Sciencemadness Discussion Board - Hydrogen ignited in Ozone gas

Hydrogen ignited in Ozone gas

D4RR3N - 1-1-2010 at 04:00

We all have seen a test-tube of hydrogen popping when ignited by a splint demonstrating the explosive nature of hydrogen igniting in oxygen. Has anyone here tried igniting hydrogen in ozone O3 gas? Would you get a bigger bang? Would water be the result of would you get hydrogen peroxide?

woelen - 1-1-2010 at 06:36

Water would still be the result of the reaction. I indeed expect a bigger bang, I can even imagine that no spark is needed to ignite a mix of pure ozone and hydrogen gas, but I am not sure about that.

hissingnoise - 1-1-2010 at 06:53

I wouldn't expect a bigger bang because it's essentially the same reaction. . .
The instability of O3 would probably cause ignition of H2 by contact.
Is it true, though, that a H2/O2 mixture won't explode by spark unless a trace of H2O is also present?

D4RR3N - 1-1-2010 at 09:16

I read that by itself Ozone is an explosive allotrope, by explosive I guess they mean unstable. I would have thought that adding hydrogen would make a bigger bang.

H2 + O3 = H2O + O1 (free radical) ??

[Edited on 1-1-2010 by D4RR3N]

12AX7 - 1-1-2010 at 10:04

The additional energy you get is due to ozone breaking down to oxygen. Nothing more. It may proceed faster, for instance O3 might break into 2-3 radicals, thus propagating the reaction faster than with O2.

Tim

D4RR3N - 1-1-2010 at 11:14

I was thinking it might be a good fuel to run an engine on ;-)
If the reaction did propagate faster that would result in a bigger bang.

[Edited on 1-1-2010 by D4RR3N]

hissingnoise - 1-1-2010 at 12:20

Ozone is not a fuel, it's an oxidiser. . .
As for using it in an engine, if it were advantageous I'm sure we'd have heard about it.

densest - 1-1-2010 at 12:51

Ozone wouldn't be easy to use in an (internal combustion) engine. Besides attacking most plastics and rubbers (used in tubing, control valves, etc.) it's unstable as a liquid or compressed. Piston engines most definitely don't want a detonation or uncontrolled fast combustion: that cracks pistons and connecting rods, bursts piston rings, and burns valves. "Octane number" for gasoline is a rating for how controlled and evenly the fuel combusts. The higher the octane number, the smoother it burns.

Racers have used nitrous oxide (N2O) occasionally to give their engines more oxygen per volume to increase power output because it will burn twice as much fuel per stroke as air. N2O is easily stored as a liquid, doesn't detonate on contact with combustibles, isn't toxic in moderate amounts, and is otherwise generally benign in comparison to ozone.

D4RR3N - 1-1-2010 at 16:07

You wouldn't need to store the Ozone so you don't need to worry about its being unstable or about it attacking plastics due to its oxidising ability. Ozone can be made by passing air through plates connected to a high voltage, the smell you get near a photocopying machine is Ozone produced by the EHT.
Hydrogen produced by electrolysis of water could be stored in metal hydride.
Instead of combustion the hydrogen with air the air could be sucked in, passed over an EHT converting it to O3 rich mix and then ignited with the H2 in the engine (no storage needed and no need to worry about the instability of O3)... also a piston engine is not the only type engine available.

[Edited on 2-1-2010 by D4RR3N]

[Edited on 2-1-2010 by D4RR3N]

not_important - 1-1-2010 at 16:56

The efficiency of making O3 from O2 suck pond scum, a large percentage of the energy is wasted. That's energy you have to provide from somewhere. On top of that the air (or O2 which gives better yields) should be clean, dry, and cool, for best yields; that adds complexity, weight, and power losses in driving the filtering and what not.

If you ran the numbers I think you'd find you'd come out ahead just installing a slightly larger engine and fuel tank.

