Prometheus Fuels Lower Cost Than Fossil Fuels

tahanson43206 · 2022-05-22 10:14:50

For SpaceNut .....

In your post #125, short as it is, you included a key thought that seems a good fit for this topic ...

Insolation is available in abundance along the proposed Interstate 80 Sea water pipeline route.

Water is a key feedstock for making synthetic fuel and related hydrocarbons.

Carbon dioxide can come from the air.

However, the point you made about sugar in another topic, combined with observations by Calliban about the ability of plants to collect carbon from the atmosphere, combine it with hydrogen from water they've split the "old fashioned" way, provides a reminder that all along that route between California and Utah, entrepreneurs could grow plants to feed a synthetic fuel plant.

The ideas of kbd512 seem (as I interpret them) to fit nicely into a vision of a low tech, long lived industrial corridor along that 700 miles, fed by sea water from the Pacific Ocean.

The supply of sea water from the Pacific would appear to be without practical limit.

The supply of solar power would appear to be of sufficient duration for humans to make long term investments.

(th)

SpaceNut · 2022-05-22 13:00:45

Not every one will have a source of sea water to gather co2 from in order to even think of making synthetic fuels.
That said not all will get that 6 hrs of day for solar collection as well. Here I get about 3 hours for about half the year with it dropping down to just under 2 hours for that high noon full power that is needed. That means you are creating for the future use rather than on demand levels.

Scaling the paper to actual daily requirement plus for other yearly needs is also a trick as that requires knowing the usage and storage allowed in your area. Most allow for the 1,000 gallon home propane tank but once you get to more than that the fire departments get into the safety aspects.

kbd512 · 2022-05-22 13:23:50

tahanson43206,

The point of having and using technology is to create useful output (energy, food, transportation, housing, medicine, etc). There is a very large contingent of the population in the western world who thinks technology is an end unto itself, and that some magical new technology will come along to fix all of their problems, real or imagined, if only they throw enough money at the problem. These people think things like that because nearly all technology, from their very limited understanding of the world, is virtually indistinguishable from magic. Generally speaking, these people are also very incurious about anything they don't understand. They have no real interest in learning, either.

As a result,they're highly susceptible to believing false claims that agree with whatever indoctrination they've received, because they have neither the interest nor the aptitude nor the education to evaluate most claims about technology, and so their ideological indoctrination into fundamentally false beliefs (valuation statements) has replaced the traditional religions with worship of other deities such as science (amoral) or technology (also amoral) or government (entirely immoral, since all governance that people don't consent to always starts with the threat of force- and they make the mistake of believing that their consent means universal consent, which it does not and never will). You can take the boy out of the church, but you can't take the church out of the boy. Corner any of these people and ask them to explain their beliefs, and they can't or won't do it, because they don't know or their belief system is so weak that it cannot withstand cursory critical examination (weak character and beliefs), because they're following the dogma of someone else they trust (argument from position of authority), who may also not have a rational and logical foundation for said beliefs (none of the apes in the cage with them understand why they're being sprayed with cold water when they go after the bananas, nor that attacking the other apes for going after the bananas when none of them are being sprayed with cold water is idiotic at best), irrespective of whether or not observable reality aligns with what they want to believe in (a refusal to examine what their beliefs have done for them in the objective sense- forget about good / bad morality, let's talk about basic survival, where there are only a limited number of outcomes that are merely survivable- there is no totally subjective way to interpret reality that is merely survivable).

Peter Zeihan, despite self-describing his political stance as being a "green", is now saying exactly what I've been saying. In his latest video, he tells us that this "green revolution" is utterly impossible using the technology we have and the supply chains we're going to have in the near future. Peter is a leftist / Democrat, not a conservative / Republican such as myself, but as he says, he can also do basic math. We share that basic ability to reason and do simple math, and then to conclude that we're not achieving our stated goals using the technology we're dumping money into. His solution, like all Democrats, is to double-down on what hasn't worked, because he's still hoping for a technological miracle that isn't coming.

