I am involved in this project. The aim is to built a demonstration plant to show the feasibility of the process and to develop a blueprint for larger plants that can produce sustainable jet fuel economically. Producing sustainable fuels is always more expensive than fossil fuels. However, upcoming legislation and taxation (at least in the EU) will change this equation.<p>Someone mentioned an efficiency of around 50% in a post here and resulting pricing, that's a fairly good estimate of the overall process and what is discussed as achievable cost for renewable synthetic fuels in general. The process is in this demonstration plant is Fischer-Tropsch. Using CO2 from an industrial point source is more efficient; however, it has potential legislative issues when it comes to certification of sustainable fuels, emission certificate trading... it's a fairly complicated topic. In addition, worldwide potential for lowest renewable energy costs does not correlate necessarily with existing CO2 point sources. That's why direct air capture makes a lot of sense.<p>Whether CCS is a better solution depends on renewable electricity pricing vs. the CCS costs, public acceptance and feasibility at the location of a plant. These vary strongly depending on where you are in the world. In many parts of Europe there is strong opposition to it as it may prolong the exploitation of fossil sources.
The jet fuel part of this is a distraction from the important (and hard) part - turning electricity into usable liquid fuel.<p>Electrolysis is easy enough, and there's plenty of places with enough water.<p>Then you have hydrogen. Hydrogen is not nice to work with, store or use, so you want to turn it into something else a bit nicer.<p>The problem is, almost all practically usable liquid or gaseous fuels contain carbon. Where do you get that from?<p>The obvious answer is the atmosphere. That's also the premise of carbon sequestration. The problem is that CO2 isn't actually particularly abundant. It's currently hovering around 400 parts per million - that's about 0.04% of air. To make a kg of hydrocarbon you need to process an awful lot of air to get enough CO2. That all takes energy. A lot of energy. Suddenly your round trip efficiency is practically zero. If these guys have cracked that problem, it would be fantastic. I hope they have, but I suspect they haven't.
The US Navy is already experimenting with producing synthetic jet fuel on aircraft carriers using power from the nuclear reactor. Their concern is with reducing the logistics chain rather than environmentalism. But if the research results are made public they could be applied to commercial aviation.
Let me get out my back of the envelope for some quick and inaccurate calculations ;-)<p>There are 10.3 kWh of energy in a litre of Jet A1 fuel.<p>Let's assume (generously I think) that the process is about 50% efficient, so it takes ~20 kWh of electricity to make a litre of Jet fuel.<p>Assuming (amortized) solar power is the same cost as grid power ~$0.1/kWh then to make your litre of fuel costs 20 *0.2 = ~$2/litre<p>According to my research Jet A1 costs about ~$0.50/litre.<p>So this is a way off at the moment, however if there was tax on fossil fuels for aviation then this could be competitive.
The question should not be whether this is too costly as compared to jet fuel, but at what carbon price is it cheaper than jet fuel? Once the cost of carbon is at the long term limit, which is equal to the cost of extracting carbon from the atmosphere, then these technologies could be much more cost effective. (But if they aren't, there would be no reason to ban flying, as the carbon price would pay for the extraction of carbon that flying produces.)<p>By not account for how much jet fuel costs with increasing carbon pricing, and by framing the alternative to allowing climate change as banning flying, it seems like the author has completely missed the story..
I guess a more low-tech approach would be to fuel jets with ethanol. Googling a bit now, the U.S. uses about 18 billion gallons/year of jet fuel[1], and produces 17 billion gallons/year of fuel ethanol [2]. The price per gallon is about $1.5 versus $1.94 [3,4]; because jet fuel has 46% higher energy density that means that the cost per Joule would increase by a factor of 1.9.<p>Obviously this is only a back-of-the-envelope thing, but it seems that even if we switched to renewable fuels using the technology that are available today, ticket prices should about double. Historically, that corresponds to going back to circa-1980 prices[6], which I guess is bad, but not exactly apocalyptic.<p>[1] <a href="https://www.eia.gov/todayinenergy/detail.php?id=31512" rel="nofollow">https://www.eia.gov/todayinenergy/detail.php?id=31512</a>
[2] <a href="https://www.eia.gov/todayinenergy/detail.php?id=32152" rel="nofollow">https://www.eia.gov/todayinenergy/detail.php?id=32152</a>
[3] <a href="https://markets.businessinsider.com/commodities/ethanol-price" rel="nofollow">https://markets.businessinsider.com/commodities/ethanol-pric...</a>
[4] <a href="https://www.indexmundi.com/commodities/?commodity=jet-fuel" rel="nofollow">https://www.indexmundi.com/commodities/?commodity=jet-fuel</a>
[5] <a href="https://en.wikipedia.org/wiki/Energy_density" rel="nofollow">https://en.wikipedia.org/wiki/Energy_density</a>
[6] <a href="https://www.theatlantic.com/business/archive/2013/02/how-airline-ticket-prices-fell-50-in-30-years-and-why-nobody-noticed/273506/" rel="nofollow">https://www.theatlantic.com/business/archive/2013/02/how-air...</a>
So, here's how to kill a few birds with one rock. Make jet fuel using nuclear energy. But nuclear energy is horribly expensive, right? No, <i>civilian</i> nuclear energy is horribly expensive. The US Navy churns out nuclear reactors at a steady pace, and operate them perfectly safely. They've never had any incident. If the Congress mandates the US Navy to become net zero carbon emitter, they can do it. And they also gain additional logistical simplification. They say that every gallon of fuel sent to the front line in Iraq costs the DoD $100. Yes, in the oil-soaked Iraq. If you shorten the supply line, maybe this price goes down to a more reasonable level. Can you imagine that, instead of getting a war for the exorbitant price of $10 trillion, you can get one for a paltry $1 trillion? We could get 10 wars for the price of one.
