Should we ban kerolox rockets

[lajoswinkler]

Carbon footprint of kerosize-LOX rocket launches is nothing compared to cars and airplanes. The only reason to stop it is if crude oil becomes a rarity, because we make materials, drugs and industrical chemicals out of it.

*Nothing* will solve global warming, it's just a natural consequence of the laws of thermodynamics. You do ANYTHING and you generate waste heat. That's just how physics works. Focusing on "carbon emissions" as "killing the planet" is just bogus.

What we need to be working on is moving the Earth out in its orbit so it cools off a little and offsets "us doing things".

The other solution is to kill everybody. http://www.vhemt.org/

That's not how the global warming works. *facepalm*

[Bill Phil]

Well... Kerosene produces water too...

Let's just say point closed. No banning kerolox.

[GreeningGalaxy]

Let's pretend GeneCash is not a troll (which is not an assumption I make, but whatever, I guess there's no point in begrudging anyone their sources of stupid/twisted entertainment. To feel better about myself for not being able to tell, I'll respond under the pretense that I'm preempting anyone who might think to agree with him).

First off, it's true that we're not 'killing the planet' with greenhouse emissions. The planet itself will endure no matter what we do to it, as will life. Killing ourselves (ourselves being the human species) is slightly more likely, but still quite a while away. The main problem will just be inconveniencing ourselves. The human race will still survive if Belgium, Florida, and pretty much every coastline city on the planet ends up underwater, but that's the sort of think we don't really want to happen, and which will most definitely happen if we burn every fossil fuel we can find in Earth's crust⁽¹⁾. If we do that, we might also end up having to live underground as the surface becomes too hot for a person to adequately reject excess body heat, which would mean that the majority of the human population would probably die (but, fortunately, not all of it!), and we would, of course, see a mass extinction of a magnitude never before seen on Earth (but, again, it's extremely unlikely that everything would die, just most of it.

Anyway, the greenhouse effect is extremely well-documented and has been clearly shown to be increasing⁽²⁾⁽³⁾, so at this point it's less that it's hard to link greenhouse emissions to climate change, and more that it's very, very hard to imagine releasing this much carbon dioxide into the atmosphere and not seeing a substantial change in global climate.

There's just so much evidence for climate change as a direct result of C02 emissions being a growing problem, and effectively no credible or verifiable evidence against it. We can keep trying to make pointless and far-fetched excuses about why it's "just natural," or caused by the gradual brightening of the sun over time, or the heat released just by "doing things" in accordance with thermodynamics (that's a new one for me, I admit), or we can listen when the evidence is presented, address it, and work to see if we can avoid making life very hard for ourselves later on. That would presumably require that a majority of people make a few of their decisions based on other things besides personal greed, which I'm honestly not very optimistic about, but my own opinion doesn't matter - these are just some facts.

[Starman4308]

Kerosene is a fossil fuel which means its not a renewable resource right? It makes the most sense in the long term to switch to methane or something that can actually be produced.

It's not like we're going to run out of petroleum tomorrow. We'll have a huge amount of lead time to move to something like hydrolox.

There's an expression I like for this scenario: "rearranging deck chairs on the Titanic". There are a million more pressing problems than what fuel the space industry uses, and the fuel of choice for the space industry is not going to have any effect on the final outcome.

[Kibble]

"rearranging deck chairs on the Titanic". There are a million more pressing problems than what fuel the space industry uses, and the fuel of choice for the space industry is not going to have any effect on the final outcome.

Haha! Ten char~

[NERVAfan]

even ignoring the carbon cost of splitting the water, you'd probably emit more net carbon with a hydrolox stage than a kerolox stage.

It's worse than that - hydrogen is generally industrially produced not by splitting water but from methane by "steam reforming" (CH₄ + H₂O -> CO + 3 H₂, then CO + H₂O -> CO₂ + H₂) which uses fossil fuels both for the methane feedstock and to provide the heat required for the reaction (though I guess you could use biogas or something).