Liquid hydrocarbon fuels are the energy of the foreseeable future. We can change how they impact the environment by taking the CO2 out of the environment, rather than extracting it from a wellhead, and at a lower total cost over time.

Energy at the End of the World Seminar - Peter Zeihan

SpaceNut · 2022-05-22 19:04:54

The business of large scale would be great but its not the easy way and having a home brewed system fit the scale of use is just as hard to design. The location and its resource are the issue to make your own fuel whether its diesel or other fuel types at a home use site.

tahanson43206 · 2022-05-22 20:43:57

For SpaceNut re #129.... In a recent post, a complete system to make fuel at home was shown as a turn-key system. That seems worth investigating further. The picture of the complete system implies that it exists, but it might be a painting for investor presentation. If the system exists, then it would mean that investors were persuaded to take the risks involved in design and prototype of a system. I would be interested in any more information is available.

We're in Prometheus ... This evening's Zoom was rewarding from my perspective. kbd512 was in fine form as he developed his ideas, faster than I could keep up, as usual.

(th)

kbd512 · 2022-05-23 14:15:40

tahanson43206,

In our meeting last night, you opined that ideology didn't matter and that what we needed most was a viable / convincing business plan. While I agree with the latter part of your assertion, I'm also of the opinion that the former can't be ignored, either. If we lived a world where business people made business plans devoid of personally-held ideological beliefs, then the former might also be true. Unfortunately for everyone, we don't live in that world. That world doesn't exist. Ideology is a "real thing" that must be addressed in our business plan, especially when there's such a profound disconnect between observable reality and ideology. The various ideological beliefs asserting that more / newer / better technology can overcome fundamental physical limitations must be dispelled. Until and unless there is widespread acceptance that "silver bullets" don't exist from a technological perspective, the artifacts of ideology will continually stymie our business plans.

"Exhibit A" for Ideology Overriding Observable Results

Here's what a couple of young / inexperienced / mathematically illiterate millennials arguing with someone from my generation, who clearly has more knowledge and experience on the subject matter, looks like:

Geopolitics, Innovation, and Deglobalization With Peter Zeihan

Gen-Xers (my generation, who came of age before the year 2000) and Millennials are only separated by about 10 years in terms of age and generational knowledge. They didn't receive nearly as much in the way of such "generational knowledge", because they've had a computer or cell phone glued to their hand from the time they were toddlers onward. My generation learned by experiment, or from father-to-son / mother-to-daughter knowledge transfer. We didn't learn how to boil an egg from the internet, and our parents though largely absent due to work requirements, still thought spending time with us was valuable, even though we were expected to be very independent. My generation learned their basic life skills and "tests of reasonability" from "actually doing it", rather than YouTube videos. We were taught "how to think" rather than "what to think", because the adults interacted with us as little as possible. Our parents were not shy about giving us a piece of their mind or hand to our backside if we did something we shouldn't have done, either. We lived in that age before internet technology took off, which is why we learned to interact with both people and technology. All of my younger siblings are "what / how thinkers", whereas I was a "why thinker". In some ways, they're smarter than I'll ever be, whereas in others they don't have a clue and probably never will. They seek out "experts" without knowing where that expertise ends and ideology begins. All of them stayed at home with mom and dad long past the time when I left to figure out life for myself. Their approach to life is a direct result of how they were taught and what they didn't learn. I’m no different in that regard.

Peter brought up the fact that Germany has now installed and activated 155% of their total peak grid demand, in terms of wind and solar grid capacity, but all that up-front money and effort represents just 7% of Germany's total energy demand. Let's give significantly more credit than is actually due, and assert that Germany supplies 10% of their power demand using wind and solar. For them to stop burning fossil fuels, their "green energy" solutions would have to supply 1550% of their peak grid demand.

These know-nothing millennials still think batteries are going to replace internal combustion engines in the very near future. They can't account for the utter lack of market penetration or achieved performance of their favored "green tech".

