In-Situ Resource Utilization: Useful Reactions

[Northstar1989]

I thought it might be nice to collect people's ideas on useful equations for In-Situ Resource Utilization. Useful for mods (like KSP-Interstellar, and perhaps other mods still not yet made), and perhaps even for the stock game, if Squad notices this thread...

Everything below relies on the following assumptions:

(1) LiquidFuel, as currently implemented, represents liquid hydrogen (H2).

(2) The ability to burn methane (CH4) as a fuel will eventually be added to the stock game as a fuel separate from LiquidFuel.

(3) Oxidizer, as currently implemented, represents liquid oxygen (O2).

(4) Duna's atmosphere is loosely based on that of Mars.

I highly recommend everybody start off *skimming* the following articles/passages to give them a bit of a brief introduction to the topic:

http://books.google.com/books?id=BnPE37Ms5awC&pg=PA156&lpg=PA156&dq=Sabatier+oxygen+production&source=bl&ots=Q96lM76Y__&sig=jJq1syeCkxq0ZfnfwTjGd96Rlj0&hl=en&sa=X&ei=xt70UoKBO7TlygGQpIGgCg&ved=0CFAQ6AEwBQ#v=onepage&q=Sabatier%20oxygen%20production&f=false

http://www.nasa.gov/mission_pages/station/research/news/sabatier.html

http://en.wikipedia.org/wiki/Sabatier_reaction

(Pay *particular* attention to the sub-section "Manufacturing Propellant on Mars" in the Wikipedia article)

Anyways, some reactions I think might be of particular importance:

[1] The Reverse Water Gas Shift (RWGS) reaction: CO2 + H2 + Energy --> CO + H2O

This reaction is fairly simple, and well-used on Earth- yet could be extraordinarily useful in a Mars-like atmosphere (rich in CO2)-such as can be assumed might be found on Duna. If you don't need to haul all your water out with you to Duna- but can just set up some sort of solar-powered (or nuclear- if you're running a mod or Squad ever adds proper reactors) processing plant to (slowly) produce Oxidizer from the local atmosphere, then this saves on fuel overall. To be useful requires running any sort of life-support mod, or Squad adding life-support to the stock game.

[2] The Sabatier Reaction: CO2 + 4 H2 --> CH4 + 2 H2O + Energy

The advantage of the Sabatier Reaction, over the RWGS reaction, is that it produces Methane- which could serve as a valuable rocket propellant; and that it is an exothermic reaction- and thus requires no continuing energy input to drive it once heated up, unlike the RWGS reaction. Especially useful when coupled with water electrolysis (reaction #3).

[3] Water Electrolysis: 2 H2O + Energy --> 2 H2 + O2

Extremely useful for bodies that contain liquid water or water-ice (like Laythe or Eve, if the oceans are made of water; or Vall or Duna- if you assume the presence of water-ice) since you get hydrogen (LiquidFuel) and oxygen (Oxidizer) in a combustible ratio. More useful still on Duna, if combined with the RWGS or Sabatier reactions- simply electroylze the water produced by these reactions, feed the hydrogen back into the cycle, and you have net production of oxygen or methane. Perform both reactions in the proper amounts, and you have oxygen and methane in the combustible ratio CH4 + 3 O2 --> CO2 + 2 H2O, useful for a methane-oxygen rocket engine such as the real-world Raptor designs.

[4] Methane Pyrolysis: CH4 + Energy --> C (solid) + 2 H2

Useful on Duna if you favor the Sabatier reaction, as it doesn't require nearly as much input energy, but end up with more Methane than you can burn with available oxygen supplies (from Water Electrolysis) as a result. Simply pyrolyze the methane, and you can recover all input hydrogen (LiquidFuel) and recycle it back into the Sabatier Process or RWGS Reaction. The solid pyrolyic graphene (carbon) produced as a result can be either dumped directly (would require occasional manually chiseling it with a Kerbal from the ISRU part- somewhat like resetting a parachute) or automatically oxidized with CO2 in a Mars-like atmosphere, with electrical pre-heating of the CO2 to speed up the reaction: C (solid) + CO2 (gas) --> 2 CO (gas)

