Hydrogen Power

[CCycle]

Just read the latest issue of Popular Science (Jan 05).
They have a very good article debunking hydrogen power pg 63.
They explain nine reasons hydrogen power will not fly in autos.
Could it be that the world is finally catching on to what we engineers knew all along?

 

[crysta1c1ear]

Yes, I think so, but slowly.

In the UK, the government has a roadmap to a hydrogen future. Paragraphs have now been added stating that there is some question about the efficiency of a hydrogen future and states that the purpose of the document is not to debate the hydrogen efficiency, but only to point out a route to get us there. The authors are therefore sort of beginning to deny responibility.

Also, a chapter, chapter 7 if I remember rightly has been removed. The idea was to store electricity in a reversible fuel cell from regenerative braking. They have deleted the chapter accepting that a battery is better.

Recently I read an article about microturbines and microgenerators being used to generate electricity, for example for cell phones. The author stupidly thought that they could also be used to generate hydrogen to power a fuel cell for a laptop.

So at the same time, we have the idea that petrol engines can create the hydrogen for fuel cells, and elsewhere the idea that hydrogen fuel cells can replace petrol engines.

I think slowly we are going to see an acknowledgement that a 60% efficient hydrogen fuel cell and an 80% efficient electric motor gives efficiency less than ½, and that's before we worry where the hydrogen is coming from.

Hona has a dual use fuel cell product. The fuel cell efficieny is 15% but the heat it produces as a by-product is also used. It serves as domestic powersupply and heater. The total efficiency is then 85%. That's not bad, and its a reasonable use of fuel cells.

 

[GregLocock]

That Honda plant is OK, but any reasonable person would use an internal combustion engine, and get 30% as low entropy energy and 30% or more as heat... with the bonus that the reject heat from an IC engine can be at > 100 degrees C if so desired. The reject heat from a fuel cell is likely to be at 80 degrees C, which may be enough for hot water but is not enough for many processes.




Cheers

Greg Locock

 

[crysta1c1ear]

Sorry, I hate lazy referencing, so I dug out and reinstalled the Alta Vista search engine on my PC. I have now found the document I had in mind.

http://www.dft.gov.uk/stellent/groups/dft_roads/documents/pdf/dft_roads_pdf_026217.pdf

Its worth a look at PDF page 4/56 as it shows that hydrogen is set to catch up with the ICE in about 2030 if all goes according to plan. The final finish figure is just under 80 grams of CO2 per kilometre, which is not unreasonable. 80 g/km is about the current figure for a VW Lupo 3L TDI or a Honda Insight. The VW is a turbo diesel with 5-speed dual clutch and the Honda Insight is a sleek shaped hybrid. The figures for the cars are tank-to-wheels and the government's aims are well-to-wheels.

Nevertheless its not unreasonable to suppose that combining the diesel efficiency of the Lupo and mild hybrid features of the Insight etc will give the Europeans the sort of 80 g/km CO2 well to wheels they are looking for in 25 years time. (To bring the average down that low is harder, but electric valves, lighter materials and so on are on their way too.)

I've been reading stuff which debunks the man-made global warming ideas recently, but as long as governments are backing the intergovernmental panel on climate change (note, not scientific panel!) there will be a pressure to reduce hydrocarbon imports, and that's no bad thing in itself.

=

So much for me remembering Chapter 7!

Step 6 - Deleted
The original 2002 Low Carbon roadmap Step 6 [1] suggested a reversible fuel cell as an alternative to
a battery for high power storage. However it is now considered that, unless there is a breakthrough in
this technology, it is not as efficient as batteries and the power capacity improvement (allowing more
regenerative energy storage) does not offset the loss in system efficiency. Therefore, this Step has
been omitted in this update. For clarity the numbering jumps straight to steps 7 and 8, as these are
similar to the technologies used in the original study with those step numbers.

 

[evelrod]

I love it when politics overlaps technology. To believe such a MAJOR change in automotive propulsion technology will come about in 25 years is, IMO, a bit of a stretch. It has taken 35 years to just clean up the engine emissions to today's levels once the politicians decided to make laws governing such emissions. Should politics again step into the mix and mandate H₂ the fuel of choice---the only way it will really happen---it will still take much longer to relegate the old ICE to the graveyard.
Global warming? Do I not recall correctly that just a few years ago it was "impending ice age"? I have lived long enough that "the end of the world" will, most probably be a few years, at least, further down the road. ;-)

Rod

 

[crysta1c1ear]

http://www.phas.ucalgary.ca/~annlisen/teaching/CHEM421/co2hist.GIF

Just have a look what the CO² level was like during previous ice-ages. (That's why many global warming graphs start around 1980!) It seems there is actually a warming effect in progress at the moment, due to increased solar activity. The main greenhouse gas is water, by a long way, clouds serving to help keep night time temperatures up. Very little water vapour is of man-made origin.
But I guess all that is best left for another thread ...