Perhaps most laughably, they think electric trucks are going to replace diesel-powered trains. The fact that there's not enough Lithium on the planet to do that doesn't affect their beliefs in the slightest (blissful ignorance), because they've clearly never done the math to know why that can't happen using today's battery / photovoltaic / wind turbine technology, which was Peter's entire point of argument with them (not that he didn’t like the idea). Peter points out that American cargo trains now carry upwards of 300 containers per trip, and these kids actually think it's going to not only be practical to replace that single cargo train with hundreds of trucks, but that the switch will somehow cost less money to both purchase and operate. That was literally their argument in the video, that such a thing was not only practical but would cost less money than using diesel-powered trains.

Simple math here folks:
$250,000 all-electric semi-truck * 300 cargo containers per train = $75,000,000USD
Each diesel locomotive cost around $2M USD.
There are over 38,000 diesel locomotives used in the US.
Figure on 3 locomotives per train (1 per 100 rail cars)
12,667 * $75,000,000 = $950,025,000,000USD

$950B USD to replace all 38,000 trains with all-electric trucks in the US (which still don't have a fraction of the range of the train; simply having a truck that can carry an ISO container, of which there are around 25 million in the US). All 38,000 trains cost $76B USD, and each one can travel coast-to-coast without refueling in about 3 days. CSX asserts that their trains require 1 gallon of diesel fuel to move each 2,000 pounds (1 US ton) of freight 492 miles. An yes, I know I didn’t bother with Imperial to metric ton conversion in what follows, because it doesn’t change the math at all.

1 US gallon of diesel is 40.7kWh.
40,700Wh per US gallon of diesel / 492miles = 82.7Watt-hours per ton-mile (truly spectacular, considering that half of the energy or less is actually converted into torque)

According to Rivian's R1T FAQ, as posted on "Inside EVs" website here, consumes 1kWh/mile while towing a 5,000kg payload, or 200Wh per ton-mile. Anyone who thinks a much much larger / heavier / higher rolling resistance all-electric semi-truck will use substantially less energy than a vehicle with a much lower frontal area and much lower rolling resistance, needs a basic math refresher course. The R1T with 180kWh battery has a 10,550 pound curb weight and the 11,000 pound payload represents 1/4 of the Tesla semi-truck curb weight, but somehow it's consuming 15X MORE POWER, so I think someone is L-Y-I-N-G here. Since we have real-world R1T performance and power consumption data, it's probably NOT Rivian! Both vehicles have 95% efficient electric motors, both vehicles are powered by Lithium-ion batteries, and both vehicles have drag coefficients better than some rifle bullets. Rivian touts a 0.3 drag coefficient, whereas the Tesla semi-truck is claimed to be 0.36. Both of those values are absolutely incredible for a truck.

Tesla claims 2kWh/mile when fully loaded (80,000lbs; 19,000lbs tractor weight, so 61,000lbs / 27.7t), but I'll believe that when I see it, because their claims have never been independently evaluated under real-world operating conditions. If Tesla's claims are to be believed, then their semi consumes 74.1Wh per ton-mile (less than a train with 1/9th of any semi-truck's rolling resistance). If the Rivian R1T's power consumption was scaled up to "payload match" the Tesla semi, then that equates to 1,108Wh/ton-mile (more than an order of magnitude worse than a diesel-powered train, which correlates exceptionally well with observed "truck vs train" energy consumption). Tesla is claiming OVER 1 order of magnitude lower power consumption than the Rivian R1T on a Watt-hour per ton-mile basis (which is 1/4 the Tesla semi-truck's gross weight, but with a better drag coefficient and lower rolling resistance), and better than what a prototypical diesel-electric train is capable of, which seems like a positively WILD over-exaggeration on Tesla's part, regarding actual power consumption while towing at max gross weight. The only alternative explanation is that the Rivian R1T fails horrendously at energy efficiency, but if it was that bad then it's no better than gasoline or diesel.