BTW - current methods of storging hydrogen are pretty poor, the volumetric energy density leaves much to be desired - big tanks are needed. You come out better storing hydrogen as ammonia, either as the liquid under moderate pressure or as its complexes with MgCl2, and burning the ammonia mixed with 5% to 10% hydrocarbon as fuel. Those storage methods result in about 50% more hydrogen per unit volume than you get with liquid H2. Methane gives even denser storage, near twice LH2, but is harder to store than NH3 and more like H2 in that aspect.

D4RR3N - 1-1-2010 at 17:33

Well the point I was making was more about what would come out of the exhaust pipe (considering all the talk about us destroying our environment). I'm aware you could just use a bigger tank and engine but increased power was not what I was considering but an environment friendly fuel was.

not_important - 1-1-2010 at 18:14

hmmm ... exactly what coming out of the exhaust pipe to you think your scheme will help with? Define "environment friendly fuel"

D4RR3N - 1-1-2010 at 18:43

Steam/water droplets would come out of the exhaust, zero effect in terms of greenhouse gases.

densest - 1-1-2010 at 18:52

You'd still get oxides of nitrogen unless you carried an oxygen concentrator and fed the engine with 95% O2. More weight and complexity :mad:

Combustion of hydrogen is HOT.

not_important - 1-1-2010 at 19:34

Quote: Originally posted by D4RR3N

Steam/water droplets would come out of the exhaust, zero effect in terms of greenhouse gases.

Ah, but where does the energy to make the H2 and O3 come from?

Electrolysis efficiency runs 60 to 75 percent, theory says 80 to 90% best unreachable case. 1 kWh worth of H2 takes 1,4 kWh of electricity. When making H2 from fossil fuels its a bit better, 80% or so.

The energy needed to store H2 is equal to 1/4 to 1/3 the energy, so to store 1 kWh energy as H2 you need to expend at least an addition quarter kWh.

Now to use the energy stashed away in the hydrogen. Heat engines in that size run 25 to 35 percent efficient, that is for every kWh tucked away as chemical energy in H2, you will get 250 to 350 Wh as useful work. The power train loses an additional almost 6% of the input energy, 60 Wh out of the kWh. So each kWh stored in H2 will deliver 190 to 290 Wh to the wheels.

Go with a PEM fuel cell, the sort generally chosen for H2 automotive designs and the results are a bit better. PEM fuel cell systems run 40 to 45 percent efficient, and can eliminate the power train but using hub or wheel motors. Say 300 to 400 Wh to the wheels for every kWh of H2 consumed.

So total up the entire chain and get:

H2 burning heat engine needs 7,5 kWh input for every kWh to the wheels, ~13% efficiency, not very far from a conventional car.

H2-PEM fuel cell needs 4,7 kWh input for every kWh to the wheels, ~21% efficiency

A pure battery-electric vehicle with current design electronics puts 90-95 percent of consumed power into the batteries, delivers 90-95 percent to the motors, which in turn deliver 80 to 90 percent to the wheels. Say 70% efficiency or 1,4 kWh input for each kWh at the wheels.

A modern coal fired power plant is around 40% efficient. The latest combined cycle gas turbine system run 55-60 percent. So if you burned fossil fuels to make the electricity for BEVs, you'd see 28% to 39% efficiency for the entire system, fuel to wheels; getting close to three times current or H2 burning ICE, or twice a H2-fuel cell system. The H2 ICE will be as responsable for almost as much CO2 generation as conventional automobiles, and for roughly 3X the BEV; if you use some other source of electricty to make the H2 then that source can be used for the BEV as well, retaining the 3X relationship.

If you want to continue to use ICE driven vehicles, then using a mix of 90% NH3 + 10% C3H8 will reduce CO2 production by 90% and give lower NOx output as well; all without the complexities of the H2 infrastructure as simple low pressure fuel tanks can be used. For North America there is a sizeable ammonia pipeline network already in place in the central regions.

You say "but I want to use O3 in the engine too" Fine, looks like around 820 Wh per mole of O2 using air(*). Thats filtered, hydrocarbon-free, -40 dew point air no warming than 20 C. The additional energy will not exceed that for 2 O3 > 3 O2, I'll leave it to you to calculate how much of that 820 Wh ends up as useful work, and how much power is needed to prepare the air as well as haul around the extra mass of the O3 generation system.