[5] Fischer-Tropsch Reaction: (2n + 1) H2 + n CO → CnH(2n+2) + nH2O

Useful for producing longer-chain hydrocarbons than methane, the Fischer-Tropsch Reaction could by run off the products of Water Electrolysis (specifically, the H2) and the Reverse Water Gas Shift Reaction (specifically, the CO). The simplest useful form of this reaction would probably be the production of Propane for higher energy-density than Methane: 7 H2 + 3 CO --> C3H8 + 3 H2O, although this reaction could be carried out to produce all the way up to Kerosene mixtures (10-16 carbon hydrocarbons). The RWGS reaction and Water Hydrolysis, with feeding back of the hydrogen into the RWGS reaction, could be utilized to produce as much CO as needed for this reaction, and as much O2 as needed to burn the hydrocarbon fuel. The nice thing about longer-chain hydrocarbons is that hydrogen- the one element that would be difficult to obtain (needing to either be obtained from local water-ice/methane or hauled from Earth/Kerbin) makes up an even smaller percentage of their mass than with Methane- allowing even greater mass-leveraging of the limited amount of hydrogen available into fuel. Longer-chain hydrocarbons also make excellent feedstock for production of structural plastics...

[6] The Haber-Bosch Process: N2 + 3 H2 → 2 NH3

Useful for Ammonia production in Nitrogen-containing atmospheres. Mars' atmosphere is 1.9% Nitrogen (N2). Ammonia is useful for the production of Hydrazine (N2H4 - Monopropellant), which in turn forms the basis for most hypergolic rocket fuels (including MMH and UDMH). http://en.wikipedia.org/wiki/Hydrazine#Rocket_fuel

[7] The Anthraquinone Process: H2 + O2 → H2O2

Useful for the production of Hydrogen Peroxide- which can be used to make Hydrazine (N2H4 -Monopropellant) when combined with Ammonia (reaction #9, below).

http://en.wikipedia.org/wiki/Anthraquinone_process

[8] Hydrogen-Peroxide Based Hydrazine (N2H4) Production: 2 H2O2 + 4 C2H5COCH3 + 4 NH3 --> 4 H2O + 4 C2H5COCH3 + 2 N2H4

Actually a two-step process, the net result, after hydrolysis of a more complex intermediate (the ketone reacts- but then is recovered again through this hydrolysis, which is also the step that produces the actual Hydrazine), is the reaction seen above. Useful for In-Situ production of Hydrazine (N2H4)- which is one of the most commonly used Monopropellants. Note the requirement for a specific ketone catalyst- which could be shipped from Earth/Kerbin as it is NOT consumed in the net reaction.

http://www.lookchem.com/Chempedia/Chemical-Technology/Inorganic-Chemical-Technology/2878.html

[9] Carbon Dioxide Decomposition: 2 CO2 + Energy --> 2 CO + O2

I'm not 100% sure how this reaction would actually be directly performed (rather than indirectly through some of the reactions listed above). But it has been studied and proven that Carbon Monoxide and Oxygen can be burned together in the reverse reaction (2 CO + O2 --> 2 CO2 + Energy) in a usable rocket engine (according to the "Mars: Prospective Energy and Material Resources" chapter cited above), and apparently there is also a way to perform this directly with some kind of available catalyst or easily-recycled co-reactant (I couldn't find which). The beauty of this reaction is, when used on Mars/Duna; it requires no hydrogen feedstock transported from off-planet, or mining of local ice for water. Instead, you simply decompose the readily-available atmospheric CO2, and burn the products together in a specially-designed rocket engine. Virtually unlimited locally-available propellant, at the cost of nothing but energy...

I would love to also see people suggest some useful reactions of a Venus-like atmosphere (i.e. Eve).

