Zero-carbon fuel PN (Calum?)

Zoo Tycoon said:
I don’t understand the figures in your table and where the table itself comes from.

The process used to convert CO2 and hydrogen into a fuel is the Fischer Tropsch.This process runs at 1100C so is vey energy intensive.

In simple terms, if the maximum theoretical thermodynamic efficiency of Fischer Tropsch is 51%< see link below & remember the real world will be less than this> then the final efficiency will further diminish with each step in the fuel production;- Carbon Capture Air induction,CO2 separation, transport, hydrogen generation, electrical power generation etc hence the final energy fraction will be very significantly less.

www.sciencedirect.com

Process efficiency of biofuel production via gasification and Fischer–Tropsch synthesis

A thermodynamic equilibrium model was used to predict the composition of syngas produced by oxygen-blown biomass gasification at different operating c…
www.sciencedirect.com www.sciencedirect.com
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So find other uses for that high heat, don't just make a single purpose factory. Distill seawater to make drinkable water. Make freaking glass if you have to. Make steam and blow the steam through turbines to make electricity.


edwest4 said:
Electric already has the range. Those who hold oil stocks are desperate to see prices go up. In the meantime, the oil industry will continue since a great deal of money has to be shifted from oil to alternatives. It appears all of that has been planned out.
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Not for heavy loads like trucks and trains.

Or even hauling an RV someplace. 300 mile range if you're cruising around in that electric F-150. Soon as you haul a trailer, though, you're recharging every 100 miles. And while I know some people who were cool with stopping every hour or so to check something out, they're distinctly in the minority of people.



F119Doctor said:
If you are going to make ethanol from either fermented sugars or cellulose, a better fuel is butanol. This 4 carbon alcohol has higher energy density, high Performance Number (100+), runs at similar fuel air ratios as gasoline, and doesn’t mix with water like ethanol.

There are challenges to be overcome to ferment butanol from sugars but a lot of research has been done to get similar conversion efficiencies as ethanol fermentations. And cellulose fermentation has the same challenges for both.
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Oh? I need to look this up. Got any recommendations to start?



Michel Van said:
BACK TO TOPIC

That what about zero-carbon petroly
There were several Attempts for that:

One is use of Hydrogen that produce watervapor
But since hydrogen need allot energy to produce it and is bulky to storage...
It never was consider as propellant by commercial Airlines

Another was Silane a Silicon-hydrogen (SiH4) consider in 1970s as replacement for Petrol
but it has similar problem like Hydrogen, plus it undergoes spontaneous combustion with air
Next to that produce the combustion SiO2 aka Sand, what you not want in Jet engine !

In 1950s USAF experiment with ZIP-Fuel aka HEF made out hydro-boron compounds
Next extrem cost to produce, that stuff does terribly things with Jet engines and exhaust was extrem toxic !
try to maintain a such Jet engine in hazmat suit...

in 2010s was also this proposal Water and Boron as Fuel for Aircrafts
by Tareq Abu-Hamed from University of Minnesota, so called "on demand hydrogen production"
Water react with Boron form Boronoxide and Hydrogene
The Hydrogene is used for Jet engine or fuelcell -> electro motor
while the Boronoxide is stored and recycled in a Plant at Airport

I think the FAA will never approve all those proposal...
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I think the best non-petroleum option for aircraft is going to be ammonia. Partially cracked using exhaust heat, sending the hydrogen up to the front of the combustion chambers to kickstart things and using a very long combustion chamber to get all the raw ammonia burned.



Dagger said:
Just some remarks:
NH3 (ammonia) is very toxic so I doubt that it will ever be used in commercial transport.
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As to the toxicity of anhydrous ammonia, well, yes. It's nasty stuff, if you happen to be sprayed by a leaking refrigerator pipe. Otherwise the way to deal with a leak is keep people away from it till the ammonia evaporates and goes up into the sky.

We have been using it for a good 100 years or more as a refrigerant. The ice plant about 6 blocks from my house still uses an ammonia plant.


Dagger said:
To produce green NH3 one needs green H2 (hydrogen) and N2 (nitrogen).
Green hydrogen is produced by electrolysis of water, which consumes a lot of electricity.
Nitrogen is produced by cryogenic distillation of air, which also consumes energy.
Then H2 and N2 are reacted into NH3 which again consumes energy.
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Nitrogen is also produced as a byproduct of making oxygen for medical and industrial use. Yes, nitrogen does have some industrial uses, but when the stuff makes up 80% of the atmosphere, there's plenty "waste" N2 generated from out current methods. All that "waste" N2 can go to ammonia fuels.

Oh, no, we need more energy to power the various processes. One word for you: NUCLEAR.


Dagger said:
The NH3 could be burnt as a fuel, of used as a hydrogen source.

If that NH3 is to be a hydrogen source then it is to be split into N2 and H2 which again consumes energy.
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If you're burning NH3 directly, the exhaust gasses will be hot enough to cover the heat needed to crack the ammonia. And then you don't need to crack all the ammonia you're burning, you only need some hydrogen to provide the initial heating. Does make for a bit of a messy fuel system, with dual injectors using different timing I believe, but it's not any worse than some modern gas engines with port and direct fuel injection.

