Bio-Hydrogen and fuel cells

[mink]

This weekend I googled for information about fuel cells and found this site which was in German language for the most part. However, there was also an English paper (PDF-File 3,9 MB), which contains a comprehensible abstract of the site.

 

I was very impressed of what I read there. Much of this was new to me,

and I did not find anything there that sounded not logically. I highly

recommend to read the paper or the website if you understand sufficient

German.

 

The terms "Hydrogen fuel cells" and "hydrogen economy" were mentioned

in some posts in the global warming thread, but these threads read like

the misinformation spread by the oil and power industry is in most

minds, as it was in my own.

 

Karl-Heinz Tetzlaff, the owner of the site, is an retired engineer who

was working for a big German chemical company. His task was to plan

industrial installations and calculate the investment and operational

costs for them. He continued to do this after his retirement but not

targeting a company anymore but the whole economy.

 

Tetzlaff's idea is to replace electricity by hydrogen as the major

secondary energy. This could be used for heating and generation of

electrical power in homes and business as well as for transport. In

any case, fuel cells should transform the hydrogen to electrical power

and heat.

 

Energy transportation should be done by the gas tube networks which

are currently used for natural gas. 50% of German homes and nearly all

major industry plants are already connected to this network. Transport

loss of energy is much less this way compared to electricity transport

via high voltage lines.

 

For the production of the hydrogen he claims that small scale reactors

are not very economic, and this is the reason why e.g. cars that have a

built-in reactor that generates the hydrogen from some liquid fuel are

too expensive. But if the car just has a hydrogen tank, a fuel cell

and an electrical engine, it would be much cheaper both in terms of

fuel consumption and manufacturing costs.

 

An interesting aspect of his work is that he first thought the

hydrogen should be mainly produced using natural gas, oil and coal.

But when the oil price raise in the last 2 years he changed his mind

and is now proposing that it should mainly be won out of bio-mass,

simply because this is much cheaper than oil even if the farmers are

paid a very fair price for their energy crops.

 

This shows that is work is not driven by green ideology or any

ideology at all. Everywhere in his site his reasoning is based on

economical considerations, and he does not believe that in

demonstrations or good will of individuals might change anything.

 

Enjoy reading the paper.

 

Karl

[luke warm]

This shows that is work is not driven by green ideology or any ideology at all

yes, there are good and sufficient reasons for finding and using alternative power methods... i just tend to rebel when taxes are spoken of as a means to an end.. there's no need to increase taxes, but there may be a need to grant tax breaks, say for fuel cell start up companies

[pbleighton]

"An interesting aspect of his work is that he first thought the

hydrogen should be mainly produced using natural gas, oil and coal.

But when the oil price raise in the last 2 years he changed his mind

and is now proposing that it should mainly be won out of bio-mass,

simply because this is much cheaper than oil even if the farmers are

paid a very fair price for their energy crops."

 

The paper is interesting, but your paragraph above identifies the key issue with hydrogen fuel cells: They are an energy transfer mechanism, not an energy source, since it takes energy to get hydrogen.I did some systems development for a company which produces industrial fuel cells. Their cells use natural gas. The environmental benefits are huge (about one thousandth of the pollution compared with burning natural gas), but they are not an energy source. There must be energy expended to create biomass. I'm not sure I found that factored into the analysis, though I must admit I didn't read it too carefully.

 

Peter

[mink]

I did some systems development for a company which produces industrial fuel cells. Their cells use natural gas.

I looked in fuelcells.org and found:

When using a fuel other than pure hydrogen, a reformer or fuel processor is required.

This makes the system more complex, more expensiveand less efficient, and it emits CO2. When thinking of a decentralized usage of fuel cells, only hydrogen fuel allows emission-free operation. Transformation of any fuel to hydrogen is done more efficiently in a centralized hydrogen factory, where it is possible to take care of the CO2 produced and the mineral ash as a fertilizer.

 

There must be energy expended to create biomass.

This is solar energy - the fuel crops like any green plants use the sunlight, CO2 and water to build their biomass.

 

Karl

[hrothgar]

This is solar energy - the fuel crops like any green plants use the sunlight, CO2 and water to build their biomass.

Plants require an awful lot more than "just" water and sunlight to produce biomass.