These are a fairly simple set of highly-useful reactions to start with, and I would love to see more of them implemented in mods (KSP-Interstellar already implements the Sabatier Process and Water Electrolysis- but worryingly none of the complementary reactions such as Methan Pyrolysis or Reverse Water Gas Shift Reaction, which eliminate the waste of producing more methane than you can burn... KSP-Interstellar currently also requires a *LARGE* continuing energy input for the Sabatier Reaction, which is unrealistic considering it's an exothermic reaction, and only needs a small spurt of start-up energy...) or eventually even the stock game. They would certainly give new use to solar panels- and maybe even make the devs (if they were added to the stock game) think harder about adding heavier-duty means of power generation (such as larger solar panels, or proper nuclear reactors), or encourage more players to install mods providing these more robust means of electricity generation (KSP-Interstellar currently offers some realistically-powerful fission reactors. NearFuture offers some unrealistically-weak nuclear reactors, as well as very large solar panels.)

Regards,

Northstar

P.S. In real-life, NASA is actually finally working on the technologies to make much of this kind of In-Situ Resource Utilization a reality on Mars, after years of dragging their heels on developing ISRU technology. Some of you might find this tiny stub from the NASA website interesting:

http://isru.nasa.gov/CarbonDioxideOxygen.html

Edited November 7, 2014 by Northstar1989

[Zephram Kerman]

Wow, this is good stuff. I'll be reading the linked resources.

While KSP normally renames everything to keep itself distinctly "game-ey", it would be very nice to find a mod for playing around with real life ISRU techniques. While a mod like this does not exist as far as I know, the ever-popular Kethane mod does come close, and could be altered to address much of what you described. Kethane does allow users to create resource types and deposits of them in the ground. (Ok, drilling for air would be weird, but oh well!) It also allows the user to alter the ratios of things produced by the two Converter parts. (Be careful to not redistribute any of the parts. Distributing only your code alterations should be fine with them.) So I think it would be a relatively simple thing to adapt the Kethane mod for real life resource conversions.

[Geschosskopf]

My favorite life support reactions are Yeast + C12H22O11 = C2H6O + CO2 = Beer, and Beer + Heat = Whiskey

[Clockwork_werewolf]

Very nice work. Thanks for all the effort.

I realise it is sort of implied but 2 H2 + O2 --> 2 H2O + Energy is also important for early carrier mode before solar or RTG's. We would need the water as a stock resource and a stock hydrogen fuel cell.

[KSK]

I'd always assumed that Liquid Fuel represented kerosene or whatever the kerbal equivalent is, simply because all the liquid fueled engines burn with a big bright flame. Also, liquid hydrogen is a real beast to handle and store, so it doesn't seem quite right to have it available from the start.

It's not a problem though - simply add the Fischer-Tropsch reaction to the list:

(2n + 1) H2 + n CO → CnH(2n+2) + nH2O

Water hydrolysis + RWGS + Fischer- Tropsch = Liquid Fuel, although methane engines would probably be easier to run from ISRU generated propellants.

[SkyHook]

I think this is a great post. Squad has decided that ISRU is not fun (independently of us ), so it won't be coming to the stock game, but I have been thinking about what might happen if we (the community) make a mod that is fun and extends gameplay beyond what can be done with kethane. It might change Squad's mind.This is a great start, I will comment more after I have read all of the things in the OP.

[Brotoro]

I'd always assumed that Liquid Fuel represented kerosene or whatever the kerbal equivalent is, simply because all the liquid fueled engines burn with a big bright flame. Also, liquid hydrogen is a real beast to handle and store, so it doesn't seem quite right to have it available from the start.

It's not a problem though - simply add the Fischer-Tropsch reaction to the list:

(2n + 1) H2 + n CO → CnH(2n+2) + nH2O

Water hydrolysis + RWGS + Fischer- Tropsch = Liquid Fuel, although methane engines would probably be easier to run from ISRU generated propellants.

I also thought liquid fuel was kerosene...since the Mk-1 fuselage that contains liquid fuel says "kerosene" right on it.

[vexx32]

Seeing as this relates to KSP's development and potential ideas and so forth, I've moved it to the Development Discussion section.

[Northstar1989]

Wow, this is good stuff. I'll be reading the linked resources.

