Future Energy Sources 3.1.2 Hydrogen & Hydrides

If you "store" the hydrogen as methane then the it's 3 kg carbon 1 kg hydrogen. And there is an existing infrastructure to handle natural gas. If the carbon is from biomass, then it's not a problem. If it's from the ground, keep in mind that the "perfect is the enemy of the good" as well as being the enemy of the optimized use of resources.

See http://www.pnas.org/cgi/reprint/0609921104v1.pdf for hydrogen storage in a Fischer-Tropsch produced diesel fuel.

Hi N&P,

You have brought up some good points. Even if we used fossil fuels as the base product for methane production it would reduce the amount of CO₂ that is being released into the atmosphere considerably. The use of methane CH4 would also remove a whole raft of nasty chemicals that are commonly found in gasoline like benzene, naphthalene, toluene etcetera that are both nasty in their own right but also create products of combustion that are equally as nasty.

While methane is not a perfect solution it's a darn side better that what we are doing now and would more than likely reduce the damage we are doing to the environment to a level that did not produce the sort of climate changes that we are starting to see.

The use of metal hydrides for hydrogen storage has been long known and studied. The links you provided do an outstanding job discussing this. But one of the problems you touched upon slightly is the 'weight penalty' one would pay for using metal hydrides for hydrogen storage in vehicles. For storing hydrogen in static locations, such as for use in the home, the 'weight penalty' is of little concern other that providing sufficient foundation support. However, in the long run, metal hydrides are not the best choice for hydrogen storage. Ih the field of nanotechnology, research is progressing rapidly for use of nanotubes for hydrogen storage with success in storing large quantities of the gas safely and without the serious 'weight penalty'.

In addition, many techniques for onsite-on demand production of hydrogen from water and bio-mass have been developed which makes the storage of hydrogen mute. For example, the tubular solid oxide fuel cell will reform most any bio-fuel within itself to extract and 'burn' the hydrogen (and carbon) at about a 50% efficiency, with an exhaust temperature of 500 to 800 degrees C. The heat from the exhaust can be then be captured and used to increase the efficiency to about 90%. As a follow-up, the water condensed from the exhaust is pure (distilled quality) and the carbon dioxide can be sequestered by one of several existing methods in use or being further developed today.

As for storage of hydrogen safely, let us consider that despite the Hindenburg, hydrogen gas is inherently safer that natural gas in our gas utility distribution network. Of course, do to its smaller atomic diameter, it can escape through a much smaller hole than can Methane but in doing so, is far less dangerous than is methane. Methane is heavier, actually the same atomic weight as oxygen (slightly heavier than air) and tends to settle in pockets in a highly explosive mixture while hydrogen tends to rapidly disperse rapidly upwardly mixing and unite with oxygen to form water without a flame or explosion. Our concern with the dangers of hydrogen storage are somewhat exaggerated and unfounded except when we try to store it at high pressure or in liquid form. However, oxygen, under the same conditions, is far more dangerous and we have a great deal of experience with storing 100% oxygen under high pressure or as a liquid.

I would suggest that we are barking up the wrong (and dead) tree when we concern ourselves with storying hydrogen with metal hydrides except for very special circumstances. There is some work being done, however, with using Aluminum for on site hydrogen production. Aluminum's affinity for oxygen makes it ideal for reacting with water to release hydrogen.

Methane has a MW of 16. O2 has a MW of 32 and N2 is 28.

Methane is lighter than air, and will rise. Granted, I would agree that H2 would disperse quicker.

Tad

tad, methane does collect in low places, so let us consider that it is not o2 or n2, but rather o and n. We, here in Texas, are pledged with gas leaks and explosions far too often from our natural gas pipelines as we ship the product north.

chtank,

I can't deny your experience, and I am sure that natural gas collects in places.

However, oxygen and nitrogen only exist as O2 and N2 (at normal temperatures and pressures). Methane is lighter than air. If you look up the gas density, you will see that methane is roughly half as dense as air.

This is not just theory. Take natural gas and bubble it through soapy water. The bubbles rise. However, I'm not sure if methane would be light enough to lift a balloon.

I used to do this as a kid, and light the bubbles with a candle. Great fun, but makes for an unhappy mother!

Tad

"In addition, many techniques for onsite-on demand production of hydrogen from water and bio-mass have been developed which makes the storage of hydrogen mute. For example, the tubular solid oxide fuel cell will reform most any bio-fuel within itself to extract and 'burn' the hydrogen (and carbon) at about a 50% efficiency, with an exhaust temperature of 500 to 800 degrees C."

Where is the energy that is consumed it the production of the H₂ coming form?

"methane does collect in low places, so let us consider that it is not o2 or n2, but rather o and n."