The environmental benefits of hydrogen fuel (in rockets, cars, or anything) are really questionable. Hydrogen (H₂) isn't found naturally on Earth in useful quantities, so it's never really a source of energy, only a storage medium. In the vast majority of cases, it would make more sense to directly use whatever energy source you'd use to make hydrogen (like just using the methane as fuel directly).

Rockets are sometimes an exception since specific impulse is really important due to the exponential nature of the rocket equation; but storing liquid hydrogen is a giant pain which is why SpaceX doesn't use it and doesn't plan to.

The "hydrogen car" people are talking about using solar power to split water and using the hydrogen just as a storage medium - but battery energy densities are improving rapidly so IMO electric cars will end up making more sense (also, there isn't anyone with the stature/resources of Elon Musk/Tesla pushing hydrogen car technology.)

Edited December 20, 2014 by NERVAfan
incomplete reaction for steam reforming; biogas comment; heat required FOR, not from, the reaction

[NERVAfan]

*Nothing* will solve global warming, it's just a natural consequence of the laws of thermodynamics. You do ANYTHING and you generate waste heat. That's just how physics works. Focusing on "carbon emissions" as "killing the planet" is just bogus.

Greenhouse gases trap more of the Sun's heat. The waste heat contribution from human activities is small in comparison (roughly 1 in 10,000 of the Sun's energy reaching the Earth, IIRC).

It's not like we're going to run out of petroleum tomorrow. We'll have a huge amount of lead time to move to something like hydrolox.

Yeah, climate problems are much more pressing than running out.

OK, I entirely agree that global warming is a real problem, but...

If we do that, we might also end up having to live underground as the surface becomes too hot for a person to adequately reject excess body heat, which would mean that the majority of the human population would probably die (but, fortunately, not all of it!), and we would, of course, see a mass extinction of a magnitude never before seen on Earth (but, again, it's extremely unlikely that everything would die, just most of it.

...that seems unlikely. CO2 levels were at 1500-1800 ppm during the Cretaceous, and maybe as high as 4000 ppm during the Paleocene-Eocene Thermal Maximum (though this latter one is very debated & poorly constrained) and warm-blooded animals were just fine (OK there were some extinctions during the P-E TM, but not literally "stuff dying of heatstroke").

(In hotter geological eras, there was much less temperature gradient with latitude, so the planet became - in the extreme cases like the warmer part of the Eocene - mostly tropical rather than the tropical regions reaching 60C or something crazy.)

[78stonewobble]

I say more CO2 neutral energy sources and no need to reduce us to rural India quality of life nor reduce the population.

Oh, and if I were really draconian, I would not ban kerosene fuel, I would just make mandatory that all carbon in it comes from captured CO2 from the atmosphere.

What... Like wood?

...

But more seriously... Why not just plant a forrest?

[MBobrik]

What... Like wood?

...

But more seriously... Why not just plant a forrest?

Plant a forest and then process its cellulose to kerosene, or cover a desert area with solar power plants, scrub the CO2 from air chemically and then synthesize kerosene. Or replace solar with nuclear. Your choice. But no fossil carbon

[RobotsAndSpaceships]

I'm having a hard time telling whether this is a bait thread or not.

[78stonewobble]

Plant a forest and then process its cellulose to kerosene, or cover a desert area with solar power plants, scrub the CO2 from air chemically and then synthesize kerosene. Or replace solar with nuclear. Your choice. But no fossil carbon

Well I meant that you could plant a forest, that entirely offsets you co2 emissions and get the kerosene as per usual, which is presumably the most efficient method, from fossil carbon. Or ie. if you build a solar plant to similarly offset co2 emissions from kerosene from regular sources, it would be smaller than a solar power plant to directly produce co2 from the air?

Otherwise it's the whole air carbon waste thing over again? o.O

[MBobrik]

Well I meant that you could plant a forest, that entirely offsets you co2 emissions and get the kerosene as per usual, which is presumably the most efficient method, from fossil carbon.