Knowledge is power, read on!

While KSP normally renames everything to keep itself distinctly "game-ey", it would be very nice to find a mod for playing around with real life ISRU techniques.

The KSP-Interstellar mod, at least, allow players to play around with the Sabatier Reaction, and Water Hydrolysis. It's not without its major faults though- for one, the Sabatier Process is actually EXOTHERMIC (that is, it is spontaneous and releases heat- like combustion on Earth) and as such requires very little input energy to keep going (as long as it's sufficiently well-insulated, just enough to remove the products and add more reactants so it reaches equilibrium. Perhaps a little more energy to keep it hot if the insulation is poor.), but the KSP-Interstellar mod treats it like a strongly endothermic process (one that is not spontaneous without large energy input, and absorbs heat) and it is actually one of the most energy-intensive reactions to run with that mod's ISRU refinery- more so even than Water Hydrolysis!

It would be nice to see some of this make it to the stock game someday though...

[Northstar1989]

Very nice work. Thanks for all the effort.

I realise it is sort of implied but 2 H2 + O2 --> 2 H2O + Energy is also important for early carrier mode before solar or RTG's. We would need the water as a stock resource and a stock hydrogen fuel cell.

Fuel cells are nice, but the whole point of ISRU is to minimize the weight (and volume) of what you haul to your destination. Oxygen is inherently heavy- nearly 16 times more massive than hydrogen on a molecule-for-molecule basis in fact.

Fuel cells don't work well somewhere like Mars or Duna because they either require hauling all your Oxygen out there with you- which is inefficient and defeats the purpose of ISRU- or essentially performing the reverse process of Water Hydrolysis, which you already performed in the first place just to get Hydrogen and Oxygen from the water produced through the RWGS or Sabatier reaction (so it would make no sense- better just to save the energy you would have spent performing electrolysis in the first place, and use THAT for your electricity needs).

They're decent as a form of energy storage (so that your astronauts can use power faster than you can produce it) I guess- but you're better off manufacturing long-chain hydrocarbons (kerosene or longer) and burning it with stored oxygen for electricity instead... (there's a reason real life cars can get a better range off hydrocarbons than hydrogen- they're a more efficient and dense form of energy storage).

Regards,

Northstar

[Northstar1989]

I'd always assumed that Liquid Fuel represented kerosene or whatever the kerbal equivalent is, simply because all the liquid fueled engines burn with a big bright flame. Also, liquid hydrogen is a real beast to handle and store, so it doesn't seem quite right to have it available from the start.

It's not a problem though - simply add the Fischer-Tropsch reaction to the list:

(2n + 1) H2 + n CO → CnH(2n+2) + nH2O

Water hydrolysis + RWGS + Fischer- Tropsch = Liquid Fuel, although methane engines would probably be easier to run from ISRU generated propellants.

Great idea with the Fischer-Tropsch Reaction. It was nagging me- I KNEW there was an important equation I was forgetting to include, and I'm pretty sure that's it... I'll add it to my list- though I originally thought maybe other players would post in such a format that the whole thread might read out like a giant list...

Not everything in KSP-I seems to perfectly parallel real life, but it's simpler if we assume that LiquidFuel is hydrogen. After all, you wouldn't run Kerosene through a NERVA engine (like the LV-N), as you wouldn't get very good ISP doing so (you would get much better thrust, however) and there is the risk of some of the byproducts of hydrocarbon combustion fouling the reactor...

There is a "Real Fuels" mod that attempts to address this question by adding both Kerosene and liquid hydrogen to fuels in the game. The kerosene engines are available sooner, and their fuel tanks have better energy density than the liquid hydrogen ones, but they don't get as much ISP- much like their relative usefulness in real life. Honestly, I'd rather have Kerosene as a fuel for classical combustion engines, just for the much higher energy density (which also means less Dry Mass to hold a given impulse in fuel, and higher fuel fraction...)

