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‘Solar tower’ system produces jet fuel from CO2, water, and sunlight
- phtrivier 4y agoWhere is the (pure ?) CO2 needed from such a plant typically sourced from ? Does it have to be captured at a gaz / coal power plant exhaust ? Or would it make sense to use CO2 captured from atmosphere (once the tech matters ?)
- bertil 4y agoAtmospheric capture today is far too energy-intensive to justify the effort. It’s likely far cheaper as of now to capture it from existing plants mixed with N2 and other gases at the plant, compress and liquefy it for purity, and truck or pipe it to the plant. That’s assuming that we have CO2-emitting factories, which are hopefully gone soon. If most of the hydrocarbon is synthetic and burned by airlines, tapping the exhaust isn’t an option. I’m not sure whether it will be cheaper to capture CO2 in the atmosphere or run alternative ways to travel.
- phtrivier 4y agoUnfortunately CO2 is not emitted only from power plant. Some industrial process just spew it on their own (cement or fertilizer production is often cited, but I don't know enough about the chemistry.)
- blacksqr 4y agoThe actual news here is that a research group has developed a new greener way to generate synthesis gas (the standard way is to inject water or steam into a chamber of burning coal). Once you have the synthesis gas, there are existing methods to manufacture a wide range of chemical products. Jet fuel being just one of them.
- jvanderbot 4y agocould you use charcoal instead of coal? That seems as green if you farmed the trees and use heat waste to make charcoal.
- Kerrick 4y agoSee also: https://news.ycombinator.com/item?id=32197012 https://news.ycombinator.com/item?id=32197012 (3 days ago)
- Animats 4y agoGas to liquid fuel is quite possible. But if it could be done economically, everything that generates excess methane would be converting it to liquid fuels. Many approaches have been tried.[1] [1] https://en.wikipedia.org/wiki/Gas_to_liquids https://en.wikipedia.org/wiki/Gas_to_liquids
- ZeroGravitas 4y agoWe've tried everything, except to stop paying people to actively flare methane rather than capture it: https://www.niskanencenter.org/taxing-flaring-and-the-politics-of-methane/ https://www.niskanencenter.org/taxing-flaring-and-the-politi... > One of the world’s leading oil and gas producers, Norway, has maintained extremely low methane release rates for generations. It combines tough regulatory standards with a hefty carbon tax explicitly applied to methane released at the point of production. The World Bank has championed the Norway model for decades, advising governments around the world to include released methane in severance tax or royalty regimes in order to reduce waste, deter both greenhouse and air-quality emissions, and capture natural resource value for citizens. > We found that Norway has no rivals in America. Emerging research suggests similar findings for Canada and Mexico, although the Australian state of Queensland includes flared and vented methane in its royalty system. In fact, many American states responded to growing methane waste concerns decades ago not by deterring emissions but by sheltering producing firms from taxation. Surgical amendments to energy tax laws placed methane off-limits from leakage fees. Those historic protections remain largely operational in the shale era, providing either explicit statutory exemption or administrative review processes that empower officials to routinely waive taxes.
- NonNefarious 4y agoGiven that this process must manufacture carbon monoxide to serve as an ingredient, I wonder if it could be installed on some CO-emitting equipment to capture and benefit from it.
- wombatpm 4y agoGiven that it wants pure CO2 as a feedstock, it could probably work better with carbon capture equipment
- bragr 4y agoOne important thing to call out about these fuels, and is often neglected in the reporting, is while they might be carbon neutral, they aren't environmentally neutral. At the very least, these fuels will still emit NOx and particulate pollution, so you cannot simply wave away all environment concerns of flying with "synthetic fuels".
- mulmen 4y agoWill the NOx and particulate emission be the same as with traditional fuels? Is there a way to refine this process or an additional process to reduce or eliminate these emissions?
- gumby 4y agoThey are making kerosene for aviation. It will replace kerosene made in a refinery, and be burned in the same engines that move the aircraft today. Thus the exhaust will be the same as today.