(*) see http://www.lenntech.com/library/ozone/generation/ozone-gener... for numbers on ozone production.

kilowatt - 1-1-2010 at 20:18

I read somewhere that 30% ozone (70% O2) has been used as a cryogenic liquid oxidizer (with hydrogen I think) in some experimental rockets. Higher concentrations are unstable and likely to explode on their own accord. The performance of the ozone blend was only slightly if any better than pure liquid oxygen, making it completely useless considering how much more energy it takes to produce. Not only that but O2 is more volatile than O3, and after shutdown the residual material in the lines would concentrate as it evaporated, eventually resulting in an explosion if it was not fully purged.

As has been said, all known methods of ozone production are miserably inefficient, making it completely useless as an oxidizer or combustion aid in any type of engine. There are numerous schemes for recovering waste energy in an engine that are far more efficient. Even if ozone could be produced efficiently it isn't that much better than regular oxygen especially considering how corrosive and explosive it is in high enough concentrations to make a difference.

Quote:

If you want to continue to use ICE driven vehicles, then using a mix of 90% NH3 + 10% C3H8 will reduce CO2 production by 90% and give lower NOx output as well; all without the complexities of the H2 infrastructure as simple low pressure fuel tanks can be used. For North America there is a sizeable ammonia pipeline network already in place in the central regions.

Unfortunately all that ammonia is produced using hydrogen obtained from methane steam reforming, resulting in just as much CO2 emission. We need a better way of producing hydrogen before we can really use ammonia or hydrogen itself as a fuel.

[Edited on 2-1-2010 by kilowatt]

D4RR3N - 2-1-2010 at 04:53

If you think about the energy used to drill a hole in the ground put a pipe down to extract gas or oil, then process that so that it can be used for a fuel in a car engine.

Compare that to water which is abundant and requires little processing apart from filtering it to prepare it to be split via solar energy. I think that those massive solar collector projects in Australia and America will probably be the means to produce hydrogen from water in large quantity in the future. Transport of hydrogen is a problem though which is why I think something like metal hydride or a better system will have to be used.

If this rocket experiment has taken place and liquid Ozone was ignited with liquid hydrogen without any dramatic increase in thrust then you are correct, it is pointless to use Ozone!.....I never heard of this rocked before and my initial question was just an idea to increase the potency of hydrogen as a fuel for cars.

Here is the thing rocket scientists are smart guys! Why did a team of rocket scientists even attempt this? A rocket is an expensive thing surely they must have calculated the result before they spent the money on the experimental rocket?
They must have at least amused it was going to produce greater thrust?

[Edited on 2-1-2010 by D4RR3N]

D4RR3N - 2-1-2010 at 05:56

I read this statment at:

http://www.time.com/time/magazine/article/0,9171,868054,00.h...

When chemists dream their fanciest dreams, they imagine powering a rocket with liquid hydrogen and liquid ozone (03). This pair is tops for energy. Its reaction has a specific impulse of 373. The specific impulse of the traditional kerosene-oxygen combination is only 249

If this is correct then a mixture of hydrogen gas and Ozone gas would be more potent as a fuel then hydrogen gas and oxygen gas.

[Edited on 2-1-2010 by D4RR3N]

not_important - 2-1-2010 at 10:57

Rockets are special cases, they always have to carry both fuel and oxidiser with them. Most of the mass of propellants must be lifted off the ground for at least a short distance, so the lighter those are the better.Storage is also not of primary concern, given the money that can be spent and support staff allowable, liquid hydrogen is acceptable for rockets but not for your car. The cost of the oxidiser and fuel is not of primary concern, nor is the overall efficiency - what for automobiles is referred to as "well-to-wheels".

Vehicles for everyday use sit surrounded by oxidiser, saving a good deal of energy by not having to carry it around (or generate it in place as for O3). The complexity, volume, and mass of the oxidiser associated apparatus adds to the production and operation costs of the vehicle; making it larger or heavier means more energy is needed to move it.

