Delta Clipper and other single-stage missiles impossible?

[sh1pman]

2 minutes ago, Dragon01 said:

Except a nuclear power plant is expensive and uranium is also expensive.

Well, it's either having your own plant or paying 4x more for the energy (in the form of gas synthesized with someone else's reactor). 

5 minutes ago, Dragon01 said:

Waste heat doesn't really matter on Earth

Im not worried about heating the planet, just that you lose 75% of nuclear energy in the process.

7 minutes ago, Dragon01 said:

CO2 is causing the sun to heat the planet up much faster than directly dumping heat into it would. 

Yea. Even if we stop producing CO2 right now, we still need to remove the extra CO2 in the atmosphere produced since the industrial revolution, just to stop the warming. Your plan won't help with this because captured carbon will need to be stored or buried somewhere forever. If it's burned or somehow escapes, well, it's back in the atmosphere again. We need a more permanent solution for that.

[Guest]

25 minutes ago, sh1pman said:

Well, it's either having your own plant or paying 4x more for the energy (in the form of gas synthesized with someone else's reactor). 

Where did you get that figure, exactly? Because if the answer is "by considering thermodynamic loses at each step", then energy business doesn't work like that. Operating a nuclear power plant is very expensive. It requires a lot of highly paid specialists, safety inspections, security and a lot more costly things. Uranium trade is highly regulated and requires a lot of precautions and special infrastructure. Buying methane and burning it in a regular plant could well be cheaper, just because of the extra overhead inherent in such infrastructure. Nuclear powers, having much of the infrastructure and expertise already in place, can distribute these costs. 

Quote

Im not worried about heating the planet, just that you lose 75% of nuclear energy in the process.

I wouldn't worry about that. There's plenty of uranium and thorium to last until fusion power is economical (and for quite a while after that, too), and after that, the fuel is literally in seawater. With reprocessing, you can get quite a lot of mileage out of nuclear fuel. Thermodynamic efficiency of the whole process, while low, is not really a problem.

Quote

Yea. Even if we stop producing CO2 right now, we still need to remove the extra CO2 in the atmosphere produced since the industrial revolution, just to stop the warming. Your plan won't help with this because captured carbon will need to be stored or buried somewhere forever. If it's burned or somehow escapes, well, it's back in the atmosphere again. We need a more permanent solution for that.

Actually, my plan will help. Because right now, we're nowhere close to even slowing down the rate at which the warming increases. If we go 100% carbon-neutral (or nearly so), removing the excess will happen naturally, via plants. If you want, you can bind the carbon up in plastics, because they can, at a somewhat steep energy cost, be synthetized all the way from methane (of course, you then end up with a bunch of plastic trash to store, but it all has to go somewhere).

[sh1pman]

39 minutes ago, Dragon01 said:

Operating a nuclear power plant is very expensive. It requires a lot of highly paid specialists, safety inspections, security and a lot more costly things

All of those things are included in the price of synthetic methane made at a nuclear plant. It won't be as cheap as natural gas. Let's say you pay 100$ for every MW*h of nuclear energy. That MW*h will be reduced to 0.25MW*h after all of the chemical conversions, just because of thermodynamics. Meaning that now you have to pay 400$ for the same MW*h. On one hand, it removes the need to build a reactor, but in the long run it's better to have your own. You can also avoid such huge energy losses with just a regular high-voltage power line from a nearby country that has nuclear power plants (unless you're on an island or something).

Quote

For example, a 100 mi (160 km) span at 765 kV carrying 1000 MW of power can have losses of 1.1% to 0.5%

And this:

39 minutes ago, Dragon01 said:

removing the excess will happen naturally, via plants

How? Plants are 100% carbon-neutral. When they die, they release all the carbon they collected back into the atmosphere. Well, unless they get buried deep underground, and after millions of years of heat and high pressure get turned into coal. 

Edited October 16, 2019 by sh1pman

[Guest]

Just now, sh1pman said:

All of those things are included in the price of synthetic methane made at a nuclear plant. It won't be as cheap as natural gas.

Yes, but economics of scale still apply. Building an nth nuclear power plant in a country is cheaper than starting a nuclear program from scratch. I never said it would be cheaper than natural gas. I said it would be cheaper than trying to force poor countries to go nuclear. Removing natural gas, coal and especially lignite (the worst of the lot) won't happen on a purely economic basis, because they're just too cheap for nuclear power to compete.