- mulmen 4y agoYou seem to be an expert on this topic. I wouldn't expect them to have the exact same characteristics. Kerosene as it is used in aviation today is distilled from crude oil extracted from the ground. This is synthesized gas that is then refined. My question is how much of NOx and particulate emission is from impurities and what the differences are between the synthetic and conventional kerosene. Is there a way to make a kerosene with less NOx and particulate emission that simply isn't practical today? Since we need to ramp up renewable energy sources to synthesize this fuel can that economy of scale justify some currently impractical process? The way I read the Wikipedia article on NOx [1] it sounds like NOx comes from nitrogen in the fuel. Is it possible to reduce or eliminate this nitrogen and then emit less NOx? I also parse the Wiki article to suggest the nitrogen is from coal and oil based fuels, which the technology in the article is not. [1]: https://en.wikipedia.org/wiki/NOx#Fuel https://en.wikipedia.org/wiki/NOx#Fuel
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- alex_young 4y agoOnly four percent of the captured solar energy was converted into chemical energy in the syngas, although they see a route to increasing that to above 15 percent Seems like a fairly significant problem. The level of investment required to make this work at scale would probably be in the same ballpark as replacing the system with high speed rail wouldn't it?
- zemvpferreira 4y agoDeveloping carbon-neutral fuels will be a worthy use of time up until we can see people lining up to take a train from Sydney to New York. Which is to say, we better keep working on it.
- bee_rider 4y agoReplacing which system with high speed rail?
- danuker 4y agoI believe the jet fuel usage industry (airlines).
- bee_rider 4y agoCould be. What has tripped me up is that we don't usually call it the "airline system." I think it is just a little typo but it is funny how ambiguous the result is. Airlines -- makes sense because we're talking about jet fuel, but "system" isn't usually used in the context of planes I don't think. Rail -- sort of makes sense because "railroad system" is at least a somewhat familiar expression. Maybe they are just using the size of the project as a point of comparison. Highway System -- similar to the previous, this makes most sense if it is just a comparison WRT the magnitude of the project. Highway system is of course a very common expression. Anyway this shouldn't be taken as needling at the original post or anything, it is just a little typo. The point is clearly that it is a very big project, and we have other worthy project of a similar magnitude and impact that we're not engaging in.
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- countvonbalzac 4y agoHow much energy does it take to produce 1 gallon of jet fuel? Could you have a small nuclear plant and have that provide enough fuel an airport? How much aviation fuel could a 100 MW power plant produce?
- darksaints 4y agoThat's the plan for nuclear powered aircraft carriers. They've had pilot programs to develop this exact capability. https://www.zmescience.com/research/us-navy-synthetic-jet-fuel-seawater-0423432/ https://www.zmescience.com/research/us-navy-synthetic-jet-fu...
- skunkworker 4y agoYeah, from the reading I have done on this, the largest draw is locality, if you were able to produce gasoline even at $20 anywhere in the world, you would definitely attract the attention of militaries. From this article [1] the "fully burdened" price of a gallon of gasoline was near $400/gal, factoring in security, transportation along every step. But this price is disputed and variable, an excerpt: "To be fair, there has been a lot of debate and controversy on the true cost of fuel. According to National Defense Magazine, basic gas costs $2.82, and then quickly rises to $13 and $42 depending on transportation methods, and up to $100 to $600 in some hostile areas. In the past, the Pentagon has been criticized for not knowing its true fuel cost, which was a more obvious issue a few years ago when oil prices were over $100 per barrel. Even even with today’s cheap gas, the military is still paying more than we could ever imagine." [1] https://www.cnbc.com/2014/12/17/you-know-whos-not-getting-cheap-gas-the-us-military.html https://www.cnbc.com/2014/12/17/you-know-whos-not-getting-ch... For a military to produce jet fuel on an aircraft carrier and gasoline in a remote and hostile locale, the supply chain advantages are staggering.