Hydrogen is a lousy fuel for general purposes. It has low volumetric efficiency, meaning that it takes up a lot of space to store a given amount of energy. It takes a lot of energy to liquefy it or store it as highly compressed gas; if you liquefy it then a significant percentage boils off every day, if you compress it then it tends to diffuse out through tiny leaks or solid metal. Metal hydrides are either quite heavy and generally fairly costly, only a few percent of their mass is hydrogen, or very reactive (LiAlH4), or "need further development" meaning "this might work, if you sink enough money into it and don't mind waiting a decade or two".

From a 2005 report on hydrogen as fuel

Quote:

Currently, the only systems that allow the storage of the DOE targeted 6.5 wt% hydrogen, with the fuel being available at less than 100C are composite cylinders containing gaseous hydrogen and heavily insulated tanks containing liquid hydrogen. Neither of these are considered acceptable for passenger vehicles.

The amount of 'punch' a rocket fuel+oxidiser system has may be of primary importance for that application, but for daily use it is not, what is important is overall cost - complexity and full system efficiency. That's why I gave those numbers for the efficiency of H2 fuel options. A low efficiency system means much more generation capacity is needed, and more generation capacity means more expense in building, maintaining, and replacing that capacity. The well-to-wheel efficiency for H2 is no better than the current fossil fuel burners, if the H2 comes from fossil fuels then it results in just as much CO2 release. If it comes from renewable energy it requires the construction of several times as much generation capacity as alternatives. For typical daily travel BEVs beat H2 fueled cars hands down, and require less infrastructure construction.

And that applies to using ozone, too. If the overall energy cost of making and transporting the O3, even making it in place as that requires pretreatment of the air, exceeds the gains to be had by using the O3, then it's quite possibly a ineffective idea. Given that the extra oomph from O3 is coming from the energy stored in its bonds over that in O2, and that it takes much more energy to make that O3 than is stored in it, using O3 will result in additional energy demands. Again, it can make sense for rockets and other special applications where alternatives are few and costs are not the primary factor, but for day-to-day applications it's wasteful.

If you want to distribute energy then power transmission lines are much more efficient than shipping about hydrogen. Liquid ammonia carries 50% more hydrogen atoms per unit volume that does liquid H2, and liquid ammonia is much easier to store and has much lower losses than does LH2. Other ways of shipping energy as fuel that are much better than elemental hydrogen include elemental Al, Si, B, and Zn.

D4RR3N - 2-1-2010 at 12:40

Electric cars will never become popular as long as a battery is the means of storing the electrical energy, takes far too long to charge up (most people wont be interested in having to plug their car in for over eight hours to charge up).

An air powered car would be probably better then an electric car, especially if using a solid air exchangeable cartridges http://www.youtube.com/watch?v=eY1KNxhd2Zs

How would you make the ammonia gas, not from fossil fuels surely?
Also the nitrogen component in ammonia, how will that react with oxygen. Will it make oxides of nitrogen?

[Edited on 2-1-2010 by D4RR3N]

densest - 2-1-2010 at 13:33

Rapid charging battery systems are in various stages of development. Charging causes metal to be deposited or generated from discharged compounds in place. This usually changes the volume of the electrode material, causing it eventually to fail. The better control of particle size, protective chemistry and mechanical factors, etc. are steadily improving charge times. When will it be 5 minutes? Demonstrations have been done; there's a -lot- of money at stake.

Improved conductive skeletons for electrodes (carbon nanofibers are a current candidate) are also important because they reduce resistance which means less waste heat while charging. Less heat means less deformation means better battery life.

Will there suddenly be a "wow, 5 minute charging tomorrow"? No. Will there be incremental improvements? Yes, they're constantly taking place. Over the last few years NiMH AA size cells went from 600 mAH to 2400 mAH and above and also went from 16 hour charge times to 45 minute or less. Similar improvements for lithium based cells are happening. Check the LiFePO4 progress, for instance.