 

[tbuelna]

If you look at the overall efficiency picture: wheel-to-well, nothing beats the good old diesel engine.

http://www.lbst.de/gm-wtw/WHEC15_GM-WtW_Reinhold-Wurster_28JUN2004.pdf

(look at the chart on page 5)

Regards,
Terry

 

[microhenry]

Evelrod wrote:
"To believe such a MAJOR change in automotive propulsion technology will come about in 25 years is, IMO, a bit of a stretch"
Have you noticed that the converion to 42V has stalled, but
GM sez they'll have commercial Fool-Cell cars by 2010!!

 

[evelrod]

I like that---"Fool-Cell"---quite appropriate in this instance!
With the politically adverserial climate existing in the U.S. today I find it not at all unusual, given we are knee deep in bad news that, any good news is being forcast even though it may, indeed, NOT contain a grain of probability.
If the GM says we will all be driving H₂ powered vehicles by 2010 who am I to argue? The fact that it takes GM more than five years just to get a new conventional design in production should not be a factor, should it?


Rod

 

[franzh]

I attended a lecture recently where the topic was global warming and CO2 buildup. It was shown that CO2 induced warming runs in naturally occuring cycles, and we are about 50 years overdue. Also, that the Human body is easily adaptable to minute temperature variations. In the last 100 years, there has been about a 1/3deg F increase in average temperatures, and I dont see people dropping like flies everywhere. In fact, I have seen record low temperatures in the last couple of years, and a record cool summer here in Texas.

I am looking in my notes for the authors name, will post when I find it.
Franz

eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[patprimmer]

Franz

When I see someone making a fuss saying it is getting warmer because we had the hottest summer in 30 years, that tells me it was hotter 30 years ago.

I will be more concerned when I see reports that say the hottest day, month summer etc ever recorded

Regards
pat pprimmer@acay.com.au
eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[evelrod]

Pat--- How much weight should we give "...hottest day, month summer etc ever recorded" given the current scientific community seems to feel that major climatic changes are in the >10,000 year range? I put it somewhere near the "fact" that by now all you folks in Oz should be radiated enough to "glow in the dark"--- "hole in the ozone layer" or some such!
Remember, especially in this climate of PCBS---Believe only half of what you see and none of what you hear.

Best wishes for a wonderful Christmas season to all.

Rod

 

[liberty]

One thing many people don't realize is how non-constant the sun is in terms of an energy source. For centuries we have observed sunspots and they are always changing. There is historical proof that the thermal energy from the sun drops during periods when there are no sunspots. It appears as though the number of sunspots increases prior to a burst of maximum solar output. Lately there has been a regular ~11-year sunspot cycle, and coinciding a few years after each peak we experience El Nino, relatively active/longer hurricane seasons, warmer ocean currents and increases in the ozone hole. Then when the sun cools off these things seem to correct themselves. 5.5 years from now people will be complaining about how cold it is and the "global warming" hysterics will fall silent once again.

Draw your own conclusions:

http://science.msfc.nasa.gov/ssl/pad/solar/sunspots.htm

I don't think the authors of the Kyoto Treaty want you to know how crazy our sun gets from time to time. It's more fun to blame those decadent Americans and Brits!

 

[HydroScope]

Well I managed to read through this thread last night and enjoyed conversation, but we seem to be missing some of the threads??, I am unsure why as the controvesy over hydrogen always shifts in the exact manner this thread represent last night. 1) efficiency of hydrogen generation distrubution and final use is not high.
2) green house gas emissions and other pollutants

lets not forget that hydrogen is already produced in large quantities for the manufacture of fertiliers and the petroleum industry. it can be achieved, what is stopping us "hydrogen storage" technology!!. who really cars if our vehicles are 10% efficient or 90% efficent!! If the car can drive 1000kms on one tank, the fuel is comparative in price to petrol and can be readily avalible plenty of petrol stations. if it has the advantage of being enviro friendly then governments will likely step in and mandate they be used.

A lot of people beleive hydrogen has a chicken and egg senerio as what comes first the cars or the stations? comments about certain companies having fuel cell vehicles ready by 2010 are certianly warranted, but the comment about fuel cells being 'Fool cells' is very incorrect. you are a fool not to have taken the time to find what market value fuel cells have at present and what they will have in the future.

there are many different types of fuel cells (further reading fuelcells.org) the type promoted for cars are the polymer electrolyte fuel cell PEFC where advancements are made readily and competition between companies is fierce. but there are others. such as Solid Oxide Fuel Cells (SOFC) these are made of ceramic materials and do not posses the same platinum poisoning that the PEFC's do. the fuel cells can use natural gas and even CO as a fuel. making them very practical for stationary applications. The efficiency of a fuel cell is defined by the gibbs free energy law and is not a a long shot above what a ICE is capable of, instead the quotes of 80% or even 90% are incorrecly made from not useing the HHV of hydrogen and assume the heat generated by the FC is also used. thus first application for FC's is not transport but stationary electrical power and heat.