- bequanna 4y agoWhat’s the endgame here? $3,000 “carbon neutral” coach class tickets from LA -> NYC? I’m being a little ridiculous but I legitimately don’t get it. Tech like this only works under some carbon credit scheme that provides no value and just transfers wealth to the inventors of these Rube Goldberg machines and their already wealthy investors.
- nycdotnet 4y agoThere will come a time when there is no more oil in the ground that is economic to extract. Land transport can use batteries with current tech fairly effectively in many scenarios but aviation, as we currently understand it, needs energy densities that are not possible with batteries (and are unlikely with current mainstream battery tech). This claims to provide a way to get kerosene from the air using (thermal) solar power, which may become economical sooner rather than later if their claimed efficiency improvements come to pass and the price of gasoline continues to rise (which is very likely due to economic infeasibility of building any more refineries due to long payback periods)
- eru 4y ago> There will come a time when there is no more oil in the ground that is economic to extract. The qualifier about needing to be economic is really important here. We will never really run out of oil, but we might run out of cheap oil. As market prices for oil rise, more and more alternative ways to get at it become economical. Shale oil was one example of this process. (Another one is to create something like oil from coal. The Germans did a lot of this kind of thing in WW2, because they had access to plenty of coal, but were short on oil. Similarly, world coal reserves seem to be much larger than oil reserves.) However, renewables are getting better and better and thus prevent energy prices from rising as fast as the cost of oil extraction will increase. Thus eventually making oil uncompetitive, as you say.
- alvah 4y agoNew tech becomes cheaper when widely adopted. See: solar panels.
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- gmuslera 4y agoIt doesn't sequester carbon, doesn't lower the net amount of CO2 in the atmosphere if done in big scale, even if in the long run could lower the demand for extracting new oil. We are in a red queen's race, carbon neutral is not enough, we might not have time for a long run.
- gus_massa 4y ago> The most important thing to do if you find yourself in a hole is to stop digging. The first step is reducing net CO2 emission, and these kind of things are a good first step. (I prefer biodiesel/ethanol instead of fancy chemistry, but both go in the same direction.)
- brippalcharrid 4y agoOnce solar/fission/fusion power has become abundant enough, we can start to engineer the atmosphere to a desired composition of gases, storing any hydrocarbon byproducts in massive natural underground wells, in case we need them again some day.
- jonnycomputer 4y agoMaking one sector of energy use carbon neutral--one particularly difficult to de-carbonize--is still a win.
- jfim 4y agoWe'd still need tens of thousands of these plants. From [0] it's mentioned that > According to Andreas Sizmann, SOLAR-JET project coordinator at BHL, a solar reactor with a 1 km2 solar field could generate 20,000 L/d of kerosene, which could fly a large 300-body commercial airliner for about seven hours. According to [1] there are about 10000 planes in the air at any moment (excluding private jets, military, and cargo planes): > Back in 2017, FlightAware determined there to be an average of 9,728 commercial airplanes in the sky at any given time. Of course, that number fluctuates on a minute-by-minute basis, given that planes are nearly constantly taking off and landing. Doing the math of 10000 × (24 ÷ 7) gives us 35285 of these one square kilometer plants, or about 12% of the area of the entire state of Nevada. So it might be actually doable from a back of the envelope math analysis, but it'd be quite a big endeavor to scale a facility that large. [0] https://www.thechemicalengineer.com/news/first-kerosene-made-from-solar-syngas/ https://www.thechemicalengineer.com/news/first-kerosene-made... [1] https://www.travelandleisure.com/airlines-airports/number-of-planes-in-air https://www.travelandleisure.com/airlines-airports/number-of...