Forest, after a short growth period becomes more or less carbon neutral. Reaching equilibrium and stuff. So to offset a steady influx of fossil carbon you would have to convert more and more of land to forest, restricting agriculture, and ultimately running out of places where forest can grow at all. But I ultimately wouldn't care how the CO2 neutrality would be achieved, so if someone wished to temporarily keep up launch rate by converting more and more area to forest, it would be his choice.

[78stonewobble]

Forest, after a short growth period becomes more or less carbon neutral. Reaching equilibrium and stuff. So to offset a steady influx of fossil carbon you would have to convert more and more of land to forest, restricting agriculture, and ultimately running out of places where forest can grow at all. But I ultimately wouldn't care how the CO2 neutrality would be achieved, so if someone wished to temporarily keep up launch rate by converting more and more area to forest, it would be his choice.

Good point, though isn't that only on short timescales? On longer time scales forests do pull co2 out of the air, after all that is where coal come from?

One could argue that agriculture does the same. Depositing carbon in animals, humans and soil?

[xenomorph555]

I'm having a hard time telling whether this is a bait thread or not.

I was being serious when I created it, we as humans have a very hard century ahead of us and we are going to have to make decisions and changes on various things.

[MBobrik]

I was being serious when I created it, we as humans have a very hard century ahead of us and we are going to have to make decisions and changes on various things.

Then we should start with the most significant things first. And space launches are ridiculously insignificant compared to other CO2 sources.

[MBobrik]

Good point, though isn't that only on short timescales? On longer time scales forests do pull co2 out of the air, after all that is where coal come from?

There are definite carbon sinks in the nature, though they are very slow acting. Peat bogs, carbon rich sediment burial ... unfortunately, the classic forest, nor agriculture, is not one of them.

Edited December 20, 2014 by MBobrik

[kujuman]

Re the notion that using H2 and O2 as propellant for the reason that it will be recycled...

Um, we're launching rockets. To space. We throw away massive amounts of valuable (in terms of cost of production and rarity) metals in these launchers. Even when they reenter, they are not recovered. Anything we throw up into orbit that's not going to decay any time soon is depriving the Earth of mass and materials. Caring about a bit of water is kinda unhelpful by comparison.

[lajoswinkler]

Plant a forest and then process its cellulose to kerosene, or cover a desert area with solar power plants, scrub the CO2 from air chemically and then synthesize kerosene. Or replace solar with nuclear. Your choice. But no fossil carbon

Most of what you've wrote here would have an even higher carbon footprint. The world and energy production-distribution is not a video game.

Processing cellulose to kerosene is impossible because cellulose is a compound, and kerosene is a highly complex mixture. Cellulose could be converted to ethanol by processing with sulfuric acid into sugars and then into ethanol, or by using GM bacteria. Whether we get negative, zero or positive carbon footprint depends heavily on the complete process cycle we use, and it would be more expensive (per joule liberated by burning in engines) than crude oil distillates.

Solar power plants can not be base load sources and therefore can not be something very helpful. They are among the poorest sources we have, by energy density, reliability, power output and net energy gain calculated after you sum up the production expenses.

Basically all densely populated, and therefore the largest energy consumers are far away from deserts. How will this energy be transmitted if the best system we know of (high voltage AC power lines) are not sufficiently effective for such things? That's why power plants are never built far from any energy consumers.

Where's the energy for chemically scrubbing CO2? We're talking about enormous energy requirements that would in the end produce net gain of CO₂.

Solar electric and nuclear fission are absolutely uncomparable sources. The first one is valuable in certain regions of Earth for addition to the grid, and nuclear fission is energy extremely dense, reliable and rich source you can put wherever you want. It is absolutely the best source we have on Earth at this moment.

