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I remembered that coal and steam where also used to create methanol.
https://www.osti.gov/servlets/purl/1509352/
https://chempedia.info/info/methanol_sy … from_coal/
What I am thinking of is upping t5he levels of carbon for the heating stage to increase efficiency.
https://www.netl.doe.gov/research/Coal/ … igurations
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The world appears to be spiralling into a global food shortage, due to loss of Russian and Ukrainian wheat exports and loss of natural gas needed to make nitrogen fertiliser. This suggests to me that near term applications for solar thermal might be better focused on synthetic ammonia. If Egypt and Morroco can use ammonia and desalinated water to grow wheat in desert areas, then this technology would ease the approaching food crisis. The approaching food crisis may turn out to be the worst humanitarian disaster since WW2. The problem is that there isn't really sufficient time to do much to mitigate it. Building out solar ammonia factories and desalination plants would take at least a decade. The most effective near term measures would be to scrap US corn ethanol mandates. But the US appears to be headed in the opposite direction.
Last edited by Calliban (2022-08-03 02:52:59)
"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."
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https://currently.att.yahoo.com/finance … 00562.html
This is a follow up report on the fuel synthesis posted earlier in the forum.
This Solar Tower Can Transform Water, Sunlight, and Carbon Dioxide Into Jet Fuel
Tim NewcombTue, August 9, 2022 at 12:10 PM
Photo credit: Synhelion
ETH Zürich professor Aldo Steinfeld spent 15 years developing a process to turn air into jet-ready kerosene.A mini refinery on the roof of the university’s Machine Laboratory conducted a successful test of the technology in 2019.
The carbon-neutral process extracts carbon dioxide (CO2) from the air during the conversion process, as outlined in a new paper published in the journal Joule.
Aldo Steinfeld, a professor at ETH Zürich’s Department of Mechanical and Process Engineering, says his system for converting ambient air into jet-ready kerosene fuel using a solar refinery tower isn’t science fiction. It’s simply thermodynamics.
In a two-year proof-of-concept test atop ETH Zürich’s Machine Laboratory building in Switzerland back in 2019, Steinfeld’s mini solar refinery first showed how the process works, and laid the groundwork to scale the project. Both carbon dioxide (CO2) and water are extracted directly from ambient air and split using solar energy, as Steinfeld describes his work in a new paper, published late last month in the journal Joule. The result is syngas, a mixture of hydrogen and carbon monoxide, which is then processed into kerosene.
⛽️ You love alternative energy. So do we. Let’s go green together—join Pop Mech Pro.
“The design of the solar reactor, the cornerstone technology, was the most challenging,” Steinfeld tells Popular Mechanics. “We evaluated the performance of the solar reactor based on five primary metrics and experientially validated its stable operation and full integration in the solar tower fuel plant.”The plant grew from mini status to a larger-scale test when the team operated a solar refiner at the IMDEA Energy Institute in Spain in 2021. It will only keep growing. “The solar-to-fuel energy conversion efficiency needs to be increased to make the technology economically competitive,” Steinfeld says. Already he’s working on optimizing the structure with 3D printing to improve volumetric radiative absorption, which leads to higher energy efficiency.
To help turn the research project into a commercial reality, Synhelion, a spinoff company from ETH Zürich’s Machine Laboratory, is already planning to commission the world’s first industrial solar tower fuel plant in Julich, Germany. In March, Swiss International Air Lines announced it will be the first airline to fly with solar kerosene.
Proving the concept was an “important milestone toward industrial-scale production.” Steinfeld says one commercial-scale solar fuel plant could collect 100 MW of solar radiative power to produce about nine million gallons of kerosene per year. He’d need about 2.3 square miles to make that work. The total land footprint Steinfeld says is needed to create enough solar plants to “fully satisfy global demand” equals about half a percent of the area of the Sahara Desert.
The thermochemical process comes via three conversion units, all in a series. First it captures the ambient air to extract CO2 and H2O before a solar redox unit converts the CO2 and H2O—solar radiation heats the chemicals—into a syngas, a specific mixture of CO and H2. The third step is a gas-to-liquid synthesis unit, which converts the syngas into liquid hydrocarbons, usable as kerosene in jet fuel.
“We have successfully demonstrated the technical viability of the entire thermochemical process chain for converting sunlight and ambient air into drop-in transportation fuels,” Steinfeld says. “The overall integrated system achieves stable operation under real conditions of intermittent solar radiation and serves as a unique platform for further research and development.”
The process is carbon neutral because solar energy is used for production and releases only as much CO2 as was previously extracted for production. If the construction materials of the solar tower plant are created using renewable energy, he says the entire process can produce zero emissions.