I'm sorry, but I must disagree with you and agree with Tad that oxygen and nitrogen in the atmosphere are always found as O₂ and N₂. When you allow for a roughly 80% nitrogen content the molar weight of air is

20% x 2 x 15.9994 + 80% x 2 x 14.0067 = 28.9105

While methane is

4 x 1.00794 + 12.0107 = 16.1388

Which means that methane is considerably less dense than air. If you look at the actual densities them methane at Standard Temperature and Pressure has a density of 0.717 Kg m^-3 while air is around 1.2 Kg m^-3 which is pretty much in agreement with the figures above.

So, there is no way methane at the same temperature and pressure is as dense as air and I would suggest that when you have had it collect in depressions or low area either it is considerably colder than air or not pure methane and it is something else that is collecting in the depressions.

All the brilliant technology in the world does not change the fact that
Hydrogen costs more energy to produce than you get back.

I'm sure that someone, sometime, will find a use for all the bells and whistles,
but as an over all energy initiatve or a carbon reduction means,
it is a waste of resources, (time & attention), better spent elsewhere..

At the present time, Hydrogen cost LESS if it is obtained correctly. When natural gas, propane, alcohol, or other bio-fuels are used used, piped directly into t fuel cell where it is, by nature, reformed directly inside the fuel cell at no additional costs. At 50% efficiency, the fuel cell's output is far better than the 35% or so best efficiency of any other heat engine used directly or to drive an electric generator. In addition, if the exhaust heat is harnessed from the fuel cell, the efficiency goes to 90% or better. I dare say that with this schema, hydrogen cost far less than with any of our current means of useful energy. It is clear we must do something soon, and by converting to the hydrogen economy in this manner, it does give our traditional fossil fuel colleagues the opportunity to adjust without wrecking their financial status. It is only those who continue to resist that may see a downturn in time. The change over will happen.

chtank:

Could you please explain "At the present time, Hydrogen cost LESS if it is obtained correctly. When natural gas, propane, alcohol, or other bio-fuels are used used, piped directly into t fuel cell where it is, by nature, reformed directly inside the fuel cell at no additional costs."? Are these bio-fuels pumped into your fuel tank and directly into the fuel cell for conversion to electricity?

DickL

Let me let you take a look at some things I have found in my research, it will explain it the best::

http://www.acumentrics.com/products-power-generators.htm

http://www.powergeneration.siemens.com/en/fuelcells

http://www.distributed-energy.com/hydrogen_generation/markets_apps/renewable_energy.html.

And finally, please read through an article I am working on at the present time:

http://freepages.genealogy.rootsweb.com/~chtank/homepower.html.

I, also, discuss this and provide some very useful links for engineers in my blog:

http://chtank.blogspot.com/.

If you are interested, please stay in touch, you may e-mail me.

Very interesting factoid! - But considering the hydrogen only is meaningless.

If you base the efficiency rating of your use of the fuel on the hydrogen alone,
what happens to the energy that is available from the carbon in the fuel?
(In methane, I believe it is about 50%). Is it recovered or lost?

Read some of my earlier posts on this list. The reform involves steam, you get six hydrogens and one carbon monoxide from the complete reform reaction. The fuel cell burn, then produces electric power wsith three H20 and one carbon dioxide.This, of course, still produces some CO2 but far less than is produce by burning methane in oxygen alone, which is two h20 and one CO2. And the efficiency, as I said before, is 50% without using the heat recovery, and 90% with heat recovery. Again, the efficiency alone would reduce the carbon emissions by a factor of 2 to 4 over conventional means. And, if we were to "enrich" the natural gas stream with hydrogen produced by a hydrogen generator, i.e., like the one in the post before this one, even more carbon dioxide reduction would result. It is my understanding that a 5 KW tubular fuel cell will be on the market teh fouth quarter of this year. My guess is that it will sell for turnkey somewhere between $2,000 and $5,000, but the selling price is only my hunch. Also, Siemens has a tubular solid oxide fuel cell about ready for the market place, too. Since this site is for and about engineering, it does behoove us to be prepared to at least offer this to our clients.

Chemistry goes over my head but you may find this interesting.

The most promising alternative to gaseous and liquid storage is solid hydride storage, in which hydrogen is stored as a solid within the structure of a metal alloy. The hydrogen can then be transported as a solid, and released as a gas for use in a fuel cell or other device.

Hydrexia is commercialising a solid hydrogen storage system based on a novel magnesium alloy developed at the University of Queensland. The storage system carries a much lower risk of explosive hydrogen release in the event of a tank rupture, and can store more than four times as much as gaseous storage. Most importantly, Hydrexia's technology is based on low cost casting processes, allowing it to produce a solid hydrogen storage medium at one-fifth the cost of competing products.