"It sure does sound amazing. It sounds like a solution to all of our problems - except that it's not," said Jorien de Lege from Friends of the Earth.<p>"If you think about it, this demonstration plant can produce a thousand litres a day based on renewable energy. That's about five minutes of flying in a Boeing 747.<p>"It'd be a mistake to think that we can keep flying the way that we do because we can fly on air. That's never going to happen. It's always going to be a niche."<p>Wow, the Naysayers really know how to build a constructive argument.
This always strikes me as missing the point. The end result is fuel to burn. It doesn't matter where it comes from, only what the net carbon budget is. Continuing to burn petroleum in jet engines is <i>fine</i>, as long as it's appropriately offset. There's absolutely no technical reason to need to bend over to implement this kind of setup. Spend those dollars on renewables and sequestering solutions instead, clean up the last 10% of fossil fuel extraction at the end of the process.
> "It'd be a mistake to think that we can keep flying the way that we do because we can fly on air. That's never going to happen. It's always going to be a niche".<p>Why did BBC include such a strong statement in the article, given that it's just someone's gratuitous personal opinion?<p>I know that it's good journalistic practice to include sceptical opinions, but couldn't they find someone who is sceptical while at the same time being able to back their opinion with some sort of evidence or arguments?<p>Edit: it's also possible that this person's contribution was a longer text, and that it was cut short due to the article length limits. Maybe the original text included better arguments? It would be unfortunate if that was the case.
Whatever happened to Prometheus? I haven't heard anything since their launch [0]. The website doesn't have any updates [1]. Complete radio silence.<p>[0] <a href="https://news.ycombinator.com/item?id=19842240" rel="nofollow">https://news.ycombinator.com/item?id=19842240</a><p>[1] <a href="https://www.prometheusfuels.com/" rel="nofollow">https://www.prometheusfuels.com/</a>
I envision a future (not too far away) where we can literally turn anything into anything else reasonably efficiently.<p>CO2 in the atmosphere with hydrogen and oxygen from water, waste into each of its base component atoms, whatever into whatever else.<p>Something like global recycling of everything, if that makes any sense.
On Saturday, Elon Musk said that SpaceX will use direct air capture to make fuel from air on Earth: <a href="https://youtu.be/sOpMrVnjYeY?t=3852" rel="nofollow">https://youtu.be/sOpMrVnjYeY?t=3852</a><p>In partnership with Climeworks, one of the leading DAC companies, I just launched a campaign on Kickstarter using carbon materials to make a bracelet made of captured atmospheric carbon dioxide. Check out the video!
<a href="https://www.kickstarter.com/projects/go-negative/negative-bracelet-captured-carbon-dioxide" rel="nofollow">https://www.kickstarter.com/projects/go-negative/negative-br...</a>
In the synthetic fuel world, how much renewable energy capacity would we need globally? We need to replace all current electricity generation with renewables, then we need to add more to power electric cars, and then some more to produce synfuel. That sounds like a lot of capacity.
"This demonstration plant can produce a thousand litres a day based on renewable energy. That's about five minutes of flying in a Boeing 747"
<i>"It sure does sound amazing. It sounds like a solution to all of our problems - except that it's not," said Jorien de Lege from Friends of the Earth.</i><p><i>"If you think about it, this demonstration plant can produce a thousand litres a day based on renewable energy. That's about five minutes of flying in a Boeing 747.</i><p>This is the same people that have faith in that technology in renewables can improve to one day surpass nuclear.