- dredmorbius 4y agoThe vast bulk of air travel is either intranational (domestic flights) or intracontinental (as with Europe, Asia, and Africa). For both, a well-developed high-speed rail network competes exceptionally well. Short-haul flights are comparatively less efficient than long-haul as the high-energy take-off portion represents a greater fraction of total flight time. Once airborne, aircraft are remarkably efficient --- rougly on par with (single-occupant) automobile travel on a per-kilometer basis. (On a unit-time basis, of course, consumption is roughly 10x greater, and the induced travel via the Jevons paradox from reduced costs is considerable.) But developing high-speed rail networks within countries and contiguous continental regions substitutes for a huge fraction of air travel. It might also offload a considerable amount of overnight / express cargo delivery which presently moves by plane. Cargo utilisation of HSR might balance out passenger travel patterns and allow flexible capacity response to boot.
- xhkkffbf 4y agoBut rail has issues of its own. The biggest may be the amount of land it takes up. While the rail lines are thin, they are very long. And if you want them to be high speed, you can't have cars crossing them. So they're very expensive to build and they require taking plenty of land out of circulation.
- la64710 4y agoSo this jet fuel produced from solar power will not emit CO2 when burned in existing jet engines?
- katdork 4y agoSurely, overall, it reaches carbon neutrality (the CO2 you put in is the CO2 you get back out) when burnt. Of course it "emits", but that has already been first taken out by being turned into this jet fuel.
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- jonnycomputer 4y agoI do wonder whether zeppelin's have any future as a practical mode of transport, either of goods or people. Intuitively, seems like it could trade speed for efficiency.
- eru 4y agoThere's a limit to that trade-off. That why taking a passenger liner across the Atlantic isn't actually more efficient than taking a plane.
- jonnycomputer 4y agoPoint taken; its about the numbers, cargo, and possibly whatever pressure there is to de-carbonize. "According to the company's CEO Alan Handley, the airship will be capable of making a transatlantic flight from the United Kingdom to the United States, consuming just 8% of the fuel of a regular airplane. It will be powered by a pair of solar-powered engines and two conventional jet engines." https://www.digitaltrends.com/cool-tech/varialift-airships-solar-powered-airship/ https://www.digitaltrends.com/cool-tech/varialift-airships-s...
- hcarvalhoalves 4y agoIt seems this experimental installation would take ~8 years to refuel a single 747 (260422 litres).
- hkt 4y agoIt is a neat process and I hope they develop it further, but it is yet another example of the kind of thing people cling to so as to avoid recognising that part of net zero requires behavioural changes. "Despite the facility taking up space equivalent to a small car park, it was only able to produce just over 5,000 liters of syngas in 9 days. " In other words, if this was our only way of powering flight, flight would become enormously uncommon and staggeringly expensive. Even if they achieved their stated aim of 15% efficiency, there's no sane hope of scaling this. It is just yet another example of tech that we cling to in the hope of not changing our lifestyles. Neat, but not the answer.
- eru 4y agoMaking stuff expensive (or cheap) is one surefire way to drive lifestyle changes.
- bluGill 4y agoThe question is how much they can scale it. There are a lot of things that the first iteration of was completely unworkable, but refinements mean we use them all over now. If you have ever see a car from the 1890s you would conclude cars will never work (the car might be gas or electric powered!), but over time we fixed the problems to the point anyone can drive them.
- ed_balls 4y agoThe military application would be quite interesting. Nuclear powered aircraft carrier has abundant energy which could be used to produce jet fuel. It would simplify the logistics, which is critical in the times of war.
- freemint 4y agoYou won't put this equipment on air craft carriers. If at all nuclear support ships might be able to run this however the econics seems reall dubious at this point.
- bluGill 4y agoI guarantee the Navy (any navy with a nuclear aircraft carrier) is interested in this idea. A significant problem for the Navy is the logistics of all the fuel needed for those aircraft, if they can produce that fuel at sea it saves them a lot of headache. Depending how much/fast it can produce it may even take less space than all the tanks they have, and they never worry about running out of fuel in a war. There are a lot of open questions as to if this can ever actually work on an air , but it need not be economical to the better answer. Navys will pay extra if it works and means they don't have to ship fuel around. Even better if it can produce enough fuel to also refuel at sea all the other ships the navy has in a carrier battle group.