Steinfeld says focusing on aviation fuel can help reduce carbon emissions from one of the leading industries contributing to that pollution. “These emissions can be avoided by substituting fossil-derived kerosene by solar-made kerosene,” he says. “Note that solar kerosene is fully compatible with the existing infrastructures for the fuel storage, distribution, and end-use in jet engines, and can be blended with fossil-derived kerosene. Thus, solar kerosene can help make aviation more sustainable.”
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The copper chloride cycle is a thermochemical cycle that reduces water into hydrogen gas and oxygen. It requires a temperature of 530°C and has a maximum efficiency (heat to chemical energy) of 43%.
https://en.m.wikipedia.org/wiki/Copper% … rine_cycle
The required temperature is within reach of concentrated solar power plants.
"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."
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For Calliban re #55
First, thanks for this neat contribution to the topic!
It seems (to me at least) this discovery/invention might work on Mars or any other off-Earth location, if the stored energy is fed into fuel cells and the output is recovered as water to be stored and re-used.
This might be considered a form of battery, I suppose.
The key element/feature is that the system works with a source of heat.
I'm wondering how the efficiency of this system might compare to others that start with a heat source.
Also (it just occurred to me) ... I wonder if the 57% of thermal energy is lost to the environment, which would imply the need for cooling as part of the design.
However (thinking out loud) .... if the system were built into a bus sized transport/habitat vehicle, then the 57% of thermal energy could be enlisted to keep the vehicle toasty warm.
A complete mobile transporter solution would need to provide for recycling of gases (CO2 to oxygen with retirement of Carbon to solid form).
The vehicle would (presumably) be able to recycle a supply of water indefinitely, and fresh CO2 could be brought inside to replenish Oxygen as needed.
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In Wyoming, we're supposed to have a Direct-Air Carbon Dioxide Capture (DAC) plant that removes 5 million metric tons / 5 billion kilograms of CO2, with the intent of storing it underground in local saline aquifers. If we're consuming 369 million gallons of gasoline per day / 134.685 billion gallons per year, which produces 8.887kg of CO2 per gallon, then we'd need 239 of those CO2 DAC plants. 1,196,945,595,000kg of CO2 from 134.685 billion gallons of gasoline. If we're consuming 1/3rd as much gasoline per day, then we need 80 of those plants. If we consume LPG instead of gasoline, then we only need 51 of those CO2 DAC plants. We probably need 100 such plants, in total, to account for all transportation fuel consumption.
America consumes about 369 million gallons of gasoline per day, 162 million gallons of diesel, and 25 to 26 million gallons of kerosene. It's probably not practical to radically reduce diesel or kerosene consumption, except by making greater use of freight trains. We could potentially limit flights between major cities to 2 or 3 flights per day by making greater use of smaller numbers of larger aircraft with more seats per plane. This would help Airline Services to reduce costs by owning / operating single types of jet aircraft (all Boeing 737s or Airbus 320s, etc), the way Southwest Airlines does.
After this point, any attempt to further "optimize" energy consumption (battery-powered everything, for example), at least using current technology, is either splitting hairs or drastically increasing cost (input energy cost and therefore monetary cost) and complexity (a Tesla is a supercomputer on wheels, drastically more complex than the Space Shuttle because software complexity is every bit as real as mechanical complexity) for no net benefit to either the consumer, nor to total global emissions and environmental impacts. Most cars, as made today, don't last for 5 years most of the time, much less the 10 to 20 years required to see significant energy reduction benefits. The electronics fail, the metal corrodes, and the wear parts which cannot be easily replaced wear out.
The Teslas made today or much better than the ones made a few short years ago, but that also means the door handles vary between the same model made in different years, and replacing them is $1,000 USD each.
Teslas are so heavy that the tires are replaced every 10,000 miles, and they cost more than $1,000 to replace all four, according to a Tesla collision repair service manager who I personally know. If you drive 10,000 miles per year, which is common for people who can afford to buy a Tesla, then that's your bare minimum annual maintenance cost, assuming nothing else ever fails. An oil change costs about $100 for a premium synthetic oil at a Jiffy Lube or some similar oil change shop. We do that every 6 months or so. So much for the asinine BS about oil changes every 6 months costing more in terms of maintenance. I think Louis told me that nonsense and now I have proof from the people who work at Tesla that it's utter nonsense. That works out to 5 years of oil changes. I've seen $1,288 USD advertised to purchase a set of 4 new tires for the Tesla Model 3. Four tires for the Tesla Model S sedan will run about $2,000 USD, roughly double what we paid for the tires on my wife's Cadillac Escalade. The reason I was given for this extreme cost disparity, which even I thought was hard to believe, is that they're specialty tires that must be heavily constructed to support the weight of the vehicle, and that if I purchased a similar tire with similar load rating requirements, that it would be similarly expensive to make.
