Audi creates synthetic diesel fuel using only CO2 and water

[Borgholio]

http://www.sciencealert.com/audi-have-s ... -and-water

German car manufacturer Audi has reportedly invented a carbon-neutral diesel fuel, made solely from water, carbon dioxide and renewable energy sources. And the crystal clear 'e-diesel' is already being used to power the Audi A8 owned by the country’s Federal Minister of Education and Research, Johanna Wanka.

The creation of the fuel is a huge step forward for sustainable transport, but the fact that it’s being backed by an automotive giant is even more exciting. Audi has now set up a pilot plant in Dresden, Germany, operated by clean tech company Sunfire, which will pump out 160 litres of the synthetic diesel every day in the coming months.

Their base product, which they’re calling 'blue crude' is created using a three-step process. The first step involves harvesting renewable energy from sources such as wind, solar and hydropower. They then use this energy to split water into oxygen and pure hydrogen, using a process known as reversible electrolysis.

This hydrogen is then mixed with carbon monoxide (CO), which is created from carbon dioxide (CO2) that’s been harvested from the atmosphere. The two react at high temperatures and under pressure, resulting in the production of the long-chain hydrocarbon compounds that make up the blue crude.

Once it's been refined, the resulting e-diesel can be mixed in with our current diesel fuel, or used on its own to power cars in a more sustainable way.

Sunfire analyses have shown that the synthetic fuel is not only more environmentally friendly, but also has superior combustion when compared to fossil fuels. The overall energy efficiency of the e-diesel is 70 percent, they report.

"The engine runs quieter and fewer pollutants are being created," said Sunfire Chief Technology Officer Christian von Olshausen in a press release.

Of course, with the initial factory only pumping out around 160 litres each day, the fuel isn’t going to have a huge impact on the market just yet. But Audi and Sunfire now want to build a bigger factory, and anticipate that once production is scaled up, the e-diesel will sell to the public for between 1 and 1.50 Euros per litre, dependent on the cost of renewable electricity.

With traditional diesel currently on the market for upwards of 1.50 Euros per litre in Germany, this would make the fuel extremely competitive, and perfectly positioned to made sustainable travel accessible to everyone. "If we get the first sales order, we will be ready to commercialise our technology", said von Olshausen.

Just imagine being able to tear around the countryside in an Audi sportscar, and not having to feel guilty for all the CO2 emissions you're producing. We can't wait.

Video at the end of the article. This is pretty neat. They just need to find a way to capture enough CO2 out of the air to actually make an impact.

[Zeropoint]

It sounds like the net process (i.e. production and combustion) is going to remove exactly zero CO2 from the air in the long run. That's still a big improvement over putting it INTO the air, though!

I'd like to know how much of the process that 70% efficiency covers. Is that sunlight to fuel tank? It obviously can't be sunlight to wheels.

[madd0ct0r]

since we're respoting stuff from reddit let's also look at the top comment:

This synthesis of fuel is called the Fischer-Tropsch process and it's been known since 1925.
Audi did not invent it. It's been used before by the countries that could not procure enough fuel by other means (i.e., Nazi Germany during WWII).
Also, it's quite energy inefficient, meaning that you will spend way more energy than you'll be able to recover when you burn the fuel. The fuel you make will be much more expensive than producing fuel from oil.

[Mr Bean]

This has been covered already, it's just an improved method of what was developed in the 1920s however... it's not all THAT much more efficient and it requires 120$ a barrel oil to make it cost effective with just digging it up and sending it across the world.

[Irbis]

This has been covered already, it's just an improved method of what was developed in the 1920s however... it's not all THAT much more efficient and it requires 120$ a barrel oil to make it cost effective with just digging it up and sending it across the world.

Yeah. Gleefulness from low oil prices we had recently makes people forgot it also kills all sorts of green technologies that can't compete.

From article, where exactly high temperature and pressure will come from when you use renewables? Electricity? Extremely wasteful. If only we had some sort of technology letting us create massive amounts of carbon neutral power in compact building with 'free' waste heat and pressure... Oh wait.

Also, didn't EU started war on Diesel recently? That alone might make this uncompetitive.

[Guardsman Bass]

If it's cost-effective at $120/barrel, I'd say that's really good news. Oil is not going to be below that forever, especially after getting above it 7 years ago.

[LaCroix]

If it's cost-effective at $120/barrel, I'd say that's really good news. Oil is not going to be below that forever, especially after getting above it 7 years ago.

I know (wife works in the opil business) that it's an open secret that the OPEC is committed to keep it at current price for as long as it needs to kill all companies that have invested in oil sand or fracking technology. The number floating around is that they can keep it at current prices for 6 years, if need be.

Regardign EU regulations - since this fuel is carbon neutral, it might be exempt from some regulations or taxes. For example, since it is not made from mineral oil, the mineral oil tax should not apply(at least not entirely, in theory) - which would drop the price significantly. Even if they only classify it as being taxxed as if it were LPG or LNG, it would reduce the tax on it by 60-80%.

[AMX]

I'd like to know how much of the process that 70% efficiency covers. Is that sunlight to fuel tank? It obviously can't be sunlight to wheels.