Of course, electrical infrastructure to supply 200KWH to each vehicle in 5 minutes each is costly and elaborate. The supply chain for delivering petroleum products is very costly and elaborate, but it was built over 100 years so we don't see it as being a big deal.

For delivery vehicles, buses, etc. which have predictable routes, scheduled times, and centralized garaging the recharge time and infrastructure is much less of a problem. Big bulk buyers of these vehicles will probably be quiet leaders because they can realize good payback and often can get subsidies, etc., to cut their pollution output. Their recharge times can be scheduled to be optimum for electric utilities so that the utility can use the "base load" plant - the cheapest and most efficient - for that service when other demand is low.

One scheme which is not wonderful but applicable right now is battery exchange at a service station. I'm sure there would be horrendous arguments and incompatible batteries for a while, but economic incentives for a standard pack would be huge. Various systems have been tried. It would take (guessing) a 1.5X to 2X increase in
power density to make a Lithium based Prius-size pack something which could be swapped in a minute or two. It might mean using numbers of standardized packs to keep the weight and size low enough for easy handling. It's a -lot- less messy than pumping many gallons of volatile, poisonous, flammable, etc. liquids for refueling.... The packs could be recharged overnight at the station or trucked (just like gasoline is trucked) to recharge points. Ugly? Yes! Feasible? Yes. Cost effective? Good question... it would take 5-10 years to get all the pieces in place.

D4RR3N - 2-1-2010 at 14:28

Yes there is a lot of money at stake with those developing battery powered electric cars but I think they should cut their losses and realise they are barking up the wrong tree. It will never take off, can you imagine the heat generated even if you could charge up a massive battery like that in five minutes! Rapidly charging up the battery and then the large electrical load on the battery with the hub motors running will knacker the battery in no time at all (expensive too!)

The air car can be filled in 3 minutes, is simple and has no expensive parts so is probably better then a battery car.

not_important - 2-1-2010 at 19:39

Compressed air power is a nice idea, but suffers from several problems. The first is low efficiency, using numbers from developers and proponents of the concept a compressed air care is between 1/2 and 1/3 as efficient as a BEV.

The next is range, compressed air at currently practical densities hold less energy per unit volume than do batteries in use today. This means that for a given amount of the vehicle given over to storing power, a compressed air car carries less energy, and uses that in a less efficient motor; range for similar weight vehicles is less for the air car.

As the air expands in the motor, it absorbs heat and drops in temperature. As this results in air colder than ambient, thus is colder than the air pulled in for compressing. This means the air in the motor will occupy less volume that it did originally, a energy loss. To compensate for this the air must be heated. This can be done in multistage motors by having heat exchangers warming the air between stages. Normally this uses ambient air as the heat source, which works fine in hot climates. But in cold climates it is a different story, Prague and Des Moines in winter are not good heat sources. Furthermore, in cool moist maritime climates the heat exchanges can become covered in ice, rendering them ineffective.

As a result several developers of such vehicles ended up adding a fuel burner to heat the air. Such a system uses less fuel than a conventional engine, internal or external, does for the same amount of output power. This is because of the energy stored in the compressed air, the overall efficiency depends on the efficiency of the compression step.

So I have the choice of driving a BEV and on returning home plugging it in to recharge overnight, or using a CAC that costs at least twice as much per km and that requires me to go out away from home into the weather, wait in line at a filling station, fumble around with my currency card, and fill the tank (or instead pay someone to either fill or swap the tank, further raising the operating cost). Makes the compressed air car seem a lot of bother as well as significantly more expensive; but if you're into S&M it just might be for you.

And that is an important point. Everyone assumes that BEVs would be used identically to a typical car of today, thus the refueling time issue. But a BEV can be recharged when you are not driving it, avoiding the need to travel to a filling station. Similarly people can't use current BEVs because of the range limit even though their daily travel distance is much less than the range of the BEV. When this is pointed out various excuses are given, ones I've heard include "we visit Grandmother twice a year and she lives 399 miles away" and "we going camping with friends for a week every year, so we need a SUV to carry everything and travel far enough"

Quote:

Through a series of press releases and demonstrations, a car using energy stored in compressed air produced by a compressor has been suggested as an environmentally friendly vehicle of the future. We analyze the thermodynamic efficiency of a compressed-air car powered by a pneumatic engine and consider the merits of compressed air versus chemical storage of potential energy. Even under highly optimistic assumptions the compressed-air car is significantly less efficient than a battery electric vehicle and produces more greenhouse gas emissions than a conventional gas-powered car with a coal intensive power mix.

