571–580 of 589 posts
( I am pretty sure even if it was 30% more expensive at Retail consumer will still be willing to paid for Clean Petrol, and that 30% could be your profits. )
At what sort of electricity cost do you expect to produce the fuel at same price as current petrol? ( I am pretty sure even if it was 30% more expensive at Retail consumer will still be willing to paid for Clean Petrol, and that 30% could be your profits. )
Earlier quoted context omitted.
Could you give a source for that? My understanding after some search is that effect of high-altitude water is hard to evaluate. I agree that at high altitudes contrails may evaporate and the water then may not fall down... Is it possible that jet exhaust water vapor accumulates in stratosphere? That would be terrible.
It is hard to evaluate, but of course being hard to evaluate does not mean it's not a real thing. The effect (not counting contrails) is about double the effect of CO2 emissions alone. Including contrails, it may be even higher. There are mitigation strategies to deal with these non-CO2 radiative forcing effects, though it's very complicated. Good article: https://www.carbonbrief.org/explainer-challenge-tackling-avi.…
https://elib.dlr.de/68051/1/fugl-2010-4648.pdf
which says
> At pressures greater than 500 hPa (i.e. below roughly 6 km), the forcing [of water vapor] is assumed to be negligible
So flying below 6km would help a lot for impact of water vapor. However, given this was not yet acted upon, IPCC is probably right that
> the effect of water vapour emissions is likely to be a significant, or even the dominant, contributor to their climate forcing.
This is even worse given the projections of aviation expansion. Right now the water does not seem to be a big problem and it could stay that way - water lifetimes even in stratosphere is counted in years, as opposed to centuries for CO2 - but if aviation expands, then it becomes more serious than CO2.
Earlier quoted context omitted.
We expect a gallon of gasoline to require approx. 60 kWh of electrical energy. If the price of that electricity is below 5 cents, the economics work. If the price is lower, the efficiency of the conversion could also be lower if that optimized other costs (like capital). Electricity is routinely below 5 cents now at utility scale (wholesale), which is where we will want to be.
60 kWh capacity EV will get you (realisticaly) 200 miles. A gallon of petrol - 40 miles (realistcally and using UK gallon). According to Tesla their charging is 92% efficient so reduce that 200 to 184 miles. Your process is 4.5 times less efficient than just putting that electricity into the EV? Is that right? If so - and your process is carbon neutral (big if) - what's the point in a future where EVs dominate?
This is really cool! I hope that you can rise above the comments of the "this isn't good enough" or "zero carbon or bust" crowd. This type of innovation is what we need to move the needle in a realistic manner and that helps to build on the infrastructure that we already have in place. I'm excited to see what comes of this in the coming years!
I'm conflicted. This is clearly better than what we have but I was really hoping for a carbon negative future. I hope projects like this are a stepping stone and not a handbrake on progress.
A few questions from a chemistry major 1. why extract from the air when you can just put a device on the smokestack of an existing coal or natural gas plant? The higher CO2 density of the effluent will make things more efficient. 2. Your key innovation isn't the part where you pull CO2 out of the air; it's the nanotube-based reverse osmosis process for separating ethanol from water. This process could just as easily…
But then, why to use solar energy to convert CO2 into fuel when you can convert the solar energy into electricity directly and remove the need for the fossil fuel based power plants?
How is this different from what the US Navy has been trying to accomplish with turning seawater into Jet fuel? I know that they are extracting CO2 from the water instead of the air, but I believe the last I heard they had large inefficiency issues. And for them they plenty of power from their onboard reactor.
Google X did a project to remove CO2 from seawater and turn it into fuel. It was called project Foghorn: https://x.company/projects/foghorn/ They couldn't get the economics right, but did succeed in making fuel. Their tech lead is an advisor of ours and is excited to get there this time!
The Navy would be highly interested in this, as they've had a project in the works for years (via NRL) to create jet fuel from seawater. They're basically 25% efficient right now, and the physical size of the device vs the output is quite prohibitive... But the advantage of making jet fuel on the carrier itself for the planes, by using onboard nuclear vs having to dispatch and maintain a fueling fleet is quite attrac…
Earlier quoted context omitted.
60 kWh capacity EV will get you (realisticaly) 200 miles. A gallon of petrol - 40 miles (realistcally and using UK gallon). According to Tesla their charging is 92% efficient so reduce that 200 to 184 miles. Your process is 4.5 times less efficient than just putting that electricity into the EV? Is that right? If so - and your process is carbon neutral (big if) - what's the point in a future where EVs dominate?
In the long term, electric vehicles may indeed replace ICE cars. That would be awesome. One way to see what we're doing is to make sure the path to that future is good. We can't burn fossil fuels while we wait to replace the existing vehicle fleet with electric cars. By using zero carbon we make sure that we are solving the problem right away.
It might also be worth looking at where airplanes tanker fuel, that is to say, carry more fuel than they need for their current leg because refueling at the next stop would be difficult or expensive. Apparently a lot of that currently happens on short flights to small islands; while I hope Wright Electric and/or the EViation Alice will eventually take over that market, in the short term that's a market that might be willing to pay a bit more for liquid fuel made from air plus local solar panels.
Fuel oil that can be burned in combined cycle power plants in the winter may also be valuable for dealing with seasonal imbalances in demand vs renewable generation that lithium ion batteries can't cost effectively balance.
Earlier quoted context omitted.
You could make a lot of stuff from the CO2 in the Martian atmosphere, for sure!
Not a chemist, but as far as I understand the process you're using to process the CO2 also needs water or at least some other source of hydrogen? Where would you get that from on Mars? (Sure, there is water on Mars but not in the atmosphere.)