated by this process or even nuclear power.

Even your windmill is an energy loser. How much energy went into making that windmill to begin with? Photovoltaic is even worse. But all of that completely ignores the most important consideration, economics.

The cheapest (best, most efficient, least likely to cause poverty, least likely to cause a recession, etc) way to "make" hydrogen is reforming fossil fuel. That leaves carbon. Perhaps making all that carbon at one place is better than doing it in lots of little mobile places (as vehicle fuel), but you still have to add in the primary energy costs of building that infrastructure. How much CO2 is created digging those pipeline ditches, making that pipeline steel, building those distribution terminals, etc? Those all count.

The most likely source is derived from petroleum, a polluting process. But, what this does do is centralize the problem of controlling emissions. If vehicles burn a clean fuel, it does not need equiptment for emission control. This allows vehicles to be less complex and removes requirements of mobile emission control, weight, size, aesthetics. Several large refineries are easier to inspect, regulate and upgrade than 100 million vehicles. Fuel could be generated at times of lower ozone risk.

New automobiles are actually pretty efficient right now. In fact, you can no longer commit suicide by locking yourself in the garage with the engine running anymore, not enough CO is produced to do more than give you a good headache. But again, the real costs, the actual fuel CONVERSION efficiency, will be lower if you move the combustion farther from the point of use (the vehicle's engine). Reforming the hydrocarbon has inefficiencies, shipping and storage add inefficiencies, and the final combustion in the vehcile is still just as inefficient. The net-net of all this is that MORE petroleum will be "burned" to get the same amount of BTUs on the road.

I don't have the data to say whether deriving hydrogen is from petroleum is economical, but I don't by the efficiency loss argument.

You don't have to buy it, just acknowledge that no pumping, storage, pipeline friction or leakage rates are realistically ignored. These all add to the losses of energy ultimately paid by the use of more petroleum fuel.

 

[arcticpenguin]

Hydrogen should not be considered as a source of energy, since it must be generated in one way or another. Instead it is a form of energy, and should probably be compared to electrical batteries in that sense.

Yes, there might be some benefit to not having every car burning fossil fuel.

On the other hand, there are recent claims that hydrogen which escapes from the process may be bad for the ozone layer. The time scale of ozone layer damage is decades or centuries, not the time of day.

Finally, if Americans had any interest in driving smaller, mor eefficient cars, they could do it today.

 

[jj]

Guys, the point about there being substantial losses in making H2 from water or hydrocarbons is quite true. No doubt about it, so let's use nuclear power and direct heat catalysis. It's been done small-scale, I believe, already...

That way, no carbon remains, only waste heat. With sensible (i.e. reprocess it, don't bury it) use of the nuclear "waste", ((*&&(* all folks, it's not WASTE, its FUEL!!!) we gain quite a bit of efficiency over present plants and cut way down on the total generated waste as well.

BUT...

Burning H2 in a fuel cell is not, I think, a bad thing, and unless they've gotten worse, fuel cells are more efficient than most anything else.

In fact, last time I did the math, IF (big if) we had home fuel cells, we could get both power and heat (for water, home) quite a bit more efficiently by using them on natural gas, and taking the 50% hit from the CO2 heat loss by using that in cogeneration.

And we'd lessen the need for infrastructure by one set of wires.

 

[TillEulenspiegel]

First of all the type of fuel cell we're talking about does not run on hydrogen, it runs on water. The seperation of the constituant molocules is processed INTERNALLY by the cell.The fuel cell generates electricity and water vapor and heat.The newest flavor is the regenerative cell...no moving parts efficiencies soaring from 50 to 80% i( I.C. engins never break %30 )f you can capture the heat component .The efficiency of fuel cells is staggering if you compare them to I.C. or waste powered turbines. Done the research . The cost now is past the break even point. I remember when digital watches first came out...$1,000 a pop, they are now a give away in cereal boxes. I usta bitch about having to take economics because I was getting my E.E. , well guess the reason was to demonstrate economies of scale. The price, once there is enough demand will not only equal the B-E point but will make the process profitable. Add the almost unlimited source of hydrogen ( most available element in the universe.) and You have a good marriage of technology, conservation and energy policy. I would also mention that I'm not sure the powers that be will allow a renewable, clean, almost free, ( except for the initial investment and membrane replacement ) energy source. Do the reaserch see for yourselves.