 

They need nutrients and (more importantly) fertilizer. In turn, fertilizer requires ammonia and ammonia requires LOTS of energy to produce.

 

All the bio-diesel and ethanol systems fall run into precisely the same problem.

 

If you don't add fertilizer into the system you destroy your topsoil.

If you do add fertilizer, you're no longer netting much in the way of energy.

 

For what its worth, I am in favor of hydrogen based systems, however, I suspect that they're going to require nuke plants to crack water for the hydrogen.

[mink]

Well, Richard, I did not plan to go into detail about growing crops, so I mentioned only the ingredients that form most of the mass of a green plant. Of course fertilizer is needed too if you harvest crops. However, you do not need additional "nutrients" as by definition fertilizer is the one or more nutrients a plant needs in small quantities. These are just different words for essentially the same thing.

 

When growing energy crops it is not important what kind of green plant you use. If you are really concerned about the ammonia, you could grow e.g. lupins, who live in symbiosis with a bacterium called Rhizobium which is able to produce this from the Nitrogen contained in the air and make it available to the plant.

 

But even in this case you still need phosphorus and potassium and a few others. But the main point is, that the energy you need to produce the fertilizer, deploy it, seed the crops and harvest them is by magnitudes smaller than the energy you can gain from the resulting biomass. And the nice point is, that you can recycle the fertilizer used when the hydrogen is produced in the reformer.

 

If this is the better way or using nuclear plants to produce hydrogen is just a matter of belief as you put it. Mr. Tetzlaff, however, has calculated all this, and his conclusion was that nuklear power is by far more expensive in this context.

 

Karl

[helene_t]

This shows that is work is not driven by green ideology or any

ideology at all. Everywhere in his site his reasoning is based on

economical considerations, and he does not believe that in

demonstrations or good will of individuals might change anything.

Note that this hydrogen thing is about a more efficient mean for energy transportation. It's not about using less energy (at the consumer side, that is), nor is it about alternative energy sources.

(Oops sorry, just noticed that Peter said this, too)

 

Biomass is an alternative energy source, of course.

Edited July 10, 2006 by helene_t

[whereagles]

For what its worth, I am in favor of hydron based systems, however, I suspect that they're going to require nuke plants to crack water for the hydrogen.

That's the only mid-term solution I see to keep using energy at today's scale. In the long-term, a down-sizing of energy expenditure will be inevitable, UNLESS

 

a. the fusion reactor at Charadache ends up working and producing more energy than it consumes to ignite/stabilize fusion

 

b. some genious comes up with a brilliant solution

[hrothgar]

For what its worth, I am in favor of hydron based systems, however, I suspect that they're going to require nuke plants to crack water for the hydrogen.

That's the only mid-term solution I see to keep using energy at today's scale. In the long-term, a down-sizing of energy expenditure will be inevitable, UNLESS

 

a. the fusion reactor at Charadache ends up working and producing more energy than it consumes to ignite/stabilize fusion

 

b. some genious comes up with a brilliant solution

As I mentionedn in the past, the power generation systems that look most promising to be are the various types of solar thermal that folks are working on. I haven't seen any really good studies of solar thermal as a closed loop system. (Its unclear how much power is required to build a solar thermal emplacement)

 

However, several technologies coming down the pipe seem as if they might be viable in a few years time.

[mink]

Note that this hydrogen thing is about a more efficient mean for energy transportation. It's not about using less energy (at the consumer side, that is), ...

This is not true. If you take a car with an electrical engine that

gets its energy from a hydrogen fuel cell and the hydrogen was

produced from biomass, the energy that reaches the wheels is at least

80% of the Energy that was contained in the biomass originally. Just

compare this to only 14% if you take a conventional car with a

combustion engine and crude oil as the primary energy.

 

If you use the fuel cell at home and use the electrical power as well

as the heat it generates, you can have a combined efficiency of even

90%. I would call this using less energy.

 

Karl

[mink]

As I mentionedn in the past, the power generation systems that look most promising to be are the various types of solar thermal that folks are working on. I haven't seen any really good studies of solar thermal as a closed loop system. (Its unclear how much power is required to build a solar thermal emplacement)

A solar thermal power plant sounds nice, but you have to build mirrors

and collectors which are expensive and have a limited lifecycle. You

get thermal energy from this. If you like to convert this energy to

hydrogen, you are facing big losses. If you just generate electrical

power, the losses are not so big, but you cannot store the energy. And

such a facility covers a big area you have to find in the first place.