From the CSX Website Page on Fuel Efficiency:

Fuel Efficiency
According to the AAR, moving freight by rail is 4 times more fuel efficient than moving freight on the highway. CSX trains can move a ton of freight approximately 492 miles on a single gallon of fuel. Efficient use of fuel means fewer greenhouse gas emissions for our planet. (Learn more at the Association of American Railroads’ website, http://www.aar.org/.)
Here is the formula for our 2018 fuel efficiency rating: (From the 2018 CSX R-1 Report)
• Schedule 750, Lines 1+3 (Line 4), Diesel Fuel Consumed (freight + switching) = 423,998,863 gallons
• Schedule 755, Line 110, Revenue Ton-Miles = 208,712,027,000 RTM
• RTM per gallon = (208,712,027,000 RTM / 423,998,863 gals) = 492 RTM/gal
CSX has invested more than $2.8 billion over the last decade to improve its locomotive fuel efficiency and reduce the corresponding emissions.
Calculating Fuel Efficiency
The ton-mile-per-gallon is a unit of measurement used to describe the efficiency of hauling freight by various modes of transportation.
The rail industry tracks and reports revenue ton-miles in the “Annual Report to the Surface Transportation Board” (commonly referred to as the R1 Report). The “Ton-Miles of Freight” annual value is reported in Schedule 755, line 110 of the R1 Report. The rail industry also tracks and reports annual fuel usage in the R1 Report, Schedule 750, line 4. These two reported values are used to determine a system-wide train efficiency value.
For example, in 2018, the CSX ton-miles of freight reported in the R1 Report = 208,712,027,000 ton-miles and the CSX 2018 combined line haul and switcher reported fuel usage = 423,998,863 gallons.
The 2018 CSX system-wide train efficiency metric equals:
208,712,027,000 ton-miles / 423,998,863 gallons = 492 ton-miles per gallon.
In other words, CSX trains, on average, can move a ton of freight nearly 500 miles on a gallon of fuel, based on our 2018 revenue ton miles and 2018 fuel use.
The fuel efficiency for a freight truck can be estimated in a similar way. For example, a heavy-duty diesel truck hauling 19 tons of freight a distance of 500 miles would consume approximately 71 gallons of diesel fuel, assuming an average 7 miles per gallon truck fuel economy and a typical truck payload of 19 tons. The efficiency of this freight haul would be calculated as:
(19 tons x 500 miles) / 71 gallons = 134 ton-miles per gallon.
This efficiency might be stated as “a truck can move a ton of freight 134 miles on a gallon of fuel.”
Similarly, a typical train might haul 3,000 tons of freight 500 miles and consume approximately 3,049 gallons of diesel fuel. The efficiency of this freight haul would be calculated as:
(3000 tons x 500 miles) / (3,049 gallons) = 492 ton-miles per gallon.
This efficiency might be stated as “a train can move a ton of freight 492 miles on a gallon of fuel.”
In this example, the train is approximately 3.7 times more efficient at hauling freight, as shown by the ratio 492 train ton-miles per gallon divided by 134 truck ton-miles per gallon.

There were 38,000,000 semi-trucks used around the world as of 2019.

I finally found a reasonably definitive source which states Tesla's batteries contain 0.0714kg/kWh (specifies the exact Panasonic battery model used in their battery packs).

Therefore, a 1MWh semi truck battery would contain 71.4kg of Lithium.

