Posted By: owlmanthe material density and it's use in practice off sets some of those differences

Right - any rule of thumb for how many kg of CF replaces how many kg of steel (or aluminium?). AFAIK it's a factor of 4 or 5?

Then there's cumulative benefits from use of CF - ultralightweight car shells for example require much less power from a smaller (weight and fuel consumption) engine, and everything else - suspension components, brakes etc - much lighter.

I was surprised/shocked at the govt-funded UKplc flagship NCS's lack of interest in eventual recycling of CF. Also lack of interest in future development of CFs - nanotubes etc. And their belief that UK and Germany lead the world in CF/composites - US lagging far behind - not sure I believe that. All seemed complacent.

Any lower-energy processes in sight for production of CF? Direct from amospheric CO2?

Of course, high kWh/kg input matters much less if the slightly degraded process heat can be captured (instead of exhausted to outside or being cooled away from the factory interior by a/c) and used on-site/nearby for a cascade of other heat-using processes, eventually at lowest-grade to heat the neighbouring housing estate.

Posted By: GarethCIron melts at about 1100 degrees C, steel at 1500, aluminium at only 660 according to a website I just checked.

Seems so
http://www.chemguide.co.uk/inorganic/extraction/aluminium.html

Posted By: fostertomRight - any rule of thumb for how many kg of CF replaces how many kg of steel (or aluminium?). AFAIK it's a factor of 4 or 5?

You would have to work that out by tensile/compression/yield point/elastic limit strength, proably Young's Modulus is used. Not a straight swap.

Posted By: fostertomOf course, high kWh/kg input matters much less

or if your energy source is pure RE.

Posted By: fostertomI was surprised/shocked at the govt-funded UKplc flagship NCS's lack of interest in eventual recycling of CF

I looked into this nearly 30 years ago. Generally recycling still allows the polymers to stay intact, it is hard to split a composite matrix up and not damage the fibres. CF is very brittle and shears easily. It is also coated to help it bond to the resins.
I did think of grinding it up and using it as a filler, but then there are really cheap fillers available.

Posted By: fostertomAny lower-energy processes in sight for production of CF? Direct from amospheric CO2?

Are you talking of making the carbon fibres from atmospheric carbon dioxide. You are then dealing with 400 ppm, and if we could do that economically, we should bury it and forget all about it. Best leave that the the trees I think.

SteamyTea 59 minutes ago

".As were most of the chemicals used back then. I used to clean the tooling with toluene, liquid styrene and acetone. I am still waiting to see what happens.

Me too ST.
I used to spray two pack PU. The isocyanates in the catalysts were supposed to be very dangerous. A chemist friend once told me they were less of a problem than some other forms of furniture lacquer AC, Pre CAT etc., as once they had evaporated, usually very rapidly, the lacquer that remained was free of any other longer term "off gassing". I'm not sure if he was right. Anyway I usually made sure I stood well upwind. . Time will tell.

Yes, plants do achieve it, but at a very slow rate and they use a huge amount of energy to do so.
Without going though the usual chestnut, the efficiency is pretty poor.

If you want a vehicles that can go a long way on a little fuel, get a motorbike.
http://gas2.org/2014/11/05/11-best-fuel-efficient-motorcycles-can-buy-2015/

Not that bikes are that great, they should be a lot better.

1: What is your present car (make, model, trim, fuel type, age)

2: Annual Mileage

3: What vehicle are you thinking of getting next

4: Dream 'Eco' Vehicle

5: Dream Vehicle



Volvo S60 d5s diesel 11yrs
Was25k now 5k
BMW m5 touring
Zero ds electric motorcycle
BMW m5 touring


Aluminium is essentially made using electrolysis as well as heat, not just heat, so huge amounts of electricity are required. Other materials just require heat, which doesn't necessarily involve electricity

I found some real world figures for the Auris, after six months driving by a motor journalist. Not 80mpg, but averaging nearer 50!

http://www.honestjohn.co.uk/our-cars/toyota-auris-touring-sports/the-final-auris-reckoning/