More info: hydrexia.com.au

Hi jdretired,

Thanks for the link. I have been doing some calculations on the sort of weigh penalty that is involved with using Hydrexia's cast magnesium alloy hydride system. Given the following data from Wikipedia and Hydrexia's web site:

• H Atomic Weight = 1.00794
• H₂ Energy Content = 286 kJ mol^-1
• H² Storage Weight ratio = 7%

We can now calculate the energy to mass ratio of H₂ as follows:

286 kJ mol^-1 ÷ (2 x 0.001794) = 79.888 MJ kg^-1

Now given thy Hydrexia's system has a 7% hydrogen to total mass ratio of

79.888 MJ kg^-1 x 7% = 5.592 MJ kg^-1

If we now look at the possible applications where this could be used and the amount of fuel normally stored:

1. Motor Cars: Most motor cars will store around 50 L of fuel so given gasoline contains about 44.4 MJ kg^-1 and the density of gasoline is 737 gL^-1 giving a mass of 37 kg and energy capacity of 1,636 MJ. An equivalent metal hydride storage system would be around 232 kg. Adding an extra 200 kg to the weight of a motor car is going to seriously reduce its overall fuel efficiency, handling characteristics and carrying capacity. While it is possible and comparable to the mass of batteries in electric vehicles.
2. Trucks: Long haul vehicles can carry up to about 400 L of diesel fuel which has a density of 850 gL^-1 which give us a mass of 340 kg. With an energy content of 34.9 MJL^-1 the total energy capacity is 11,866 MJ. An equivalent metal hydride system would have a mass of 2,122 kg. While adding over 2 tones to the mass of the prime mover would impact the overall economy and reduce the load that could be carried it is not completely out of the question.
3. Railway Locomotives: The capacity varies dramatically but recent designs can carry up to 6,400 L of diesel fuel which has a mass of about 5,440 kg and energy capacity of 190,000 MJ. A metal hydride system would have a mass of 38,327 kg. This seems to be high but when compared to the overall mass of a train it is negligible so using metal hydrides in locomotives if probably the most practical use of metal hydrides. However, there may be a problem trying to fit a hydride storage tank in a locomotive but there is no reason that the fuel could not be carried in a separate carriage.
4. Ships: If we look at the worlds larges container ship the Emma Mærsk which has a fuel storage of about 600,000 L with a mass of 510,000 kg and energy capacity of 17,800,000 MJ. This would require a metal hydride storage system with a mass of around 3,183,000 kg. While this seems a considerable amount it is less than 2% of the total weight of the ship when it is fully laden so in this case it would more than likely be viable. The only thing that could be of serious concern is what would happen if the metal hydride were exposed to sea water. Many hydride will release all the hydrogen explosively when exposed to water and this could result in a explosion that released about 10% of the Hiroshima bomb. That could be a serious problem if the ship were ever to founder.
5. Aircraft: If we look at the Boeing 747-400ER which has a capacity of around 241,140 Liters of jet fuel that weighs around 190,000 kg and energy capacity of 8,322,000 MJ. An equivalent metal hydride would come in at around 1,353,000 kg which is over three times the 412,775 kg maximum take off weight. The single most factor in aircraft design is mass and adding over a thousand tones of dead weight to an aircraft has about as much chance of getting off the ground as Adolf Hitler and Joseph Stalin have of receiving a joint posthumous Nobel peace prize.

While metal hydride hydrogen storage does show potential it is not a solution that suits every application and has some fairly serious limitations.

Hello jd

Only now I came across your interesting comments. Just one small point I would like to clarify which is the energy content of Diesel fuel as mentioned under the heading of "Trucks".

You state 34.9 MJ/kg for Diesel while gasoline you list as 44.4 MJ/kg.

I always thought that diesel and gasoline were very close, both near 43 to 44 MJ/kg.

Since Diesel weighs more (I agree with your numbers) there is more energy content in diesel fuel when measured per volume, roughly 10% more.

In general you are almost too precise I find. But that is not a critic.

Regards

G'day Floram,

I am glad that you managed to find this thread even though it is nearly two years since I started it. I hoped that by leaving it online even though inactive would allow others who were not CR4 participants at the time of writing to find it in the future.

You may also be interested in the various other technologies that were discussed as part of the "Possible Technologies for the Future of Energy Production" series. While most of the threads have been dormant for some time they are all still active and any participants will be notified of new posts. The easiest way to get to the threads is via the Masu on Machines Table of Contents page where you will find the title and links to all the threads in the series.

If you can think of any technologies that have not already been covered I would be interested in any information and links you have so that I can start a thread on it. You can send me a personal message by following the link to the CR4 PM system.

Regards, masu

Hello Masu,

Thanks for the reply. I know it is a long time ago when this was discussed here. But it is still a forefront topic.

I just glanced at some of these comments. Well, I just saw another link in which the author clearly states that H2 is not an automotive fuel. Thanks goodness, finally someone is waking up.

Can't wait for the day when it will be generally accepted that CO2 is not the prime reason for climate change and is actually a good natural substance that gets recycled continuously and is needed for growth, plant and animal. I am not sure if you share these thoughts but I am firmly convinced that car emissions are the least responsible for Global warming. Many other factors contribute much more to the so-called greenhouse effect. Not the least the sun itself.