Also, you might find it interesting that the Fischer-Tropsch Reaction also nicely sets you up for manufacturing structural plastics... This is another topic that has been extensively discussed in real-life; because if you build structures out of structural plastic, and only have to haul out the hydrogen component of these structures- or better yet managed to obtain the hydrogen from local water and so utilize an entirely locally-made material as your main structural component, then you greatly reduce the mass you have to haul from Earth to set up a sustainable Mars outpost or colony...

Plastic may SEEM like a flimsy structural material, but there are actually some rather tough solid hydrocarbon polymers available- and polyethylene (a weaker material) is actually one of the best insulators against solar radiation on a pound-for-pound basis out there (it's a lot less effective than lead per foot of thickness, but it's a LOT lighter- and you can actually stop more radiation with the same mass...)

Even if the main habitation modules were made out of metal (which might also be locally produced), plastic would make a GREAT cheap material to make storage and greenhouse modules out of- and any Mars outpost would need a LOT of greenhouses to be truly self-sustaining from a food and oxygen perspective (although extra oxygen could always be reduced from the atmosphere via RWGS and Water Hydrolysis, with enough available energy).

Regards,

Northstar

Edited February 8, 2014 by Northstar1989

[KSK]

Cheers - and yes - you can do a lot with polymers!

In principle there's a lot of scope here for some quite complex polymers and other industrial chemicals. First tweak your Fischer Tropsch reaction to give you alkenes as well as alkanes. Then you have syngas (CO/H2) and alkenes to work with, which gives you alcohols and aldehydes (through hydroformylation) and then trivially, carboxylic acids. If you can find a source of nitrogen then you can also make ammonia and from ammonia, amines. Once you have alkenes, amines, alcohols, aldehydes and carboxylic acids then there's not a lot you can't make.

The devil would be in the details though - making a suitably light and robust set of reactors to do all this would be challenging to put it mildly. Not to mention keeping them running.

[Clockwork_werewolf]

Fuel cells don't work well somewhere like Mars or Duna because they either require hauling all your Oxygen out there with you

Well of course, thats why I said

important for early carrier mode before solar or RTG's.

Its an inefficient (weight to power) method of producing energy but its what the Apollo and space shuttle used. You would never want to use it for a Mars/Duna mission but it might be all you have for a Mun mission.

[Northstar1989]

Cheers - and yes - you can do a lot with polymers!

In principle there's a lot of scope here for some quite complex polymers and other industrial chemicals. First tweak your Fischer Tropsch reaction to give you alkenes as well as alkanes. Then you have syngas (CO/H2) and alkenes to work with, which gives you alcohols and aldehydes (through hydroformylation) and then trivially, carboxylic acids. If you can find a source of nitrogen then you can also make ammonia and from ammonia, amines. Once you have alkenes, amines, alcohols, aldehydes and carboxylic acids then there's not a lot you can't make.

The devil would be in the details though - making a suitably light and robust set of reactors to do all this would be challenging to put it mildly. Not to mention keeping them running.

Indeed- there's not a lot that's impossible once you start making your own polymers off-world.

Mars' atmosphere is 1.9% Nitrogen. I would assume Duna is pretty much the same. That's a reliable, if slow, source of nitrogen if you transform it into Ammonia (with the Haber-Bosch Process- now listed as Reaction #6 on the revised OP).

I can imagine rows after row of all-plastic hydroponics greenhouses, made entirely from local resources; already set up, planted, seeded with perennial crops (mainly with a mix of food and medicinal plants), and grown to maturity- all by complex probes/robots- before the first Martian colonists even arrive, some day...

Regards,

Northstar

Edited February 9, 2014 by Northstar1989

[Northstar1989]

For those of you curious, or who came across this separately, I've been trying to get the attention of FractalUK- the creator of the KSP-Interstellar mod- to have him include more of the reactions mentioned here on this thread in KSP-Interstellar's ISRU system...

Currently, the Sabatier Reaction and Water Electroylysis are included; as well as a water-based version of the Anthraquinone Process, and an inaccurate version of the Hydrogen Peroxide method for Hydrazine synthesis (the stoichiometric ratios are off, and it doesn't seem to produce much, if any, water); but the mod is missing a number of key reactions needed to complement the existing reactions.