Our tiddly 1.24 petrol Ford Fiesta has a combined figure of 50mpg according the Ford advertising. Real world figures always below 40. Even if I drive it very carefully and see the average figure of 50 on the computer, measuring brimfill to brimfill gives a figure below that of the computer, generally by ~7%

My 2000 Ford Focus 1.6 (petrol )always returns above 40 mpg and on a longer run at motorway speeds will return 45+

I have no idea what will replace my trusty old car when it goes to that great car park in the sky

Posted By: cjardAluminium is essentially made using electrolysis as well as heat, not just heat, so huge amounts of electricity are required. Other materials just require heat, which doesn't necessarily involve electricity

It's not the electrolysis per se - steel is also made in a carbon arc furnace. It's simply the energy containing within Al2O3 is much higher than in Fe2O3 - if you look at the enthalpies of formation of these:


Al2O3: −1669.8
Fe2O3: −826
FeO: −272

The main ore for Al is Bauxite - which is as easy to mine as iron ore, but then it has to be converted to the oxide via sodium hydroxide. Then the Al203 is fluxed with sodium fluoride to give a lower melting point and three electrons are required per atom of aluminium - so it all adds up to a lot of energy. Iron is easy - carbon is able to reduce the oxides to CO, CO2 and liquid iron.

Paul in Montreal.

My experience is the reverse of Mikel's. On long runs I can achieve 60mpg driving mainly on cruise control. I lived in North Yorkshire and my average was around 54mpg mixed driving. In February we moved down to Cornwall and the day to day economy is way down such that my overall average (it's about 8000 miles since I last reset the computer) is now reading under 50mpg after just three months.
The quality cars have the best technology. I reckon a good gearbox makes a big difference. Mine has a 7 speed dual clutch auto and I let it do the decision making.
Cornwall and Devon are locked into the 1960s in communications of all forms, roads, public transport and the internet is about 12 years behind Yorkshire. Cornwall is trying but also lying about its broadband but Devon is just a total shambles.
The VED rates are daft. My wife's IQ is zero and my car is £130 but my car burns less fuel in reality, it is diesel though.

Posted By: renewablejohnDont underestimate the amount of aluminium which is recycled at far lower energy content

Oh, I'm not! It's just that there was a comparison earlier of the energy cost of new materials. Aluminium is easier to less energy intensive to recycle than steel.

Paul in Montreal.

Posted By: SteamyTeaBouncing around Cornish lanes is never going to be great for fuel economy. I would think than a cruise along the M11 is probably pretty good.

The opposite in a hybrid. Cornish lanes not unlike urban stop-start, where hybrids are supreme. Hybrids poor on motorways.

What's the embodied energy in your new Auris hybrid ST?

Where does the tipping point occur in terms of buying a new efficient vehicle versus continuing to run an older less efficient vehicle until such time as it is uneconomic to repair it?

Seems like the Auris or Prius hybrids wouldn't be a good choice for me anyway as most of my commute is A road and motorway.

A small diesel such as the Peugeot 208 HDi would seem like a better bet as a commuter vehicle although I have just seen photos of the new model Skoda Superb and it looks very tasty.

When someone tail gates me I like to entertain the kids by flooring the accelerator quickly
making the auto drop a gear and surrounding the car behind in black smoke :-)
Oh how we giggle as they drive by later shaking their clenched fists

Posted By: Chris P BaconWhat's the embodied energy in your new Auris hybrid ST?

I not got a new Auris, just used it as an example.

Google hit number one (about Prius) was this one:
http://www.motherearthnews.com/green-transportation/embodied-energy-prius-vs-hummer-zb0z1206zmat.aspx

No idea if it is true or not. Not actually read it all, got bored.

Very late in the day; can I give you our vital stats?

1. BMW 328i, rust edition, P, 1997
BMW M3, lightweight, P, 1996
. Seat Alhambra, 1.9 haute luxo, D, 2000
. VW Touran, 1.9 basic, D, 2010

2. 3k
. 1k
. 12k
. 20k

3. Alhambra will need replaced soon (240k miles)
prob with another one, same age, lesser miles.

4. i8

5. Mr. Atkinson's old F1?