It is all BS to go after CO2 emissions in the transport sector. What about industry and these chimneys? It is all political. Climates always change, if we want it or not.

Anyway, it will sort itself out. H2 as fuel is pretty much out and is accepted that it is. The believe on the fuel cell still lingers on. It will take a little longer.

In another article the future and the development was put this way:

1. Internal combustion and its improvement, 2. Alternate fuels, 3. Hybrids, 4. Fuel cells.

1. is ok. 2. is really the ICE as well, 3. is also the ICE with some electrics, and 4. will never come. As you can see the ICE will be around for a long time. The pure E-versions will only be good for the city and short hops.

The next developments are Hybrids, which one will be found out the hard way. Mr. Lutz is on the wrong ship too. He has not realized yet was is going on around him. He should be fired just like the GM boss was.

Oh yeah, you have used the too low number for diesel in other threads. Please recheck as it is wrong.

Regards

G'day gals, guys & gurus,

• Internal combustion and its improvement, 2. Alternate fuels, 3. Hybrids, 4. Fuel cells.
• 1 is ok. 2. is really the ICE as well, 3. is also the ICE with some electrics, and 4. will never come. As you can see the ICE will be around for a long time. The pure E-versions will only be good for the city and short hops.
• The next developments are Hybrids, which one will be found out the hard way. Mr. Lutz is on the wrong ship too. He has not realized yet was is going on around him. He should be fired just like the GM boss was.

There are a couple of fundamental problems with internal combustion engines that makes them less than ideally suited for use as a form of propulsion in road vehicles that makes them inefficient.

The main problem is the way they deliver their power. In a road vehicle the maximum torque is required when the vehicle is stationary and is accelerating to its cruising speed, which is exactly the opposite to the way an ICE works. As a result you need to have a way of matching the changing the speed of the vehicle to the optimal speed for the engine. This requires a complex drive train that consumes a large wad of the engines output not to mention the extra mass that needs to be lugged around.

On the other hand an electric motor delivers maximum torque when it's not rotating which is exactly what you want. Not only does this mean that they are more efficient but if you correctly engineer the motors you can do away with the entire drive train, gearbox, differentials, drive shafts, etcetera.

Next up we have braking. To slow a vehicle with an ICE the kinetic energy is converted to heat in the brakes whereupon it is transferred to the air and wasted. On the otherhand with an electric powered vehicle you can use the motor to slow the vehicle and recover much of the energy that would be wasted. By storing this energy you can then use it to help accelerate the vehicle which in the stop start driving of city traffic can add up to a considerable saving.

A well engineered electric vehicle can have phenomenally good performance as electric motors are far better suited to road vehicles than the internal combustion engines. I have seen numerous demonstrations of this including one where an electric vehicle was put up against a Ferrari and NASCAR on a race track. While both the Ferrari and NASCAR had tops speed well in excess of the electric vehicle they could not compete with the acceleration. As a result when the vehicles accelerated from the standing start the electric vehicle easily out accelerated both ICE powered vehicles easily taking the lead. Even though the ICE vehicles had a better top speed the difference was not great enough for them to pass the electric vehicle and thus they never managed wrestle back the lead from the electric vehicle.

Ok, the main problem with electric vehicles is the storage of electric energy. However, if the leading car manufacturers put the money they spend on nothing more than cosmetic changes to their vehicles into researching electric storage systems the internal combustion engine would be dropped like a hot potato.

Regards, masu

Hello Masu,

Who killed the electric car? Damn, I knew it, it was not due to its overall troubles but someone actually did it. We need to find out who and bring him/her to justice.

So far there is no storage media available that comes even close to the energy storage of fuel on a size and weight basis.

Even if we had one, the recharging is another 'problem'. To do it in a short time, lets say in half an hour, the cable has to be too big for a human to lift. Only trickle feed so far is possible. Besides, having either high voltage or high amperage flow becomes dangerous.

In case we have that problem solved too, which is near impossible, other than changing out the whole 200+ lb battery every time you want to fill up, the electric grid that is now in place can't handle the extra distribution of power. BTW a 200+ hp E-motor is not that small or light either which you would need for the acceleration you are speaking of. The weight of batteries so far is also considerable.

Another point is to make the power in the first place. Where would you get all these power stations from overnight so to speak.

Now we are back to making the power, from what? Electricity is just a carrier not a fuel as we all know.

As you hopefully can see, there is a long and winding road ahead to the all electric car. Having electrics combined with an ICE makes more sense and it is coming, actually it is already here in the form of hybrids. ICE combined with electrics for recovery of braking power which, together with good acceleration, is its only advantage. Good for city but not for highway driving.

My bets are on the ICE for a long time to come. Mr. Lutz will find out soon enough.

Why is the present acceleration with the ICE not good enough?

Regards

G'day gals, guys & gurus,

• So far there is no storage media available that comes even close to the energy storage of fuel on a size and weight basis.