"You can expect your Tesla tires to last for years with proper care." <- A fundamental L-I-E, according to someone who manages the service of these vehicles. They get replaced about once year, or once per 10,000 miles, according to her.
The tires we were sold at the Cadillac dealership were supposed to last for 30,000 miles. We're at about 15,000 miles and there's almost no tread left. The different brand that only lasted about 20,000 miles were also advertised as lasting much longer than they actually did. An Escalade is a very heavy vehicle, so this should not be the last bit surprising to anyone. Were we "lied to"? Duh! It's blatant false advertising and/or false claims about tire life, based on nothing real / measurable.
Crushing Weight + Lots of Friction = Accelerated Wear <- The only equation you need to know, apart from tire cost
How do I "know this"?
The tires on my 2012 Chevy Silverado (the "light" regular cab model with only 3 seats, used for hauling, but not heavy towing), before it was stolen and never found again, lasted about 30,000 miles. They were considerably larger and heavier than the tires on a Model 3, yet both vehicles have almost identical curb weights. If I had put "mini tires" on that truck, then they would wear much more quickly and, for people who do that kind of thing to create "low rider trucks", those tires also last 10,000 to 15,000 miles at most. It's basic physics that won't be overcome by any amount of magical thinking.
After 5 years, the money saved on not replacing all of the tires every year, as is required with a Tesla Model S or Model 3, apparently, is enough to replace the entire engine in a gasoline powered car. Junkyard LS V8 engines go for $500 to $1,000 USD, most of which don't even require new bearings, just a thorough cleaning, disassembly, and reassembly. If you have a smaller modern tubocharged inline-4, then you can buy a professionally re-manufactured engine that comes with a warranty, and pay to have it re-installed into your car for that kind of money.
In 5 years, or 10 years so I achieve significant energy payback, will that Tesla still be using its original battery? Is someone recycling the batteries? We quickly "run out of Lithium" if they're not. Can we make new batteries out of the old ones, or do we need more virgin Lithium? I know that I will never save a penny over gasoline by buying a Tesla Model 3 and can only hope to reduce emissions by driving it long enough, so will I at least achieve energy payback before the battery or electronics controlling the battery are killed by the Texas heat or minor manufacturing defects? I'm willing to keep the car if I can actually achieve some kind of real benefit, obviously not for my wallet but maybe for the environment. The battery must "go the distance", or it's a basic energy economics non-starter and pollutes more than gasoline, and certainly more than LPG. The things I've heard from their repair center manager don't give me much confidence in the car living long enough, and she sees dozens of these things per day. She did say that the electric motors are good-to-go and that they very rarely see problems with those, so that's a point in favor of the EV. As always, the battery is the real "sticking point" to "making it work". We are quite clearly "not there yet".
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Kbd512, that is an excellent post and it demonstrates the futility of trying to use electrochemical energy with an energy density of <1MJ/kg, to replace an energy source with ED of 40MJ/kg. As we head into a world with more expensive energy, more expensive capital and weaker supply chains, the BEV will be even less practical than it is now. I think tire wear is going to be the least of anyones worries.
I have been reviewing this article on compressed air hybrid vehicles. The idea is to use pneumatic or hydro-pneumatic systems to recover braking energy.
https://www.sciencedirect.com/science/a … 2116305287
Below is a quotation from the article, describing the prototype hybrid produced by Peugeot back in 2013.
In 2014 Paris Autoshow, PSA Company exhibited the improved
version of a hybrid air prototype called hybrid air 2 L. Turkus [122]
stated that PSA made many improvements such as weight re-
duction through the use of mixtures of steels, composite materials,
and aluminum. All the three materials are bonded by using ther-
moplastic technology. Also, this new prototype has improved in
term of its parts design, drag coefficient, and aerodynamic fea-
tures. The improvement managed to save 100 kg from the based
car 208 model. The weight of hybrid air 2 L is around 860 kg and
use 2 L to move as far as 100 km based on NECD standard.