38,000,000 semi-trucks * 71.4kg of Lithium per 1MWh battery pack = 2,713,200,000kg / 2,713,200t of Lithium

Global Lithium reserves are estimated at 14,000,000,000kg or 14,000,000t

There are 284 million cars registered in the US. If each vehicle contains a 100kWh battery pack, then 284,000,000 passenger cars * 7.14kg of Lithium per 100kWh battery pack = 2,027,760,000kg / 2,027,760t of Lithium

The US market for motor vehicles alone, plus the global market for semi-trucks, represents 33.6% of total global economically recoverable Lithium reserves (Lithium from the ground, rather than from sea water). There are presently over 1 billion passenger cars in active use around the world, which means the 20Mt of Lithium would then exceed the total known reserves all on its own. You can stretch the supplies by using electric motorcycles vs cars, or smaller cars, but if there’s 1 passenger car per 8 people (1 large SUV equipped with a 100kWh battery pack), then that’s 143% of the known Lithium reserves right there. That is not practical, end of story. If you eliminate private transport, then you need massive numbers of large / heavy buses, so more 1MWh battery packs. You can’t “win this way”, because it’s not possible, let alone practical. If we consume all that Lithium, then that also means 100% of the Lithium must be recycled, or there is no more transport period. This also implies no more cell phones or laptop computers with Lithium-ion batteries. How practical would that be?

Anyone who thinks that looks practical to apply at a global scale is either wildly delusional or profoundly ignorant of material / natural resource limits and manufacturing capacity constraints. As Peter goes on to say, 1/10th of the world's population could conceivably make wind and solar work for them in a practical / affordable manner, and most of those people already live in affluent countries. The other 9/10ths of the world's population are who these adult children have no answer for, nor ability to address, because their ideology has rendered them incapable of basic math.

Millennials also think bitcoin represents a useful store of value. You can't eat it and it doesn't work without "grid scale battery storage" (their own words), but they think this will replace the traditional currencies. Where is the evidence to support such an assertion? There is none. It's all based upon ideology, which is why ideology is so important.

Millennials further think that the availability of new-ish communications technologies equates to structural changes in society. It makes teleconferencing easier, but we've had phones for more than a century now. Phone calls have not proven to be acceptable substitutes for in-person meetings thus far.

Basically, these millennials have ideas about reality that diverge from reality. They've been fed a steady diet of neo-liberal techno-ideology their entire lives, but refuse to take stock of achieved results because they’re incurious and ideologically-motivated. This is what youthful inexperience, combined with a lack of both greater perspective (which only comes from experience) and deeper understanding (I'd settle for basic accounting skills) looks like.

Calliban · 2022-05-24 16:16:33

Agreed, Kbd512. Very few people have the detailed knowledge required to make informed decisions on technologically complex topics like energy production. But that doesn't prevent every man and his dog from having an opinion. And without technical knowledge and analytical capabilities, people are vulnerable to whatever idealism happens to take their fancy. And the key thing is, even if their judgements are wrong and poorly informed, they can still believe in them passionately. And that belief ends up being politically powerful, ultimately leading companies and entire countries in disasterously inappropriate directions. The German decision to close off all avenues for pursuing new nuclear power and set the end goal of running their economy on ambient energy, was a predictable disaster to anyone with an understanding of physics. But it didn't stop the Germans from pursuing this policy, with the consent of public opinion. The decision was based on political ideology. And it was made by people that had grown complacent and had enjoyed material prosperity for so long, that they didn't even bother to understand where that prosperity came from.

Human beings like to think of themselves as rational creatures, but they very rarely are. The human mind essentially has two layers. There is the primative emotional part, which decides what it wants. The intelligent part then justifies desires and forms the strategy for realising them. Ultimately, most opinions are formed, not on the basis of what is sensible, but on what is emotionally appealing to the subconscious. The rational brain is then employed to justify the opinion. Most people have an internal mythology that guides their belief system. This mythology is driven by the emotional appeal of certain ideas, not by logic. The more threatening the outside world is to most people, the more they cling to that inner mythology for dear life. It is ultimately irrelevant whether it is a useful way of dealing with the world. We all work this way to some degree.