That's not the case at all. lithium ion and nickel metal hydride batteries can give cars a range equivalent to that of the average internal combustion powered vehicle.

There are also several new technologies under development like super-capacitors and flow batteries that don't have the charging delays of other energy storage technologies.

How often do you or anybody else for that matter, get in a car with a full tank of fuel and in one trip drive far enough to require refuelling?

Not very often and at a guess I would say that well under 1% of trips taken in the average car would.

Almost all travel in cars is with one person, i.e. the driver, over relatively short distances that could easily and far more efficiently be covered by an electric powered vehicles that have only a fraction of the storage capacity as a car like the Tesla Roadster.

What we need to do is change the way we think and look at ways of more efficiently supplying our transport needs. For nearly every trip undertaken by the average motorist a vehicle like the Persu (see image at right) would be more than adequate and far more efficient and economical.

Ok, there is a limit to the carrying capacity but if you do need to carry more then why not have a smaller vehicle like the Persu that has the ability to extend it's carrying capacity with a trailer. You can actually get trailers for motor bikes so there's nothing new here.

Personally, when an all electric vehicle like the Persu becomes available in Australia I will be giving it will be a very serious contender for our next car.

• BTW a 200+ hp E-motor is not that small or light either which you would need for the acceleration you are speaking of. The weight of batteries so far is also considerable.

Yes, a 150 kW (200 hp) electric engine is fairly large, but if you construct it utilizing rear earth metals it is possible to reduce its mass and size to something that is comparable to a ICE. However, because the torque profile of an electric motor is more suited to the requirements of motor vehicle means you don't need a gearbox, differential or drive train. As a result you don't need anything like the same sort of power output from an electric motor to produce a performance comparable to that of an internal combustion engine. If you don't believe me have a look at this YouTube video of a race between a purely electric vehicle and Ferrari. While the Ferrari has a better top speed it can't compete with the acceleration the electric car has and as a result can't keep up with it.

You can't do a direct power comparison of electric and internal combustion engines. Like anything you have to look at the problem as a whole and as the video clearly shows it is possible to construct an electric car that can outperform some of the world's great super cars.

• Another point is to make the power in the first place. Where would you get all these power stations from overnight so to speak?

Again, you have to look at the problem as a whole and yes, you do need to make sure that you're not making the problem worse. At the moment most of the world's electrical energy is produced by burning coal so while an electric vehicle doesn't pollute itself the power stations that generate the electricity do. However, the demand for electricity is usually much less at night than it is during the day, but it's very difficult to adjust the amount of power such generating facilities create. As a result there is not only a surplus of generating capacity at night, but there is often a surplus of energy being generated so power utilities sell it at greatly reduced rates and sometimes just burn it off.

What I'm trying to get across is the concept that we need to start thinking laterally and try out new ideas rather than sticking doggedly with a concept that hasn't change much in over a century. Come on folks, if the automotive industry had improved at the same sort of rate the electronics industry has we would all be driving cars that on the outside were the size of a matchbox but were so big inside that you could fit in a swimming pool, could travel at twice the speed of light and get to the other side of the Earth on a thimble full of cheap brandy of whisky.

Then again, considering the mess the big car manufacturers have managed to get themselves into by doggedly sticking to outdated concepts they may not be here much longer. We can only hope that whatever evolves to replace them has more imagination and willingness to experiment with new concepts and ideas.

Early in my career as an engineer I worked for a world leading automation and control company that not only embraced failure but encouraged it. You see 999 out of 1,000 new ideas or concepts will end in failure but unless you try those 1,000 harebrained ideas you will never find the one that is the revolutionary concept that leads the world forward. This concept had worked well for over a century and produced numerous technologies that made them world leaders. However, not long after I started the accountant style managers got their grubby little mitts on the purse string. The pushed the concept that we could no longer afford to invest time and money on as they put it failures. Yea, right, we did save money on research and development but it also meant that we never found the one in a thousand new ideas that had made the company what it was. It totally stifled the lateral thinking and it wasn't long before the people with the new ideas threw their hands up in disgust and went to other companies where their talents were recognised, appreciated and used. Now, guess what? It wasn't long before the company started going backwards and while it's still in existence is only a shadow of its former self.

Twice in my working life I have had direct experience with the stifling of lateral thinking that comes from being over zealous with profitability and insisting that everything that is undertaken be profitable. Profit is important and overall a company must remain profitable to survive, but unless you put the money into research and development and try those ideas that fail you will soon be going backwards. In one case the company no longer exists which is a great pity as when it disappeared it took several concepts and technologies that could have greatly beneficial to the industry.

We are at a crossroads and the developed nations need to seriously rethink how they do things. As the lesser developed nations strive to become more affluent it's going to place more and more pressure on dwindling resources. With some imagination and lateral thinking we can continue to advance and improve the standard of living for all the worlds inhabitants, however, if we do not move forward and address the wasteful and inefficient way we go about our daily lives we are going to be in serious trouble.