Nevertheless, not all coming from the hybrid air is safe. A
problem that may be needed to be debated is the operating
pressure of the hydraulic system. It is too high for the passenger
car function. The operating pressure can reach up from 220 bar to
300 bar. The pressure is very high and can cause adverse effects on
the safety of a vehicle. Replied to this, the head of the project,
Karim Mokaddem, and Andres Yarce gave assurance that there is
no safety hazard. They led a survey on the issue of the gunshots,
fire and lots of unusual places. The engineers are convinced that
the system will not explode. The company estimate to put the
technology into production in 2016 and the price surely be lower
than the hybrid electric car. It is because they are using the com-
mon parts of existing hydraulic and pneumatic part. It makes the
setup robust. Other than Peugeot 208 hybrid air, with the same
technology, the company also launched Citroën Cactus C4 airflow
concept [123] which returned the same 2 L/100 km fuel con-
sumption [124]. To date, PSA Peugeot still looking for a cost-
sharing partner to cover the high development cost [125]. They
claimed that the technology requires a production of about
500,000 cars a year to make economic sense because of the ad-
ditional cost of components. The company initiates to commer-
cialize the technology in 2016, however, if looks from the current
situation; it seems hard to be fulfilled [126].
for a specified period. The reliability has not only affected the
performance of the system and safety, but it will determine the
cost effectiveness of the system too. At the moment, there is no
commercialize hybrid air passenger car on the road. It is the factor
that worries the customer to adapt this technology. Although the
same system already tailored to the truck, to minimize the system
in a passenger car is a different story. The end users still think that
the hybrid air system itself is not suitable for a passenger car. Most
researchers agreed that the hybrid air can reduce the initial cost
compared to the electric hybrid. However, if the current existing
vehicle is going to use the hybrid air system, the initial cost of the
vehicle expected to increase due to its additional components such
as accumulator and motor [129]. As the hybrid electric having
reliability issues such as battery degradation about 5% per year,
cost, safety, and availability, the hybrid air is also unexceptionally
[130,131]. Among the issues expected to invite doubt are the hy-
brid subsystem is too complex; fluids are used as propulsion
medium, and the safety risk of the accumulator as high pressure is
used. Peugeot-Citroen tried to overcome this problem by produ-
cing the prototype of the hybrid air passenger car. The system is
working, but the technology is lack of research data and public
disclosure. The technology is developed by a small group of 100
Research and Development (R&D) staffs and time spent to produce
the car is too short. These are the factors that contribute to the
anxiety. Regards to this, one of the solutions is to increase the
interest among the researchers. It is hoped that there will be more
research in the years to come. The research outcome is not only
representing the functionality of the system, but it also has its own
influenced and significance. It will show the level of how reliable is
the system, how matured is the technology and indirectly con-
tribute to the increase of the end user confident level.
In many cases, it happens that the manufacturer has the tech-
nology to save energy and reduce pollution, but they are having a
problem to commercialize it. To bring new technologies to the
market, it involves an enormous financial impact. However,
A fuel consumption of 2L per 100km, is 117mpg! If we can make cars that are as fuel efficient as that, then battery electric vehicles are clearly not worth pursuing. If fuel efficiency can be around 100mpg, then a clean burning synthetic fuel like methanol or ammonia should be affordable.
The lightweight vehicle used a hydro-pneumatic braking energy recovery system. Recovered braking energy is then used to accelerate the vehicle. Over an average driving history, this was found to reduce fuel consumption by 36%. The addition of hydro-pneumatic braking energy recovery, reduced fuel consumption from an already impressive 75mpg to 117mpg.
Many idealists have failed to understand how significant such an improvement in fuel efficiency is and what it means in terms of the human energy resource base. They assume that a 36% reduction in fuel consumption is only solving 36% of the problem. But this is untrue. Our fossil fuel resource base is a pyramid, with high EROI resources at the top and with enormously larger, but energetically less proffitable energy reserves as you head towards the bottom of the pyramid. The reason that most of those low EROI resources remain untapped, is that consumers can only afford to pay so much for the energy service provided by the fuel. This is why high oil prices cause recessions. However, if you only need half to two thirds as much fuel to get the same energy service, then the price you can afford to pay is higher. This extends the fossil fuel resource base by allowing lower grade deposits to be exploited. It also makes (climate freindly) synthetic fuels far more affordable.
There is no discussion in this article as to how much fuel a hydro-pneumatic hybrid could save if applied to a truck. Under urban driving conditions, we would expect the improvement in mpg to be even more significant than a car, because a much larger proportion of fuel is consumed accelerating the heavy load against inertia and air resistance losses are less significant. If hydraulic hybrid technology could deliver a 20% improvement in fuel efficiency across all transit and freight modes, the results are enormously significant. Even ignoring the potential for synthetic fuels, this would extend the lifetime of the global oil resource base by at least a few decades.
With synthetic fuel production included, it is not obvious that we face any near term depletion problems, because CO2 and N2 are infinitely recyclable. The problem here is affordability. 1 barrel of oil contains 6GJ of stored chemical energy. If our synthetic fuel factory is able to convert electrical energy into synfuel at an efficiency of 50%, then each barrel of product would need 12GJ (3333kWh) of electricity to make it. If that electricity were to cost $0.1/kWh, then the energy cost of the fuel alone would be $333/barrel. That is 4x what WTI is trading at presently. Two things are clear. For synfuels to be affordable: (1) The energy source used to produce them must be cheap; (2) The vehicles that use them must be very fuel efficient.