Quote

How? Plants are 100% carbon-neutral. When they die, they release all the carbon they collected back into the atmosphere Well, unless they get buried deep underground, and after millions of years of heat and high pressure get turned into coal. 

Yeah, you know how long, say, an oak tree can live? Also, you're wrong. Plants do not release all the carbon they have collected. Some of it ends up in bacteria that feed on a dead tree. Some of it ends up in the deer that fed on its leaves when it was alive. Even better, if someone chops the tree down and turns it into, say, a fancy cabinet, the carbon ends up in the cabinet. Short of the building burning down, or the cabinet being chopped up for firewood, you can count most of the carbon in that particular tree as being out of the environment.

Outside the rainforests (where the degradation really is that fast), trees are carbon-neutral on ridiculous timescales. Other plants aren't quite as good, but there are many species that live for quite a while, as well. Sure, forests burn down, wooden stuff gets burned sometimes, or thrown out and degraded, and really short-lived plants don't lock down carbon on an appreciable scale, but as long as the total mass increase of all trees and shrubbery outweighs the mass that's burned or digested, you'll get a net decrease in atmospheric CO2 (barring other factors).

[sh1pman]

11 minutes ago, Dragon01 said:

Yeah, you know how long, say, an oak tree can live? Also, you're wrong. Plants do not release all the carbon they have collected. Some of it ends up in bacteria that feed on a dead tree. Some of it ends up in the deer that fed on its leaves when it was alive. Even better, if someone chops the tree down and turns it into, say, a fancy cabinet, the carbon ends up in the cabinet. Short of the building burning down, or the cabinet being chopped up for firewood, you can count most of the carbon in that particular tree as being out of the environment.

Outside the rainforests (where the degradation really is that fast), trees are carbon-neutral on ridiculous timescales. Other plants aren't quite as good, but there are many species that live for quite a while, as well. Sure, forests burn down, wooden stuff gets burned sometimes, or thrown out and degraded, and really short-lived plants don't lock down carbon on an appreciable scale, but as long as the total mass increase of all trees and shrubbery outweighs the mass that's burned or digested, you'll get a net decrease in atmospheric CO2 (barring other factors).

According to my calculations, there are ~180 gigatons of excess carbon in the atmosphere. All plant life on Earth weighs ~450 gigatons. We'll need a LOT more plants to trap all that carbon. If an average tree weighs, let’s say, a ton, we need to plant 180 billion new trees and keep them growing, replanting dead ones. Monstrous task.

[mikegarrison]

You're both right, sort of. Plants are nearly carbon neutral, but they are also nonetheless carbon sinks. A lot of carbon in the cycle moves through plants, and a small but significant fraction of it gets fixed into the soil.

[kerbiloid]

3 hours ago, mikegarrison said:

Plants are nearly carbon neutral, but they are also nonetheless carbon sinks.

Only the plants growing on cold bogs where the carbon stays on bottom forever before becomes coal.
Other plants rot or become eaten and return all their carbon to the atmosphere. They are nothing for the carbon balance. Only Siberia and Canada are planet lungs.

7 hours ago, magnemoe said:

if you want to be carbon neutral you buy methane or LNG and sell clean power to compensate. 

Spending a tonne of same methane more to produce eco-green plastics for the clean power. And then to utilize it.

P.S.
Strange to read that building 4 times more nuclear plants to produce the methane can be as cheap as building just one to use its power directly.

Edited October 16, 2019 by kerbiloid

[mikegarrison]

2 minutes ago, kerbiloid said:

Only the plants growing on cold bogs where the carbon stays on bottom forever before becomes coal.

It's not just "coal". In fact, making coal or peat bogs is not the main way that plants fix carbon. All soil is basically organic material mixed in with inorganic material. That organic material contains carbon that has been pulled in by plants.

[kerbiloid]

3 minutes ago, mikegarrison said:

All soil is basically organic material mixed in with inorganic material.

And the soil organics gets spent or eroded, so the soil gets depleted and stays bad and thin in most places on the Earth.

[mikegarrison]

9 minutes ago, kerbiloid said:

Strange to read that building 4 times more nuclear plants to produce the methane can be as cheap as building just one to use its power directly.