(I bet the neighbors would not like that).

 

Agricultural area that is not used for food production is available in

Europe. It would also be a good idea for some of the areas used for

food production currently to be dedicated to energy production in

order to reduce the overproduction of food in Europe. In order to use

this for energy production you have to invest nothing. Farmers could

just use the machinery they already have and start to produce biomass.

Only some central facilities for the conversion of biomass to hydrogen

need to be built. This is a much smaller investment than building

thermal power plants that yield a similar amount of energy.

 

Karl

[whereagles]

As I mentionedn in the past, the power generation systems that look most promising to be are the various types of solar thermal that folks are working on. I haven't seen any really good studies of solar thermal as a closed loop system.

You mean boiling water (or any other liquid) to make a steam engine run? Well, if so, the steam engine thermodynamic efficiency should be something like 50%. Dunno typical solar heating efficiency, though.

 

In any case, since the solar power shining on Earth is about 1 kilo-watt per square meter on a sunny day, we fall into the usual problem of renewables: scalability. You'd need a huge facility to produce a small amount of usable energy.

 

Some of it will have to be done in the long run, though.

[hrothgar]

As I mentionedn in the past, the power generation systems that look most promising to be are the various types of solar thermal that folks are working on.  I haven't seen any really good studies of solar thermal as a closed loop system.

You mean boiling water (or any other liquid) to make a steam engine run? Well, if so, the steam engine thermodynamic efficiency should be something like 50%. Dunno typical solar heating efficiency, though.

 

In any case, since the solar power shining on Earth is about 1 kilo-watt per square meter on a sunny day, we fall into the usual problem of renewables: scalability. You'd need a huge facility to produce a small amount of usable energy.

 

Some of it will have to be done in the long run, though.

The following URL provides a good introduction to different solar thermal technologies.

http://www.volker-quaschning.de/articles/f...s2/index_e.html

 

I've always been most interested in the so-called "solar chimneys" and dish-stirling systems.

 

You're completely correct when you note that these systems require large amounts of land. Then again, there's a lot of desert out there...

[whereagles]

these systems require large amounts of land.  Then again, there's a lot of desert out there...

yeah.. not that many mirrors/panels to cover it, though.

 

thx for the link. ill have a look at it later.

[mink]

This could also be in the gas prices thread:

 

Mr. Tetzlaff predicts if we started with the hydrogen economy right

now that a fuel cell car in 2015 would need 0.26 kg hydrogen per 100

km, which can be compared to 1 liter / 100 km. Expenses for that will

be 0.42 Euro / 100 km - including German VAT but no other taxes. There

should be no other taxes if the hydrogen is produced from biomass, as

there is no fuel tax on bio-fuels today.

 

The car for which this is calculated is comparable to todays

middle-class cars with a top speed of 260 km/h. With a 100 liter tank

of compressed hydrogen the operating range would be 1500 km.

 

Needless to say that such a car would also be cheaper when you buy it,

as a combustion engine and all additional aggregates needed (e.g.

generator for electrical power) is much more complex than an fuel cell

combined with a electrical engine.

 

This information is taken from

http://www.bio-wasserstoff.de/h2/Brennstof...obil/mobil.html and

just translated.

 

Karl

 

edited - corrected typing mistake in the Euro/km figure given

[helene_t]

Hybrid cars polute less than conventional cars and they're available. Fast-breading nuclear reactors are available. Windmills are available. Fuel cells and hydrogen are nice science fiction dreams. What about magnetic cars that run inside vacuum tunnels? The energy expenditures could be zero, in theory.

 

I don't understand all this attention to fuel cells and hydrogen. I have a vague "conspiracy theory" that it's about diverding attention from the real issue of reducing the distances we drive, and driving smaller cars.

 

A brain-storm about cool futuristic technology that might some day become avaliable, is fine of course. But if carbon dioxide emmision and/or depletion of fosil fuels are real problems (I have no clue if they are, but assuming they are) then I think realistic solutions deserve some attention.