Back in 2008, the average US passenger car achieved about 13km per litre. The economy ran into trouble when oil prices started rising above $100/barrel. Oil eventually peaked out at $140/barrel in 2008. The Peugeot air hybrid achieved 50km per litre. That is about 4x better than the average passenger car in 2008. This implies that from a consumer viewpoint, we could build passenger cars that would allow consumers to tolerate the cost burden of synthetic fuel production. For trucks, it would be more difficult I think. One way of reducing fuel consumption would be to extend railway lines to the point where every significant urban area and industrial user is no more than a few tens of km from a rail freight yard. We coukd then limit trucks to transporting goods to and from rail freight yards. I think for most of the US, this is probably already the case. The changes would mainly be logistical. But for countries without decent rail infrastructure, building the necessary infrastructure would be expensive and time consuming.
Last edited by Calliban (2022-10-17 14:37:09)
"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."
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Calliban,
Passenger car BEVs with range performance roughly equivalent to a gasoline powered vehicle demand 120 to 160 pounds of rubber, every single year, because physics doesn't care about feelings or ideology. Over 5 years, that's more weight of rubber than I intend to use in terms of fiber-filled PET plastic in the chassis of my proposed economical 25hp to 50hp practical / affordable cars. We're already short of Carbon Black to make tires, which comes from natural gas. At no point will it be possible for EV emissions to equal the emissions from my proposed passenger vehicles, unless battery technology drastically improves. That defeats the entire purpose of the EV, which was not what I intended, it just worked out that way.
I'm aiming for 60mpg, because that can be achieved with early 20th century engine technology. Anything over the top of that is ICE-ing on the cake. There will be no pardoning of my puns. I don't give one rusty ratrod about what other people think of them, either. That said, I'd generally agree that if our cars are capable of over 100mpg, then goofing off with batteries and electronics is an utter waste of time and energy.
It's good to know that the automotive engineering world has spent the last decade goofing off with batteries when we had hybrids that were already about as efficient as any practical BEV was likely to be using technology that didn't exist back then and still doesn't exist today. When people get fixated on specific results, they lose all perspective of the trees surrounding them, and tend to forget that what they're actually in, is what the rest of us call "a forest". Think of how much money and time has been squandered trying to fit round pegs into square holes.
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A new catalyst has been developed that allows reduction of carbon dioxide to carbon monoxide.
https://peakoil.com/alternative-energy/ … l-at-scale
I believe this may have been discussed previously. To make methanol, the following reaction steps must take place:
CO2 + H2 = CO + H2 (Reverse gas shift)
CO + 2H2 = CH3OH
By passing methanol over a zeolite based catalyst, heavier hydrocarbons can be created. Methanol itself is a useful fuel. Producing carbon monoxide is the most difficult reaction step. Having a cheap and long lived catalyst significantly improves the viability of this process. Ultimately, any electricity source can be used to carry out the electrolysis needed to produce the source hydrogen. The navy have different needs to commercial operators. For the navy, reliability, not cost, is the driving requirement. For commercial operations, you want cheap electric power delivered at high capacity factor.
Last edited by Calliban (2022-12-02 14:51:19)
"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."
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Although I cannot vouch for how valid this material is, I think it would fit in well on Mars, if it is practical.
Query: "SCIENTISTS JUST MAD HYDROGEN OUT OF NOTHING BUT AIR!!!, "The Tesla Domaine""
https://www.youtube.com/watch?v=dPfIU27RGow
If it works, what I am thinking is that this might draw moisture from a "Greenhouse" atmosphere. The plants are a large part of an evaporator. The less CO2 in the greenhouse the larger they will have to open their Stomata. This will cause them to release more water vapor to the air. Of course the plants then have to be supplied enough CO2 and some water.
Then if the output is "Burned" it will yield fresh water.
The water consumed, then becomes wastewater to process. If it does not produce bad results after a degree of treatment, then the water supplied to the plants.
Both the greenhouses and the electrolysis would provide Oxygen.
And if the CO production method or an alternative were available, the one from Caliban or the equivalent in the just prior post.
So, then liquid fuels or Methane might become available by various methods.
I think that the loops are relatively simplified, as you do not have to have a separate distillation device.
Done
Last edited by Void (2022-12-07 12:08:30)
I am starting to ask seriously "Why do I do this?"