We saw the power of that mythology in action on this board in the posts of Louis. An intelligent man who drove a great many interesting discussion topics on this board. But the idea of powering the world with what he saw as being 'natural' energy was for some reason at the absolute core of his internal mythology. It quite literally had a spiritual appeal to him. The technical people on this board analysed his utopian ideas and repeatedly found problems with them. But that didn't prevent Louis from continuing to believe in natural ambient energy sources as the core around which a techno-utopian fantasy future could be built. When analysis kept demolishing this worldview and he realised he could not sell that future here, he actually quit the board rather than help develop practical solutions. Too bad. But my point is, many, maybe even most people, really do work this way. It isn't about developing a practical way forward. It is about realusing an internal mythology. And that mythology is based on emotional appeal that will stubbornly resist the real world.

A world powered by intermittent, ambient energy, which is percieved as being somehow natural, is quite a common internal mythology for idealistic minded people. These people have done everything they can to push the world in that direction. They will not be convinced by any rational argument to the contrary. For them it isn't about the practicality of the idea. It is about the idealistic purity of the idea itself. It is this kind of thinking that allows idealists to ruin the world. Ultimately they are happy to sacrifice almost anything on the alter of a idea that they worship.

Last edited by Calliban (2022-05-24 16:30:20)

Calliban · 2022-05-24 16:52:03

Peter Zeihan is more sanguine on the prospects of US shale than I personally would be. This tight oil revolution took place at a time when oil prices were high and capital was almost free for large institutional investors. Companies could borrow huge amounts from banks or through the bond market and pay pittance returns on capital. This allowed the oil from new wells to pay off the almost peppercorn interest payments on the capital borrowed to finance wells that decline by 60% in their first 12 months of operation. In fact, they could pretty much sit on their hands whilst inflation eroded the value of their debt. But now interest rates are rising. And most of the sweet spots in shale basins are now in depletion phase. How will that effect the future of shale production? I wish I could say. But most players in the shale patch are increasing output only slowly.

Another thing I note is that Peter does not appear to be aware that shale oil must be blended for refining. It is to light for US refineries. This is where Canadian syncrude is useful. It doesn't really matter if it is more expensive than shale oil on a MJ basis. It is needed to achieve the right blend, with the right density, viscosity and volumetric heat capacity to be refineable.

Last edited by Calliban (2022-05-24 16:53:58)

kbd512 · 2022-05-24 18:29:44

Calliban,

I deal with the same issues. My irrational brain lusts after "design perfection", while the logical part of my brain always steers me back towards pragmatism and economy (the "Why spend money for sake of spending it? / What problem are you actually trying to solve?" part). I have to admit that while I don't favor inefficiency, I won't allow my lusting after the pinnacle of design efficiency to lead me towards impractical solutions.

Beyond that, if some part of observable reality disagrees with my belief system, then I change my beliefs. When I first joined New Mars Forums I didn't believe that CO2 emissions could warm the Earth until I proved to myself that the effect was very real immutable simple physics. Josh pointed me in the direction I needed to go to understand thermal power transfer / conversion mechanisms, and then it was painfully obvious that my beliefs were wrong, so I changed them. I took no issue with admitting that I was wrong, because it was readily apparent to me after doing the required math (I didn't reply for about a month or two while I took a crash course in basic thermodynamics, which required a lot more reading than I thought it would), and then I simply accepted that I learned something new that I didn't know beforehand, merely the end result of not having the required technical knowledge. For my part, that was more of an "oh, sh!t, we're in deep trouble" moment than a "my core beliefs are shattered" moment.

That exchange between Josh and I then prompted me to review what we were doing about the problem, and after doing a lot more basic math I came to the conclusion that all of our proposed "solutions" clearly involved "accelerating the living hell out of climate change" (by burning everything in sight to create these "new electronic machines" to do what combustion did for so long). As you can imagine, that little "discovery" was very puzzling to me, until I came to the conclusion that all of the proposed solutions were based in ideology rather than math and science. They all failed to account for incredibly basic issues, such as 95% of the photovoltaic panels produced being the end product of burning lots of coal and gas, or that there wasn't enough Lithium in the ground to make all the batteries required- very basic stuff like that.