From http://www.iop.org/EJ/article/1748-9326/4/4/044011/erl9_4_04... a recent analysis of compressed air vehicle efficiency, full document is freely available.

A slightly more favorable evaluation focusing on just the compression-expansion aspect, and getting about 60-70 percent efficiency, is in this PDF http://www.efcf.com/reports/E14.pdf

From http://www.greencarcongress.com/2009/06/revetec-20090606.htm...

Quote:

That volume of air (.27 m^3, or cubic meter), if expanded isothermally at room temperature, can generate only 12.8 kwh. However, the expansion process is not isothermal, but more like polytropic, emitting very cold air out of the exhaust pipe, so, you can get but ~1/2 of that energy before even considering mechanical losses in the air motor. I don't see how can any USA-street-worthy car run for 40 miles out of 6.5 kwh. (The formula is 100xlnPa/Pb kJ/m^3 of initial gas volume before compression = 100xln300x0.27x300= 100x5.7x0.27x300=46,200 kJ = 46,200kJ/3600= 12.8kwh)

An efficient BEV can do 4 miles/kwh, so 6.5kwh x 4mi/kwh = 26 miles range max. The French "Air Car" can get only 7-10 miles range in real life when demonstrated to reporters.

not_important - 3-1-2010 at 01:00

As for the ammonia, it was meant to illustrate that there are better choices than elemental hydrogen. There are two options

A) Today, Haber-Bosch using H2 produced the same way you would for using H2 as fuel. While there are energy losses in the ammonia plant, the lesser energy cost of storing ammonia, plus the increased convenience of that storage and its greater density of hydrogen, offsets those losses as compared to H2.

B) there are several new ammonia production processes in development. In general these run at much lower pressures than Haber-Bosch, and take steam and N2 as their feedstocks - no separate H2 generation. One process runs at atmospheric pressure, another fairly low pressure looks to be more energy efficient than Haber-Bosch

http://www.energy.iastate.edu/Renewable/ammonia/ammonia/2007...
http://www.springerlink.com/content/05714h07p14p71mw/
http://www.sciencemag.org/cgi/content/abstract/282/5386/98
http://www.reeis.usda.gov/web/crisprojectpages/192890.html

if your H2 fuel is going to use yet-to-be-developed storage means, I'm allowed to refer to processes yet in the labs.

watson.fawkes - 3-1-2010 at 07:47

Quote: Originally posted by not_important

B) there are several new ammonia production processes in development. In general these run at much lower pressures than Haber-Bosch, and take steam and N2 as their feedstocks - no separate H2 generation. One process runs at atmospheric pressure, another fairly low pressure looks to be more energy efficient than Haber-Bosch

Thanks for this. Very interesting.

The solid state technology under development shares a lot with SOFC (solid oxide fuel cells). It's essentially the same subfield of ceramics science to get the materials right. Widespread use of SOFC's is limited by material limitations, principally cost and 600° C operating temperatures. Luckily the technology here requires only a proton ionic conductor, rather than the oxygen ionic conductor required for SOFC. I can't seem to find the relevant patent application, unfortunately. If actually filed in 2007, as stated, it should be published by now.

I did find the Lynntech patent: Electrochemical synthesis of ammonia.

D4RR3N - 3-1-2010 at 07:50

Currently these air cars are using compressed air from a pump, I think they should use solid air which resembles dry ice. Go to the filling garage and fill the tank with solid air pellets which would revert to compressed air at a controlled rate in a thermal vacuum sealed tank. This way filling time would be like a regular car and mileage would be increased.