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The era of cheap oil has come to an end.
https://oilprice.com/Energy/Crude-Oil/T … n-End.html
Strictly speaking, it ended in 1973, with another step change taking place in 2005. Energy resource depletion is a slow motion problem, which has tightened the screws on industrial economies over a period of many decades. The COVID crisis and Ukraine war has accelerated geoplotical transitions that are leading to supply disruptions. All of this should be an opportunity for synthetic fuel production. OPEC as a group, no longer has the capacity to increase output above 33m b/d. US shale production can expand in the Permian for a while longer, but beyond this decade it faces structural cost problems as it expands into areas with poorer resources.
The wild card in any assessment of the future is demand. Peak oil demand will occur as many regions (China, Russia, Europe) deindustrialise and become poorer. The problems causing this are partly deteriorating energetics and party demographic. These places just don't have enough young people to man the factories or act as a consumer base a decade from now. Without industry and urbanised populations, oil demand will plummet. Paradoxically, oil may become cheaper and less affordable simultaneously. The United States is the obvious place to launch a synfuel initiative, as these fuels can gradually take up the slack as shale production declines. Unlike the rest of the world, the US will have enough domestic demand to make synfuel possible.
Last edited by Calliban (2022-12-19 05:29:22)
"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."
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Calliban,
Assuming we wish to transition to something other than energy poverty for everyone, we need to rapidly bring synthetic fuel production online.
There will never be a "green energy" revolution without it.
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For post 60 we know how to break down co2 as that is what MOXIE is doing on mars. So feed the co2 into the catalyst inside the pipe of a trough and make the magic happen.
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For SpaceNut ....
Thanks for your continuing investigation of considerations for flow of fluids through a solar trough system.
It seems to me that a small amount of automation would be helpful. If the goal is to heat the fluid to some desired temperature, then sensors can measure temperature and pressure, and allow fluid to leave the tube when conditions are right. As hot fluid leaves the output end, cold fluid can be admitted (or more likely pushed into) the cavity.
Please keep watch for any news/information you may find about direct production of hydrogen/oxygen from a Solar Trough system. The output of such a system is NOT a hot fluid, but instead, it is a flow of the separated gases.
How that separation might take place is certainly a mystery (to me for sure) but the NewMars archive include posts that hint it might be possible. Recently Calliban said he is investigating a possible method for using Solar energy to separate oxygen and hydrogen directly, and thus cutting out the middleman of electrolysis.
(th)
pipe dream of 800c or less as the answer is https://www.thenakedscientists.com/arti … and-oxygen
2,000 c plus....this requires a lot smaller reaction area than a trough, so this becomes this
I would think that a low temperature reverse fuel cell operation would be better.
https://www.altenergy.org/renewables/re … cells.html
that said feed the output of MOXIE and the reverse cell into a Sabatier reactor and call it good with ethane outputs depending on temperature and catalyst
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For SpaceNut .... re Post #65
To (hopefully) add to the content that a student of this topic might follow, here is a link to an article about research on thermal decomposition of water using solar power.
https://www.frontiersin.org/articles/10 … 66191/full
The article includes information points very similar to ones you've posted recently.
The article opens with criticism of solar powered electrolysis as inefficient, but after reading most of the article at the link above, I came away thinking that simple electrolysis is starting to look ** really ** good in comparison.
Solar powered electrolysis may be inefficient, but it appears to be simple in comparison to thermal alternatives, and there are regions of the Earth where space is available for large collections of equipment.
(th)
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In continuing to search for possible solutions to the challenge of producing hydrogen using solar power (and the solar trough design in particular) I found this article:
https://www.epa.gov/sites/default/files … erants.pdf
This article includes a survey of numerous kinds of refrigeration systems. I was not familiar with the use of the Stirling cycle for refrigeration, but apparently it is a suitable method for liquefying certain gases.
I am interested in the possibility of using the Stirling cycle in association with a standard fluid filled solar trough tube, such as those SpaceNut has shown us recently. The advantage (as I see it) is that high temperatures are not required for productive of useful motion by the machine, which means that the relatively low temperatures produced by simple solar trough equipment might be harnessed with success.
(th)
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The Stirling engine is the same units being used on the KRUSTY reactor that causes the motion to turn a generator shaft that create electricity.
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For SpaceNut re #68
Thanks for noting the NASA selection of the Stirling engine for the KRUSTY power generator!
For the Solar Trough application, I am concerned about cost vs the small amount of power that would be generated by the trough.
In addition, a concern is how to provide a heat sink for the engine, assuming one is required.
The hint by Calliban, that it would be most efficient (in the greater scheme of things) to isolate hydrogen using trough solar collectors, is where I am trying to focus.
The information you provided about thermal isolation of hydrogen shows that it can be done, but that it appears (to me at least) to be more difficult than simple electrolysis. Electrolysis is regarded (apparently) as inefficient, but at this point, if it works at all, it is many times better than processes that don't work in practice.