Obviously it's not, but how are you going to attach a rocket or an airplane to the power grid?

[kerbiloid]

Just now, mikegarrison said:

Obviously it's not, but how are you going to attach a rocket or an airplane to the power grid?

Do the rockets and planes need so much hydrocarbons compared to other consumers?

[mikegarrison]

Just now, kerbiloid said:

Do the rockets and planes need so much hydrocarbons compared to other consumers?

No. And that's kind of the point, actually. Artificial sustainable hydrocarbons should be used mainly for the applications where replacing hydrocarbons is impractical.

(Says the guy whose aviation emissions job is 100% based on airplanes using hydrocarbons.)

[kerbiloid]

Just now, mikegarrison said:

Artificial sustainable hydrocarbons should be used mainly for the applications where replacing hydrocarbons is impractical.

I would say, any hydrocarbons should.

[mikegarrison]

Just now, kerbiloid said:

I would say, any hydrocarbons should.

Fair enough, but the goal should be that all hydrocarbon use is eventually sustainable zero-net-carbon hydrocarbons.

[OOM]

7 hours ago, Dragon01 said:

Actually, methane from atmospheric CO2 makes sense as an energy storage. Nuclear power is great and ecological, but nuclear reactors are heavy and bulky. 

It depends on which reactors. You can create a relatively small reactor with a very dense power in relation to size (for example, KIWI reactors). And because of the expensive Uranus, you can use Thorium, but for this you need a reactor with molten salt, plus it has a high core temperature and does not require a very solid structure, because thanks to the molten salt there is no high pressure,
https://en.wikipedia.org/wiki/Molten_salt_reactor

Edited October 16, 2019 by OOM

[mikegarrison]

4 minutes ago, OOM said:

And because of the expensive Uranus

I hate when my Uranus gets too expensive.

[OOM]

7 minutes ago, mikegarrison said:

I hate when my Uranus gets too expensive.

I like Thorium better... 

Edited October 16, 2019 by OOM

[magnemoe]

7 hours ago, Thor Wotansen said:

From Wikipedia:

 

The reaction is exothermic, meaning it produces heat.  This means you can remove heat while still maintaining the 300-400 °C needed for the optimal reaction.  Heat can be used for all sorts of useful things, like powering a sterling engine to run a generator to electrolize water for hydrogen, or liquefy air to extract pure CO2, with a cryocooler.  So yes, as long as you don't let any methane escape into the atmosphere, you can have some of your lunch for free.

 

Leaving out two issues, first is producing the hydrogen, second is extracting the 0.4% co2 from the atmosphere as you can not run this in an oxygen atmosphere, or rather you could but you would just get water out. 

[Guest]

3 hours ago, kerbiloid said:

Strange to read that building 4 times more nuclear plants to produce the methane can be as cheap as building just one to use its power directly.

That's modern economics for you.  Regulations, infrastructure, manpower and local conditions all play a role, and can easily outweigh the costs of raw energy. Nuclear power has an enormous overhead. Using it to produce methane for other powerplants is wasteful, but if there were no other sources, it would definitely be more economical, at least in short run. In long run, of course, it'd come with some caveats, such as being dependent on nuclear powers for energy supply (then again, most countries would have to buy uranium abroad, as well). For those that can't afford nuclear infrastructure, this is the only way to deal with their emissions. Renewables are easier than nuclear from infrastructure standpoint, but also quite expensive, and many of those are highly dependent on having a good place to put them, so I don't believe they'll ever be anything but a sideshow to combustion and nuclear plants.

2 hours ago, magnemoe said:

Leaving out two issues, first is producing the hydrogen, second is extracting the 0.4% co2 from the atmosphere as you can not run this in an oxygen atmosphere, or rather you could but you would just get water out. 

Both are incredibly easy. Making hydrogen is simple - just electrolyse some water. Making CO2 is even simpler - just freeze it. That's how you make dry ice. 0.4% doesn't sound like a lot, but it's not hard to get out of the air.

7 hours ago, sh1pman said:

According to my calculations, there are ~180 gigatons of excess carbon in the atmosphere. All plant life on Earth weighs ~450 gigatons. We'll need a LOT more plants to trap all that carbon. If an average tree weighs, let’s say, a ton, we need to plant 180 billion new trees and keep them growing, replanting dead ones. Monstrous task.