Particularly these include the Reverse Water Gas Shift Reaction (to produce more oxygen via water electrolysis for burning the Sabatier's methane with), the Haber-Bosch Process (to produce Ammonia from atmospheric Nitrogen, for Hydrazine synthesis- currently Ammonia is hard to come by- I think you can only get it on Eve), and the gas-based version of the Anthraquinone Process (this version is, as far as I can tell, the more common one in real-life, and more useful in KSP- as it's much easier to come by Hydrogen and Oxygen separately than it is water- which the mod also provides no way to produce directly from its constituent gasses, such as via fuel-cell.)

If you're interested to see the discussion, or would like to chime in and say something yourself, here is the link to the page on the (very long) KSP-Interstellar thread where I most recently posed on the topic (page 653)

http://forum.kerbalspaceprogram.com/threads/43839-0-23-KSP-Interstellar-%28Thermal-Helper-Solar-Sail-Impactors-Fusion%29-Version-0-10-3/page653

Regards,

Northstar

P.S. Some of you might catch that I make reference to earlier posts I made on the same topic trying to get FractalUK's attention. For those of you desiring context, the links for those earlier posts (two pairs of posts, posted on pages 640 and 647)

http://forum.kerbalspaceprogram.com/threads/43839-0-23-KSP-Interstellar-%28Thermal-Helper-Solar-Sail-Impactors-Fusion%29-Version-0-10-3?p=954910#post954910

http://forum.kerbalspaceprogram.com/threads/43839-0-23-KSP-Interstellar-%28Thermal-Helper-Solar-Sail-Impactors-Fusion%29-Version-0-10-3?p=956244#post956244

Edited February 9, 2014 by Northstar1989

[Zephram Kerman]

I just discovered Open Resource System. This, combined with the kethane converter adapted to the various processes, might just be exactly what you need to introduce realistic resource processing.

[Northstar1989]

I just discovered Open Resource System. This, combined with the kethane converter adapted to the various processes, might just be exactly what you need to introduce realistic resource processing.

Not exactly what I was looking for.. I'm not a modder myself, and in no position to implement many of these reactions. I was more hoping to lobby existing mod-makers, like Fractal_UK (the creator of KSP-Interstellar) to include more of these reactions; or perhaps eventually bring them to the attention of Squad for their planned resource system... (It'll happen- SOMEDAY!)

Regards,

Northstar

P.S. KSP-Interstellar already makes use of the Open Resource System. It's actually the given example for the crustal resources type in the mod description...

[aeTIos]

I noticed that a lot of these reactions have CO as a 'waste' product. I'm not 100% sure how stuff works but I do think that you need a very good safety system to ensure that no CO comes into the air. Such a system might add quite a bit of weight to a mission.

[technicalfool]

Okay, now I'm thinking of SpaceChem as a minigame in KSP.

Okay it'll never (officially) happen. But holy pants, if someone were to mod KSP to have Reactor and Storage parts, mod Spacechem to take atoms and molecules as input from KSP and provide processed outputs to KSP, with some kind of coding glue in the middle, that would be.. I dunno. Probably awesome.

[db48x]

Indeed- there's not a lot that's impossible once you start making your own polymers off-world.

Mars' atmosphere is 1.9% Nitrogen. I would assume Duna is pretty much the same. That's a reliable, if slow, source of nitrogen if you transform it into Ammonia (with the Haber-Bosch Process- now listed as Reaction #6 on the revised OP).

I can imagine rows after row of all-plastic hydroponics greenhouses, made entirely from local resources; already set up, planted, seeded with perennial crops (mainly with a mix of food and medicinal plants), and grown to maturity- all by complex probes/robots- before the first Martian colonists even arrive, some day...

Regards,

Northstar

A beautiful vision indeed, although there is one necessary component you've left out of your list: bacteria. Soil is more than just wet dirt; it needs a lot of bacteria living in it before plants can actually grow. Once you have people in the area the most readily available source is probably night soil.