The goal of this topic is to arrive at a design for a set of equipment that can make synthetic fuel. Hydrogen is a synthetic fuel (as well as an energy carrier) and many products can be made with hydrogen as a feed stock, so (from my point of view) it seems well worth pursuing.
The images (and text) you have shown recently in the Solar Trough topic hint at possible contacts we might make to try to find a contact who would be willing to encourage this line of thought.
A system would include:
Solar Trough with fluid flow as the energy collection mechanism
Stirling engine to capture as much energy as possible from the heated fluid
Generator to make electricity to feed electrolysis unit
Electrolysis unit to make hydrogen (oxygen might be salable as well, since it is a byproduct)
Hydrogen/oxygen collection and storage system.
The goal I've defined for discussion purposes is to size the system to collect one kilogram of hydrogen in a Terrestrial Day.
It should be possible to work backward from the goal to size the components needed.
The electrolysis unit could be made smaller by buffering the flow of electricity by adding a battery to the mix.
With suitable choice of components, the electrolysis unit could (presumably) operate for 24 hours at a constant rate.
The battery introduces it's own losses, so now we have a chain of losses that is daunting....
Never-the-less, every loss down stream means the Solar Trough system has to be larger....
I'm not clear (at this point) on whether the Stirling Engine needs auxiliary cooling, or if it cools itself by doing work to produce electricity.
In any case, the Stirling Engine needs to provide force to move the coolant through the energy collection pipe in the Solar Trough, so some energy goes there.
Losses Inventory:
1) Resistance to fluid flow at introduction to pipe
2) Failure of fluid to absorb solar energy
3) Losses in operation of Stirling Engine
4) Losses in operation of generator
5) Losses in battery to even current flow to electrolysis unit
6) Losses in electrolysis unit
7) Losses in any equipment needed to draw water into the system
8) Losses in any processes needed to prepare sea water for input to electrolysis unit
That's a daunting list, and it probably does not cover everything.
This post is intended as a starting point for a thoughtful evaluation.
I'm assuming this concept is entirely feasible, and that it could be achieved on Earth in 2023.
(th)
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The flow of the source media inlet can act as the coolant for the sterling engine head. For KRUSTY the efficiency is just 25% of the wattage at 10kw theoretical with higher being possible as the size of the heat is increased.
https://builditsolar.com/Projects/Solar … ngines.htm
The 1kg of hydrogen means you need a little mor than 2 but less than 3 gallons of water with a typical figure of 48 kWh per kg to make the hydrogen. According to wikipedia ( Energy density - Wikipedia ) one kg of Hydrogen gas at 25°C and 1 atm, can produce 36.3598 kWatts aprox., in a range between [33.3139 - 39.4056] kWatts. Reminds me of its 9kg topic where we wanted to get the fuel on mars to refuel a starship from regolith. Salable oxygen is 8kg from the process.
Moxie is gaseous inlet of co2 for how its process works with heat to breakdown the to co + o2 and so is the Sabatier reactor.
Positioning the collector
https://builditsolar.com/SiteSurvey/site_survey.htm
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kbd512 has proposed capturing sunlight on a massive scale, to make hydrocarbon fuels to replace ground source ones.
I think this is a good idea, and I support his work, recognizing that an effort on this scale is comparable to the Normandy Invasion in scope, investment and personnel involvement.
The current idea of this topic, to enlist existing nano-machinery to make oil from sunlight and original source materials, is comparable in scope.
Of the two, enlisting plants to make oil, and extracting the oil for heating, seems to me a bit easier to sell to investors.
For one thing, the technology has (apparently) been around for 4000 years. I ran across a citation yesterday, indicating that residents of ? Cypress ? were using olive oil to make molten metal 4000 years ago. That is pretty impressive technology for that time period.
The proposal of kbd512 has some advantages with respect to the proposal to grow plants to make heating oil. For one thing, the plants need Nitrogen and other nutrients. Both systems need an ample supply of fresh water, and both systems require plenty of sunlight.
On the face of it, I would imagine that both systems require plenty of land for all that sunlight.
In the case of growing plants, existing data provides a firm data set for acreage needed for a given volume of oil to be produced. However, I expect the land needs to be given opportunities to grow other crops in the normal rotation.
The proposal of kbd512 requires construction of high tech equipment that does not currently exist. The plant-to-heating-oil proposal does require more equipment, but nothing new is needed, and existing farm managers have the knowledge and skills needed. The proposal of kbd512 will require enlistment and training of a massive army of personnel.
The trick is to keep cost to produce low and that is recovery of waste that is near free to use as inputs to the fuel creating system.
Collection of tainted water, human and other biologic crop waste ect... once provided to the breakdown system then inputting into the unit, we have the cheapest of fuels possible.