[whereagles]

mink: mr. Tetzlaff's calculation of 0,26€/100 km cannot be right. Right now energy is STILL just about as cheap as water because oil is very cheap and very energetic.

 

Given we are quite tight in oil production and there's no expectancy of it relieving (quite the opposite, actually), energy prices will inevitable rise quite a lot and that will have an impact on hydrogen as well.

 

In other words, if you buy hydrogen at 0,26€/100 km, everybody will rush out to do the same and price will increase to the same as oil price.

[whereagles]

1. Fast-breading nuclear reactors are available. Windmills are available.

 

2. Fuel cells and hydrogen are nice science fiction dreams.

 

3. What about magnetic cars that run inside vacuum tunnels? The energy expenditures could be zero, in theory.

 

4. I don't understand all this attention to fuel cells and hydrogen. I have a vague "conspiracy theory" that it's about diverging attention from the real issue of reducing the distances we drive, and driving smaller cars.

 

5. But if carbon dioxide emmision and/or depletion of fosil fuels are real problems (I have no clue if they are,

 

6. but assuming they are) then I think realistic solutions deserve some attention.

1. Fast breeders have faced technical difficulties that prevented them to operate as intended in theory. Whether or not these can be solved is unknown. Economics tells us that it is only when uranium starts to deplete that scientists will address that problem. By the way, if those difficulties are solved and uranium extraction from sea water is made real, we're looking at a potential 100 000+ years of energy consumption at present rates. If you can put up with a nuclear plant every city, of course.

 

2. Well, they're feasible. Just not yet scalable to mass production.

 

3. Unfeasible. Trains, maybe. Cars, no way. It's just not practical.

 

4. I think this is because people are getting desperate about fuel prices. There are alternatives to hydrogen out there that are perhaps easier to install, like, for instance methanol. You can use electricity to synthetise methanol from water and CO2 (at around 60% efficiency), and methanol can use today's distribution infrastructures.

 

5. They are. A scientist at a recent conference pretty much summed it up when he said: "The only thing worse than running out of oil is not running out of oil!"

 

6. Unfortunately, they'll only be implemented when oil reaches $250-300 a barrel. Below that, it will be cheaper to just keep using oil.

[Gerben42]

6. Unfortunately, they'll only be implemented when oil reaches $250-300 a barrel. Below that, it will be cheaper to just keep using oil.

 

There is always the option of driving smaller, more energy-saving cars. It appears in this aspect Europe is way ahead of the USA (probably not technologically but state-of-mind, big cars are "in" in the US)

[whereagles]

6. Unfortunately, they'll only be implemented when oil reaches $250-300 a barrel. Below that, it will be cheaper to just keep using oil.

 

There is always the option of driving smaller, more energy-saving cars. It appears in this aspect Europe is way ahead of the USA (probably not technologically but state-of-mind, big cars are "in" in the US)

That's due to high taxation in Europe. Smaller, more efficient, cars help but they keep burning fuel anyway, so it won't solve the problem in the long run.

 

However, I do believe a mix of things like

 

- serious use of renewable energies

- strong government control on urbanization

- improvement of mass transist systems

- increase of efficiency of engines and buildings

 

might prevent the death of the automobile.

[mink]

Hybrid cars polute less than conventional cars and they're available.

They do pollute less because they need less fuel because they do not

waste fuel. Of course this is true only if the car is travelling in

urban areas where much stop and go occurs. When travelling on the

highway, a hybrid car has no advantage at all. This is probably the

reason why I have never heard about hybrid trucks - trucks relatively

seldom drive into the middle of the city.

 

Fuel cells and hydrogen are nice science fiction dreams.

This is the essential misconception. Production of syngas from coal

started already in the 19th century. It was first used for street

illumination, and became available to homes for heating and cooking in

the early 20th century. The hydrogen portion in the gas was 50%. What

needs to be done in order to get pure hydrogen is just separate it,

which is no problem with todays technology. This means, it is easy and

efficient to produce hydrogen from biomass or any other hydrocarbon

material. The technology is available.

 

Fuel cells are available as well. If you plan to operate them with

hydrogen you need a most simple device with no moving parts inside,

which could be produced very cheaply if high quantities were demanded.