Regards, masu

Hello MaSu,

While I disagree with the first half of your reply and the concept of the electric car except for specific uses, I admire and applaud the second half of your writing. All well said and so true.

Without innovation we move backwards.

I wished more people would think along these lines of your thinking. Today it seems that short term profit is king. That we must change and think much more long term. In a nut shell I think greediness and profit at all cost has taking over. Herein lies our downfall. A good example of how not to do it is GM at present. There is too much "GM"-thinking out there. There are too many greedy investors to be satisfied.

Lets apply your innovation thoughts everywhere. Good words, thanks for stating that. It is the basis of our survival which I fully agree with. Hope others will too.

Regards

G'day Floram & JMM

· "While I disagree with the first half of your reply and the concept of the electric car except for specific uses,"

Why not the other way around?

I haven't been able to find any hard data on it, but I would hazard to say that in excess of 99% of journeys undertaken in a motor vehicle are single occupant short duration trips that are far better suited to an electric rather than internal combustion powered vehicle.

In other words, use the electric vehicle for all those short stop start one person trips then utilize the SUV when and only when it's performance is a necessity.

If anybody can direct me to statistics on the use of motor vehicles I would appreciate any links to it so I can properly work out how suitable/unsuitable different types of vehicles are.

Regards, masu

Floram,

I appreciate your comments and interest, along with those from Masu; glad I stayed subscribed to this thread. I realize that conventional thinking may characterize electricity as just a carrier not a fuel as we all know. In the physics I learned many decades ago, electricity is an energy source; but it is not in the form we often associate with fuel. Yet it can be stored in batteries, magnetic fields, and capacitors. Please consider revising your statement to be: Electricity is a fuel that we do not know well. Consider that even water stores energy in potential form as elevated storage or kinetic form as heat, so it can be viewed as a specialized "fuel".

Consider also the ratio of horsepower to weight for the ICE over the 100+ years it has been in existance. Looking at electric motors we can see a similar trend and there are a number of changes that can accelerate this reduced size/weight for a given power output. Consider the possibilities with better magnetic materials, or the smaller coil sizes with a higher frequency for an AC motor.

I fully agree with the philosophy behind the idea that the present acceleration with the ICE is good enough. Unfortunately even groups like Consumer's Union have given higher ratings to greater power and acceleration, following the philosophy that this contributes to accident avoidance and safety. Perhaps we should say that the present power and acceleration capabilities of the automobile with an ICE today are too much.

--Peace, JMM

Jmueller,

Thank you for your kind words, and sorry for my delay.

So, you think Electricity is a fuel. You can't dig it out of the ground, you can't put it into a container, store and transport it. I think we must first have a definition of what constitutes a "fuel".

To me electricity has to be made, just like H2. Consequently it is not a fuel, it is just and energy carrier. Compressed air would be another energy carrier and there are many others. Have you noticed lately that the the euphoria about H2 as an automotive fuel has dwindled? For good reason of course. The same will happen with electricity and also for good reason. The idea of an Electric car is not new, it is as old as the car itself.

Just recently I saw a statement by the chief engineer (I guess that was his title) from Toyota, saying that we need a mayor break-through in Battery technology before the all electric car can become viable. I fully agree with him. Besides that, it takes too long to charge a battery. That problem is a very tough one too.

If one considers overall cost, weight of batteries and E-motors, the long charge time, the unavailability of copper etc, etc. the all E-drive is a farce, and that includes the CO2 emissions.

I am all for new and better technologies. But with the E-car I am very skeptical. Of course, all to its own. That is just my thinking.

Regards.

Floram,

I think we must first have a definition of what constitutes a "fuel". I agree fully. What is yours? Mine would be "A fuel is energy stored in a usable form." Under this definition, in some cases electric charge is a fuel (as in a capacitor), while in many others it is, as you say, a carrier. H₂ is a fuel, but not what we normally term a "fossil fuel". All this, of course, is semantics; and does not need to detract from the validity of the wider debate that this blog is party to.

In the early years of the 1900's, battery-powered delivery trucks were manufactured and marketed in some cities. I agree that the convenience and ubiquitous nature of vehicles powered with internal combustion engines is very significant. Hydrogen-fueled cars were marketed in prototype form in the late 1970's, in the form of after-market conversion kits to provide dual-fuel capacity to a standard car. At that time the superiority of hydrides for storage (as opposed to compressed H₂) was emphasized, along with the inherent relative safety of such storage when the storage tanks were subjected to the forces of collisions or punctures.

The low energy density of hydrogen is well-stated as an inherent drawback to its use in transportation. However, we should not be so closed-minded as to dismiss its use entirely. As a fuel for fuel cells, the much greater overall efficiency of converting its chemical energy into kinetic energy (as compared to combusting it in an IC engine), is worth remembering. Future needs, environmental dictates, or other circumstances can cause us to give it a strong second look.