The only problem with hydrogen is a storage problem but I thing hydrogen from water using solar concentrator towers is the future. The oil fields of the future may be replaced with fields of mirrors instead collecting sunlight and concentrating it at a central tower.

densest - 3-1-2010 at 22:45

Ummmm... forgive me, but I'm laughing. I -really- want a process which would let me store oxygen in quantity. I work borosilicate glass in fuel/oxygen torches. I use insane quantities of oxygen. I can get a very nice dewar with 200 liters of liquid oxygen. 7/8 or so of the bulk of it is insulation. 1/8 of it is oxygen. I have oxygen concentrators (8 of them) which can't keep up with my torch. If I could store oxygen while I was not working it would be incredibly useful. The -best- option today to store oxygen from my concentrators is about $10,000 worth of pumps, $1000 worth of tanks, and a -lot- of power. And I'd buy it if I could afford it, because in a few years it would probably pay for itself - I can easily use 8 tanks of oxygen in a day. The alternative is a large garage-sized building containing an oxygen balloon - 5000 cubic feet or so would be really nice. The torch is about 30KW - in the range of a small car engine.

"solid air pellets" are somewhere around -230C. The amount of energy required to produce liquid air (or oxygen, nitrogen, etc.) is very large. Solid? Much more.

Please do a little more research - there are very strong practical limits on insulation and cooling. If you work out a method for storing air or equivalent gases at densities close to 1g/cm3 (even .1g/cm3) at room temperature, or a method for chilling to below -200C cheaply, and/or a method for insulating a low temperature storage unit with really low heat leakage, you will be very very rich. None of these are easy problems. A lot of very bright people have worked very hard on them. Strange chemistry and bizarre absorption might help you with storage. Thermodynamics puts hard limits on chilling costs. Black body radiation, etc. put strong (though perhaps not insuperable) limits on insulation effectiveness. Aerogels are remarkably good insulators but are not good enough for me to walk away from a tank of liquid oxygen for more than a few days without significant and expensive losses.

Believe me, I'd be right in line for a storage unit like you propose! And every glass artist, scientific glassblower, and welding artist would be right behind me!

Oh yes - current technology can produce batteries with very high charge and discharge rates. A car starter requires hundreds of amperes and those batteries have been around for more than 75 years. Over 60 years ago submarines used banks of batteries for propulsion underwater (not easy to get air for your diesels there!). So saying that heating, etc., make rapid charge BEVs impossible is false. Perhaps difficult? Yes. Not impossible. NiCd batteries would be very good if they weren't so heavy and didn't contain truly nasty amounts of very expensive and poisonous cadmium. They have very good discharge rates and good charge rates. NiMH batteries don't take high discharge rates well but are lighter and much less toxic. Li-ion batteries are new (relatively) and may be ready in a few years - even a pessimistic extrapolation would give less than 10 years to a very high recharge rate.

A fuel cell which used hydrocarbons directly without a reformer and was otherwise cost effective would also be a ticket to a few billion dollars....

[Edited on 4-1-2010 by densest]

12AX7 - 4-1-2010 at 05:05

What are you using 30kW of torch for? Could it be better served with a carbon arc torch or dielectric heating? (Hot glass absorbs microwaves pretty good, maybe not such a great occupational hazard. High frequency induction ca. 13.56MHz may be useful.)

Tim

D4RR3N - 4-1-2010 at 09:20

I don't agree with you that exotic chemistry is needed to produce solid air pellets. The tank in the car would be like a large thermal tank (reflective inner, vacuum sealed wall, thick insulation jacket).

The filling pump at the garage would only store a very small quantity of these pellets, more or less producing them as needed.

See video link and rough sketch

http://www.youtube.com/watch?v=grDe-iF_a6w

solid air 2.JPG - 37kB

bbartlog - 4-1-2010 at 10:26

Quote:

I don't agree with you that exotic chemistry is needed to produce solid air pellets.

Well, that's one way to win an argument, at least in your own head: pretend that the other guy said something he didn't. It's the *energy costs* associated with producing liquid air that pose the problem. Chemistry was suggested as something that might possibly help with storage.