Did you account for what is dissolved in the oceans? Besides, the goal is not to reduce CO2 content to pre-industrial levels, or we'll have an ice age at some point. We don't want that. We just want to throttle the warming so that we can preserve the status quo. 

That'll still be a whole lot of shrubbery, but it's not exactly a bad thing. 

[kerbiloid]

1 hour ago, Dragon01 said:

Making hydrogen is simple - just electrolyse some water.

Of course, this is an expensive way of false simplicity. Nobody widely does this irl, hydrogen is produced from the natural methane.

1 hour ago, Dragon01 said:

Making CO2 is even simpler - just freeze it.

Just rotate a turbine powered with a power plant to freeze ammonia for that or to freeze it directly.

1 hour ago, Dragon01 said:

Regulations, infrastructure, manpower and local conditions

Are written by people for particular conditions

Edited October 16, 2019 by kerbiloid

[Guest]

2 hours ago, kerbiloid said:

Are written by people for particular conditions

Excuse me while I laugh uproariously. No they aren't. It's obvious that you never dealt with any sort of international regulations. They're the same (that is, written for rich countries), no matter if you can afford them, or not. Yes, you can get Chinese to sell you cheap junk that does not meet European standards, but it's just not gonna fly with fissile materials or sensitive, nuclear-related technology. 

And that's just regulations. If you think people have any say in what local conditions and existing infrastructure are... well, then you're not very bright indeed. They don't. If you want a poor country like Chad or Zimbabwe to stop polluting, asking them to build nuclear power plants will only get you laughed out of the country.

Quote

Of course, this is an expensive way of false simplicity. Nobody widely does this irl, hydrogen is produced from the natural methane.

It is simple. It's just that making hydrogen from natural gas is cheaper. You can perform small scale electrolysis at home, it's a grade school level experiment. It's just that doing this on scale requires a lot of electricity.

[sh1pman]

4 hours ago, Dragon01 said:

Did you account for what is dissolved in the oceans?

No, because oceanic uptake is a very slow process, and equilibrium with atmospheric CO2 is reached over thousands of years. Not useful for us now. 

[kerbiloid]

1 hour ago, Dragon01 said:

It's obvious that you never dealt with any sort of international regulations.

The international regulations are written by international people for particular conditions.

1 hour ago, Dragon01 said:

It's just that doing this on scale requires a lot of electricity.

So, it takes less power to produce from the natural gas.

Edited October 16, 2019 by kerbiloid

[Guest]

1 hour ago, kerbiloid said:

The international regulations are written by international people for particular conditions.

That is, by far, the silliest thing you said in this thread. Just who do you think those "international people" are? There are no "international people". There are Germans, Americans, French, Russians, Chinese... They negotiate the international treaties. They set the regulations. And it has nothing to do with your "particular conditions". It has to do with what suits them, not for convenience of poor people trying to get clean power. If another country is to get nuclear power, they need to do it on their terms, unless it wants to risk working with the likes of North Korea and Iran.

Do take some time to learn about how hard nuclear power really is. I've had several university courses about handling and otherwise dealing with radioactive materials, while you lack basic information needed to discuss the subject in an informed way. 

1 hour ago, sh1pman said:

No, because oceanic uptake is a very slow process, and equilibrium with atmospheric CO2 is reached over thousands of years. Not useful for us now. 

Actually, it is. Oceans are absorbing CO2, and any analysis needs to account for them. The rate at which they do so is very much nontrivial. This is a potential concern, too, because despite their impressive capacity (and don't forget seaweed!), if they become too acidic, then we're in for a really bad time.

[kerbiloid]

9 minutes ago, Dragon01 said:

That is, by far, the silliest thing you said in this thread. Just who do you think those "international people" are? There are no "international people". There are Germans, Americans, French, Russians, Chinese... They negotiate the international treaties. They set the regulations. And it has nothing to do with your "particular conditions". It has to do with what suits them, not for convenience of poor people trying to get clean power. If another country is to get nuclear power, they need to do it on their terms, unless it wants to risk working with the likes of North Korea and Iran.

Any document has an issue date. All of them get expired and replaced.
What people establish, that people can change if they decide.
30 years ago most of those documents didn't exist, 30 years later nobody will remember the current ones. None of them are physical constants.

Edited October 16, 2019 by kerbiloid