Looks like it's electricity to crude-equivalent:

In two further steps, the hydrogen reacts with the CO2 in synthesis reactors, again under pressure and at high temperature. The reaction product is a liquid made from long‑chain hydrocarbon compounds, known as blue crude. The efficiency of the overall process – from renewable power to liquid hydrocarbon – is very high at around 70 percent. Similarly to a fossil crude oil, blue crude can be refined to yield the end product Audi e‑diesel. This synthetic fuel is free from sulfur and aromatic hydrocarbons, and its high cetane number means it is readily ignitable. As lab tests conducted at Audi have shown, it is suitable for admixing with fossil diesel or, prospectively, for use as a fuel in its own right.

[Darth Tanner]

At 70% efficiency you would need 2.3MWh of electricity to make a barrel of oil and at US average energy cost of $98/MWh that means making a barrel of oil would cost $226. To be cost effective at $120 you would need your energy to be costing around $52 assuming all your equipment, staff and distribution is free. I imagine that's doable if you have a direct connection to the generator with excess capacity or its renewable and generation subsidies are meeting most of the actual energy cost.

[Irbis]

Regardign EU regulations - since this fuel is carbon neutral, it might be exempt from some regulations or taxes. For example, since it is not made from mineral oil, the mineral oil tax should not apply(at least not entirely, in theory) - which would drop the price significantly. Even if they only classify it as being taxxed as if it were LPG or LNG, it would reduce the tax on it by 60-80%.

I meant this:

http://www.bbc.com/news/science-environment-26257703

EU recently woke up to the fact diesels produce a lot of soot and nitrogen dioxides, something running against air pollution regulations which will only get worse with time as the standards are raised and pollution accumulates.

Incidentally, in quite a few new EU states old diesel cars from west EU have their particulate filters cut off for valuable metals scrap, making engines slightly stronger and produce a lot more toxins, raising diesel pollution average for whole EU. In the west, such practice is illegal and heavily fined, in south and east, who cares, the regulations are communist, we need cars NOW!

[Sky Captain]

At 70% efficiency you would need 2.3MWh of electricity to make a barrel of oil and at US average energy cost of $98/MWh that means making a barrel of oil would cost $226. To be cost effective at $120 you would need your energy to be costing around $52 assuming all your equipment, staff and distribution is free. I imagine that's doable if you have a direct connection to the generator with excess capacity or its renewable and generation subsidies are meeting most of the actual energy cost.

Maybe they plan to use renewable electricity when there is overproduction and price is low although that means their (most likely very expensive) fuel plant would stay idle when electricity prices are high.

[salm]

Wouldn´t something like this be part of a solution to the energy storage problem the renewable energy sector is craving?

[madd0ct0r]

airplanes aren't getting off hydocarbons any time soon, and this would allow production near the airports - shipping air fuel is a major constraint, especially in planning scenarios where shimpements cannot be guaranteed.

I believe worry about this had got to the point they were looking at biomass plantations near airports for feedstock in the same eventuality.


Salm - storage weak suace for electricity. 70% loss going into hydrocarbon form and less the 40% of that 70% comes back out the generator, so 35% storage with significant 'pipe' issues (how big does the conversion plant have to be to catch the surplas spikes, how long would it stand idle between them)

[Darth Tanner]

Wouldn´t something like this be part of a solution to the energy storage problem the renewable energy sector is craving?

Depends, as it stands their a little vague on the costs. Using electricity to make hydrogen and then turn that hydrogen into barrels of oil strikes me as a significantly more expensive enterprise than they seem to admit. The electrical means of making hydrogen at present are very expensive as you need very expensive metals to run the process let alone turning them into oil. It also does little to help the fact running oil generation for electricity generation would be insanely expensive, its the reason most oil power stations are either shut or used solely as emergency reserve.

If you were using this process to provide reserve for a renewable grid you would face the immediate problem that your storage medium is giving a return journey on your electricity of less than even terrible quality batteries as you must first generate the electricity (from subsidised renewables) pay to turn it into oil at 70% efficiency, refine that oil into your needed fuels, move that oil to your power station before burning it in a 30-40% efficient plant.

For every MWh you wanted out of this storage medium you would have to put in at least 3.6 times as much electricity to the process and that before infrastructure, refining and distribution. You'd be better off just keeping it as hydrogen and running it into fuel cells but that's not economic either.

For applications which absolutely need oil like substances though, air travel and heavy machinery though it seems a good solution to relying on actual fossil fuels.

[aerius]

I call bullshit. The first step in their process is high temperature electrolysis of water to produce hydrogen. This is about 60-70% efficient the last time I checked, though it is possible in theory to get it up to the 90% range if you use waste heat from a high temperature nuclear reactor or something of that sort. Then you still need to run Fischer-Tropsch which as I recall is in the 60% range for gas to liquids, plus there's the energy needed to filter CO2 out of the air, so overall efficiency would be in the 40% ballpark at best.

Now, if they said they'd be using a high temperature gas or liquid metal cooled nuke reactor to provide the heat & electricity for the everything, it would make make sense. The reactor can provide heat for both the high temp electrolysis and the Fischer-Tropsch steps of the process, as well as generating the electricity needed for electrolysis, CO2 filtering, and all the other steps. Running it on renewables is horribly inefficient in comparison.