CrystalClear I think maybe the reason for the removal of the reversible fuel cells from the document, is that out of all the types of fuels cells under developement progress from reversible fuel cells is the slowest and I only konw of one developer for applications on sailing boats in the 1-10Kw range. removing the noisey smelling diesels from the otherwise envir friendly moving boat.

Hydrogen is also not confined to use in fuel cells it can be easily used in ICE. it is capable of 20% more power from an ICE when direct injection is used. direct injection also solves some of the pre-ignition issues that have ocurred in past hydrogen ICE's. A bonus of hydrogen onboard is it's ability to be used as highly efficent reductant agent in NOx traps for lean engine operation ( a problem for diesels). BMW Ford and Mazda are exploring hydrogen internal combustion engines. Ford CEO beleives hydrogen IS the fuel of future and over 20 auto manufactures world wide have already built a FC's vehicles!! so if fool cells are foollish what are they doing?? spend billions because they can?? because governments are happy to hand them tax payers money? or is it because everybody appreciates clean air? and hydrogen provides an answer.

Well I don't think any bold statements about what I beleive hydrogens future is going to be worth while here, but I will leave you with the following senerio's

Vehicle emission restrictions are ever increasing
fuel standards are being raised (lower sulphur etc.)
catalytic converters are reaching there overall potential (start-up still a big problem)
Renewable electrical energy generation size is on the increase Fast!!. i.e wind turbines
some power plants are being refused due to there environmental consequences. redbank Vic aust.

For me these lead to one solution, we need to be able to use renewable electrical energy for almost all applications, since renwable energy can be unreliable we need to store it and hydrogen is the answer, while likely not the most efficient, the efficiency while important it is not the be all if you got a cheap renewable energy source in large quantities to begin with. it is only becomes a measure of the cheapest method of prod. distr. and final use. Take wind turbine competing with coal fired power and now as large as 5MW

http://www.repower5m.com/impress_flash_uk.htm

lets take for example what most cities have to get people around "the bus". here in sydney we have had a succesful project converting most busses to run on natural gas where a small amount of diesel is used to ignite the nat gas. this has lowered emissions where it is most needed the city!

converting this bus to then use hydrogen instead of nat gas is another step in the evolution of lowering emissions. as long as the hydrogen was generated from a renewable source. nat gas does not like to be burned in a lean environment and for all u green house gas fans methane has 21 times the GHG potential of CO2 this means while nat gas busses lower particulate emissions they increase green house emissions over regular diesel, hydrogen like would solve this.

the trends that are going to combine for hydrogen use as a fuel are:

1) larger and larger renewable power stations be it wind, solar thermal, wave, geothermal.

2) Water in australia becoming harder and harder to come by inducing the need for a desalation plant in sydney!.

3) solid oxide fuel cells hitting a large market for use with natural gas. (once hydrogen pipes for distribution of renewable energy, hydrogen will likely be cheaper dispalcing the use of nat gas for electricy and heat)

4) hydrogen readily avaliable and cheap people begin to convert cars to hydrogen and fuel cell vehicles are finally reliable and cheap.

the problem is putting a timeline on these.

p.s crystal clear can you put a link up where all those diagrams came from I sore the other night? I liked what I sore I wish to follow them up. ;o)

 

[evelrod]

spend billions because they can?? because governments are happy to hand them tax payers money?

It saddens me to say that the answer is almost universally YES !

HydroScope, I agree with what you post, mostly. However, at least in the SoCal area, we have thousands of windmills that stand idle most of the time (eg, Palm Springs area)and the Dagget Solar Power Station is never in use when I pass it on the way to and from Vegas!
H₂ will never be in wide use until and unless there is a substantial increase in demand---be it from "real" demand or "legislated" demand and that, IMO, is not likely anywhere in the near future. We have the technology right now, today, to build effecient 'hybrid' ( I don't really like that terminology) CI or SI electric compound power plants with little added expense but, and this is a very big BUT, we can't even get the folks around here to give up their SUV's!!! As long as petrol is only $2.00 a gallon---I guess I need not say more.
Hydrogen power? Yes, a definate possibility. Just not by 2010, indeed, probably not by 2030 either.

Rod

 

[GregLocock]

My guess is that we won't see hydrogen power as a significant contributor to transportation in our lifetmes (and that includes the 10 year olds reading this).