 

[arcticpenguin]

First of all the type of fuel cell we're talking about does not run on hydrogen, it runs on water. The seperation of the constituant molocules is processed INTERNALLY by the cell.The fuel cell generates electricity and water vapor and heat.The newest flavor is the regenerative cell...no moving parts efficiencies soaring from 50 to 80% i( I.C. engins never break %30 )f you can capture the heat component .The efficiency of fuel cells is staggering if you compare them to I.C. or waste powered turbines. Done the research . The cost now is past the break even point. I remember when digital watches first came out...$1,000 a pop, they are now a give away in cereal boxes. I usta bitch about having to take economics because I was getting my E.E. , well guess the reason was to demonstrate economies of scale. The price, once there is enough demand will not only equal the B-E point but will make the process profitable. Add the almost unlimited source of hydrogen ( most available element in the universe.) and You have a good marriage of technology, conservation and energy policy. I would also mention that I'm not sure the powers that be will allow a renewable, clean, almost free, ( except for the initial investment and membrane replacement ) energy source. Do the reaserch see for yourselves.

A fuel cell that runs on water? Woo-woo-woo.

 

[TillEulenspiegel]

I'm not sure if that was derision or what , it is not a perpetual motion machine as there are waste factors ..heat generation, consumption of both water and media... There's thousands of sites starting with : http://www.firstgov.gov/fgsearch/in...rs.gov&db=www-fed-all&st=AS&rn=6&parsed=true. Kinda wierd that the quirey line has so many filters. doncha think?

 

[toddjh]

I'm not sure if that was derision or what , it is not a perpetual motion machine as there are waste factors ..heat generation, consumption of both water and media...

If you're trying to tell us that a fuel cell can run on only water (and air, I suppose), you're either trying to pull a fast one, or you've been taken in yourself. Can you detail the supposed chemical reaction that powers the cell?

Jeremy

 

[Agammamon]

I am a newbie so go easy on me.

Looking at Bob Park's What's New for last Friday, he discusses the efficiency fallacy of hydrogen fuel, i.e. the energy required to make hydrogen fuel is greater than energy provided.

It takes more energy to create gas than you get out of it also. You have to take into consideration where that energy is coming from, and the storage/energy density needs of your supply.

Hydrogen may require more energy to make than you get out of it but;

1) that energy is not provided by you any more than the energy to make gas was
2) you can make hydrogen using energy supplies that would otherwise be inconvenient for your purposes (not having to have an acre of soloar cells strapped to the roof of your car or carrying a nuke reactor in the trunk).
3) you get efficiencies of scale in power generation. If everyone had tocreate their own hydrogen from scratch then they all have to purchase, maintain, and run production facilities. Same with petroleum. Can you imagine 10's of millions of little refineries all over the country? While this is certainly workable, the entry costs become higer than if you centralize production in a "factory" setting. You gain from efficiencies of scale, pollution control is more effective, etc.

 

[Agammamon]

Also, fuel cells don't run on water. They take a pure (as pure as possible since impurities poison the membranes pretty quickly) hydrogen and oxygen input (sometimes from cracking petrochems with a converter and running through a filter to gert the H2) and output electricity and water . It takes more electricity to crack water into H2 and O2 than you can get back, that's why you can scavenge e- in the reverse.

 

[LaserCool]

Riddle me this Batman:

Let's suppose all the infrastructural problems and storage problems of hydrogen power have been solved (I know, all you Engineers are groaning, so am I).

Let's even suppose that fuel cells are highly efficient and cheap.

Exactly where are we going to get the electricity to catalyze water into hyrdogen and oxygen, or catalyze petrochems into hydrogen?

We can't get more energy out of hydrogen production that it requires (the second law of thermodynamics holds here), so that means we have to come up with more energy to make this sparkling new fuel.

From oil buring generators perhaps?


Just thinking. Don't mind me.

 

[toddjh]

We can't get more energy out of hydrogen production that it requires (the second law of thermodynamics holds here), so that means we have to come up with more energy to make this sparkling new fuel.