[NWM]

(1) LiquidFuel, as currently implemented, represents liquid hydrogen (H2).

- by its density and the signal on the jet fule tank it is kerosene!

[Northstar1989]

A beautiful vision indeed, although there is one necessary component you've left out of your list: bacteria. Soil is more than just wet dirt; it needs a lot of bacteria living in it before plants can actually grow. Once you have people in the area the most readily available source is probably night soil.

Absolutely and completely false. You're dead-wrong. Take it from a biologist (that's my real-life specialty).

Plants don't REQUIRE bacteria to grow- all they need is the proper nutrients.

In nature, bacteria digest decaying organic matter into some of the necessary nutrients, pull others from the atmosphere (these are the 'symbiotic bacteria' you might have heard about- mainly they are geared to turn nitrogen into a usable form for plants), and sometimes even attack/parasitize the plants trying to grow there...

There's no actual need for the bacteria, however. You can grow plants with nothing but nutrient-enriched water: which is precisely what I was referring to when I talked about "hydroponics" before. In fact, you probably don't know what hydroponics are- look it up:

http://en.wikipedia.org/wiki/Hydroponics

The first *sentence* from the Wikipedia article (emphasis added) "Hydroponics is a subset of hydroculture and is a method of growing plants using mineral nutrient solutions, in water, without soil."

And, from a couple lines later, in case you were thinking this only applied to certain plants:

"Almost any terrestrial plant will grow with hydroponics."

Regards,

Northstar

P.S. Even better yet, you can grow crops with nothing but a nutrient-enriched mist, via Aeroponics:

http://en.wikipedia.org/wiki/Aeroponics

Edited February 18, 2014 by Northstar1989

[Northstar1989]

(1) LiquidFuel, as currently implemented, represents liquid hydrogen (H2).

- by its density and the signal on the jet fule tank it is kerosene!

You're not the first person to point out the symbol on the jet fuel tank (look earlier in the thread), but you're wrong about the density. The density chosen in-game for most things is completely arbitrary- just look at the density chosen for Xenon- a fuel we can definitively compare to a known substance.

It works, though- because they never specify the units (they could be just about anything). What's actually MORE interesting, is the mass ratios they choose for LiquidFuel and Oxidizer to burn in: 9 to 11. In real life, none of the likely fuels (Hydrogen+Oxygen, Oxygen+Kerosene, etc.) burn in that mass ratio- they all burn a LOT more Oxidizes mass relative to the LiquidFuel mass. Although, the Kerbals might be pumping the rocket engines with excess LiquidFuel to ensure all of the Oxidizer gets used up, it wouldn't come THAT close to an even mass ratio in any reasonable burn ratio- ever.

The symbol is Kerosene for the JET FUEL tank, but they explicitly point out in the description that the fuel is "lighter" than rocket fuel. This could be understood to mean it doesn't require any Oxidizer- but it could also be understood to mean that the single entity "LiquidFuel" actually is meant to represent a variety of different rel-life fuels, rather than any one single substance.

Regards,

Northstar

[NWM]

@Northstar1989

The ratio is not correct, but as you said for H2 used O2 as oxidizer, not a liquid oxidizer, but for CN-fuel liquid oxidizer used(in ratio of 3:2 ~ wich is more but more similar in ratio) If you count the size of the fuel tanks - one unit is about 5L and the density is correct.

[rhoark]

This will be a helpful list, thanks. I'm working on an overhaul of resource containers and flows that will include mixing and reacting fairly arbitrary collections of substances. The emphasis is on simulating combustion and resulting thrust/ISP, but ISRU will tie in very naturally at a later point.

Anthraquinone is unfortunately a bit too specialized to include in my reaction pathways, but it's apparently viable (if not economical) to produce H2O2 from H2 and O3.

At some point I'll scrape together the pennies for this: http://www.amazon.com/dp/0891813829/ref=wl_it_dp_o_pC_S_ttl?_encoding=UTF8&colid=1OM1HGEN91WIN&coliid=I31ZZNWVF8BVK1

Edited February 18, 2014 by rhoark