1) Well to wheel efficiencies are no better than what is currently available from a diesel engine

2) No practical method of storage and distribution

3) doesn't solve the fundamental problem

Just in case you've missed the point the fundamental problem is supposedly that we are burning hydrocarbons or carbon and creating CO2 and water.

If we have the energy, via nukes, solar or wind, then we can MAKE hydrocarbon fuels via century old technology, or we can use electric cars.

If we don't have the energy then all this is moot.




Cheers

Greg Locock

 

[evelrod]

Greg, I guess I was erring on the side of caution considering the volatility of the subject of late. Truth of the matter is that I don't think hydrogen as a motor fuel or power alternative will EVER make a substantial contribution to correcting our transportation problems in the long term. Short term, interim or special case---perhaps but, not in the long run, IMO.
I am a tecno geek (at least I have lost enough $ in the market to qualify as one) and my "confidence is high" in the assumption that a solution to our transportation, emission, etc. problems is right "at our fingertips". Had I told one of my professors that I would be communicating, real time, with engineers in Australia, indeed, the entire world in 40 years I would have been laughed out of class. Point of fact, no one of that time period, as far as I know, had even envisioned the WWW! There is a chance, remote that it may be, that I will still be here in 30 years---I'll get back to you then.

Merry Christmas, Greg

Rod

 

[HydroScope]

1) Well to wheel efficiencies are no better than what is currently available from a diesel engine

efficiency means nothing when you have a cheap renewable source of energy.

2) No practical method of storage and distribution

10,000 psi tanks, meet all required standards and fail safe, and hold hydrogen at 11.5% wt.
liquid hydrogen, metal hydrides

3) doesn't solve the fundamental problem

fundamanetal problem is not CO2 and water!! it is SOx, NOx, CO, CO2 and PM


hydrogen(from renewable source) ICE will rid these to almost unreadable levels (SOx,CO,CO2, PM) and substially lower the other NOx

a hydrogen FC has the potential to do further zero SOx NOx CO CO2 and PM!! problem solved!!

. . . . well not really as if a Life cycle assement is made then emission and pollution are made by limestone manufacturing to concrete for wind turbine foundation etc. and steel works and platnium mining etc. but these add up to be far lower the current expoltion of exhast emissions.

Also I was supprised to get my hands on N.S.W average pollution levels readings for the last 30 years to see all but PM and ground Ozone, has reduced dramatically. cheers to unleaded fuels and catalitic converters. but what these have no effect on is the increase in population over the last 30 years. If you bought a house in sydney 30 years ago you probably would have bought one 10Kms from the center of the city, since then the city has expanded 10times and now everyone is driving past your house pulling up for traffic lights and accelerating away. my point is local pollution, almost dosn't matter where you live it has increase likely 100 fold in the same 30 years average pollution gone down. thus a better answer needs to be found. Hydrogen. for above reasons.

If we have the energy, via nukes, solar or wind, then we can MAKE hydrocarbon fuels via century old technology, or we can use electric cars

as far as I am aware the chemical reaction in a battery can be summarised as hydrogen Ions moving through an electrolyte. lets remove the heavey electrolyte and carry hydrogen on it's own, yes hydrogen storage still needs large improvements but they are happening.

synthetic manufacture of hydrocarbons fuels is reality. but if you are talking about growing crops for ethanol and bio-diesel. how much land is needed for these crops? and they don't even solve the problem of NOx, CO, PM , these are ever increasing on a local basis.

If you are talking about using hydrogen generated by renewables to be catalytically combined with carbon to produce say methane, ethane or ethanol etc. the above problem is still true.

"Had I told one of my professors that I would be communicating, real time, with engineers in Australia, indeed, the entire world in 40 years I would have been laughed out of class. Point of fact, no one of that time period, as far as I know, had even envisioned the

http://WWW!"

. . . . . my point exacly . .. in one word . . . nanotechnology . . . ;o)

 

[evelrod]

. . . . . my point exacly . .. in one word . . . nanotechnology . . . ;o)

Accepted. My opinion still stands. Hydrogen as a motor fuel will, in all probility, never have a major impact on the transportation industry in my lifetime, if ever.

Rod

 

[shbazjinkens]

You seem to be missing a very valid point Hydro.. when you make Hydrogen it is either made cheaply with fossil fuels or expensively with clean electricity. How many square miles of windmills and solar collectors do you think it'd take to produce the required electricity to split water into hydrogen at less than 50% efficiency? At what cost? If fossil fuels are used to make the hydrogen is it any better than burning straight from the vehicles?

I think we'll see veggie oil and ethanol come into play when the oil supplies start dwindling. There are a lot of reasons for that, new tech and brilliant ideas that no one with cash is pursuing right now.