Each square meter of photovoltaic panel is around a 4,000MJ+ energy investment. Each square meter of polished metal solar trough concentrator is a fraction of that. If each square meter of said concentrator requires 50kg of steel (reflector plus a seriously stiff / strong mount), then it's a 1,000MJ energy investment. The photovoltaics degrade continuously from the moment they're made. A polished piece of steel will remain a polished piece of steel for most of eternity, especially in a dry desert environment. You don't have to be very good at basic math to understand how wildly impractical continuously producing and recycling comparatively short-lived electronics made from scarce materials will be, but you do have to accept that multiplication is required to understand what you're asking for when you want to do something in a specific way, and then scale that idea up to the point where it's universally-used technology.

The energy inputs into electronic devices like photovoltaics and batteries are bonkers compared to thermal engines with very few moving parts. All that energy has to come from somewhere, and at present nearly all of it comes from fossil fuels. For that paradigm to change, we would've had to start running the mining and refining equipment on photovoltaics and batteries, but nobody does that because they can't make it work using any amount of money that they can actually afford to devote to metals mining and smelting. It's not that the engineers are dumb, or never thought about it, or never experimented with the technology, they simply can't make it minimally feasible using current technology. Until we can change that paradigm, we're left spinning our wheels trying to do things like electrify cars and trucks. Even more disconcerting, we flat-out lack the production capacity to produce some of the required materials (Copper, Lithium, Cobalt, etc), in the required quantities, to achieve that goal.

Regarding your note that Peter doesn't understand that American light sweet crude has to be blended with Canadian heavy crude for our refineries to work, he made specific mention of that fact a number of times in at least the last two videos that I've watched, which means you either didn't pay attention to what he said about that problem or didn't watch the entire video. He has also explicitly talked about oil refineries in other parts of the world being optimized to refine a specific type of crude. The products that most countries use crude oil to make, the US uses natural gas to make- fertilizers, plastics, lubricants, etc. Peter has several slides devoted to this topic, and has also lamented the fact that our refineries can't produce enough diesel without heavy crude imports.

Calliban · 2022-05-25 00:19:07

Regarding Prometheus Fuels: I cannot access their website on my device. But the Wikipedia page provides some technical details that allow a description of their proposed process to be pieced together.

https://en.m.wikipedia.org/wiki/Prometheus_Fuels

1. CO2 enriched water enters an electrolysis cell, where electrolysis generates hydrogen ions. These reduce CO2 into alcohols in solution. The electrolysis cells have copper electrodes. The copper cathode also provides a cataytic surface upon which alcohols can form.

2. Nanofiltration using carbon nanotubes embedded in a polymer, removes the alcohol from the solution.

3. Zeolites catalyse condensation reactions between the alcohols, building up longer chain hydrocarbons.

All in all, an ingenious process. A few technical notes.

Firstly, the process relies on electrolysis to produce hydrogen to reduce carbon dioxide at the cathode. Integrating carbon dioxide into the feed water is a neat step, that appears to eliminate the need for a separate sabatier type reactor. However, the process is still essentially electrolysis. There is no other way of generating the required hydrogen ions. The whole process is essentially the electrolytic conversion of water and CO2 into alcohols.

Secondly, the process relies upon concentrated CO2 dissolved in the feed water. Presumably, some sort of amine scrubbing will be needed to produce a concentrated CO2 feed. This is highly desirable in raising the power density of tye whole process. Also note, that CO2 is not the only gas dissolved in water exposed to air. So really we need a process that removes CO2 from water and concentrates in the feed water entering the electrokysis stack. If not, most of the hydrogen ions that are generated will react with oxygen dissolved in the water. The original description of the process talked about using CO2 dissolved in seawater. However, sea water cannot be directly electrolysed. It would produce chlorine gas and alkali hydroxides. The chlorine would corrode the hell out of the anode and the alkali hydroxides would chemically bind to CO2, forming insoluble carbonates that would precipitate out. So amine scrubbing will be neccesary.