Hydrogen has been suggested as an energy carrier (as in our initial discussion). In the last few years, significant advances have been made at the laboratory level with molecular biology to allow direct production of hydrogen gas from sunlight. Such processes are inherently very low in CO₂ production. In addition, the oxidation of hydrogen (whether in a fuel cell or an IC engine) only produces pollutants to the extent that they are a byproduct of the presence of other gases or chemicals at the time of the combustion; and not a product of the reactants themselves. (In other words, things like NO_x are formed because the ~78% N₂ present in the air portion of the IC engine's mix reacts with some of the O₂ because of the pressure and temperatures involved. No CO, CO₂, or hydrocarbons are produced.)

Regards--John M.

G'day gals, guys & gurus,

• "So, you think Electricity is a fuel. You can't dig it out of the ground, you can't put it into a container, store and transport it. I think we must first have a definition of what constitutes a "fuel"."

First off there are a couple of laws of physics and chemistry which are really the same. There called the law of conservation of energy and the law of conservation of matter. Basically they state that no matter what you do you can neither create nor destroy matter or energy. No matter what, when, where, how you go about absolutely anything the amount of energy and matter that you start with is exactly the same as the amount of energy and matter that you finish with.

The only deviation from these laws covers how you convert matter to energy and vice versa which is covered by Einstein's famous equation,

which really demonstrates that energy and matter are really just different manifestations of the same ting. So in reality the two laws of conservation are actually the same law.

However, since matter energy conversions are nucleic reactions, which you are not going to come across in a motor vehicle we can ignore it and state that energy nor matter can neither be created nor destroyed.

Ok, having said that what does it mean?

It means that in a motor regardless of the technology or method of propulsion you need to add energy to get it to move then subtract that energy to make is stop. Further it means that as you can't create nor destroy energy you must be getting the energy from somewhere when the vehicle accelerates and sending it somewhere when the vehicle decelerates.

With an internal combustion engine the energy comes from the RedOx reaction (scientific speak for Reduction Oxidation which is a fancy way of saying burning) of a combustible compound and the oxygen in the atmosphere. Where this energy originally comes from depends on the type of fuel but ultimately it nearly all comes from the Sun and is stored in a chemical form by the photosynthesis of plants.

In an electric vehicle the energy comes from complex chemical reactions within the batteries, however, with rechargeable batteries and unlike the RedOx reactions in the internal combustion engine, the process can be reversed.

Now, it doesn't really matter whether you call it fuel or battery power, at a fundamental level you are using stored energy that is converted by the vehicles motor into kinetic energy or the energy of motion.

• "If one considers overall cost, weight of batteries and E-motors, the long charge time, the unavailability of copper etc, etc. the all E-drive is a farce, and that includes the CO2 emissions."

Frankly that's total and complete rubbish.

The fact that Tesla Motors can produce an all electric vehicle that has performance and range equivalent or even better than any super car clearly demonstrates that it is perfectly possible to build an all electric vehicle.

Admittedly it takes longer to recharge batteries than to add fuel to a tank, However, it is extremely rare for a motor vehicle to undertake a single trip that is in excess of it's maximum range. As a result with a little foresight and change in attitude it would be perfectly practical to use an all electric vehicle without the recharging time having any impact on the use of the vehicle. In fact you would more than likely spend less time recharging the batteries than you spend refuelling a vehicle at a service station. I say this because if you set up the infrastructure properly you can recharge the vehicle whenever it is not in use. As a result you would never need to specifically stop at and refuel so there would be no lost time driving to and then sitting at the fuel pumps.

Further more, while it is important to make sure that the energy being used to charge an electric vehicle is not coming from a highly polluting fossil fuel this doesn't take into account several factors:

• Efficiency: Electric motors and the greatly simplified transmission in an all electric vehicle are considerably more efficient in converting chemical potential energy to kinetic energy. In an electric vehicle the overall efficiency of the motor/transmission is around 80% while in an internal combustion vehicle it come in at somewhere between 20% and 40%.
• Regenerative Braking: If you use the motors in an electric vehicle to slow the vehicle you can recover up to around 64% of the energy that can then be reused when the vehicle accelerates. In an internal combustion vehicle this energy is totally wasted as it is converted into heat by the brakes where there is no way to recover it.
• Stationary Idling: With an internal combustion vehicle whenever the engine is running it consumes energy. This means that in the stop start driving most vehicles are utilized in you consume a not insignificant amount of energy standing at intersections, traffic lights, in traffic, etcetera. However, in an electric vehicle the engine use no energy at all when the vehicle is not moving so you don't have the same sort of wast when you're sitting around in stationary traffic.
• Moving Parts: The dramatic reduction in the number of moving parts in an electric vehicle means that there is far less wear. Not only does this reduce the amount of energy needed to make the vehicle move but it increases the life expectancy of the vehicle dramatically.
• Delivery of Power: An internal combustion vehicle is really using a series of explosions to deliver the power. As a result the energy comes in short bursts that place the power train under short periods of extreme tension. This creates vibrations that can both wear out the drive train faster but also damage other critical assemblies including the structure of the vehicle itself. An electric motor supplies the power more smoothly and this can dramatically reduce the peak strains the drive train is subjected to.