From oil buring generators perhaps?

Yep. The difference, as others have pointed out, is that you can do it on a large scale and keep the pollution-creating steps in the process in a central location, where you can minimize emissions. You're sacrificing some energy to gain clean-burning fuel for vehicles.

Jeremy

 

[Ziggurat]

Hydrogen generation

There's actually another way to generate hydrogen that most people overlook, but may play a rather large role in the future: nuclear reactors. Now it's obvious that you can do electrolysis using electricity from nuclear reactors, but that's actually only part of it. Nuclear fission also produces hydrogen by itself - neutrons from fission reactions decay into protons, which of course form hydrogen. In current nuclear reactors this hydrogen is essentially a waste product, but if you had a hydrogen fuel infrastructure, it might start making sense to harvest this hydrogen, in addition to the thermal output of the nuclear reactors.

Not to say there aren't problems with the hydrogen fuel idea - the primary one being that it's mostly an excuse to let car manufacturers off the hook from having to take steps now that we DO have the technology to implement. Is anyone else embarassed that there isn't a single hybrid vehicle available from US manufacturers? Or that the tax code gives small business owners huge tax breaks for buying luxery SUV's instead of smaller cars?

 

[jj]

First of all the type of fuel cell we're talking about does not run on hydrogen, it runs on water.

Err, what is the energy input then?

Fuel cells burn O2 and H2 and make water vapor, yes, but if you're saying that they turn water into water vapor with no other energy input, you're saying something very odd.

 

[jj]

Re: Hydrogen generation

There's actually another way to generate hydrogen that most people overlook, but may play a rather large role in the future: nuclear reactors.

Now, I'm hardly arguing with you on this point, but I'd swear I already said that a few articles above yours.

 

[Jon_in_london]

Best thing to do would be to fit each car with a windmill generator to spilt the hydrogen first. But since its not practical to have one big windmill, we should have lots of little windmills all over the car- each attached to its own little electrolysis aquifer for H2 generation. Purified H2 should then be piped to a centralised storage facility in the back seat of the car before being fed into the fuel cell. Of course the only problem is that the faster the car goes, the more wind and thus more fuel being produced. It would therefore be difficult to slow the car down once it starts to accelerate and this would result in a fatal crash, however, if the ecxess hydrogen produced could be fed into a secondary storage unit, this could be discharged at collection points across the road network (a bit like a gas- station but the other way round) and fed to power plants which would replace damaging nuclear and fossil fuel burning power plants to cool/heat our homes and provide us with all our power requirements and also Im completely mad.

 

[Leif Roar]

Riddle me this Batman:

Let's suppose all the infrastructural problems and storage problems of hydrogen power have been solved (I know, all you Engineers are groaning, so am I).

We've already solved this for gasoline, so why not? (In fact, despite the problems of producing, transporting, storing and selling gasoline; we've actually created a system for the distribution of many different forms of gasoline and diesel.)

<SNIP>
Exactly where are we going to get the electricity to catalyze water into hyrdogen and oxygen, or catalyze petrochems into hydrogen?
<SNIP>
From oil buring generators perhaps?

Certainly - but mark that that's oil, and not gasoline - that is a pretty big advantage in itself. Hydrogen can also be produced by other energy sources, which means we can diversify our energy production - which is another big advantage. We also gain a lot of flexibility since we can use (practically) any energy source to drive our cars: if we had an energy crisis today, we would not be able to redirect the energy that's used for space heating or heavy industry to road transportation, or vice versa.

Secondly, while burning oil to produce hydrogen won't reduce the emissions of CO2, it might reduce the emmisions of other pollutants that's caused by burning gasoline - such as CO, sulphur dioxide, nitrogen oxides and other.

Neither fuel cells or electrically driven cars really give us "clean energy" - there's always a matter of pollution. Some forms of energy storage might be cleaner, though - and even if it can't be said to be cleaner in all regards, it might still be advantageous to use a mix of energy storage forms, to "spread the problem evenly around", so to speak.

That hydrogen fuel cells are not a silver bullet that solves all our energy and pollution problems, doesn't mean that it's no better than the status quo.

(Edited to fix the Quote tags)