[Starman4308]

Processing cellulose to kerosene is impossible because cellulose is a compound, and kerosene is a highly complex mixture. Cellulose could be converted to ethanol by processing with sulfuric acid into sugars and then into ethanol, or by using GM bacteria. Whether we get negative, zero or positive carbon footprint depends heavily on the complete process cycle we use, and it would be more expensive (per joule liberated by burning in engines) than crude oil distillates.

Oh, it's almost certainly possible to get a petroleum-like mixture out of cellulose: you would just need to use bacteria, catalysts, or enzymes which promote hydrocarbon chain formation. It wouldn't matter exactly what you get, so long as it's got roughly the same chemical distribution as the fuel of choice. I also disagree with the implication that it must be more expensive than crude oil distillates. If cellulose extraction, transport, conversion, and transport back to distribution centers can be done more cheaply than petroleum extraction, refinement, and transport, it should be cheaper in the end.

Problem being, of course, that right now, it's really hard to devise chemical processes which are cheaper than petroleum extraction. It's like the old joke with lignin: you can make anything from lignin but money. If we can move to all biofuels, nuclear, and renewable, we can go to a net-carbon-neutral situation where each year's carbon production is taken up by the next year's crops, but that isn't going to happen soon for several unfortunate reasons.

[Frozen_Heart]

Combining nuclear fission with renewable seems like the best bet short term. Would also allow things like hydrogen to be generated in a carbon neutral way.

Long term fusion seems like a good prospect but its way too far off to take over from fossil fuels straight off.

[MBobrik]

Processing cellulose to kerosene is impossible because cellulose is a compound, and kerosene is a highly complex mixture.

Wrong. Any organic material can be partially pyrolyzed and then converted to hydrocarbon mixture via fischer tropsch.

I don't say it is the most efficient, or even acceptably efficient route, but you can do it. And, if there will be no other carbon inputs it has to be CO2 neutral by definition.

Solar power plants can not be base load sources and therefore can not be something very helpful.

good thing that driving fuel synthesis does not place the same demands on the source as power grid base load.

Basically all densely populated, and therefore the largest energy consumers are far away from deserts.

HVDC, or convert it to fuels on site. Your choice.

Where's the energy for chemically scrubbing CO2? We're talking about enormous energy requirements that would in the end produce net gain of CO₂.

We are talking about small fraction of the overall energy flow through the system.

Solar electric and nuclear fission are absolutely uncomparable sources. The first one is valuable in certain regions of Earth for addition to the grid, and nuclear fission is energy extremely dense, reliable and rich source you can put wherever you want. It is absolutely the best source we have on Earth at this moment.

That is my opinion too, but some people want to avoid the n*** word at all cost. So I say doesn't matter. If you think you can go without it, just go on, your choice. The only restriction is zero fossil carbon.

[Nuke]

Re the notion that using H2 and O2 as propellant for the reason that it will be recycled...

Um, we're launching rockets. To space. We throw away massive amounts of valuable (in terms of cost of production and rarity) metals in these launchers. Even when they reenter, they are not recovered. Anything we throw up into orbit that's not going to decay any time soon is depriving the Earth of mass and materials. Caring about a bit of water is kinda unhelpful by comparison.

we probibly get all that material replaced by incoming natural space debrits (not our space junk). while small, it still a great many tons more than we put up there. and likely much of it replenishes our limited resources, all be in in a shotgun sort of way.

[DaveofDefeat]

Lets start using lithium and fluorine rockets! Its the perfect solution.

[Starman4308]

we probibly get all that material replaced by incoming natural space debrits (not our space junk). while small, it still a great many tons more than we put up there. and likely much of it replenishes our limited resources, all be in in a shotgun sort of way.

We probably get more net flux of resources through tectonic action than from space.

EDIT: Slightly misunderstood the post. Still, for the most part, what we have is what we have, and what we send to space is an utterly negligible fraction of what we have.

Edited December 20, 2014 by Starman4308

[shynung]

Lets start using lithium and fluorine rockets! Its the perfect solution.

I sincerely hope you're just kidding.

What's next? Dimethyl mercury and dioxygen difluoride?