Unfortunately the car industry and new technologies and ideas are an oxymoron of similar ilk to military intelligence and airline food. The love to tinker with all these complex technologies that provide marginal improvement at best while sticking with a technology that is about as good as it's likely to get. At the end of WWII the aircraft industry clearly saw that the use of reciprocating engines had reached it's peak and that if aircraft were to get bigger, faster and safer they would need a new power source. The gas turbine or jet engine was then adopted as the way to go and the industry has not only grown tremendously but is now close to if not the safest way to travel. Unfortunately, over the same period the automotive industry has doggedly with reciprocating engine. Admittedly they have managed to increase the overall efficiency and power to weight ratio but only by an incredibly small amount when compared to the aviation industry.

What we need to do is change the way we think and go about our daily lives. With only small changes to our thinking we could easily produce electric vehicles that were not only perfectly adequate but can fulfil our transport needs better than the current crop of petrol driven cars.

Hello Masu.

Interesting analysis, but I would like to expand a little on what has been said.

In one of the posts the extraction of hydrogen in power station was mentioned, as means of suppling the future market (cost effective). This is done I believe by subjecting the PF (pulverised Fuel) to steam to extract Hydrogen, then putting it through a catalyst. Not sure of my facts as its been a while since reading it. But the point I'm leading up to is that the hydrogen produced by this method had storage problems as it embrittles any vessel it is stored in? So apart from the point you raised regarding transport how does it rate for storage and distribution, and what about other views on a secondary energy storage such as solar energy. How does it stack up coupled with a fuel cell against battery's. Just a few thoughts? And though the arguments raised are valid, it revolves around the fact that we will have a choice in the future, suggest reading info on the internet . Hubberts Peak.

Regards JD.

Hi jdretired

"In one of the posts the extraction of hydrogen in power station was mentioned, as means of suppling (sic) the future market (cost effective). This is done I believe by subjecting the PF (pulverised (sic) Fuel) to steam to extract Hydrogen, then putting it through a catalyst. Not sure of my facts as its been a while since reading it."

Wikipedia has some interesting stuff on the coal gasification process. One of the interesting concepts is converting it to syngas as it is called, and then using it to drive a gas turbine for electricity generation.

Currently over half the worlds electricity is generated by burning coal in boilers and then using the steam to drive steam turbines. Overall this is only about 30% efficient which means you are wasting about twice as much energy as you are using and producing three times as much pollution. There are some compound gas turbines around that are claiming an overall efficiency of 60% which could dramatically reduce the amount of pollution created by generating electricity.

I am not sure exactly how they achieve the 60% efficiency with the gas turbines but I believe that they use the high temperature exhaust of the gas turbine to boil water in a boiler thus producing steam that drives steam turbines. I don't know if it's possible but I would think that it would be possible to retrofit existing steam turbine power stations with gas turbines that are which then generates the steam to drive the existing steam turbines. If you could achieve an overall efficiency of 60% you could basically double the output of existing power stations without consuming any more fuel or producing more pollution.

You also raised a series of other questions which are quiet relevant, however, I will need a little time to answer them, so in the meantime have you checked out all the other threads in the An Engineer's Look at the Future of Energy series? If you follow this link to the blog's table of contents you will see a list of all the topics with links to the threads that have already taken place. If you think there is something that you believe warrants a thread of its own and is not already on the list please send me an email and I will happily include it. If you do have a suggested topic it would be greatly appreciated if you could include any relevant URL with your request. It's not essential but it certainly makes my life easier if I have somewhere to start.

Masu:

As any fuel, Hydrogen reacts with O2 exothermicaly and relices clean gases -yes- but adds heat as well -that over heats atmosphere which affects climates and change them, it is a fact-.

Whom understands this fact will agree that Hydrogen as well as -natural or bio- gasolines, diesels, carbons, hidrocarbon gases, alcohols, etc.......etc......etc..... and no matter if the burnt clean or smoking....but all........all........all are fuels which heat causes global warming...............so, forget hydrogen engines, they will be more of the same.

cheers.

As I stated in my responded to this post in the Improved External Combustion Engines thread it is not the energy itself that is warming the atmosphere but rather the products of combustion that are opaque to infrared radiation that are causing the problem.

As you are new to this forum I can understand that you are not familiar with it, but in general it isn't worth posting the same thing in multiple threads as it only results in the participants receiving multiple copies of the same thing. The best solution is to utilize hyperlinks in subsequent posts that point back to your original comment. If you cut the post link as shown below from the thread you can paste it to a post in any other thread that readers can use to jump to you post.

This not only makes it easier on you but stops others receiving multiple copies of the same thing.