None of this is commercial and is design for its purpose.
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For SpaceNut re #71
Thank you for bringing the biodiesel discussion over to this topic.
Your closing statement needs authentication. I am hoping you intended to provide references but just got in a hurry.
Here is what Google found for just one year.... it has figures for numerous other years, and figures for several biofuel types:\
Biodiesel production in the U.S. 2001-2021 - Statistahttps://www.statista.com › ... › Petroleum & Refinery
May 12, 2022 — In 2021, the total volume of biodiesel production in the United States amounted to some 1.6 billion gallons.
SpaceNut .... 1.6 billion gallons is a commercial operation.
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commercial off the shelf equipment to execute the process is built on site to the industrial process as designed to meet the goals.
COTS, or commercial-off-the-shelf, is a product that remains "as is." This means that the hardware is a standard product that already exists and is available from commercial sources. COTS products are designed to be easily installed and interoperate with existing system components. Meaning it's no longer in the experimental designing phase but can be bought to application use.
Sure, what the commercial manufacturing companies are doing can is scalable downwards. These are make do systems with regards to low volume needs.
Here is the system as designed for use on the ISS
https://tfaws.nasa.gov/wp-content/uploa … S-2018.pdf
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For SpaceNut .... I asked Google who (in the United States) is still using fuel oil, and apparently you live right in the middle of the region where oil remains popular.
il heat is ubiquitous in the US Northeast, with 82% of households using oil as their primary energy source, which amounts to 5.5 million residents. In addition to the residential use, 35% of commercial fuel oil use is also in the Northeast.
Jan 21, 2021
Why is Oil Heat So Popular in the Northeast? - Tragar Express
tragarexpress.com › cod-blog › why-oil-heat-popular-in-northeast
About Featured Snippets
People also askWhich states use the most heating oil?
What percentage of US homes are heated with oil?
How common are oil furnaces?
How many US homes have furnaces?
The Geography of Heating Oil and Propane - Energy Institute Blog
energyathaas.wordpress.com › 2021/11/01 › the-geography-of-heating-oil-...
Nov 1, 2021 · The map above reflects that pattern, with high usage in predominantly rural states like North Dakota (14%), Montana (14%), New Hampshire (17%), ...
Where our heating oil comes from - U.S. Energy Information ... - EIA
www.eia.gov › energyexplained › where-our-heating-oil-comes-from
Sep 14, 2022 · The United States has two primary sources of heating oil: Domestic oil refineries. Imports from other countries.Use of heating oil - U.S. Energy Information Administration (EIA)
www.eia.gov › energyexplained › heating-oil › use-of-heating-oil
Feb 23, 2022 · Heating oil is mainly used for space heating. Some homes and residential commercial buildings also use heating oil to heat water but in much ...The Fuel You Use For Heating Depends on Where You Live
www.climatecentral.org › news › your-heating-fuel-depends-on-where-you...
Sep 25, 2014 · Heating oil is nearly unheard of outside the Northeast, which represents about 80 percent of all U.S. heating oil use. More than 30 percent of ...
If there is a market for vegetable oil as a totally green replacement for ground-sourced heating oil, it would appear to be right there in your region.
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If there is a market for vegetable oil as a totally green replacement for ground-sourced heating oil, it would appear to be right there in your region.
(th)
Have you considered wood as a replacement fuel? The convenience of oil is that it can be stored as liquid for months in a steel tank. During those bitterly cold winter months, an oil furnace can provide you with heat fluxes that are difficult to achieve in other ways. And oil is automatic. You don't need to load it, it flows by gravity into the boiler's centrifugal injection pump.
Provided you have the space to store it and are prepared to load the stove, wood may be a good alternative. It can be grown as coppice on marginally hilly land that isn't suitable for any other agriculture. There are also high yielding energy crops like miscanthus giganticus. Biomass can be converted into oils using flash pyrolysis and then hydrogenated to remove oxygen. But burning wood directly in a stove with a water jacket will be cheaper and more energy efficient. In the eastern USA and Canada, you have the space and plenty of low grade land to do this.
Dry wood only has about half the energy density of oil. But you can stack it in a shed or in a yard in piles under polythene. I live in England where wood is more scarce, but it is still a cheaper alternative to oil. My parents meet all of their space and water heating needs using wood. I have less space, but wood provides half of my space heating needs. Natural gas does the other half. They live out in the sticks and do not have a gas supply. LPG and oil are things they have considered, but the cost of both is high. My father built a large greenhouse on the back of their house. That reduced their heating season considerably. My father and I looked into building a solar heating system using seasonal heat storage. But the thermal store would have been huge and their space is limited. Wood is their only practical option.
Last edited by Calliban (2023-01-01 05:21:31)
"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."
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