I'm not a huge fan of hydrogen fuel cells except for very specific uses. As a general propulsion option or electrical generator? No thanks, dealing with hydrogen sucks too much. If you absolutely have to use fuel cells somewhere and are using ammonia as the easier-handling option, I'd set up some large burners to make enough heat to crack all the ammonia you need while using some ammonia burned directly for heat. I think you can get away with that with catalysts.
 
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Scott Kenny said:
I think the best non-petroleum option for aircraft is going to be ammonia. Partially cracked using exhaust heat, sending the hydrogen up to the front of the combustion chambers to kickstart things and using a very long combustion chamber to get all the raw ammonia burned.
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yes that good alternative

Scott Kenny said:
I'm not a huge fan of hydrogen fuel cells except for very specific uses
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there efficiency is low to power high Performance electrical engine like for Aircraft...
 
F119Doctor said:
A starting place for bio-Butanol
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Biobutanol has been used as a fuel in motor racing in the recent past. A DuPont-Shell joint venture was producing it from wood waste and other biomass in the early 2010s, and because it could be freely blended with gasoline, it was adopted in the American Le Mans Series for a time.

Because it has a higher energy density than ethanol, it had some benefits in terms of vehicle packaging and fewer pit stops.

IndyCar used denatured ethanol for many years. Not sure what they will be using under the new rules package, now that Shell is the fuel sponsor (real Shell, not Motiva).

Total supplies the World Endurance Championship with a synthetic fuel derived from wine waste.
 
GeorgeA said:
Biobutanol has been used as a fuel in motor racing in the recent past. A DuPont-Shell joint venture was producing it from wood waste and other biomass in the early 2010s, and because it could be freely blended with gasoline, it was adopted in the American Le Mans Series for a time.

Because it has a higher energy density than ethanol, it had some benefits in terms of vehicle packaging and fewer pit stops.

IndyCar used denatured ethanol for many years. Not sure what they will be using under the new rules package, now that Shell is the fuel sponsor (real Shell, not Motiva).

Total supplies the World Endurance Championship with a synthetic fuel derived from wine waste.
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I bet. The usual hit to MPG from going from gasoline to E85 was something like 2/3. 24mpg on gas, 16 on E85. So the money savings of burning the cheaper fuel were taken out by the increased fuel consumption.

But if you're burning E85 for performance, it's significantly better. You can run higher boost from a turbocharger without detonation, since the E85 will evaporate in the intake and cool the air down enough to condense water(!).
 
E85 will just evaporate in a small fraction in the intake of naturally aspirated engines and the large amount of evaporation heat hinders the homogenisation in the cylinder. Starting a MPI engine with E85 can be tricky and the engines will have problems with load changes. I drove quite a lot with "E60" (E85 plus some gazoline) without modifications in my old Astra, it worked well once the engine was warm.
 
Nicknick said:
E85 will just evaporate in a small fraction in the intake of naturally aspirated engines and the large amount of evaporation heat hinders the homogenisation in the cylinder. Starting a MPI engine with E85 can be tricky and the engines will have problems with load changes. I drove quite a lot with "E60" (E85 plus some gazoline) without modifications in my old Astra, it worked well once the engine was warm.
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Hence my comment about running a lot more boost.
 
Foo Fighter said:
What is the F1 variety?
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Currently, F1 uses E10, with the ethanol made from non-food sources.

The target for the 2026 rules package is 100% sustainable fuel. The actual composition is unclear at this point. It might be fuel created using the Porsche-Exxon direct CO2 capture process, or another alternative process from Aramco.

F1 has used some pretty exotic brews in the past. The dominant Honda turbo V6 of the 1980s used a fuel composed of 84% toluene and 16% heptane.
 
F1 in the 1980's was absolute madness. 1984 McLaren had 1500 hp in quals in... Monaco. It scared the living shit even out of the late Lauda.
 
Before the Honda, the Porsche V6 was dominant, it shouldn't be forgotton, as well as Ranault V6 which was the first Turbo engine in F1.

The fuel rules changed several times during the 80 th, but the fuel wasn't really much better than ordinary fuel from the gas station. A lot of effort was taken, to optimize the volumetric energy content while keeing the Octane number relatively low (because of the rules).
 
At least most of the time, thats indeed correct for a typicall 1.0 L downsizing engines with a long gear ratio.
 
Nicknick said:
At least most of the time, thats indeed correct for a typicall 1.0 L downsizing engines with a long gear ratio.
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And of course me being an evil hot rodder at heart, I want to use the electric motor core of most of those turbos but on bigger compressor/turbine wheels. So that a 4 rotor wankel that can spin at 10krpm will still have boost at 2krpm.
 
Nicknick said:
Sounds intresting, but what do you mean with "electric motor core of most of those turbos"? Elektrik supported turbo chargers are common in large two stroke engines and Formula1 race engines but other than that only prototypes do exist.

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Mercedes/AMG is using a couple of them. One with a 48v electric motor to go with their mild hybrid system, another one with a 480v motor in the top of the line model.
 
Nicknick said:
Before the Honda, the Porsche V6 was dominant, it shouldn't be forgotton, as well as Ranault V6 which was the first Turbo engine in F1.

The fuel rules changed several times during the 80 th, but the fuel wasn't really much better than ordinary fuel from the gas station. A lot of effort was taken, to optimize the volumetric energy content while keeing the Octane number relatively low (because of the rules).
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