The diagram you provide (besides suggesting a certain lack of discipline in learning to use new tools, as free CAD programs are easy to use) doesn't tell us anything about how you would propose to deal with the end-to-end efficiency problems described above. Of course it's possible to produce solid air via some series of steps corresponding roughly to your schematic. Now if you had actual engineering skills, you could look at each part of this, spec out components that would do the job for some desired product throughput, and figure out roughly how much energy each of the machines used per gram of air solidified. And then you could abandon your fantasy and move on to something more promising.

D4RR3N - 4-1-2010 at 11:49

bbartlog,

For your information I can use both autocad and solidworks, but I can do a sketch in 2 mins flat. Actually I happen to know quite a few Engineers and product designers, you will find they all sketch too ;-)

I don't feel storage of the solid pellets is a massive problem either, yes they will gradually decompose into gas and the air pressure in your tank will rise as this happens (you would have an air pressure release valve). You would also probably have to fill up every 2 or 3 days but would take no more time then filling with regular fuels.

Efficiency, well with solid air pellets in the tank you would increase your mileage on a full tank. Efficiency of use to a end user may be more important then the efficiency involved with the convention of compressed air to preform mechanical work.

Pumping oil out of the ground, refining it and then converting it to fuel suitable for use in an engine is hardly a very efficient process yet we do it.

The energy to run the fuel system I sketched would mainly come from solar energy. Compressed air cars are already being produced, I just suggested that their mileage could be increased and fill time reduced by using pellets instead of what they are using right now "compressed air".

http://www.youtube.com/watch?v=jgwfpIOOb-c&feature=relat...

[Edited on 4-1-2010 by D4RR3N]

not_important - 4-1-2010 at 18:03

For transportation, efficiency is measured as Well-to-Wheel, the percentage of the source's energy that ends up turning the wheels of the vehicle.

The term 'well' means any energy source, for hydro the theoretical energy contentin the water behind the dam for example. For some sources, such as wind where the limit on energy extraction is 59.3% (Betz limit), you could use either the total energy, the Betz limit energy, the mechanical power actually captured, or the power out of the generator - but you should specify which you are using; generally in this case it is the electrical power output of the generator. In some case it is important to specify the actual vs theoretical numbers, while wind turbines are generally specified by their actual electrical output for a given wind speed, photovoltaic system should specify actual output and their conversion efficiency so that the system's size can be estimated.

This can be broken down into Well-to-Pump, the losses in getting the energy from source to consumer, and Pump-to-Wheel, loses in the consumer's utilisation of the stored energy.

So would you care to give numerical valuse for WtW, WtP, PtW for convensional petroleum fueled ICE, compressed air, your solid air idea, hyrogen fueled vehicles - both ICE and fuel cell based, and Battery Electric Vehicles? Or are you just hand waving wth no real data?

Aurus - 5-1-2010 at 02:56

D4RR3N, it seems to me that Liquid Helium, which you propose using for cooling air is not exactly a household material... Not part of the usual laboratory reagents either...
It is an expensive very low temperature liquid boiling at 4K.

12AX7 - 7-1-2010 at 07:08

Quote: Originally posted by D4RR3N

Pumping oil out of the ground, refining it and then converting it to fuel suitable for use in an engine is hardly a very efficient process yet we do it.

Actually, it's on the order of ~500% efficient (i.e., a net producer of energy), while the methods you propose are on the order of 10% down to 0.1% or less (highly wasteful).

Tim

bquirky - 7-1-2010 at 10:08

I think another major problem with air cars is a saftey issue. a presure vesle rupturing in an acident with that amount of energey in it is quite posibly going to make you dissapear. sadly flywheels suffer from a simalar problem

at least with a petrol/LPG/CNG/syngas/whatever tank the speed of the reaction going to be limited by the avalible oxygen in a fire. i think electric cars are potentialy very safe in this regard. and you can surley do some cleaver things in regards to positioning the mass of the batterys to benifit crash saftey.

i dont think lithium cells are the answer though.. im not sure there is enough of it to go around

what do the numbers look like for giant rubber bands ?