Thirdly, the process relies on nanofiltration out of the electrolysis cell. That is a neat step. It can be enhanced by a positive pressure gradient across the membrane. The plastic surface is naturally hydrophobic.

Finally, zeolite is used to catalyse condensation reactions at room temperature. That is quite impressive. I had no idea that zeolite could do that. As heavier hydrocarbons build up, they should separate by gravity as they become progressively less soluble. My only comment would be that at room temperature this will happen quite slowly. Given that we are using solar thermal energy to power the electrolysis process, it would make sense using some heat to accelerate the downstream chemical reactions that convert alcohol into longer chains.
****************************************************************************************

PS. I found this.
https://arpa-e.energy.gov/sites/default … yhouse.pdf

CO2 is far more soluble than CO and H2, but far less soluble than alcohols. One way of keeping the gases in solution is to maintain the whole system under high pressure. According to McGinnis, the carbon nanotubes will act as a filter removing ethanol and methanol from the cell but will keep other components within the cell.

Last edited by Calliban (2022-05-25 03:17:34)

Calliban · 2022-06-01 07:45:53

The simultaneous electrochemical reduction of water and CO2, using ionic electrolytes.
https://www.sciencedirect.com/science/a … 5820300163

A paper that is highly relevant to what Prometheus Fuels is proposing to do, I would suggest.

To convert dissolved CO and H2 into methanol, a catalytic sponge made from Cu/ZnO/Al2O3 can included within the electrolysis stack.
https://aip.scitation.org/doi/10.1063/5.0000870

Solvent would circulate through the electrolysis cells, up into the catalytic sponge, before passing down through filtration membranes which remove the methanol. Reagents (water and CO2) could be injected at high pressure to give rise to the flow needed. A pressure gradient across the filtration membranes will drive methanol across them.

I would propose building electrolysis stacks in large sizes and operating at high pressure and temperature to both maximise reagent concentration, cell current density and reaction rate on the catalytic surfaces. To keep costs to a minimum, I would propose a stainless steel clad hybrid pre-stressed cast-iron and concrete pressure vessel. Liquid water and liquid CO2 would be injected into a pre-mix, pre-heating chamber using separate centrifugal pumps. The extraction membranes would slot into tubes around the periphery of the vessel, allowing easy replacement in the event of fouling. The catalytic surfaces would form a matrix of modules above the exit apertures from the electrolysis cells.

Last edited by Calliban (2022-06-01 08:10:27)

tahanson43206 · 2022-06-01 08:31:39

For Calliban re Post #136 and entire recent series of posts ...

In noting activity on the Internet, I am seeing hints/indications that more and more folks are starting to think about synthetic production of long chain hydrocarbons. Thanks for providing the technical insights that will underlie investments on the scale needed.

While you have said on numerous occasions that you do not anticipate becoming directly involved in any of the many visions you've published here, it seems to me this latest series deserves consideration for funding. I sure hope ** something ** comes to pass along the lines you've described.

(th)

Calliban · 2022-09-14 02:51:18

The Prometheus concept involved extracting CO2 from sea water. Another option would be to build the fuel factory alongside a compressed air energy storage plant. CO2 is present in air in a concentration of ~400ppm. When air is compressed to a pressure of 10-100 bar (dependant on temperature), the CO2 will liquefy if the mixture is passed through a heat exchanger. This is one way of getting CO2 almost for free.
https://en.m.wikipedia.org/wiki/File:Ca … iagram.svg

For every tonne of air that is compressed, some 0.6kg (0.5 litre) of liquid CO2 can be harvested. In a pure carbon capture scheme, this would either be drained into the ground or ocean as liquid. It makes more sense to put it to productive use.

Last edited by Calliban (2022-09-14 02:55:04)

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Re: Prometheus Fuels Lower Cost Than Fossil Fuels

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Re: Prometheus Fuels Lower Cost Than Fossil Fuels

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