 

A network for the transportation of hydrogen from the biomass

converters to homes and business is available, too: I was first used

for the syngas, today it is used for natural gas, and can be easily

used for hydrogen in future.

 

This concept is unique because prevents pollution, saves very

significant amounts of money and eliminates the dependency from the big

energy multies and oil producing countries.

 

The only problem is that you cannot start to produce hydrogen if

nobody has fuel cells and there is no point in buying a fuel cell if

hydrogen is not available. Therefore, the society would have to decide

to restructure the energy distribution by converting from electrical

current to hydrogen. This is not easy of course as both oil industry

and the providers of electrical energy would lose their whole business

if this succeeds. But the advantages are so great that I think it is

worth a try. This is why I started this thread: to promote the idea.

It can only become true if at least many people know about it.

 

Karl

[mink]

mink: mr. Tetzlaff's calculation of 0,26€/100 km cannot be right. Right now energy is STILL just about as cheap as water because oil is very cheap and very energetic.

You are right in one respect: 0.26 Euro/100km was incorrect, I made a

mistake when copying the figure. The correct value is 0.42Euro/100km.

 

I did not have the time yet to verify all of Mr. Tetzlaff's

calculations. However, my impression is that his work is well-though

and the presentation is flawless. I have already asked him a similar

question by email and was satisfied by his response.

 

Your idea, however, to compare prices of energy and water, does not

sound serious, as energy is measured in kWh and Water in m3. It makes

no sense to say 1 kWh Energy can be compared with 1 m3 water and then

compare the prices for both. But what we could do is compare the fuel

costs for hydrogen out of biomass with the fuel costs of gasoline out

of crude oil. A year ago the German gasoline price was 1.20

Euro/liter. Without taxes this is 0.36 Euro/liter. Density of gasoline

is about 0.72 kg/l, so we have exactly 0.50 Euro/kg. Energy density

for gasoline is 12 kWh/kg, so we have 0.042 Euro/kWh. Mr. Tetzlaff has

calculated 0.041 Euro/kWh for hydrogen as it would be available at the

filling station. So you could say it is the same price. What makes the

difference is the fuel cell. The efficiency of the system fuel cell -

electrical engine - wheel is 80 % at least, while the efficiency of a

gasoline car is only 14%. This means, if you calculate the energy

price for the energy that arrives at the wheels of the car, you get

3.00 Euro/kWh for the gasoline car but only 0.51 Euro/kWh for the

hydrogen car. This is roughly factor 6.

 

Given we are quite tight in oil production and there's no expectancy

of it relieving (quite the opposite, actually), energy prices will

inevitable rise quite a lot and that will have an impact on hydrogen

as well.

 

In other words, if you buy hydrogen at 0,26€/100 km, everybody will

rush out to do the same and price will increase to the same as oil

price.

This of course is only true if you do not have enough bio-hydrogen for

all. Mr. Tetzlaff claims at least in Europe it would be no problem for

the farmers to meet the demand. (He has presented his concept at

farmer meetings already.) However, if this was really the problem, you

could generate hydrogen from natural gas or crude oil and still enjoy

the cost benefits of a hydrogen car.

 

On the other hand, when you really have enough hydrogen in a developed

bio-hydrogen economy, then it will be impossible to sell oil anymore.

 

Karl

[whereagles]

Well, even factoring that hydrogen engines are more efficient than motor engines, I am very, very skeptical that farmers can produce the amounts of hydrogen necessary to keep energy usage at current levels. I'd say they'd be lucky if they could produce 2 or 3%.

[mink]

I have every trust in Mr. Tetzlaffs word that they can, and even would

like to. What helps in this respect is that you do not need to wait

until the crops are mature, but you can harvest them after the initial

growth is completed, which also requires less fertilizer. This way you

can gain several harvest per year even in Europe. Selecting the right

crops further optimizes this, and different crops should be grown in

order to make efficient use of the soil.

 

Karl

[Blofeld]

A back of the envelope calculation (should be correct to within an order of magnitude or so) suggests that if getting energy out of sunlight is ~1% efficient then we'd need to devote about 5% of the earth's landmass to cover the world's total energy usage.

 

The 1% I used for efficiency may well be too high a figure.